ARRT Computed Tomography (CT) Certification Examination — Questions and Answers

Question 1: Which window setting is most appropriate for evaluating pulmonary nodules in the lung parenchyma?

Window width ~1500 HU, window level ~-600 HU (Correct answer)
Window width ~200 HU, window level ~80 HU
Window width ~400 HU, window level ~40 HU
Window width ~3000 HU, window level ~300 HU

Correct answer: Window width ~1500 HU, window level ~-600 HU

Lung windows use a wide width (~1500 HU) and negative level (~-600 HU) to display the full range of lung attenuation from air to soft tissue.

Question 2: Which entity must sponsor a continuing education activity for it to count toward ARRT CT recertification?

The technologist's employing hospital
The American College of Radiology only
Any national radiology organization
An ARRT-approved CE sponsor (Correct answer)

Correct answer: An ARRT-approved CE sponsor

ARRT only accepts Category A CE credits from activities provided by ARRT-approved sponsors, ensuring quality and relevance.

Question 3: Which artifact is caused by patient movement during CT data acquisition and appears as blurring or ghosting on the reconstructed image?

Cupping artifact
Partial volume artifact
Aliasing artifact
Motion artifact (Correct answer)

Correct answer: Motion artifact

Motion artifacts result from patient movement during scanning, causing inconsistent data at each projection angle and manifesting as blurring or streaking.

Question 4: In multi-detector CT (MDCT), increasing the number of detector rows primarily allows:

Higher kVp settings
Reduced x-ray tube heat loading per scan
Simultaneous acquisition of more slices per rotation, improving z-axis coverage speed (Correct answer)
Elimination of pitch requirements

Correct answer: Simultaneous acquisition of more slices per rotation, improving z-axis coverage speed

More detector rows mean more slice data acquired per rotation, covering a larger anatomical volume per gantry revolution and reducing scan time.

Question 5: What is one key reason that ACR-accredited imaging facilities value technologists with ARRT CT certification?

ACR accreditation prohibits hiring uncertified technologists
Certified technologists help demonstrate staff qualifications required during ACR accreditation reviews (Correct answer)
Accreditation requires a minimum ratio of 10 certified techs per scanner
ARRT CT certification is issued by the ACR

Correct answer: Certified technologists help demonstrate staff qualifications required during ACR accreditation reviews

ACR accreditation reviewers assess staff qualifications, and ARRT CT certification is recognized evidence of competency that supports accreditation approval.

Question 6: In CT quality control, 'low-contrast detectability' refers to the system's ability to:

Measure exact CT numbers for each tissue type
Determine the maximum scan field of view
Resolve fine structural detail in bone
Distinguish objects with small differences in attenuation from background (Correct answer)

Correct answer: Distinguish objects with small differences in attenuation from background

Low-contrast detectability measures the scanner's ability to visualize objects with subtle attenuation differences, which is critical for soft-tissue diagnosis.

Question 7: Respiratory motion artifacts on chest CT can best be minimized by:

Increasing slice thickness
Increasing kVp
Using breath-hold technique during acquisition (Correct answer)
Widening the display window

Correct answer: Using breath-hold technique during acquisition

Instructing the patient to suspend respiration during CT acquisition eliminates breathing motion, preventing blurring and step artifacts in the chest.

Question 8: An applicant discloses a misdemeanor conviction on the ARRT ethics pre-application. What is the likely next step?

The misdemeanor is ignored if more than 5 years old
The applicant is approved with a probationary credential
The application is automatically denied
ARRT conducts an ethics review before granting or denying eligibility (Correct answer)

Correct answer: ARRT conducts an ethics review before granting or denying eligibility

Any disclosed violation triggers an ARRT ethics review, which evaluates the nature and context of the offense before deciding eligibility.

Question 9: The window level (WL) in CT display refers to:

The minimum threshold for bone segmentation
The reconstruction matrix size
The center Hounsfield unit value of the displayed grayscale range (Correct answer)
The total range of Hounsfield units shown

Correct answer: The center Hounsfield unit value of the displayed grayscale range

Window level sets the midpoint of the HU range being displayed, determining which tissue densities appear as medium gray on the monitor.

Question 10: Which regulatory body sets the annual occupational effective dose limit of 50 mSv in the United States?

ARRT
FDA
CDC
NRC and Agreement States (Correct answer)

Correct answer: NRC and Agreement States

The Nuclear Regulatory Commission (NRC) and Agreement State regulations set the 50 mSv/year occupational effective dose limit (10 CFR 20).

Question 11: A CT of the chest shows a 2.5 cm solitary pulmonary nodule with central 'popcorn' calcification. What is the most likely diagnosis?

Bronchogenic carcinoma
Hamartoma (Correct answer)
Carcinoid tumor
Metastatic deposit

Correct answer: Hamartoma

Popcorn calcification within a pulmonary nodule is characteristic of a pulmonary hamartoma.

Question 12: Which oral contrast agent is most commonly used in CT of the abdomen and pelvis to opacify the bowel?

Gadolinium-based oral agent
Manganese chloride solution
Barium sulfate suspension or dilute water-soluble iodinated contrast (Correct answer)
Air alone as a negative contrast agent

Correct answer: Barium sulfate suspension or dilute water-soluble iodinated contrast

Barium sulfate or dilute iodinated contrast (e.g., dilute Gastrografin) are the standard oral agents used to opacify the GI tract in abdominal/pelvic CT.

Question 13: Iterative reconstruction (IR) techniques in CT offer which primary advantage over filtered back projection?

Higher spatial resolution
Faster reconstruction speed
Elimination of all artifacts
Reduced image noise at the same or lower radiation dose (Correct answer)

Correct answer: Reduced image noise at the same or lower radiation dose

IR algorithms use repeated mathematical modeling of the imaging process to suppress noise, allowing diagnostic image quality to be maintained at reduced mAs and dose.

Question 14: Under ARRT policy, which of the following best describes the purpose of mandatory continuing education for CT technologists?

To protect patients by ensuring technologists stay current in their field (Correct answer)
To standardize CT protocols across all imaging facilities
To generate revenue for accreditation bodies
To reduce malpractice insurance premiums for employers

Correct answer: To protect patients by ensuring technologists stay current in their field

The fundamental purpose of mandatory CE is patient protection — ensuring technologists maintain the knowledge and skills needed for safe, effective practice.

Question 15: What is the difference between arteries and veins?

Arteries carry blood away from the heart; veins carry blood toward the heart (Correct answer)
Veins are thicker than arteries
Arteries are only in the lungs
They carry the same blood in the same direction

Correct answer: Arteries carry blood away from the heart; veins carry blood toward the heart

Arteries carry blood away from the heart (usually oxygenated) while veins carry blood toward the heart (usually deoxygenated). Arteries have thicker walls to handle higher pressure.

Question 16: The Hounsfield unit (HU) value of pure water is:

+1000
0 (Correct answer)
-1000
+100

Correct answer: 0

By definition, pure water is assigned an HU value of 0 on the Hounsfield scale used in CT imaging.

Question 17: In a renal stone protocol CT, intravenous contrast is typically:

Not administered (Correct answer)
Administered after scanning only
Administered in a split-bolus technique
Administered before scanning only

Correct answer: Not administered

Non-contrast CT is the gold standard for detecting urolithiasis because stones are visible without IV contrast and contrast can obscure small calculi.

Question 18: What does CT stand for in medical imaging?

Computed Tomography (Correct answer)
Cardiac Testing
Clinical Therapy
Central Treatment

Correct answer: Computed Tomography

CT (Computed Tomography) uses X-ray technology and computer processing to create detailed cross-sectional images of the body.

Question 19: Which of the following is an advantage of holding ARRT CT certification when seeking a job?

It limits you to working only in CT imaging departments
It guarantees immediate employment at any facility
It allows you to bypass the interview process
It demonstrates specialized knowledge and commitment to the field, making you a more competitive candidate (Correct answer)

Correct answer: It demonstrates specialized knowledge and commitment to the field, making you a more competitive candidate

In a competitive job market, ARRT CT certification acts as a powerful differentiator. It signals to potential employers that a candidate possesses specialized knowledge, has met national standards, and is dedicated to their profession, significantly enhancing their competitiveness for CT technologist positions.

Question 20: How does ARRT CT certification influence a technologist's ability to work at facilities affiliated with academic medical centers?

It only matters for technologists who also teach radiology students
Academic medical centers often require specialty certifications for positions involving advanced imaging modalities (Correct answer)
It is disqualifying because academic centers prefer non-certified staff
It is irrelevant because academic centers set their own competency standards independently of ARRT

Correct answer: Academic medical centers often require specialty certifications for positions involving advanced imaging modalities

Academic medical centers frequently list specialty ARRT certifications as required or preferred qualifications for CT positions due to their high-acuity patient populations.

Question 21: Which of the following would trigger an automatic review by the ARRT Ethics Review Committee?

A technologist failing to submit CE on time
A program director retiring
A credential holder being convicted of a felony (Correct answer)
A technologist changing their employer

Correct answer: A credential holder being convicted of a felony

A felony conviction is a serious ethics matter that ARRT's Ethics Review Committee must evaluate to determine whether the credential can be maintained.

Question 22: A patient with known Crohn's disease undergoes CT enterography. Which finding most specifically indicates active inflammation?

Mesenteric lymphadenopathy alone
Non-enhancing bowel wall thickening
Ascites
Bowel wall thickening with mural hyperenhancement and the comb sign (Correct answer)

Correct answer: Bowel wall thickening with mural hyperenhancement and the comb sign

Active Crohn's disease shows mural hyperenhancement, wall thickening, and engorged vasa recta (comb sign) on CT enterography.

Question 23: Which of the following is a potential benefit of obtaining ARRT CT certification?

A significant reduction in the required continuing education hours
Eligibility for an automatic salary increase
Increased job security and advancement opportunities (Correct answer)
Exemption from state licensure requirements

Correct answer: Increased job security and advancement opportunities

Obtaining ARRT CT certification demonstrates a specialized skill set and commitment to professional standards, which is highly valued by employers. This often translates into increased job security, as certified professionals are preferred, and opens doors to advancement opportunities within the medical imaging field.

Question 24: On axial CT at the level of L4-L5, which structure is found anterior to the vertebral body?

Abdominal aortic bifurcation (Correct answer)
Superior mesenteric artery origin
Celiac axis
Inferior mesenteric artery origin

Correct answer: Abdominal aortic bifurcation

The abdominal aorta bifurcates into the common iliac arteries at approximately the L4 vertebral level.

