ARRT CT Computed Tomography Certification Exam 2026:
Comprehensive Post-Primary Practice Test — Patient Care,
Radiation Safety, Image Production, CT Physics & Imaging
Procedures — 190 Multiple-Choice Questions with Answers &
Detailed Rationales
Section I: Patient Care
Question 1
A patient arrives for a CT abdomen/pelvis with IV contrast and reports a prior allergic
reaction to shellfish. Which action is most appropriate?
A. Cancel the examination and recommend MRI.
B. Proceed with the examination using a low-osmolar, non-ionic contrast agent.
C. Administer epinephrine prophylactically before contrast injection.
D. Require the patient to sign a waiver before proceeding.
Correct Answer: B
Explanation: Shellfish allergy does not reliably predict iodinated contrast reaction; low-
osmolar non-ionic contrast with standard monitoring is appropriate.
Question 2
A 4-year-old child weighing 18 kg requires a contrast-enhanced CT chest. The protocol
specifies 2 mL/kg of contrast. What volume should be administered?
A. 18 mL
,B. 24 mL
C. 36 mL
D. 45 mL
Correct Answer: C
Explanation: 18 kg × 2 mL/kg = 36 mL; weight-based dosing ensures appropriate pediatric
contrast volume.
Question 3
During a CT pulmonary angiography, a patient develops diffuse urticaria, dyspnea, and
hypotension immediately after contrast injection. What is the technologist's priority action?
A. Complete the scan to avoid repeat exposure.
B. Stop the examination, call for emergency assistance, and prepare epinephrine.
C. Administer oral diphenhydramine and continue scanning.
D. Reassure the patient and monitor for 5 minutes.
Correct Answer: B
Explanation: These signs indicate anaphylaxis; epinephrine is first-line treatment and
emergency response must be activated.
Question 4
A patient reports a metallic taste and mild nausea during contrast injection. What is the
most appropriate interpretation?
,A. Severe allergic reaction requiring immediate epinephrine.
B. Vasovagal reaction requiring supine positioning.
C. Mild physiologic reaction that is typically self-limiting.
D. Contrast extravasation requiring warm compresses.
Correct Answer: C
Explanation: Metallic taste and mild nausea are common physiologic responses to contrast
osmolarity and do not require intervention.
Question 5
A 68-year-old patient with diabetes has a serum creatinine of 1.8 mg/dL and is scheduled for
contrast-enhanced CT. What is the technologist's most appropriate action?
A. Proceed with the scan as ordered without modification.
B. Cancel the examination independently.
C. Consult the radiologist regarding risk-benefit and alternative imaging.
D. Administer half the standard contrast dose.
Correct Answer: C
Explanation: Elevated creatinine indicates increased risk for contrast-induced nephropathy;
the radiologist must assess risk-benefit.
Question 6
A technologist prepares to administer IV contrast through a power injector. Which vein is
preferred for access?
, A. Brachial artery
B. Antecubital fossa vein
C. Dorsal hand vein
D. Femoral vein
Correct Answer: B
Explanation: Antecubital veins are preferred for high-flow power injection due to their size
and accessibility.
Question 7
An automatic injector is set at 3 mL/sec for a contrast volume of 120 mL. What is the
injection duration?
A. 30 seconds
B. 40 seconds
C. 50 seconds
D. 60 seconds
Correct Answer: B
Explanation: 120 mL ÷ 3 mL/sec = 40 seconds; injection time is volume divided by flow rate.
Question 8
A patient scheduled for CT urogram has an eGFR of 25 mL/min/1.73m². What is the most
significant risk?
Comprehensive Post-Primary Practice Test — Patient Care,
Radiation Safety, Image Production, CT Physics & Imaging
Procedures — 190 Multiple-Choice Questions with Answers &
Detailed Rationales
Section I: Patient Care
Question 1
A patient arrives for a CT abdomen/pelvis with IV contrast and reports a prior allergic
reaction to shellfish. Which action is most appropriate?
A. Cancel the examination and recommend MRI.
B. Proceed with the examination using a low-osmolar, non-ionic contrast agent.
C. Administer epinephrine prophylactically before contrast injection.
D. Require the patient to sign a waiver before proceeding.
Correct Answer: B
Explanation: Shellfish allergy does not reliably predict iodinated contrast reaction; low-
osmolar non-ionic contrast with standard monitoring is appropriate.
Question 2
A 4-year-old child weighing 18 kg requires a contrast-enhanced CT chest. The protocol
specifies 2 mL/kg of contrast. What volume should be administered?
A. 18 mL
,B. 24 mL
C. 36 mL
D. 45 mL
Correct Answer: C
Explanation: 18 kg × 2 mL/kg = 36 mL; weight-based dosing ensures appropriate pediatric
contrast volume.
Question 3
During a CT pulmonary angiography, a patient develops diffuse urticaria, dyspnea, and
hypotension immediately after contrast injection. What is the technologist's priority action?
A. Complete the scan to avoid repeat exposure.
B. Stop the examination, call for emergency assistance, and prepare epinephrine.
C. Administer oral diphenhydramine and continue scanning.
D. Reassure the patient and monitor for 5 minutes.
Correct Answer: B
Explanation: These signs indicate anaphylaxis; epinephrine is first-line treatment and
emergency response must be activated.
Question 4
A patient reports a metallic taste and mild nausea during contrast injection. What is the
most appropriate interpretation?
,A. Severe allergic reaction requiring immediate epinephrine.
B. Vasovagal reaction requiring supine positioning.
C. Mild physiologic reaction that is typically self-limiting.
D. Contrast extravasation requiring warm compresses.
Correct Answer: C
Explanation: Metallic taste and mild nausea are common physiologic responses to contrast
osmolarity and do not require intervention.
Question 5
A 68-year-old patient with diabetes has a serum creatinine of 1.8 mg/dL and is scheduled for
contrast-enhanced CT. What is the technologist's most appropriate action?
A. Proceed with the scan as ordered without modification.
B. Cancel the examination independently.
C. Consult the radiologist regarding risk-benefit and alternative imaging.
D. Administer half the standard contrast dose.
Correct Answer: C
Explanation: Elevated creatinine indicates increased risk for contrast-induced nephropathy;
the radiologist must assess risk-benefit.
Question 6
A technologist prepares to administer IV contrast through a power injector. Which vein is
preferred for access?
, A. Brachial artery
B. Antecubital fossa vein
C. Dorsal hand vein
D. Femoral vein
Correct Answer: B
Explanation: Antecubital veins are preferred for high-flow power injection due to their size
and accessibility.
Question 7
An automatic injector is set at 3 mL/sec for a contrast volume of 120 mL. What is the
injection duration?
A. 30 seconds
B. 40 seconds
C. 50 seconds
D. 60 seconds
Correct Answer: B
Explanation: 120 mL ÷ 3 mL/sec = 40 seconds; injection time is volume divided by flow rate.
Question 8
A patient scheduled for CT urogram has an eGFR of 25 mL/min/1.73m². What is the most
significant risk?
