Order Wisely: Selecting the Optimal Abdominal CT Protocol
Quick question: How is abdominal CT performed with & without IV contrast?
- (+) IV but no PO contrast
- (+) PO but no IV contrast
- scan pre & post IV
- scan pre & post PO
Answer:
C. Abdomen CT with & without contrast involves a non-contrast scan (no IV, no PO) and 1 or more scans following IV contrast infusion. This protocol delivers 2-4 times more radiation to the patient compared to abdomen CT with IV contrast and is more expensive for patients and payers.
The most widely used protocol for abdominal imaging is CT with IV contrast. Why is IV contrast important? Because the contrast enhancement of vessels & organs enables radiologists to make many diagnoses that are not apparent on a noncontrast scan.
When does CT with & without IV contrast add value for abdominal imaging? This protocol should only be used for the following indications:
- Renal lesion characterization – mass vs cyst
- Hematuria work up – to evaluate kidney, collecting systems and bladder for cancer
- Indeterminate adrenal nodule characterization – adenoma vs metastasis
- Follow-up after endovascular aortic stent repair – to evaluate for endoleak
- Gastrointestinal hemorrhage – to identify bleeding in the bowel
- Characterizing a focal liver mass – benign vs malignant
Otherwise, if patients don't have contraindications to IV contrast, order CT abdomen +/- pelvis with IV contrast. Radiologists generally need the pelvis to fully characterize abdominal pathology. Exceptions include:
- Adrenal nodule characterization
- Pancreatic cyst follow-up
- Renal mass vs cyst with prior imaging
The best resource for questions about imaging test or protocol is your radiologist. Reach out and a Johns Hopkins radiologist will help you pick the best exam and the correct protocol. Johns Hopkins providers can now reach out via Epic on the sign-in page under “Radiologist Services” with step-by-step instructions.
Abdomen CT: Protocol Selection
CT with IV contrast | CT with & without IV | CT without IV |
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Clinical indications
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