Question 25: On axial CT at the level of the umbilicus, which abdominal wall muscle is most lateral?

External oblique (Correct answer)
Internal oblique
Transversus abdominis
Rectus abdominis

Correct answer: External oblique

The external oblique is the most superficial and lateral of the flat abdominal wall muscles, lying outside the internal oblique.

Question 26: What is the ALARA principle in radiation safety?

As Low As Reasonably Achievable — minimize radiation exposure (Correct answer)
Automated Limiting Adjustment for Radiation Applications
All Labs And Rooms Assessed
Always Lock And Restrict Access

Correct answer: As Low As Reasonably Achievable — minimize radiation exposure

ALARA means keeping radiation doses as low as reasonably achievable while still obtaining diagnostic-quality images, balancing benefit against risk.

Question 27: If an ARRT CT candidate fails the examination, what is the mandatory waiting period before retaking it?

One full year
90 days (Correct answer)
30 days
180 days

Correct answer: 90 days

ARRT mandates a 90-day waiting period between examination attempts for post-primary specialty exams including CT.

Question 28: A standard high-resolution CT (HRCT) chest protocol uses which reconstruction approach to evaluate interstitial lung disease?

Thick slices with soft tissue kernel
Thin slices with high-frequency (sharp) kernel (Correct answer)
Thin slices with soft tissue kernel
Thick slices with bone kernel

Correct answer: Thin slices with high-frequency (sharp) kernel

HRCT uses thin slices (≤1.5 mm) with a high-spatial-frequency kernel to maximize edge detail of lung parenchyma and airways.

Question 29: Which factor primarily determines the z-axis (longitudinal) resolution in a multislice CT scanner?

kVp setting
Gantry rotation speed
Reconstruction matrix size
Detector row width (Correct answer)

Correct answer: Detector row width

Z-axis resolution is primarily determined by detector row width (collimation), which defines slice thickness in the longitudinal direction.

Question 30: How does ARRT CT certification benefit patients receiving CT imaging services?

It ensures patients pay lower co-pays for CT exams
It guarantees the exam will be read by a board-certified radiologist
It signals that the performing technologist has met a validated standard of CT knowledge and skill (Correct answer)
It eliminates the possibility of radiation dose errors

Correct answer: It signals that the performing technologist has met a validated standard of CT knowledge and skill

ARRT CT certification assures patients and referring physicians that the technologist has demonstrated competency through a rigorous standardized examination.

Question 31: CT colonoscopy (virtual colonoscopy) relies on which post-processing technique to create a simulated fly-through view of the colon lumen?

Volume rendering with endoluminal navigation (Correct answer)
Minimum intensity projection
Subtraction imaging
Maximum intensity projection

Correct answer: Volume rendering with endoluminal navigation

Volume rendering with endoluminal navigation uses the air-distended colon as a flight path, generating a simulated colonoscopic perspective of the mucosal surface.

Question 32: A patient states, 'I am Jehovah's Witness and refuse any blood transfusion.' The radiologic technologist should:

Contact the patient's family to override the decision
Document the statement and notify the supervising clinician immediately (Correct answer)
Proceed with the procedure and allow physicians to decide later
Disregard the statement as the patient may not understand their condition

Correct answer: Document the statement and notify the supervising clinician immediately

A competent adult patient has the right to refuse treatment; the technologist must document this and notify the care team to ensure informed refusal is properly handled.

Question 33: Multiplanar reformation (MPR) in CT refers to:

Subtracting pre-contrast from post-contrast images
Reconstructing axial images into coronal, sagittal, or oblique planes (Correct answer)
Generating 3D surface models from volumetric data
Applying color to CT images based on Hounsfield units

Correct answer: Reconstructing axial images into coronal, sagittal, or oblique planes

MPR uses the volumetric CT dataset to create reformatted images in any anatomical plane without additional radiation exposure to the patient.

Question 34: When using a mechanical patient lift (Hoyer lift), the sling should be placed under the patient:

After the patient is partially elevated to assess comfort
Only under the torso, leaving the legs unsupported
Only when the patient is completely unconscious
Correctly positioned before activating the lift, with all attachment points secured (Correct answer)

Correct answer: Correctly positioned before activating the lift, with all attachment points secured

All sling attachment points must be secured and the sling properly positioned before activating the lift to prevent the patient from falling.

Question 35: The windmill artifact in multislice CT helical acquisitions is MOST pronounced when:

Low mAs is used with a smooth kernel
Small FOV is selected with fine matrix
High kVp is used with thin collimation
High pitch values are combined with thick slice reconstruction (Correct answer)

Correct answer: High pitch values are combined with thick slice reconstruction

Windmill artifact stems from undersampling in the z-direction; it is most visible with high pitch (sparse data) and thick reconstructions that exaggerate interpolation errors.

Question 36: The annual occupational dose limit for the lens of the eye, as updated by NCRP Report No. 172, is:

50 mSv
5 mSv
150 mSv
20 mSv (Correct answer)

Correct answer: 20 mSv

NCRP Report No. 172 (2016) lowered the recommended annual occupational lens dose limit to 20 mSv/year averaged over 5 years, consistent with ICRP 103.

Question 37: What is the window level and window width on CT images?

Settings that control the brightness and contrast of displayed images (Correct answer)
Scan speed controls
Physical measurements of the CT scanner
Patient positioning parameters

Correct answer: Settings that control the brightness and contrast of displayed images

Window level sets the center brightness (what HU appears as middle gray) and window width controls contrast range (how many HUs span from black to white).

Question 38: 3D volume rendering of CT data allows the display of internal structures through which technique?

Selecting only the highest attenuation voxel per projection ray
Assigning opacity values to voxels based on their Hounsfield units (Correct answer)
Subtracting bone from the dataset
Applying a smooth kernel to the raw data

Correct answer: Assigning opacity values to voxels based on their Hounsfield units

Volume rendering assigns transfer functions that map each HU value to a color and opacity, allowing semi-transparent visualization of multiple tissue types simultaneously.

Question 39: What is the window level and window width on CT images?

Physical measurements of the CT scanner
Scan speed controls
Settings that control the brightness and contrast of displayed images (Correct answer)
Patient positioning parameters

Correct answer: Settings that control the brightness and contrast of displayed images

Window level sets the center brightness (what HU appears as middle gray) and window width controls contrast range (how many HUs span from black to white).

Question 40: On axial CT of the head at the level of the fourth ventricle, which structure is immediately posterior to the fourth ventricle?

Pons
Cerebellum (vermis) (Correct answer)
Choroid plexus
Medulla oblongata

Correct answer: Cerebellum (vermis)

The cerebellar vermis forms the posterior wall of the fourth ventricle on axial CT images.

Question 41: Which CT parameter most directly controls the amount of radiation dose delivered to the patient?

kVp
mAs (Correct answer)
Reconstruction kernel
Pitch

Correct answer: mAs

mAs (milliampere-seconds) directly determines the number of X-ray photons produced and is the primary controller of patient dose.

Question 42: Which of the following scan parameters most directly affects the z-axis (longitudinal) spatial resolution in CT?

Slice thickness (Correct answer)
Matrix size
Window width
Field of view (FOV)

Correct answer: Slice thickness

Slice thickness determines the size of the voxel in the z-direction and therefore directly controls longitudinal (through-plane) spatial resolution.

Question 43: A ring or band artifact centered on the image is most likely caused by a malfunction of which CT component?

Collimator
A single detector element (Correct answer)
Gantry motor
X-ray tube

Correct answer: A single detector element

Ring artifacts result from a miscalibrated or malfunctioning detector element producing a circular artifact at a fixed radius from the isocenter.

Question 44: Partial volume averaging artifact in CT is BEST minimized by:

Increasing the reconstruction matrix
Using thinner slice collimation (Correct answer)
Using a smoother reconstruction kernel
Decreasing the tube current

Correct answer: Using thinner slice collimation

Thinner slices reduce the z-axis extent of each voxel, decreasing the chance that multiple tissue types are averaged into a single voxel.

Question 45: A CT technologist with ARRT CT certification wants to teach at a community college radiologic technology program. How does the certification help?

It demonstrates content expertise that many programs require or prefer for adjunct CT instructors (Correct answer)
It only qualifies the technologist to teach radiography, not CT specifically
It is a disqualifying credential for educational roles
It automatically grants a teaching license in all states

Correct answer: It demonstrates content expertise that many programs require or prefer for adjunct CT instructors

Community college and vocational radiologic technology programs often require or prefer instructors to hold advanced ARRT credentials in the specialty they are teaching.

Question 46: A technologist reconstructs axial CT images with 5 mm thickness then reforms sagittal images showing 'staircase' appearance. The BEST solution is:

Use a sharper reconstruction kernel
Increase mAs for the next scan
Increase the reconstruction FOV
Reconstruct using thinner overlapping slices before reformatting (Correct answer)

Correct answer: Reconstruct using thinner overlapping slices before reformatting

Staircase artifact on reformats results from thick axial slices; reconstructing thinner overlapping slices provides finer z-axis sampling and smoother multiplanar reformats.

Question 47: What is the function of red blood cells?

To produce hormones
To fight infection
To clot blood
To transport oxygen from lungs to tissues and CO2 back (Correct answer)

Correct answer: To transport oxygen from lungs to tissues and CO2 back

Red blood cells (erythrocytes) contain hemoglobin that binds oxygen in the lungs and delivers it to tissues, then carries carbon dioxide back for exhalation.

Question 48: On axial CT at the level of the pelvis, the external iliac artery is located relative to the external iliac vein in which position?

Anterior and medial to the vein (Correct answer)
Posterior to the vein
Lateral to the vein
Medial to the vein

Correct answer: Anterior and medial to the vein

The external iliac artery lies anteromedial to the external iliac vein along the pelvic brim.

Question 49: Increasing the reconstruction field of view (FOV) while keeping matrix size constant will:

Have no effect on spatial resolution
Increase noise while improving contrast
Increase pixel size and decrease spatial resolution (Correct answer)
Decrease pixel size and increase spatial resolution

Correct answer: Increase pixel size and decrease spatial resolution

Larger FOV with the same matrix means each pixel covers more area, increasing pixel size and reducing spatial resolution.

Question 50: A CT scan protocol using 'prospective ECG gating' for cardiac imaging acquires data only during which part of the cardiac cycle?

Only during a pre-selected phase of diastole (Correct answer)
During both systole and diastole equally
Throughout the entire R-R interval
Only during systole

Correct answer: Only during a pre-selected phase of diastole

Prospective ECG gating triggers X-ray exposure only during a selected quiescent diastolic window, substantially reducing radiation dose compared to retrospective gating.

