Question

Match List-I with List-II: 

List-I	List-II
(A) Iopanoic acid	(I) Myelography
(B) Iohexol	(II) Contrast enhanced CT
(C) Barium sulphate	(III) Cholecystography
(D) Gadolinium based contrast agents	(IV) Gastrography

Choose the correct answer from the options given below:

• (A) - (III), (B) - (I), (C) - (II), (D) - (IV)
• (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
• (A) - (III), (B) - (I), (C) - (IV), (D) - (II)
• (A) - (IV), (B) - (I), (C) - (III), (D) - (II)

Hint:

To remember key contrast agents:
- Barium: Strictly for the GI tract (never give intravenously or intrathecally).
- Iohexol: Non-ionic, safe for myelography (spinal cord).
- Gadolinium: Standard agent for MRI/Advanced Contrast CT.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Contrast agents are radiopaque or paramagnetic substances administered to animals to highlight specific organs, vessels, or fluid-filled spaces during diagnostic imaging studies.

Step 2: Detailed Explanation:
Let us match each contrast agent with its primary clinical application:
- (A) Iopanoic Acid: This is an oral, iodinated contrast agent that is absorbed in the gut, excreted by the liver, and concentrated in the gallbladder.
It is used specifically for imaging the gallbladder, a procedure called cholecystography (III). Thus, (A) matches with (III).
- (B) Iohexol: This is a water-soluble, non-ionic iodinated contrast medium.
Because it has low neurotoxicity, it is the agent of choice for injection into the subarachnoid space to perform spinal cord imaging, known as myelography (I). Thus, (B) matches with (I).
- (C) Barium Sulphate: This is an insoluble, highly radiopaque powder administered orally or rectally.
It is used exclusively to evaluate the gastrointestinal tract, a procedure known as gastrography (IV) or a barium series. Thus, (C) matches with (IV).
- (D) Gadolinium-based contrast agents: These are paramagnetic agents used primarily in Magnetic Resonance Imaging (MRI) and contrast-enhanced CT (II) to highlight vascular perfusion and identify tissue inflammation or tumors. Thus, (D) matches with (II).
This matching sequence gives: (A) - (III), (B) - (I), (C) - (IV), (D) - (II).

Step 3: Final Answer:
The correct match is (A) - (III), (B) - (I), (C) - (IV), (D) - (II).