CASE BASED PRESENTATION

HOW TO READ CT ABDOMEN

Case I

28 year-old male with abdominal pain

Focal nodular hyperplasia Focal nodular hyperplasia (FNH) is a benign tumor-like mass of the

liver, second only to haemangiomas in frequency FNH is most frequently found in young to middle aged adults, with a

strong female predilection. 10 - 20% occur in men CT - On non contrast scanning the lesion is usually hypo- or isodense, but may appear hyperdense if the rest of the liver is fatty. A hypodense central scar can be seen in up to 60% of lesions over 3 cm in size . - FNH demonstrates bright arterial contrast enhancement except for the central scar which remains hypodense . - In the portal venous phase the lesion becomes iso dense to liver. - The scar demonstrates enhancement on delayed scans in up to 80% of cases

CASE II

History young-age female patient with abdominal pain

Superior mesenteric artery syndrome Compression of 3rd portion of duodenum between the aorta and

superior mesenteric artery (SMA) Females more affected than males

Most often in older children, adolescents Some doubt the true existence of the syndrome Pathophysiology

Narrowing of angle between SMA and aorta SMA usually forms an angle of 45 degrees with the aorta

Clinical findings Epigastric pain ,Nausea and Repetitive vomiting Abdominal cramping Typically findings are worst in supine position and may be relived by

changing to the prone or left lateral decubitus positions Imaging findings

Usually requires upper GI or CT of abdomen for diagnosis Megaduodenum

Pronounced dilatation of 1st and 2nd portion of duodenum and frequently stomach Best seen in supine position Compression of duodenum between aorta and SMA

CASE III

History A middle-aged female presents with abdominal pain and swelling

Omental and peritoneal calcified metastatic disease from bilateral ovarian serous cystadenocarcinomas. Left hydronephrosis indicates distal ureteric encasement

Omental Cake An omental cake refers to infiltration of the omental fat by material of soft-tissue density. The most common causes are metastases from ovary, stomach or colon. Tuberculous peritonitis may also give this appearance.

CASE IV

42 year-old female with abdominal pain

Ulcerative colitis with colonic mass

CASE V

Diabetic patient with right iliac fossa pain

Emphysematous cholecysitis

Occurs more often in men As opposed to gallbladder disease in general which occurs more often in

women Mostly elderly patients (>60) with diabetes Gas may occur in the wall and/or the lumen

May spread to pericholecystic tissue Rarely, gas may escape into the bile ducts

CT findings of (non-complicated) cholecystitis Most common is gallbladder wall thickening >3mm, and Cholelithiasis Increased density of bile (>20 H) Loss of clear definition of gallbladder wall Pericholecystic fluid such as a halo of edema

Case VI

History 60-year old male with non-specific pain

Mesenteric lipodystrophy ( stage II sclerosing mesentritis )

Sclerosing mesentritis is a rare idiopathic disorder characterised by chronic non-specific inflammation involving the adipose tissue of the bowel mesentery

The disease is said to pass through 3 stages, although some authors believe these to be separate entities :

1- mesenteric panniculitis: inflammatory reaction 2-mesenteric lipodystrophy: degeneration of mesenteric fat 3- retractile mesenteritis: fibrosis, which may be associated with distortion or lymphatic obstruction CT - CT features are somewhat dependent on the main tissue component and include a well-demarcated or ill-defined mesenteric mass like lesion with misty attenuation, soft-tissue attenuation, or both. - The mesentery demonstrates positive mass effect and may have a ground glass opacity. Typically the traversing mesenteric vessels and soft tissue nodules have a spared fat halo (this has sometimes been referred to as the fat ring sign) . Its orientation is aligned with the root of the jejunal mesentery. Punctate / coarse calcifications as well as small lymph nodes (usually <5 mm) may be present within the region