Question 51: The ARRT CT examination is delivered at:

ARRT headquarters only
Online via live proctoring from any location
Pearson VUE testing centers (Correct answer)
Accredited radiologic technology schools

Correct answer: Pearson VUE testing centers

ARRT partners with Pearson VUE to administer the CT post-primary examination at authorized testing centers.

Question 52: Which of the following BEST describes noise power spectrum (NPS) in CT?

A measure of how noise is distributed across spatial frequencies in an image (Correct answer)
The ratio of signal to total detector noise
A test of detector linearity across HU ranges
The standard deviation of HU values in a uniform phantom

Correct answer: A measure of how noise is distributed across spatial frequencies in an image

NPS characterizes the frequency content of image noise, showing whether noise is more granular (high-frequency) or blotchy (low-frequency) depending on reconstruction parameters.

Question 53: Adaptive statistical iterative reconstruction (ASIR) improves CT image quality primarily by:

Improving temporal resolution
Eliminating beam hardening artifacts
Increasing spatial resolution beyond filtered back projection
Reducing image noise while maintaining resolution (Correct answer)

Correct answer: Reducing image noise while maintaining resolution

ASIR uses statistical modeling to reduce noise, allowing diagnostic images at lower dose without proportional loss of spatial resolution.

Question 54: On a non-contrast CT of the abdomen, a renal calculus most likely to be missed is composed of which material?

Indinavir (drug-related) (Correct answer)
Calcium oxalate
Struvite
Uric acid

Correct answer: Indinavir (drug-related)

Indinavir stones are radiolucent and have very low Hounsfield units, making them nearly invisible on non-contrast CT.

Question 55: Which CT finding is most characteristic of acute mesenteric ischemia due to superior mesenteric artery occlusion?

Bowel wall thickening with hyperenhancement
Ascites alone
Retroperitoneal hematoma
Pneumatosis intestinalis (Correct answer)

Correct answer: Pneumatosis intestinalis

Pneumatosis intestinalis (gas within the bowel wall) indicates bowel infarction and is a hallmark of severe mesenteric ischemia.

Question 56: Which technique is most commonly used to reduce metal artifact in CT imaging of patients with hip prostheses?

Metal artifact reduction (MAR) software (Correct answer)
Increasing slice thickness
Decreasing kVp
Using a smaller FOV

Correct answer: Metal artifact reduction (MAR) software

Metal artifact reduction (MAR) algorithms replace corrupted projection data near metal with interpolated data, significantly reducing streaking artifacts.

Question 57: For a CT-guided biopsy protocol, which parameter is typically reduced to minimize patient dose during the procedure?

Slice thickness
Gantry rotation speed
Tube current (mA) (Correct answer)
Tube voltage (kVp)

Correct answer: Tube current (mA)

Fluoroscopic CT guidance uses low-mA (fluoroCT) settings to reduce cumulative dose while maintaining adequate image quality for needle visualization.

Question 58: A pediatric patient is uncooperative and crying during a radiographic exam. Which approach is most appropriate?

Speak calmly, involve the parent or guardian, and use age-appropriate distraction techniques before attempting immobilization (Correct answer)
Administer sedation without physician order to calm the child
Physically restrain the child immediately to complete the exam quickly
Reschedule the exam for another day without attempting to proceed

Correct answer: Speak calmly, involve the parent or guardian, and use age-appropriate distraction techniques before attempting immobilization

A calm approach with parental involvement and distraction is the least traumatic first step and often allows successful completion of the exam without restraint.

Question 59: The dose length product (DLP) is calculated by multiplying CTDI_vol by which parameter?

Number of detector rows
Scan length (cm) (Correct answer)
Pitch factor
Rotation time

Correct answer: Scan length (cm)

DLP = CTDI_vol × scan length (cm), providing a single value that reflects the total radiation energy deposited during the scan.

Question 60: The inverse square law states that radiation intensity is related to distance by which relationship?

Intensity decreases linearly with distance
Intensity is inversely proportional to the square of the distance (Correct answer)
Intensity is directly proportional to distance
Intensity is inversely proportional to the cube of the distance

Correct answer: Intensity is inversely proportional to the square of the distance

The inverse square law: I ∝ 1/d², meaning doubling the distance from the source reduces intensity to one-quarter of its original value.

Question 61: On axial CT of the abdomen, the superior mesenteric artery (SMA) is typically located:

Within the hepatoduodenal ligament
Lateral to the inferior vena cava
Directly anterior to the abdominal aorta, surrounded by fat (Correct answer)
Posterior to the splenic vein

Correct answer: Directly anterior to the abdominal aorta, surrounded by fat

The SMA arises from the anterior aorta and is typically seen as a vessel surrounded by a halo of mesenteric fat on axial CT.

Question 62: What is the purpose of contrast media in CT scans?

To reduce radiation dose
To enhance the visibility of specific structures and pathology (Correct answer)
To speed up the scan
To make the patient comfortable

Correct answer: To enhance the visibility of specific structures and pathology

Contrast media (dye) enhances the visibility of blood vessels, organs, and abnormalities by changing how X-rays interact with specific tissues.

Question 63: A CT technologist retires and allows their ARRT registration to expire for 8 years, then wishes to return to practice. What is required?

Completion of 24 CE credits and a reinstatement fee
A letter of recommendation from a radiologist
Submission of a reinstatement fee only
Retaking the ARRT CT certification examination (Correct answer)

Correct answer: Retaking the ARRT CT certification examination

After an extended lapse beyond ARRT's reinstatement window, technologists are typically required to retake the certification examination to demonstrate current competency.

Question 64: Which CT image quality parameter is measured using a modulation transfer function (MTF)?

Noise power spectrum
Contrast resolution
Temporal resolution
Spatial resolution (Correct answer)

Correct answer: Spatial resolution

The MTF quantifies spatial resolution by describing how faithfully the CT system reproduces objects of varying spatial frequencies.

Question 65: Windowing in CT (setting window width and level) affects:

The actual CT numbers in the reconstructed data
Only the display of contrast by mapping HU values to gray shades (Correct answer)
The spatial resolution of the image
Radiation dose to the patient

Correct answer: Only the display of contrast by mapping HU values to gray shades

Windowing is a display operation that maps selected HU ranges to the visible gray scale; it does not alter the underlying image data.

Question 66: During a CT angiography of the neck (CTA neck), the scan direction is typically:

Axial only without table movement
Caudal to cranial (Correct answer)
Cranial to caudal
Bidirectional simultaneously

Correct answer: Caudal to cranial

CTA of the neck scans caudal to cranial to follow the contrast bolus as it travels superiorly through the carotid and vertebral arteries.

Question 67: Which career pathway is most directly opened by holding ARRT CT certification?

Lead CT technologist or CT supervisor (Correct answer)
Radiology billing and coding specialist
Nuclear medicine physician
Radiation oncology physician assistant

Correct answer: Lead CT technologist or CT supervisor

CT certification establishes the specialized credential often required for leadership roles such as lead CT tech or CT department supervisor.

Question 68: The ARRT CT post-primary examination content specifications are reviewed and updated approximately every:

5 years (Correct answer)
10 years
Every certification cycle (2 years)
1 year

Correct answer: 5 years

ARRT reviews and updates examination content specifications on approximately a five-year cycle through its practice analysis process.

Question 69: Which CT feature differentiates an acute from a chronic subdural hematoma?

Location over the convexity
Crescent shape
Hypodense (low attenuation) appearance of the collection (Correct answer)
Mass effect on the brain

Correct answer: Hypodense (low attenuation) appearance of the collection

Chronic subdural hematomas become hypodense (isodense to CSF) over weeks as hemoglobin degrades, unlike acute hyperdense collections.

Question 70: To troubleshoot a CT image showing significant noise (grainy appearance), the technologist should first consider adjusting which parameter?

Increasing mAs (Correct answer)
Decreasing kVp
Reducing matrix size
Increasing pitch

Correct answer: Increasing mAs

Increasing mAs raises the number of X-ray photons, directly reducing quantum noise and improving signal-to-noise ratio.

Question 71: The 'cupping artifact' in CT, where the center of a uniform object appears less dense than its periphery, is a manifestation of which phenomenon?

Quantum noise
Partial volume averaging
Aliasing
Beam hardening (Correct answer)

Correct answer: Beam hardening

Cupping artifact is a form of beam hardening where the edges of the object appear brighter because the beam hardens less traveling a shorter path length.

Question 72: The ARRT CT post-primary examination is a computer-based test (CBT). Approximately how many scored questions does it contain?

100 questions
165 questions (Correct answer)
200 questions
75 questions

Correct answer: 165 questions

The ARRT CT examination consists of approximately 165 scored questions plus a small number of unscored pilot questions.

Question 73: Which post-processing technique is most appropriate for evaluating luminal stenosis of the carotid arteries on a CT angiogram?

Standard axial images only
Volume rendering alone
Multiplanar reformation combined with MIP (Correct answer)
Minimum intensity projection (MinIP)

Correct answer: Multiplanar reformation combined with MIP

Combining MPR (which shows vessel walls and plaques in cross-section) with MIP (which shows the lumen in projection) gives the most complete assessment of carotid stenosis.

Question 74: Which scan parameter change will REDUCE patient dose while keeping all other factors constant?

Decreasing scan length from 40 cm to 30 cm (Correct answer)
Increasing mAs from 200 to 300
Decreasing pitch from 1.5 to 0.75
Increasing rotation time from 0.5 s to 1.0 s

Correct answer: Decreasing scan length from 40 cm to 30 cm

Reducing scan length directly reduces the total volume irradiated and therefore lowers DLP and patient dose.

Question 75: A technologist holds ARRT primary certification in Radiography and a post-primary in CT. How many total CE credits are required per cycle?

24 total, with at least 6 specific to CT
24 total, shared across both credentials (Correct answer)
48 total — 24 for each credential separately
36 total — 24 for primary plus 12 for post-primary

Correct answer: 24 total, shared across both credentials

ARRT allows the same 24 Category A CE credits to satisfy renewal requirements for both the primary and post-primary certifications simultaneously.

Question 76: Which of the following is NOT a requirement for ARRT CT post-primary certification eligibility?

Graduating from a JRCERT-accredited CT-specific degree program (Correct answer)
Meeting clinical experience requirements in CT procedures
Completing required structured education in CT
Holding a current, unrestricted ARRT credential in a qualifying discipline

Correct answer: Graduating from a JRCERT-accredited CT-specific degree program

CT certification does not require graduation from a JRCERT-accredited CT degree program; structured education and clinical experience through other approved pathways are accepted.

