Question

Choose the correct sequence that depicts the following events during intravenous urography, starting from first to last:
(A). Pyelogram
(B). Nephrogram
(C). Cystogram
(D). Ureterogram
Choose the correct answer from the options given below:

• A. (D), (B), (C), (A).
• B. (C), (B), (D), (A).
• C. (B), (A), (D), (C).
• D. (A), (B), (D), (C).

Hint:

To remember the phases of an excretory urogram, follow the anatomical flow of urine:
Kidney tissue (Nephrogram) \(\rightarrow\) Renal Pelvis (Pyelogram) \(\rightarrow\) Ureters (Ureterogram) \(\rightarrow\) Bladder (Cystogram).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Intravenous urography (also known as excretory urography) is a contrast radiographic study used to evaluate the kidneys, ureters, and urinary bladder.
An iodinated contrast medium is injected intravenously, and radiographs are taken at timed intervals to track its excretion through the urinary system.

Step 2: Detailed Explanation:
Let us trace the physiological path of the contrast medium over time:
1. Nephrogram Phase (B): Immediately after injection (typically within 10 to 60 seconds), the contrast medium fills the renal vasculature and is filtered into the functional renal parenchyma (glomeruli and tubules), opacifying the entire renal cortex and medulla. This is the first phase.
2. Pyelogram Phase (A): Within 1 to 3 minutes, the filtered contrast concentrates in the collecting ducts and enters the renal pelvis and diverticula, highlighting the pelvic anatomy. This is the second phase.
3. Ureterogram Phase (D): As peristalsis moves the contrast-filled urine out of the kidneys (typically within 3 to 5 minutes), the ureters become visible as thin radiopaque lines. This is the third phase.
4. Cystogram Phase (C): Finally, the contrast accumulates in the urinary bladder (typically starting at 5 to 15 minutes), outlining the bladder wall and lumen. This is the final phase.
This sequence is represented by the order: (B) \(\rightarrow\) (A) \(\rightarrow\) (D) \(\rightarrow\) (C).

Step 3: Final Answer:
The correct chronological sequence is (B), (A), (D), (C). This corresponds to option (C).