Abdomen

Question 1

what is a good projection for a ? perforated bowel?

Answer 1

• erect chest x-ray (patietn has to be sitting upright for 10 minutes prior to xray)
• if patietn unable to sit up, left decubitus positioning with a horizontal beam
• left decubitus is done instead of right as any free air from a perforation will rise to the top (e.g. around liver). If patient was in right decubitus position, air would get lost or confused with a gastic bubble within the stomach
• air under the hemidiaphragm on a chest x-ray is indicative of a perforation

Question 2

use of a erect AXR?

Answer 2

• can sometimes show fluid levels within the bowels e.g. the string of pearls sign which indicates a mechanical obstruction to the small bowel

Question 3

dilated small bowel with no gas in the colon

Answer 3

suggests a complete mechanical obstruction to the small bowel

Question 4

dilated small bowel with gas in an undistended colon

Answer 4

either an incomplete small bowel obstruction 
or 
paralytic ileus (very common after surgery)

Question 5

dilated small bowel with gas in the distended colon

Answer 5

mechanical obstruction of the large bowel with an incompotent ileo-caecal valve
or
a generalised paralytic ileus

Question 6

dilated of large bowel but no small bowel dilation

Answer 6

mechanical obstruction of the large bowel