Question 77: In CT, the term 'isotropic voxel' means:

The voxel represents a single tissue type
The voxel has no noise contribution
The voxel dimensions are equal in all three axes (x, y, z) (Correct answer)
The voxel's HU value is calibrated to water

Correct answer: The voxel dimensions are equal in all three axes (x, y, z)

An isotropic voxel has equal dimensions in x, y, and z directions, enabling multiplanar reformats of equal quality in any plane.

Question 78: The Hounsfield unit (HU) value of pure water is defined as:

0 HU (Correct answer)
+500 HU
-1000 HU
+1000 HU

Correct answer: 0 HU

The CT number scale defines water as 0 HU and air as −1000 HU, with other tissues placed relative to these references.

Question 79: What is the purpose of an After Action Review (AAR)?

To analyze what happened, why, and how to improve (Correct answer)
To assign blame
To plan the next mission only
To write performance reviews

Correct answer: To analyze what happened, why, and how to improve

AARs are structured reviews analyzing what was planned, what happened, why there were differences, and what can be improved.

Question 80: Which of the following correctly defines 'effective dose' (E) in radiation protection?

The absorbed dose to a single organ multiplied by the quality factor
The weighted sum of equivalent doses to all irradiated tissues, reflecting overall stochastic risk (Correct answer)
The dose measured at the surface of a standard phantom
The total energy deposited in the patient during a CT scan

Correct answer: The weighted sum of equivalent doses to all irradiated tissues, reflecting overall stochastic risk

Effective dose uses tissue weighting factors to sum equivalent doses across organs, yielding a single value (in mSv) that represents whole-body stochastic risk.

Question 81: A CT technologist is audited by ARRT and cannot produce records for completed CE activities. What is the most likely consequence?

Their CE credits may be disallowed and registration revoked (Correct answer)
ARRT will contact the CE sponsors on their behalf
A formal written warning is issued
They are required to repeat the certification exam

Correct answer: Their CE credits may be disallowed and registration revoked

During an audit, failure to document CE activities can result in disallowance of credits and potential revocation of registration.

Question 82: Which statement BEST describes the relationship between CT noise and mAs?

Noise is inversely proportional to mAs
Noise is directly proportional to mAs
Noise is unaffected by mAs changes
Noise is proportional to 1/√mAs (Correct answer)

Correct answer: Noise is proportional to 1/√mAs

CT noise follows Poisson statistics; doubling mAs quadruples photons but only reduces noise by a factor of √2, making noise proportional to 1/√mAs.

Question 83: Which employment sector has seen the fastest growth in demand for ARRT CT-certified technologists in recent years?

Dental radiography offices
Film-based radiology departments
Veterinary imaging clinics
Outpatient and freestanding imaging centers (Correct answer)

Correct answer: Outpatient and freestanding imaging centers

The rapid expansion of outpatient and freestanding imaging centers has driven increased demand for ARRT CT-certified technologists outside traditional hospital settings.

Question 84: Which CT feature of a pulmonary nodule is most associated with malignancy?

Stippled central calcification
Smooth well-defined margins
Laminated calcification pattern
Spiculated margins with pleural tethering (Correct answer)

Correct answer: Spiculated margins with pleural tethering

Spiculated margins with pleural tethering are high-risk features indicating likely malignant invasion of adjacent lung parenchyma.

Question 85: When evaluating a CT image for streak artifacts emanating from a hip prosthesis, the BEST corrective technique is:

Decreasing the mAs by 50%
Increasing the kVp to 140
Widening the reconstruction FOV
Metal artifact reduction (MAR) reconstruction algorithm (Correct answer)

Correct answer: Metal artifact reduction (MAR) reconstruction algorithm

Metal artifact reduction algorithms use iterative or sinogram-based techniques to model and subtract metal-induced streaks from the image.

Question 86: Which premedication regimen is most commonly recommended for elective contrast administration in patients with a prior mild allergic-like contrast reaction?

Oral prednisone 50 mg at 13, 7, and 1 hour before contrast plus diphenhydramine 50 mg 1 hour before (Correct answer)
No premedication is needed for mild prior reactions
IV epinephrine 30 minutes before contrast
IV methylprednisolone only, given 1 minute before injection

Correct answer: Oral prednisone 50 mg at 13, 7, and 1 hour before contrast plus diphenhydramine 50 mg 1 hour before

The ACR-recommended premedication protocol for non-emergent cases includes oral prednisone at 13, 7, and 1 hour before contrast plus diphenhydramine 50 mg 1 hour before.

Question 87: What is preventive maintenance?

Regular scheduled maintenance to prevent equipment failure (Correct answer)
Cleaning only
Fixing equipment after it breaks
Replacing all equipment annually

Correct answer: Regular scheduled maintenance to prevent equipment failure

Preventive maintenance involves regular, scheduled inspections and servicing to prevent unexpected breakdowns and extend equipment life.

Question 88: When a CT abdomen protocol specifies 'nephrographic phase,' scanning typically occurs at what delay after IV contrast injection?

30–45 seconds
80–120 seconds (Correct answer)
5–10 minutes
15–25 seconds

Correct answer: 80–120 seconds

The nephrographic phase occurs at approximately 80–120 seconds post-injection when both cortex and medulla enhance uniformly, optimizing renal parenchymal visualization.

Question 89: A candidate applies for CT certification under the structured education pathway. Which type of program must they have completed?

A self-designed independent study program
Any radiology-related online course
A hospital orientation program
A CT-specific structured education program accredited by a recognized body (Correct answer)

Correct answer: A CT-specific structured education program accredited by a recognized body

The structured education pathway requires completion of a CT program accredited by a body recognized by ARRT, such as JRCERT.

Question 90: Minimum intensity projection (MinIP) post-processing is particularly useful for displaying which anatomical structures?

Dense bone and calcifications
Solid abdominal organs
Contrast-enhanced blood vessels
Air-filled airways and lung parenchyma (Correct answer)

Correct answer: Air-filled airways and lung parenchyma

MinIP projects the lowest attenuation voxel along each ray, making it ideal for displaying air-containing structures like the tracheobronchial tree or emphysematous lung.

Question 91: Which of the following is the correct action if a detector ring artifact is identified during a quality control check of the CT scanner?

Decrease the FOV
Increase mAs to compensate
Recalibrate the detector and notify the medical physicist (Correct answer)
Continue scanning and note in the patient report

Correct answer: Recalibrate the detector and notify the medical physicist

A ring artifact indicates a detector calibration issue that must be corrected by recalibration or service; the medical physicist should be notified per QC protocols.

Question 92: On axial brain CT, the sylvian fissure (lateral sulcus) separates which lobes?

Frontal lobe from occipital lobe
Parietal lobe from occipital lobe
Frontal lobe from the parietal lobe only
Frontal and parietal lobes from the temporal lobe (Correct answer)

Correct answer: Frontal and parietal lobes from the temporal lobe

The sylvian (lateral) fissure separates the frontal and parietal lobes superiorly from the temporal lobe inferiorly.

Question 93: Partial volume averaging artifacts in CT are best reduced by which acquisition parameter adjustment?

Widening the display window
Increasing mAs
Increasing kVp
Using a thinner slice thickness (Correct answer)

Correct answer: Using a thinner slice thickness

Thinner slices reduce partial volume averaging by ensuring each voxel contains tissue from a smaller volume, improving accuracy of CT numbers.

Question 94: How many continuing education credits must ARRT-registered CT technologists earn during each 2-year renewal cycle?

36 credits
24 credits (Correct answer)
12 credits
48 credits

Correct answer: 24 credits

ARRT requires 24 Category A continuing education credits per 2-year renewal cycle for registered technologists.

Question 95: A patient with a cardiac pacemaker presents for chest CT. Which artifact should the technologist anticipate?

Ring artifact
Windmill artifact
Metallic streak artifact from the pacemaker leads and generator (Correct answer)
Cupping artifact

Correct answer: Metallic streak artifact from the pacemaker leads and generator

Pacemaker generators and leads are highly attenuating metallic objects that produce characteristic beam hardening streak artifacts on chest CT.

Question 96: What is a Hounsfield unit?

A quantitative measurement of tissue density on CT images (Correct answer)
A unit of image resolution
A unit of radiation dose
A measure of scan speed

Correct answer: A quantitative measurement of tissue density on CT images

Hounsfield units (HU) measure tissue density on CT, with water at 0 HU, air at -1000 HU, and dense bone at +1000 HU or higher.

Question 97: Quantum mottle in CT images is primarily caused by:

Excessive table speed
An insufficient number of detected photons (Correct answer)
High kVp beam hardening
Detector calibration errors

Correct answer: An insufficient number of detected photons

Quantum mottle (noise) occurs when too few photons reach the detector, causing statistical fluctuations that appear as grainy image texture.

Question 98: Which of the following is a prerequisite for pursuing ARRT Computed Tomography certification?

Holding an ARRT certification in radiography, nuclear medicine, or radiation therapy (Correct answer)
Bachelor’s degree in radiologic sciences
At least five years of experience in radiologic technology
Completion of 40 hours of CT-specific continuing education

Correct answer: Holding an ARRT certification in radiography, nuclear medicine, or radiation therapy

The ARRT Computed Tomography (CT) certification is a post-primary certification, meaning candidates must first hold a primary ARRT certification. Specifically, one must be certified in radiography (R), nuclear medicine technology (N), or radiation therapy (T) to be eligible to pursue the CT certification. This ensures a foundational understanding of radiologic principles before specializing.

Question 99: The primary advantage of iterative reconstruction over filtered back projection (FBP) in CT is:

Faster image processing time
Reduced image noise at equivalent or lower dose (Correct answer)
Elimination of all beam hardening artifacts
Larger field of view capability

Correct answer: Reduced image noise at equivalent or lower dose

Iterative reconstruction algorithms reduce noise by modeling the imaging system and iteratively comparing projection data, allowing lower-dose acquisitions.

Question 100: What physiologic mechanism underlies contrast-induced nephropathy (CIN)?

Systemic vasodilation leading to prerenal azotemia
Obstructive uropathy from contrast precipitation in the collecting ducts
Immune-mediated glomerulonephritis triggered by iodine
Renal medullary ischemia and direct tubular cell toxicity from contrast (Correct answer)

Correct answer: Renal medullary ischemia and direct tubular cell toxicity from contrast

CIN results from renal medullary vasoconstriction causing ischemia combined with direct cytotoxic effects of contrast on tubular epithelial cells.

