• frequency increases with age detected with CT or US exam
• well-marginated anechoic lesion with thin walls
• a few thin septa may be present (5% of cysts)
• a small amount of intracystic hemorrhage/debris may be present, and may require further evaluation (5% of cysts)

• Most patients tend to present between 30-60 years of age
• incidence is high, seen in as many as 5% of women and 12% of males
• The most common stone is calcium oxalate (75%)

• A type of benign renal neoplasm and are composed of vascular, smooth muscle and fat elements.
• They can spontaneously haemorrhage, which can be fatal
• Age of presentation: 43 years
• A strong female predilection

• The commonest malignant tumor of the gastrointestinal tract and the second commonest malignant tumor in men and women
• The peak incidence is between 50 and 70 years of age
• The predominant histological type is adenocarcinoma (70%), followed by mucinous carcinoma (20%) and anaplastic carcinoma
• Approximately 90% of all colorectal carcinomas arise from polyps

CT

• show an exophytic, polypous type of growth with frequent central degeneration, and they tend to infiltrate the bowel wall
• More than 50% of colorectal carcinomas occur the rectum and sigmoid colon

• Regional lymph node metastases involve the pericolic and perirectal nodes
• Potential complications of colorectal carcinoma includes: bowel obstruction, perforation, hemorrhage, fistula formation

• Focal or circular wall thickening
• or intramural masses that show enhancement with intravenous contrast
• CT colonography is indicated to detect additional lesions proximal to a stenotic primary that cannot be passed by the endoscope

• CT is more sensitive than plain film radiography for the detection of a small pneumoperitoneum and unsuspected gastroduodenal perforation
• Perforation can be result of an injury (seat belt, steering wheel or iatrogenic) or an intrinsic lesion (Crohn’s disease, diverticulitis)
• Perforation of the jejunum, ileum or colon may cause substantial amounts of intra-abdominal free air

• In mechanical bowel obstruction, dilated bowel loops with gas-fluid levels are seen proximal to the obstruction
• CT usually provides more detailed information of the cause (e.g. adhesions, tumor) and location of the obstruction

• The peptic ulcer disease is encountered more frequently in males (M:F 3:1)
• Usually in the older population
• Risk factors include: Helicobacter pylori infection, NSAIDs, corticosteroid

• An inflammatory bowel disease which predominantly affects the colon
• Typically ulcerative colitis manifests in young adults (15-40 years of age) and is more prevalent in males
• X-Ray: a mural thickening with thumbprinting

• Is very common in westernised countries
• Typically found in older individuals
• At 40 years of age, approximately 5% of the population have diverticula
• At 60 approximately 30%, increasing to 50-80% by the age of 80