This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
I/V contrast is not used in – 
Select and explain. 
A. HRCT, B. MRI, C. IVP, D. Myelography
D: Myelography
Answer: D: Myelography 
Explanation: IV contrast agent is given in :-


X-ray based investigation (Radiocontrast agent) :- Radiography (simple x-ray), CT-Scan.
MRI (MR contrast agents).
Ultrasound (USG contrast agents).


IVP (intravenous pyelography) as the name suggests, the contrast agent is given intravenously.
In myelography, the contrast agent is injected into subarachnoid space.