Question 101: The spatial resolution of a CT image is primarily limited by which factor?

Room temperature
Patient age
Type of reconstruction filter used alone
Focal spot size and detector aperture (Correct answer)

Correct answer: Focal spot size and detector aperture

Focal spot size and detector cell aperture are the primary hardware factors limiting spatial resolution in CT.

Question 102: Which statement about the ARRT recertification renewal deadline is correct?

Renewal is due on the last day of the technologist's birth month in the renewal year (Correct answer)
ARRT automatically renews registration if CE is on file
Renewal must be completed by January 31st of the renewal year
Renewal can be completed any time within the 2-year window

Correct answer: Renewal is due on the last day of the technologist's birth month in the renewal year

ARRT renewal deadlines are tied to the technologist's birth month in the renewal year, serving as the annual deadline.

Question 103: Which of the following is the correct documentation entry after administering IV contrast?

Contrast given per radiologist order
Type of contrast, lot number, dose, route, rate, patient response, and technologist's signature (Correct answer)
Contrast given — no issues noted
Patient tolerated procedure well

Correct answer: Type of contrast, lot number, dose, route, rate, patient response, and technologist's signature

Complete contrast documentation must include the agent name, lot number, dose, route, rate of administration, patient response, and the administering technologist's identification.

Question 104: What is the first priority in any emergency situation?

Save equipment
Write a report
Contact the media
Ensure the safety of all personnel (Correct answer)

Correct answer: Ensure the safety of all personnel

In any emergency, the first priority is always the safety and well-being of all personnel. Equipment and materials can be replaced; lives cannot.

Question 105: What is a key requirement related to clinical experience for ARRT CT certification eligibility?

Work in a CT department for a minimum of one year
Perform at least 10 supervised CT scans
Attend a CT-specific conference or seminar
Document and complete a set of clinical competencies in CT imaging (Correct answer)

Correct answer: Document and complete a set of clinical competencies in CT imaging

A crucial requirement for ARRT CT certification is demonstrating practical proficiency through documented clinical experience. Candidates must complete a specified set of clinical competencies, which involve performing and documenting various CT procedures under supervision. This ensures they have hands-on experience and can safely and effectively operate CT equipment.

Question 106: Which phenomenon explains why CT numbers for bone may appear elevated at the center of a thick bony structure compared to peripheral bone?

Ring artifact
Beam hardening cupping artifact (Correct answer)
Undersampling artifact
Partial volume effect

Correct answer: Beam hardening cupping artifact

Beam hardening causes preferential absorption of lower-energy photons; more hardening occurs centrally, leading to erroneously high CT numbers at bone edges and low values centrally (cupping).

Question 107: Iodinated contrast media produces vascular enhancement in CT primarily because iodine:

Emits positrons that scatter X-rays
Has a high atomic number that strongly attenuates X-rays (Correct answer)
Reduces blood viscosity, increasing flow speed
Increases the paramagnetic properties of blood

Correct answer: Has a high atomic number that strongly attenuates X-rays

Iodine (atomic number 53) has a high atomic number that dramatically increases X-ray attenuation in blood vessels and tissues, creating contrast enhancement on CT.

Question 108: For a CT of the paranasal sinuses ordered to guide functional endoscopic sinus surgery (FESS), which plane is most critical for the surgeon?

Oblique plane
Coronal plane (Correct answer)
Sagittal plane
Axial plane

Correct answer: Coronal plane

The coronal plane directly depicts the ostiomeatal complex, sinus drainage pathways, and the relationship to the orbit and skull base — essential for FESS planning.

Question 109: On axial CT, the cisterna chyli is typically located at which vertebral level and position?

Posterior to the aorta at T4-T5
Lateral to the right crus of the diaphragm at L1-L2
Within the retrocrural space at T12-L1
Anterior to L2-L3 between the aorta and IVC (Correct answer)

Correct answer: Anterior to L2-L3 between the aorta and IVC

The cisterna chyli is a lymphatic sac located anterior to the L1-L2 vertebral bodies, between the abdominal aorta and the inferior vena cava.

Question 110: Which of the following best describes 'overranging' (z-overscanning) in helical CT?

Extra rotations acquired beyond the requested scan range to complete helical reconstruction (Correct answer)
Applying too wide a display window
Using a higher kVp than needed
Scanning beyond the prescribed FOV diameter

Correct answer: Extra rotations acquired beyond the requested scan range to complete helical reconstruction

Overranging refers to the additional tube rotations at the start and end of a helical scan needed to reconstruct the first and last requested slices, increasing dose.

Question 111: What is the primary advantage of CT over conventional X-ray?

CT provides cross-sectional images with superior soft tissue contrast (Correct answer)
CT takes less time
CT is cheaper
CT uses no radiation

Correct answer: CT provides cross-sectional images with superior soft tissue contrast

CT provides detailed cross-sectional images with much better soft tissue contrast resolution than conventional X-rays, allowing visualization of subtle differences between tissues.

Question 112: At the level of the aortic arch on axial CT, which vessel arises first (most rightward/anterior) from the arch?

Right subclavian artery
Left subclavian artery
Left common carotid artery
Brachiocephalic (innominate) artery (Correct answer)

Correct answer: Brachiocephalic (innominate) artery

The brachiocephalic artery is the first and most rightward branch of the aortic arch, followed by the left common carotid and left subclavian.

Question 113: Which statement about self-referral in the ARRT CE system is accurate?

Only activities from ARRT-approved sponsors qualify for Category A (Correct answer)
Technologists may self-report any learning activity for Category A credit
Technologists can create their own CE modules and claim credit
Reading ARRT-published newsletters counts as Category A credit

Correct answer: Only activities from ARRT-approved sponsors qualify for Category A

Category A credits require the activity to be organized and offered through an ARRT-approved CE sponsor — self-reported or self-created activities do not qualify.

Question 114: Within how many years of completing structured education must a candidate apply for ARRT CT post-primary certification under the structured education pathway?

5 years (Correct answer)
2 years
1 year
10 years

Correct answer: 5 years

Candidates pursuing the structured education pathway must apply within 5 years of completing the qualifying program.

Question 115: When performing a venipuncture for contrast administration, the needle bevel should be oriented:

Facing up (bevel up) (Correct answer)
Parallel to the skin surface, bevel sideways
Facing down toward the vein wall
At a 90-degree angle to the skin

Correct answer: Facing up (bevel up)

The bevel-up orientation allows the needle to enter the vein smoothly and reduces the risk of piercing the posterior vein wall.

Question 116: What is the difference between arteries and veins?

Arteries carry blood away from the heart; veins carry blood toward the heart (Correct answer)
Arteries are only in the lungs
They carry the same blood in the same direction
Veins are thicker than arteries

Correct answer: Arteries carry blood away from the heart; veins carry blood toward the heart

Arteries carry blood away from the heart (usually oxygenated) while veins carry blood toward the heart (usually deoxygenated). Arteries have thicker walls to handle higher pressure.

Question 117: A hospital's Imaging Director wants to ensure staff are competent in CT protocols. Which credential most directly validates CT-specific competency?

Basic Life Support (BLS) certification
OSHA safety training certificate
ARRT CT post-primary certification (Correct answer)
ACR accreditation badge

Correct answer: ARRT CT post-primary certification

ARRT CT post-primary certification specifically validates a technologist's advanced knowledge and skills in computed tomography.

Question 118: Which artifact appears as a dark band between two high-density objects on a CT image and is caused by beam hardening?

Windmill artifact
Shadowing or 'dark band' artifact (Correct answer)
Moiré artifact
Ring artifact

Correct answer: Shadowing or 'dark band' artifact

Dark bands (also called 'shadowing' or 'cupping' between dense objects) arise from extreme beam hardening where few low-energy photons survive to reach the detector between two dense structures.

Question 119: Cupping artifact on a CT image of a large cylindrical phantom most likely indicates:

Patient motion during scanning
Beam hardening due to preferential absorption of lower-energy photons (Correct answer)
Incorrect detector gain calibration
Excessive pitch value

Correct answer: Beam hardening due to preferential absorption of lower-energy photons

Cupping artifact occurs because low-energy photons are preferentially absorbed by the periphery, hardening the beam and making the center appear falsely darker.

Question 120: An applicant for ARRT CT certification discloses a prior misdemeanor conviction on their application. What happens next?

The conviction is ignored if more than 5 years old
ARRT's Ethics Review Committee evaluates the disclosure on a case-by-case basis (Correct answer)
The applicant must wait 10 years before reapplying
The application is automatically denied

Correct answer: ARRT's Ethics Review Committee evaluates the disclosure on a case-by-case basis

ARRT's Ethics Review Committee reviews all disclosed violations individually to determine eligibility.

Question 121: Automatic tube current modulation (ATCM) in CT primarily aims to:

Maximize image spatial resolution for all body regions
Maintain consistent image noise while minimizing patient dose (Correct answer)
Eliminate motion artifacts in cardiac imaging
Improve temporal resolution in dynamic studies

Correct answer: Maintain consistent image noise while minimizing patient dose

ATCM adjusts mA based on patient attenuation in real time, delivering higher current through thicker/denser regions to maintain uniform noise and reducing dose elsewhere.

Question 122: What is the recommended IV injection rate range for a CT angiography of the aorta using a power injector?

3.0–6.0 mL/sec (Correct answer)
0.5–1.0 mL/sec
1.0–2.0 mL/sec
8.0–10.0 mL/sec

Correct answer: 3.0–6.0 mL/sec

CTA of the aorta typically requires injection rates of 3–6 mL/sec to achieve sufficient intravascular iodine concentration for diagnostic arterial enhancement.

Question 123: On axial CT of the upper abdomen, Gerota's fascia encloses which structures?

Kidney, adrenal gland, and the descending colon
Kidney and adrenal gland within the perirenal space (Correct answer)
Kidney only, not the adrenal gland
Adrenal gland only within the suprarenal space

Correct answer: Kidney and adrenal gland within the perirenal space

Gerota's fascia (renal fascia) surrounds both the kidney and the ipsilateral adrenal gland within the perirenal fat space.

Question 124: Which of the following is a non-financial benefit of ARRT CT certification that directly impacts a technologist's daily work?

Exemption from hospital-wide mandatory training
Increased confidence and clinical decision-making ability in CT protocols (Correct answer)
Reduced number of CT scans assigned per shift
Automatic scheduling priority for day shifts

Correct answer: Increased confidence and clinical decision-making ability in CT protocols

Preparing for and passing the CT exam deepens protocol knowledge, which enhances the technologist's confidence and quality of clinical decisions.

