Anatomy, embryology, pathophysiology ◼ Adenocarcinoma: inactivation of multiple antioncogenes, as well as issues with deoxyribonucleic acid mismatch repair ( BRCA2 ). Smoking, diet high in meat and solvent exposure are risk factors. ◼ Neuroendocrine tumors: multiple chromosomal losses. Associated with…
Anatomy, embryology, pathophysiology ◼ The pancreas is a lobulated, unencapsulated gland located in the anterior pararenal space of the retroperitoneum. ◼ Pancreatic development: two outpouchings or buds develop from the endodermal lining of the duodenum. The ventral bud will eventually…
Anatomy, embryology, pathophysiology ◼ There are three major anatomic regions that may contribute to right lower quadrant pain. Organ systems with differential diagnoses include: ◼ Gastrointestinal system: cecum, ascending colon, appendix. ◼ Acute appendicitis. ◼ Acute cecal diverticulitis. ◼ Inflammatory…
Anatomy, embryology, pathophysiology ◼ There are three major anatomic regions that may contribute to right upper quadrant pain. Organ systems with differential diagnoses include: ◼ Gastrointestinal system: liver, biliary, pancreas, and duodenum. ◼ Liver. ◼ Hepatic steatosis. ◼ Infectious hepatitis.…
Anatomy ◼ Adenomas can develop anywhere in the colon or rectum but are seen with the greatest frequency in the sigmoid colon. ◼ The frequency of polyp occurrence in each section of the colon is approximately as follows: rectum 15%;…
Anatomy ◼ The arterial supply of the small bowel is predominantly from the celiac axis and superior mesenteric artery (SMA). ◼ The inferior mesenteric artery (IMA) and the internal iliac arteries may become important contributors in the setting of arterial…
Types of bowel surgeries, their indications, and postprocedural anatomy Esophagectomy All esophagectomy techniques involve partial or complete resection of the esophagus with a new anastomosis to esophagus, stomach, or bowel. Benign indications include esophageal perforation (iatrogenic from endoscopy/biopsy/balloon dilation, traumatic…
Anatomy, embryology, pathophysiology ◼ Most of the small and large bowels originate from the midgut, except the proximal duodenum (up to the ampulla of Vater), which originates from the foregut, and the portion of the colon distal to the proximal…
Anatomy, embryology, pathophysiology ◼ The small bowel is a long, mobile, and compressible tubular structure located in the mid-abdomen, surrounded circumferentially by the large bowel. ◼ The small bowel caliber is normally smaller than 3 cm (outer wall to outer…
Anatomy, embryology, pathophysiology ◼ Extraluminal air is a worrisome finding that should immediately heighten the suspicion of the radiologist to a potentially life-threatening complication. ◼ The gastrointestinal (GI) tract is lined by inner circular and outer longitudinal muscularis layers, except…