Abdominal X-rays (AXR) are requested in many patients, especially those with an "acute abdomen". Though they often do not provide a lot of information and may appear "normal" therefore it is key to keep the clinical picture in mind. They can be performed with contrast, e.g. barium follow through to highlight abnormal anatomy (e.g. strictures and masses occluding the lumen of the bowel).
- Check the patient details
- When the AXR was taken
- How the AXR was taken, they are mostly AP (from front to back) with the patient supine (lying down)
- Bones, soft tissue surrounding the abdomen and any artefact (e.g. buttons, jewelry, drains)
- Check the lung bases if they are visible
Then start from the top and work down:
- Stomach (usually has air in)
- Small bowel - identifiable as has lines that run all the way across it called valvaulae
- Large bowel - identifiable as around the edge of the abdomen and the lines do not go all the way across it
- Rectum - may contain faeces (have mottled appearance due to the presence of air inside)
Then look at the other organs (if you can see them):
- Kidneys and bladder (a specific x-ray, the KUB (kidneys, ureter, bladder) is performed to look at these in more detail)
And have a quick check of the bones (mainly spine and upper pelvis), you may see the characteristic bamboo spine of ankylosing spondylitis.
Some abnormal findings
- Small bowel obstruction
- This will look like large dilated loops of small bowel (remember the lines go all the way across small bowel)
- Large bowel obstruction
- This will look like large dilated loops of large bowel (the lines don't go all the way across)
- Also look at the anatomical position, large bowel will be more around the edges of the AXR
- Toxic Megacolon
- This is an extremely dilated large bowel and is a life threatening condition.
- Stones and calcifacation
- These may be visible opacities and you may be able to locate them anatomically, e.g. large gallstones in the RUQ
- Air under the diaphragm
- This indicates that there is a perforated bowel, but is usually identified in an erect chest x-ray as thin slivers of black under the diaphragm. It is important in patients with a suspected perforation to request both a chest and abdominal x-ray.