Question 125: Which of the following best describes the continuing education requirement to maintain ARRT CT certification?

No continuing education is required once certified
24 continuing education credits every 2 years (Correct answer)
10 credits per year with no renewal cycle
50 continuing education credits every 5 years

Correct answer: 24 continuing education credits every 2 years

ARRT requires 24 continuing education credits biennially to maintain all post-primary certifications including CT.

Question 126: A radiologic technologist notices that CT images of the liver appear uniformly noisy despite using standard mAs. The MOST appropriate first corrective action is:

Verify that the correct reconstruction kernel and algorithm are applied (Correct answer)
Switch to a narrower window width for display
Double the mAs for the repeat scan immediately
Reduce the reconstruction FOV by 50%

Correct answer: Verify that the correct reconstruction kernel and algorithm are applied

Verifying protocol settings (kernel, algorithm, slice thickness) first ensures the source of apparent noise is identified before unnecessarily increasing dose.

Question 127: What does CT stand for in medical imaging?

Computed Tomography (Correct answer)
Cardiac Testing
Central Treatment
Clinical Therapy

Correct answer: Computed Tomography

CT (Computed Tomography) uses X-ray technology and computer processing to create detailed cross-sectional images of the body.

Question 128: Which of the following scan coverage ranges is standard for a CT of the abdomen and pelvis?

Lung apices to pubic symphysis
Diaphragm to iliac crests only
Umbilicus to pubic symphysis
Diaphragm to pubic symphysis (Correct answer)

Correct answer: Diaphragm to pubic symphysis

A standard abdomen and pelvis CT extends from the diaphragm superiorly to the pubic symphysis inferiorly to cover all abdominal and pelvic organs.

Question 129: Regarding the ARRT CT eligibility requirement for moral character, which of the following is TRUE?

Moral character requirements apply only to new graduates, not experienced technologists
ARRT does not have a moral character requirement for post-primary certifications
Candidates must attest to meeting ARRT Standards of Ethics at the time of application (Correct answer)
Moral character is only evaluated after the examination is passed

Correct answer: Candidates must attest to meeting ARRT Standards of Ethics at the time of application

All ARRT applicants must attest to meeting the Standards of Ethics, including moral character, as part of the application process.

Question 130: ARRT's recertification policy allows CE credits earned through which type of structured journal activity?

Informal article reading without assessment
Any peer-reviewed radiology journal subscription
ARRT-approved self-assessment modules or journal-based CE with post-tests (Correct answer)
Department-based journal clubs without an approved sponsor

Correct answer: ARRT-approved self-assessment modules or journal-based CE with post-tests

Journal-based CE activities qualify only when they include a post-test and are offered through an ARRT-approved sponsor, not casual reading alone.

Question 131: What is the role of the ARRT Board of Trustees in the accreditation and credentialing process?

They directly score individual certification examinations
They perform on-site inspections of clinical training sites
They issue state radiologic technology licenses
They govern ARRT policy, including eligibility requirements and ethical standards (Correct answer)

Correct answer: They govern ARRT policy, including eligibility requirements and ethical standards

The ARRT Board of Trustees is the governing body responsible for setting policy, eligibility criteria, and ethical standards for the organization.

Question 132: A newly certified CT technologist wants to transition from a general hospital to an outpatient imaging center. How does ARRT CT certification help?

It eliminates the need for any additional facility orientation
It demonstrates specialized competency that outpatient centers increasingly require for hiring (Correct answer)
It automatically transfers the technologist's state license to the new facility
It restricts employment to inpatient facilities only

Correct answer: It demonstrates specialized competency that outpatient centers increasingly require for hiring

Outpatient imaging centers often prefer or require ARRT CT certification as proof of specialized competency, making job transitions easier.

Question 133: Which factor related to ARRT CT certification most directly contributes to long-term job security for a radiologic technologist?

Employers cannot legally terminate certified employees
Certified technologists are more difficult to replace, increasing their value during staffing reductions (Correct answer)
ARRT monitors all employer actions against certified staff
Certification guarantees tenure after three years of employment

Correct answer: Certified technologists are more difficult to replace, increasing their value during staffing reductions

Certified specialists are harder to replace than generalists, making them more valuable to departments and more likely to be retained during organizational changes.

Question 134: Which type of iodinated contrast media is considered safest for patients at risk for contrast-induced nephropathy?

High-osmolar ionic contrast
Low-osmolar ionic contrast
High-osmolar nonionic contrast
Iso-osmolar nonionic contrast (Correct answer)

Correct answer: Iso-osmolar nonionic contrast

Iso-osmolar nonionic contrast (e.g., iodixanol) has the lowest nephrotoxic potential and is preferred for high-risk patients.

Question 135: For a CT scan of the spine performed to evaluate for disk herniation, which reconstruction kernel is preferred?

Lung (high-frequency) kernel
Bone (high-frequency) kernel
Standard soft tissue kernel (Correct answer)
Ultra-high-resolution kernel

Correct answer: Standard soft tissue kernel

A standard or intermediate soft tissue kernel is preferred for disk and neural structure evaluation, reducing noise while preserving relevant detail.

Question 136: Which of the following scenarios would trigger ARRT's mandatory ethics disclosure requirement?

A technologist changes their legal name
A technologist receives a civil traffic violation
A technologist works per diem at multiple facilities
A technologist is convicted of healthcare fraud (Correct answer)

Correct answer: A technologist is convicted of healthcare fraud

ARRT's Standards of Ethics require self-disclosure of criminal convictions, including healthcare fraud, within 30 days of the conviction.

Question 137: Which of the following best describes a 'Category A' CE credit in the ARRT system?

Clinical hours logged during overtime shifts
Structured educational activity provided by an ARRT-approved sponsor (Correct answer)
Any learning activity self-reported by the technologist
Peer-reviewed article reading logged in a journal

Correct answer: Structured educational activity provided by an ARRT-approved sponsor

Category A credits are earned through formal, structured educational activities provided by sponsors recognized and approved by ARRT.

Question 138: How often must an ARRT CT certification be renewed?

Every 3 years
Every 10 years
Every 5 years
Every 2 years (Correct answer)

Correct answer: Every 2 years

ARRT CT certification, like most ARRT credentials, requires regular renewal to ensure technologists maintain current knowledge and skills. Certified professionals must renew their certification every two years. This biennial renewal process typically involves meeting continuing education requirements.

Question 139: What is the maximum number of times a candidate may attempt the ARRT CT examination?

Unlimited attempts within the eligibility window
No limit on attempts, but a new application is required after 3 failures
6 times total (Correct answer)
3 times total

Correct answer: 6 times total

ARRT allows a maximum of 6 examination attempts for any given credential.

Question 140: CT of the neck in a patient with a palpable mass shows a cystic lesion at the angle of the mandible deep to the sternocleidomastoid muscle. This is most consistent with:

Dermoid cyst
Branchial cleft cyst (Correct answer)
Thyroglossal duct cyst
Lymphatic malformation

Correct answer: Branchial cleft cyst

Branchial cleft cysts characteristically appear as unilocular cystic masses at the angle of the mandible adjacent to the sternocleidomastoid muscle.

Question 141: The windmill artifact seen in helical CT is most commonly associated with which acquisition parameter?

Low kVp
Large detector collimation
Small reconstruction FOV
High pitch values (Correct answer)

Correct answer: High pitch values

Windmill artifacts appear as alternating dark and bright streaks rotating around structures and are caused by the under-sampling that occurs at high pitch values.

Question 142: Which generator component is responsible for converting AC power to the high-voltage DC supply required by the X-ray tube in modern CT systems?

Filament transformer
High-frequency inverter generator (Correct answer)
Autotransformer
Rectifier diode bridge

Correct answer: High-frequency inverter generator

Modern CT systems use high-frequency inverter generators that convert line AC to high-frequency AC, then rectify it to produce a near-constant high-voltage DC supply for the tube.

Question 143: What is a Hounsfield unit?

A quantitative measurement of tissue density on CT images (Correct answer)
A measure of scan speed
A unit of radiation dose
A unit of image resolution

Correct answer: A quantitative measurement of tissue density on CT images

Hounsfield units (HU) measure tissue density on CT, with water at 0 HU, air at -1000 HU, and dense bone at +1000 HU or higher.

Question 144: Which of the following correctly identifies the position of the common bile duct on axial CT?

Medial to the hepatic artery within the liver parenchyma
Within the fissure for the ligamentum teres
Posterior and to the left of the portal vein in the hepatoduodenal ligament
Anterior and to the right of the portal vein in the hepatoduodenal ligament (Correct answer)

Correct answer: Anterior and to the right of the portal vein in the hepatoduodenal ligament

In the hepatoduodenal ligament, the common bile duct lies anteriorly and to the right of the portal vein, with the hepatic artery to the left.

Question 145: During a multi-phase CT liver protocol (non-contrast, arterial, portal venous, delayed), which action BEST reduces cumulative patient dose?

Increase kVp for each phase to reduce noise
Increase slice thickness per phase to reduce total acquisitions
Eliminate phases not essential for the clinical indication and use dose modulation for each phase (Correct answer)
Use the maximum mAs for all phases to guarantee image quality

Correct answer: Eliminate phases not essential for the clinical indication and use dose modulation for each phase

Eliminating unnecessary scan phases and applying tube current modulation to each remaining phase are the most effective strategies to reduce cumulative multi-phase CT dose.

Question 146: Which artifact appears as bright or dark bands radiating from high-density structures like metal implants?

Streak artifact (Correct answer)
Ring artifact
Partial volume artifact
Beam hardening artifact

Correct answer: Streak artifact

Streak artifacts arise from highly attenuating objects (metal, dense bone) causing inconsistent projections that reconstruct as linear streaks.

Question 147: Which of the following is the primary reason for using a low-osmolar, non-ionic iodinated contrast agent for intravenous CT contrast?

It significantly reduces the risk of adverse reactions compared to ionic agents (Correct answer)
It provides higher iodine concentration per mL
It is less expensive than ionic contrast
It requires a lower injection rate

Correct answer: It significantly reduces the risk of adverse reactions compared to ionic agents

Non-ionic, low-osmolar contrast agents have a much lower rate of adverse reactions (including severe reactions) compared to older high-osmolar ionic agents.

Question 148: Which financial benefit is most commonly associated with passing the ARRT CT certification exam for staff technologists?

