Abdominal X-Ray: Basics

Interpreting the abdominal x-ray

General format:

Bowel gas pattern
-Large and small bowel and free gas

Abnormal gas collections
-Biliary gas, retroperitoneal gas, bowel wall gas

Abnormal calcification
-Gall stones, renal tract, pancreas, vascular

Viscera
-Liver, spleen, kidneys

Retroperitoneum and abdominal wall
-Psoas lines, abdominal wall muscles and peritoneum

Bones
-Lumbar spine, pelvis, proximal femora, ribs

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Small bowel gas pattern

Note the following features: -Valvulae (2mm) -Narrow curvature -3.5cm proximally -3cm mid -2.5cm distally -Fluid levels <5 and short

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Large bowel gas pattern

Note the following features: -Haustral folds -Peripheral -Faecal residue < 6cm transverse colon < 9cm caecum

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Viscera

Liver: -Hepatomegaly

Kidneys: -3.5 vertebral bodies and disc spaces -Obliquely orientated

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Retroperitoneum

Psoas lines: -Absent in 20% of normal individuals -Loss of line may indicate retroperitoneal mass or haematoma

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Acknowledgement: revise4finals would like to thank Dr Niall Moore (John Radcliffe Hospital, Oxford) for providing images and explanations used in this section.