Abdomnal x-ray (AXR)
AXR should be taken if after examination the following conditions are suspected:
- Bowel obstruction - in order to confirm this diagnosis and locate the site of the blockage
- Perforation of hollow viscous - although a vertical chest x-ray would be more senstitive
- Complications of Crohn's disease or ulcerative colitis - obstruction, mucosal thickening, toxic megacolon and perforation
- Pancreatitis - exclude peptic ulcer, look for appearance of a "sentinel loop" which is a dilated segment of the small bowel seen in the upper abdomen
Sentinel Loop is indicated below:
AXR should not be taken if the following conditions are suspected:
- Acute gastrointestinal bleed - an AXR cannot reveal its location
- Palpable mass - CT scan would be preferential as accurating sizing and organ of origin can be confirmed
- Constipation - history and examination more sensitive to quantify extent of condition
- Cholecystitis - ultrasound more sensitive, only 10% gallstones seen on AXR
- Appendicitis - requires a clinical diagnosis; if uncertain, ultrasound more sensitive
An example of a normal AXR is below:
There are a number of questions that are important to ask yourself when looking at an AXR:
- Bowel gas pattern - normal, too little, too much - which parts affected? which parts normal?
- Is there free gas? - evidence of perforation
- Bowel wall thickening? - which part is affected? colon most common site
- Abnormal opacities? - usually due to calculi