Free continuing education paid by ARRT
Automatic promotion to radiologist
Permanent exemption from performance reviews
Eligibility for a certification differential or bonus pay (Correct answer)

Correct answer: Eligibility for a certification differential or bonus pay

Many hospitals and imaging facilities offer a certification differential—extra hourly pay or a one-time bonus—when staff earn specialty credentials.

Question 149: On a CT system, what does the term 'isocenter' refer to?

The midpoint of the scan field of view display
The center of the X-ray beam at the detector plane
The precise center of gantry rotation where the X-ray beam and detector array intersect (Correct answer)
The center of the patient table surface

Correct answer: The precise center of gantry rotation where the X-ray beam and detector array intersect

The isocenter is the exact point at the center of gantry rotation where the X-ray beam is focused, and proper patient centering at this point optimizes image quality and dose.

Question 150: Which of the following activities qualifies as a Category A continuing education credit for ARRT recertification?

Reviewing patient charts for quality assurance
Attending an ARRT-approved educational seminar (Correct answer)
Reading a radiology textbook independently
Performing additional clinical shifts

Correct answer: Attending an ARRT-approved educational seminar

Category A credits require structured learning through ARRT-approved providers such as accredited seminars, courses, or self-assessment activities.

Question 151: A horizontal band of decreased attenuation passing through the posterior fossa on a head CT is a classic example of which artifact?

Partial volume artifact
Motion artifact from cardiac pulsation
Ring artifact
Beam hardening between the petrous bones (Correct answer)

Correct answer: Beam hardening between the petrous bones

The dense petrous temporal bones cause preferential absorption of lower-energy photons, producing a dark band across the posterior fossa known as a beam hardening artifact.

Question 152: The pitch value in helical CT is defined as:

kVp divided by mA
Table travel per rotation divided by total beam collimation width (Correct answer)
Slice thickness divided by detector row width
Gantry rotation speed divided by table speed

Correct answer: Table travel per rotation divided by total beam collimation width

Pitch = table distance traveled per 360° rotation ÷ total collimated beam width, and values >1 indicate gaps in data coverage.

Question 153: On axial CT of the pelvis, the obturator internus muscle is best identified by its location:

Posterior to the sacrum in the gluteal region
Lining the lateral wall of the true pelvis adjacent to the obturator foramen (Correct answer)
Anterior to the pubic symphysis forming the pelvic floor
Between the iliacus and psoas muscles in the iliac fossa

Correct answer: Lining the lateral wall of the true pelvis adjacent to the obturator foramen

The obturator internus lines the lateral wall of the true pelvis, arising from the inner surface of the obturator foramen.

Question 154: A CT enterography protocol differs from a standard abdominal CT primarily in which way?

Scanning only the large intestine
Higher tube current for better resolution
Intravenous contrast is not used
Use of oral contrast to distend the small bowel (Correct answer)

Correct answer: Use of oral contrast to distend the small bowel

CT enterography uses large volumes of neutral oral contrast (e.g., VoLumen) to distend and visualize the small bowel mucosa.

Question 155: On CT spine, which finding is most consistent with a herniated nucleus pulposus at L4-L5 causing left leg radiculopathy?

Right paracentral disc protrusion compressing the L4 nerve root in the lateral recess
Left foraminal stenosis at L3-L4
Central disc bulge at L3-L4
Left paracentral disc extrusion compressing the left L5 nerve root (Correct answer)

Correct answer: Left paracentral disc extrusion compressing the left L5 nerve root

A left paracentral extrusion at L4-L5 compresses the traversing L5 nerve root in the lateral recess, causing ipsilateral radiculopathy.

Question 156: How does ARRT CT certification support a technologist's participation in quality improvement initiatives within their department?

It only applies to patient scheduling improvements
It provides the advanced protocol and dose optimization knowledge needed to contribute meaningfully to QI projects (Correct answer)
It transfers QI responsibilities entirely to the radiologist
It disqualifies technologists from serving on quality committees

Correct answer: It provides the advanced protocol and dose optimization knowledge needed to contribute meaningfully to QI projects

The depth of CT knowledge required for ARRT certification equips technologists to identify protocol inefficiencies, dose issues, and image quality problems in QI settings.

Question 157: How often must ARRT CT technologists renew their registration?

Every 2 years (Correct answer)
Every 5 years
Annually
Every 3 years

Correct answer: Every 2 years

ARRT registration is renewed on a biennial (every 2 years) basis, coinciding with the CE credit cycle.

Question 158: When treating a severe anaphylactic reaction to contrast media in an adult patient, what is the first-line drug and route of administration?

Diphenhydramine 50 mg IV
Epinephrine 0.3 mg (1:1000) intramuscular injection into the anterolateral thigh (Correct answer)
Methylprednisolone 125 mg IV bolus
Atropine 1 mg IV push

Correct answer: Epinephrine 0.3 mg (1:1000) intramuscular injection into the anterolateral thigh

Epinephrine 0.3 mg of 1:1000 concentration given IM into the anterolateral thigh is the first-line treatment for severe anaphylaxis due to its rapid absorption and alpha/beta adrenergic effects.

Question 159: Stochastic effects of radiation are characterized by which of the following?

A threshold dose below which the effect cannot occur
Occurring only in radiosensitive tissues such as bone marrow
No dose threshold; probability of occurrence increases with dose (Correct answer)
Severity increasing proportionally with dose above the threshold

Correct answer: No dose threshold; probability of occurrence increases with dose

Stochastic effects (e.g., radiation-induced cancer) are assumed to have no threshold; their probability, not severity, increases with dose.

Question 160: What is the primary reason CT scanners use slip-ring technology?

To increase the kVp range of the X-ray tube
To synchronize gantry rotation with patient respiration
To improve detector quantum efficiency
To allow continuous gantry rotation by eliminating the need for cables to wind and unwind (Correct answer)

Correct answer: To allow continuous gantry rotation by eliminating the need for cables to wind and unwind

Slip-ring technology uses electrical contacts that rotate with the gantry, enabling continuous 360° rotation without cable entanglement, which is essential for helical/spiral CT.

Question 161: Which patient condition is an absolute contraindication to intravascular iodinated contrast media administration?

Serum creatinine of 1.2 mg/dL
Previous severe anaphylactic reaction to iodinated contrast without premedication (Correct answer)
Age over 70 years
History of mild contrast allergy treated with antihistamines

Correct answer: Previous severe anaphylactic reaction to iodinated contrast without premedication

A prior severe anaphylactic contrast reaction is a contraindication unless the patient is premedicated and the benefit outweighs the risk; the radiologist must be involved.

Question 162: What is the largest organ in the human body?

Brain
Liver
Skin (Correct answer)
Heart

Correct answer: Skin

The skin is the largest organ, covering approximately 20 square feet in adults and weighing about 8 pounds. It serves as the primary barrier against the environment.

Question 163: When comparing filtered back projection (FBP) to model-based iterative reconstruction (MBIR) at matched noise levels, MBIR typically demonstrates:

Equivalent resolution but increased beam hardening artifacts
Lower spatial resolution but equivalent noise
Longer reconstruction times with no image quality advantage
Higher spatial resolution with fewer artifacts at lower dose (Correct answer)

Correct answer: Higher spatial resolution with fewer artifacts at lower dose

MBIR models the entire imaging chain including optics and statistics, achieving better resolution and artifact suppression at lower dose than FBP.

Question 164: What is the ALARA principle in radiation safety?

Always Lock And Restrict Access
As Low As Reasonably Achievable — minimize radiation exposure (Correct answer)
All Labs And Rooms Assessed
Automated Limiting Adjustment for Radiation Applications

Correct answer: As Low As Reasonably Achievable — minimize radiation exposure

ALARA means keeping radiation doses as low as reasonably achievable while still obtaining diagnostic-quality images, balancing benefit against risk.

Question 165: A CT pelvis shows a complex ovarian mass with solid components, calcifications, fat density, and hair-like structures. This is most consistent with:

Serous cystadenocarcinoma
Mucinous cystadenoma
Mature cystic teratoma (dermoid cyst) (Correct answer)
Endometrioma

Correct answer: Mature cystic teratoma (dermoid cyst)

Mature cystic teratomas contain fat, calcium, and soft tissue elements (including teeth or hair) from multiple germ cell layers.

Question 166: Which of the following scenarios would make a technologist INELIGIBLE to apply for ARRT CT certification?

Working in a facility that performs fewer than 50 CT scans per month
Holding both R and RT credentials simultaneously
Holding an ARRT credential that is currently suspended (Correct answer)
Having graduated from a JRCERT-accredited program more than 3 years ago

Correct answer: Holding an ARRT credential that is currently suspended

A suspended credential is not considered active and unrestricted, which is a prerequisite for CT post-primary eligibility.

Question 167: Which category of ARRT continuing education credit requires direct patient care activities or case-based learning?

Category A (Correct answer)
Category C
Category B
Category D

Correct answer: Category A

ARRT Category A credits are structured learning activities, often directly tied to clinical or patient-care-relevant content.

Question 168: What is the main clinical use of dual-energy CT (DECT)?

Reducing scan time by half
Material decomposition to differentiate tissue composition (e.g., iodine vs. calcium) (Correct answer)
Eliminating the need for contrast agents entirely
Increasing patient dose efficiency

Correct answer: Material decomposition to differentiate tissue composition (e.g., iodine vs. calcium)

DECT acquires data at two different kVp levels; the difference in attenuation at each energy allows material decomposition to characterize tissue composition.

Question 169: What is the minimum number of Category A CE credits that must be completed in the final year of a 2-year ARRT renewal cycle?

6 credits minimum per year are required
0 — credits can all be earned in one year (Correct answer)
12 credits minimum in the second year
All 24 credits must be earned evenly each year

Correct answer: 0 — credits can all be earned in one year

ARRT does not require credits to be distributed evenly across both years; all 24 Category A credits can technically be earned at any point during the 2-year cycle.

Question 170: A CT technologist is selected for a random ARRT CE audit. How far back must they be able to document their CE activities?

3 years
1 year
Current renewal cycle only (up to 2 years) (Correct answer)
5 years

Correct answer: Current renewal cycle only (up to 2 years)

ARRT audit documentation requirements focus on the current renewal cycle, so technologists must retain records for the most recent 2-year period.

Question 171: Which of the following best describes an out-of-field artifact in CT?

Blurring from respiratory motion
Ring caused by detector failure
Streaking caused by anatomy extending beyond the scan FOV (Correct answer)
Noise from low mAs

Correct answer: Streaking caused by anatomy extending beyond the scan FOV

Out-of-field artifacts occur when part of the patient's anatomy lies outside the calibrated scan FOV, causing truncation of projection data and bright peripheral streaks.

