Abdominal radiograph interpretation
Introduction
- Patient: name, DOB, hospital number, age, sex
- Previous films for comparison
Radiograph detail
- Date
- Type (supine, upright, lateral decubitus)
- Adequacy
- Area (diaphragm to pelvis)
- Rotation
- Penetration
Upper limits of normal bowel diameters – the 3-6-9 rule
3cmΒ = small bowel
6cmΒ = large bowel
9cmΒ = caecum and sigmoid
Interpretation (BOB)
Briefly mention obvious abnormalities first.
Bowel
- Small bowel
- Identify by: central position; plicae circulares/valvulae conniventes (mucosal folds that cross the whole width of the bowel)
- Should be <3cm in diameter (enlarged in small bowel obstruction)
- Large bowel
- Identify by: peripheral position; faecal contents; haustra (pouches that protrude into the lumen)
- Should be <6cm in diameter (enlarged in large bowel obstruction)
- Faeces (mottled appearance)
- Gas (normal in fundus and large bowel only): extra-luminal gas indicates perforation; check for gas in rectum if bowel obstruction suspected (presence makes complete obstruction less likely)
- Fluid levels seen in perforation/infection
Other organs
- Soft tissue shadowsΒ (mayΒ be seen)
- Liver
- Spleen
- Kidneys
- Gallbladder
- Psoas shadow (lost in retroperitoneal inflammation or ascites)
- Calcification of pancreas (chronic pancreatitis), abdominal aorta (atherosclerosis) or renal stones/gallstones
Bones
- Spine and pelvis: Pagetβs disease (cotton wool lytic/sclerotic pattern); metastasis (lytic/sclerotic lesions); osteoarthritis (loss of joint space, osteophytes, subchondral sclerosis/cysts); vertebral fractures
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To complete
- βTo complete my analysis, I would examine previous films and ascertain the clinical history.β
- βIf there is any suspicion of perforation, I would request an erect chest x-ray to look for air under the diaphragm.β
- Summarise and suggest differentials
Test yourself – what are the radiographic features of these common pathologies
Small bowel obstruction
- Small bowel distension >3cm
- No gas in large bowel
- Fluid levels if erect
Large bowel obstruction
- Large bowel distension >6cm
Toxic megacolon
- Colonic dilatation without obstruction
- Associated with colitis
Chronic pancreatitis
Volvulus
- Twisting of bowel on its mesentery
- CausesΒ coffee-beanΒ appearance if sigmoid volvulus or βfetalβ appearance if caecal
PneumoperitoneumΒ
- Occurs due to viscus perforation or recent surgery
- Riglerβs double wall sign β both sides of bowel wall visible due to air outside the bowel
Here’s some radiographs for you to interpret!
This patient presented with vomiting. Click the image to enlarge.
Systematically interpret the above radiograph
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How would you investigate/manage the patient?
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This patient presented with abdominal pain. Click the image to enlarge.
Systematically interpret the above radiograph
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How would you investigate/manage the patient?
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What about the lead pipe sign associated with toxic megacolon?