Question

X-ray features of sigmoid volvulus.

Hint:

The "coffee bean" sign is highly indicative of sigmoid volvulus on X-ray. Early identification can guide prompt decompression or surgical intervention.

Answer 1

Step 1: Understanding Sigmoid Volvulus.
Sigmoid volvulus occurs when the sigmoid colon twists around its mesentery, leading to bowel obstruction. It is a common cause of large bowel obstruction, especially in elderly patients. X-ray imaging is often used as an initial diagnostic tool.

Step 2: Key X-ray Features of Sigmoid Volvulus.
1. Coffee Bean Sign: The most characteristic X-ray finding in sigmoid volvulus is the "coffee bean" sign. This sign appears as a large, curved, gas-filled structure resembling a coffee bean, representing the distended sigmoid colon twisted on its mesentery.
2. Frontal View: On a frontal abdominal X-ray, the twisted colon appears as a distended, centrally located loop of bowel with a characteristic curved shape. The ends of the loop are often seen in the upper abdomen.
3. Inverted U-shape or Bird's Beak: In some cases, the X-ray may show an inverted U-shape or a bird's beak appearance at the site of the twist. This indicates where the sigmoid colon has rotated and narrowed at the point of torsion.
4. Bowel Obstruction Signs: In addition to the characteristic sigmoid appearance, there may be generalized signs of bowel obstruction such as dilated loops of bowel and absence of gas in the distal colon.

Step 3: Conclusion.
The X-ray features of sigmoid volvulus, particularly the coffee bean sign and the inverted U or bird's beak appearance, are key to diagnosing the condition. Prompt recognition on X-ray can help guide further management, such as decompression or surgery.