Question 172: What does the term 'half-scan reconstruction' refer to in CT?

Acquiring data with only half normal mAs
Reconstructing only half the detector channels
Using 180° + fan angle of data instead of a full 360° to reduce motion artifact (Correct answer)
Reducing matrix size by half to speed processing

Correct answer: Using 180° + fan angle of data instead of a full 360° to reduce motion artifact

Half-scan reconstruction uses approximately 180° + fan beam angle of data, which can reduce cardiac or other motion artifacts by shortening effective scan time.

Question 173: Which of the following best describes the purpose of ARRT's Standards of Ethics in the accreditation context?

They outline equipment quality standards
They set radiation dose limits
They establish imaging protocols
They define conduct requirements candidates must meet to obtain and maintain credentials (Correct answer)

Correct answer: They define conduct requirements candidates must meet to obtain and maintain credentials

The ARRT Standards of Ethics outline the professional conduct requirements that candidates and credential holders must satisfy.

Question 174: Under ARRT's ethics requirements, a technologist who is convicted of a felony must do which of the following?

Request a voluntary suspension of registration
Self-report the conviction to ARRT (Correct answer)
Notify their state licensing board only
Immediately surrender their certificate

Correct answer: Self-report the conviction to ARRT

ARRT's Standards of Ethics require technologists to self-report criminal convictions, including felonies, to the ARRT within 30 days.

Question 175: On an axial CT image at the level of the carina, which structure lies immediately posterior to the ascending aorta?

Superior vena cava
Right pulmonary artery (Correct answer)
Left pulmonary artery
Azygos vein

Correct answer: Right pulmonary artery

The right pulmonary artery passes posterior to the ascending aorta at the level of the carina.

Question 176: Under ARRT's Continuing Qualifications Requirements (CQR), what must credential holders demonstrate?

Completion of a new clinical rotation every 10 years
Ongoing competency through self-assessment and structured activities related to their discipline (Correct answer)
Employer attestation of satisfactory job performance
A passing score on a repeat certification exam every 10 years

Correct answer: Ongoing competency through self-assessment and structured activities related to their discipline

CQR requires credential holders to complete self-assessment and structured CE activities demonstrating continued competency in their specialty.

Question 177: What is the window level and window width on CT images?

Physical measurements of the CT scanner
Settings that control the brightness and contrast of displayed images (Correct answer)
Scan speed controls
Patient positioning parameters

Correct answer: Settings that control the brightness and contrast of displayed images

Window level sets the center brightness (what HU appears as middle gray) and window width controls contrast range (how many HUs span from black to white).

Question 178: What is the Continuing Qualifications Requirements (CQR) process for ARRT CT certification?

A mandatory exam that must be passed every 5 years
A self-assessment and continuing education program every 10 years (Correct answer)
A review of clinical competencies performed every year
A recertification application process every 5 years

Correct answer: A self-assessment and continuing education program every 10 years

The Continuing Qualifications Requirements (CQR) is a distinct process from the biennial CE requirements. For ARRT CT certification, CQR involves a self-assessment and targeted continuing education program that must be completed every 10 years. This ensures long-term competency and addresses any identified knowledge gaps.

Question 179: Which of the following best describes a 'dual-phase' liver CT protocol?

Non-contrast and delayed phases only
Non-contrast and arterial phases only
Portal venous and delayed phases only
Arterial and portal venous phases (Correct answer)

Correct answer: Arterial and portal venous phases

A dual-phase liver protocol acquires images in both the hepatic arterial phase and the portal venous phase to characterize liver lesions.

Question 180: Which CT post-processing technique displays only voxels above a selected threshold, making it useful for 3D visualization of bones and vascular structures?

Surface shaded display (SSD)
Volume rendering (VR)
Multiplanar reformation (MPR)
Maximum intensity projection (MIP) (Correct answer)

Correct answer: Maximum intensity projection (MIP)

Maximum intensity projection (MIP) selects and displays the highest attenuation voxel along each ray through the dataset, ideal for visualizing contrast-enhanced vessels or calcifications.

Question 181: Aliasing artifacts in CT, which appear as fine streaks or Moiré patterns, are caused by which factor?

High kVp settings
Incorrect table speed
Excessive patient size
Insufficient detector sampling (Correct answer)

Correct answer: Insufficient detector sampling

Aliasing artifacts occur when the object being imaged contains spatial frequencies higher than the detector sampling rate can capture, per the Nyquist theorem.

Question 182: On CT urography, a urothelial carcinoma of the ureter would most likely appear as:

Intraluminal filling defect with upstream hydronephrosis (Correct answer)
Ureteral wall calcification
Periureteral fat stranding only
Smooth fusiform dilation of the ureter

Correct answer: Intraluminal filling defect with upstream hydronephrosis

Urothelial carcinoma typically presents as an intraluminal filling defect causing partial or complete obstruction with upstream hydronephrosis.

Question 183: What is the minimum passing score typically required on the ARRT CT certification examination?

68
75
85
The ARRT uses a scaled score, not a percentage (Correct answer)

Correct answer: The ARRT uses a scaled score, not a percentage

ARRT reports exam results as a scaled score rather than a raw percentage, with 75 being the passing scaled score.

Question 184: A technologist is scanning a patient with metal hip implants. To reduce dose while managing metal artifact, which approach is MOST appropriate?

Double the mAs in the hip region to overpower artifacts
Skip the hip region entirely regardless of clinical indication
Switch to a lower kVp to increase contrast resolution
Use metal artifact reduction (MAR) software at standard dose rather than routinely increasing mAs (Correct answer)

Correct answer: Use metal artifact reduction (MAR) software at standard dose rather than routinely increasing mAs

Metal artifact reduction software effectively manages implant artifacts at standard dose; routinely increasing mAs adds unnecessary patient dose without eliminating artifacts.

Question 185: On CT of the head, lenticular (biconvex) hyperdensity is identified adjacent to the temporal bone. What is the most likely cause?

Middle meningeal artery rupture causing epidural hematoma (Correct answer)
Berry aneurysm rupture
Hypertensive hemorrhage
Bridging vein rupture causing subdural hematoma

Correct answer: Middle meningeal artery rupture causing epidural hematoma

Epidural hematomas result from middle meningeal artery injury and form a biconvex hyperdense collection limited by dural attachments at sutures.

Question 186: Under ARRT policy, which of the following represents a 'primary pathway' to CT certification?

Passing a state licensing exam only
Graduating from any 4-year college program
Completing 40 hours of online CT training
Holding an ARRT credential in a related discipline and meeting CT requirements (Correct answer)

Correct answer: Holding an ARRT credential in a related discipline and meeting CT requirements

The primary pathway requires holding an ARRT credential in a related radiologic science discipline and fulfilling CT-specific education and clinical requirements.

Question 187: A starburst pattern of streaks emanating from the edge of the patient's shoulders during a neck CT is most likely caused by:

Beam hardening from bone and soft tissue interfaces (Correct answer)
Detector malfunction
Incorrect windowing
Gantry tilt error

Correct answer: Beam hardening from bone and soft tissue interfaces

Dense cortical bone at the shoulder causes beam hardening, producing characteristic streak artifacts that radiate into adjacent soft tissues.

Question 188: A CT image shows ring artifacts. The MOST likely cause is:

Too low an mAs setting
Patient motion during scanning
A malfunctioning or miscalibrated detector element (Correct answer)
Incorrect kVp selection

Correct answer: A malfunctioning or miscalibrated detector element

Ring artifacts appear as circular bands centered on the isocenter and are caused by a single detector element producing consistently incorrect readings.

Question 189: In CT, the filtered back projection (FBP) reconstruction algorithm applies a mathematical filter primarily to:

Align misregistered projection data
Segment soft tissue from bone
Remove quantum noise before reconstruction
Correct for star artifacts inherent in simple back projection (Correct answer)

Correct answer: Correct for star artifacts inherent in simple back projection

FBP applies a ramp or other convolution filter to projection data before back-projecting to eliminate the blurring ('star artifact') produced by simple back projection.

Question 190: What is homeostasis?

A disease state
An organ system
A type of cell division
The body's ability to maintain stable internal conditions (Correct answer)

Correct answer: The body's ability to maintain stable internal conditions

Homeostasis is the body's dynamic process of maintaining stable internal conditions (temperature, pH, blood sugar) despite external changes.

Question 191: What is the primary purpose of the bow-tie filter in a CT scanner?

Calibrate the detector array
Increase tube current
Remove scatter radiation from the detector
Compensate for the cylindrical shape of patients to reduce peripheral dose (Correct answer)

Correct answer: Compensate for the cylindrical shape of patients to reduce peripheral dose

The bow-tie (wedge) filter shapes the beam so less radiation hits the thinner periphery of the patient, reducing dose and preventing detector saturation.

Question 192: When performing a CT colonography, the technologist selects a 0.625 mm detector row width versus 5 mm. This change PRIMARILY improves:

Contrast resolution for soft tissue differentiation
Longitudinal (z-axis) spatial resolution enabling multiplanar reformats (Correct answer)
Patient dose efficiency
Temporal resolution for cardiac gating

Correct answer: Longitudinal (z-axis) spatial resolution enabling multiplanar reformats

Thinner detector rows provide finer z-axis sampling, enabling isotropic voxels and high-quality multiplanar reformats for polyp detection.

Question 193: Which of the following is NOT an acceptable method for documenting completed CE credits with ARRT?

Submitting certificates directly to ARRT upon renewal
Verbal confirmation from a supervisor (Correct answer)
Online entry through the ARRT website
Having the approved sponsor report credits to ARRT directly

Correct answer: Verbal confirmation from a supervisor

ARRT requires verifiable documentation of CE credits; verbal confirmation from a supervisor is not an accepted method.

Question 194: What are the four basic tissue types in the human body?

Epithelial, connective, muscle, and nervous (Correct answer)
Smooth, rough, dense, and loose
Brain, heart, lung, and liver
Skin, bone, blood, and fat

Correct answer: Epithelial, connective, muscle, and nervous

The four fundamental tissue types are epithelial (covering/lining), connective (support/connection), muscle (movement), and nervous (communication/control).

ARRT Computed Tomography (CT) Certification Examination

The ARRT CT certification exam assesses entry-level knowledge and cognitive skills required for computed tomography practice, covering patient care, radiation safety, image production, and CT imaging procedures across all major anatomical regions.

195

Questions

180 min

Time Limit

75%

To Pass

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