Abdominal XRay

Bones: spine, ribs, pelvis, and upper femurs. Look for si of arthritis, Fx, and bone lesions

Soft tissues: masses, calcifications.

Air under diaphragm in an upright film or next to the abdominal wall in a lateral decubitus film denotes perforated viscus.

Gastric air bubble. A large air-distended stomach suggests some form of obstruction

Bowel gas pattern. Small volume of air is generally seen in the colon, while the small bowel is generally devoid of air.

• Fecal material is often visible in colon. Large amounts may be seen in patient with constipation.

• The colon may become greatly distended with air in colonic obstruction (colonic distention proximal to obstruction) or ileus.

• Unless the colonic distension is severe, haustral markings are maintained.

• Large bowel markings are differentiated from small bowel markings by their wider spacing, and the incomplete crossing of the lumen.

• When the ileocecal valve is incompetent, large bowel obstruction may also cause distension of the small bowel.

• Distension of the small bowel may be seen in mechanical obstruction and ileus.

• Small bowel striations are much more numerous and completely cross the lumen. With mechanical obstruction there is distention proximal to the obstruction and clearing of air distally.

• Appearance of ileus is much less distinct. There is discontinuous air in the small and usually large bowel. Distention is less marked and discontinuous

Air-fluid levels do not distinguish mechanical obstruction from ileus. The may be seen in both conditions.