Abdominal Imaging

The abdominal radiograph

Why do we see any structure on a normal abdominal radiograph?

• It has to be surrounded by tissue of different attenuation (x-ray stopping power).

• we therefore see margins delineated by air (the mucosal surface of air filled bowel)

• Things outlined by fat (usually the kidneys. the psoas margins ,the bladder and the abdominal wall).

We can only see

• gas

• soft tissue (effectively water density)-viscera, bowel and bowel wall, bladder.

• bone and calcium-stones, calcified lymph nodes,stones(90% renal, 10% gallstones)

• Fat

Properitoneal fat

Transversus abdominis

A FEW INTERESTING RADIOGRAPHS

Gas outside the bowel .

Outling both the inside and outside of the bowel.

Free gas

DILATED LARGE BOWEL WITH NO BOWEL WALL THICKENING

Turned out to be a sigmoid tumour.

Gross large bowel wall thickening.

Secondary to ulcerative colitis

Causes of colitis

• Inflammatory bowel disease

• Ischaemic colitis

• Pseudomembranous colitis

• Amoebic,schistosoma etc

Gas outside the bowel .

Outling both the inside and outside of the bowel.

Free gas

Aortic aneurysm

Basic CT Anatomy

mhv

rhv

IVC

anterior

posterior

right left

gb

rk

ra

cl (1)

stomach

anterior

posterior

right left

spleen

pv

ha

anterior

posterior

rightleft

rk

lk

pancreas

svd

cd

Fluid in lesser sac

gallbladder

Renal pelvisRenal artery

Renal vein

uu

anterior

posterior

rightleft

uu

anterior

posterior

Right left

anterior

posterior

rightleft

u u

bladder

nav

Left gastric A

Gastroduodenal A

Common Hepatic A

Splenic A

Pancreaticoduodenal A

Right gastric –small, from proper hepatic or Lt gastric

Image of an aneurysm to discuss suitability