What are some of the indications for AXR?
Undifferentiated abdo pain
- ?toxic megacolon in IBD
- bowel obstruction/ischaemia
- perforation of a viscus with free air
- renal tract calculi
- foreign bodies
Preliminary evaluation of bowel gas in emergency setting
Evaluation of radiopaque tubes and lines
Evaluation for post-procedural intraperitoneal/retroperitoneal free gas
Monitoring the passage of contrast through the bowl
Monitoring the amount of bowel gas in post-op ileus
Colonic transit studies
Outline the assessment of an AXR.
Air/gas
- any part of hollow tube visible if filled with gas
- transit time: slow (stomach and small bowel) or fast (large bowel)
- extra-luminal gas is always abnormal
Bones
Calcifications/artefacts/foreign bodies
- abnormal e.g. gallstones, renal calculi
- within normal structure but pathological e.g. nephrocalcinosis, pancreatic calcification
- within normal structure and physiological e.g. lymph node calcification
Soft tissues
- visible organs: kidneys, spleen, liver, bladder, psoas muscles
What is Rigler’s sign?
Bowel wall visualised (double wall sign) due to presence of intra-luminal AND extra-luminal gas
What is falciform ligament sign?
Falciform ligament outlined when patient has free abdominal gas
What is the football sign?
Massive pneumoperitoneum, looks like an American football
What does lead pipe colon indicate?
Loss of haustra due to chronic inflammation
What does thumbprinting indicate?
Thickened mucosa
