AN51.1-2 | Sectional Anatomy — Glossary

Addison's plane at L1 level, halfway between jugular notch and pubic symphysis; passes through the pylorus, kidney hila, SMA origin, and pancreatic neck

Transverse slice through the body perpendicular to the long axis; the standard orientation for CT imaging

Median sagittal section dividing the body or pelvis into equal right and left halves through the midline

CT density scale: bone +400 to +1000, soft tissue +20 to +80, water 0, fat -100, air -1000

Opening in the diaphragm at T10 through which the oesophagus and vagal trunks pass; site of hiatal hernias

Opening in the central tendon of the diaphragm at T8 through which the IVC and right phrenic nerve pass

Opening in the diaphragm at T12 through which the aorta, thoracic duct, and azygos vein pass

Most dependent part of the male peritoneal cavity between the bladder and rectum

Pouch of Douglas — most dependent part of the female peritoneal cavity between the uterus and rectum

Shallow peritoneal reflection between the bladder and uterus in the female; less clinically significant than the pouch of Douglas

Retropubic space — extraperitoneal space between the pubic symphysis and the bladder; accessed in suprapubic cystostomy

Formed behind the pancreatic neck by the confluence of the superior mesenteric vein and splenic vein; carries nutrient-rich blood from the GI tract to the liver

Loss of the normal border between two adjacent structures of the same density on X-ray, indicating disease in the adjacent tissue

Branch of the common hepatic artery crossing anterior to the pancreatic neck; erosion by a posterior duodenal ulcer causes massive haemorrhage

CT display parameters (width and level) that optimise visibility of different tissues: soft tissue (W=400), lung (W=1500), bone (W=2000)

Behind the peritoneum; structures include the kidneys, adrenals, ureters, aorta, IVC, pancreas (except tail), and ascending/descending colon

Aspiration of fluid from the pouch of Douglas through the posterior vaginal fornix; used to diagnose ectopic pregnancy rupture or pelvic abscess

Left vagus becomes the anterior vagal trunk and right vagus becomes the posterior vagal trunk as they pass through the oesophageal hiatus at T10

Hepatic vein thrombosis causing liver congestion; hepatic veins drain into the IVC at the T8 level

Herniation of the stomach through the oesophageal hiatus at T10; sliding type is most common, causing gastro-oesophageal reflux

Pancreaticoduodenectomy — surgical resection of the pancreatic head, duodenum, distal bile duct, and gallbladder; requires knowledge of pancreatic neck relationships