Abdomen & GI system FINAL RT 91- Pathology Spring 2011

Regions & Quadrants of Abdomen

Contents of Abdominal Cavity Digestive system Stomach and Intestines Hepatobiliary System Liver, gallbladder, & pancreas Urinary system Kidneys, ureters and bladder Circulatory system spleen

Gastrointestinal System Alimentary tract- serves to digest & absorb food Consists of Mouth Pharynx Esophagus Stomach SM & LG bowel Rectum

Small Bowel 21 FT long Duodenum Jejunum Ileum Duodenal c-loop ends at ligament of Treitz Jejunum Connects to ileum Ileum Terminates at ileocecal junction

Large Intestine 6 FT long Extends from ileocecal junction Hepatic flexure Splenic flexure 6 FT long Extends from ileocecal junction Ascending colon (hepatic flexure) Transverse colon (splenic flexure) Descending colon Sigmoid Rectum Anus Sigmoid

Congenital and Hereditary Anomalies

Esophageal Atresia Looping of the feeding tube 2. Atypically short esophagus & terminates in blind pouch 2. Air in stomach

Esophageal Atresia Congenital anomaly Esophagus fails to _______________ past some point Symptoms come soon after birth Salivation, gagging, choking, dyspnea, cyanosis

Tracheoesophageal Fistula

Tracheoesophageal Fistula

Duodenal Atresia On x-ray a “double-bubble” sign is demonstrated gas in stomach is one bubble Gas in proximal duodenum is the second bubble

Duodenal Atresia Congenital anomaly ________________ of duodenum does not exist Resulting in a complete _________________

Colonic Atresia

Colonic Atresia Congenital failure of development of the ________________ Frequent complication includes fistula formation to the genitourinary system Must be repaired surgically

Hypertrophic Pyloric Stenosis

Hypertrophic Pyloric Stenosis Pyloric canal leading out of the stomach is greatly narrowed

Hypertrophic Pyloric Stenosis

Hypertrophic Pyloric Stenosis Congenital anomaly of the stomach Pyloric canal leading out of the stomach is greatly narrowed because of hypertrophy of the pyloric sphincter Most common indication for surgery in infants

Malrotation Small bowel on right and colon on left Cecum is not located in the RLQ

Malrotation Intestines are not in their normal position Usually asymptomatic Can lead to bowel volvulus or incarceration of bowel Surgery is required with a resection of bowel involved Cecum on left

Hirschsprung's Disease ______________ Dilated ______ colon with massive amounts of feces Narrowed segment just below the dilatation Feces Narrowing Dilated Sigmoid

Hirschsprung’s Disease AKA Congenital Megacolon Absence of neurons in the bowel wall This absence prevents normal relaxation of the colon & subsequent peristalsis Results in gross dilatation

Meckel’s Diverticulum Difficult to diagnose with x-ray Nuclear Medicine is better Sac-like anomaly within ileocecal valve

Meckel’s Diverticulum Congenital ________________ of the distal ileum Is remnant of a duct connecting the SB to the umbilicus in the fetus Meckel’s Diverticulum

Celiac Sprue X-rays show segmentation of the barium column, flocculation (resembling tufts of cotton) & edematous mucosal changes

Celiac Sprue Hereditary disorder with increased sensitivity to gluten Interferes with normal _____________ and _____________ of food

Inflammatory Disease

Esophageal Strictures X-rays show peristalsis is transitory Contour appears ragged

Esophageal Strictures Caused by ingestion of caustic materials Household cleaners Detergents Sulfuric acid Sodium hydroxide ____ the esophagus causing edema, swelling, & possible perforation Requires repeated _______________

Incompetent ______ sphincter allowing backward flow of gastric acid and food into esophagus ________________ ________may not be evident with barium swallow but strictures & ulcers may be present GERD

GERD

Erosion of the mucous membrane of the esophagus, stomach & duodenum Primarily affects PT’s over 40 years Diagnosis is made mostly with endoscopy Peptic Ulcer

Peptic Ulcer

Barrett’s Esophagus Peptic ulcer of the esophagus often with a stricture Fibrotic healing of the ulceration

Barrett’s Esophagus

Crohn’s Disease Radiographically looks like “cobblestone” The ______________________ sign is demonstrated where the TI is so diseased and stenotic

Regional Enteritis (Crohn’s Disease) Chronic inflammatory disease of no cause Typically occurs in lower ileum but can be seen throughout bowel String sign

Appendicitis CT is the gold standard Shows an appendiceal abscess As a round or oval soft tissue Density that may contain gas Appendix is dilated

Fecolith within Appendix Common cause of Appendicitis

Appendicitis Inflammation of the appendix resulting from an __________ Caused by a fecolith or neoplasm (rarely) Most common abdominal surgery in the US Sonography & CT used in diagnosis Appendicitis

Ulcerative Colitis BE demonstrates an irregular outline of the colon _______ _________ appearance

Ulcerative Colitis Inflammatory lesion of the colon mucosa Causes abscess leading to epithelial necrosis & ulceration It is idiopathic, thought to be an autoimmune disease

Esophageal Varices On x-ray looks like wormlike defects within the column of BA

Esophageal Varices Varicose veins that are abnormally lengthened, dilated& superficial Can be fatal Occurs from conditions such as cirrhosis that bypass the normal venous drainage mechanism

Gastritis Evidenced by gas bubbles (produced by bacteria) in the stomach Wall

Endoscopy for Gastritis

Gastritis 1. Inflammation of the _______ of the stomach 2. Results from various irritants: alcohol, corrosive agents, & infection 3. Most commonly demonstrated with ___________________ Gastritis

Degenerative Diseases

Inguinal Herniation

Protrusion of a loop of bowel through a small opening, usually in the abdominal wall. Can cause obstruction Can be surgically repaired, sometimes needing resection Inguinal Herniation

Hiatal Hernia

Hiatal Hernia Weakness of esophageal hiatus that permits some portions of the stomach to herniate into the thoracic cavity Chronic herniation can be associated w/ ______

Schatzki’s Ring A type of hiatal hernia Occurs when a portion of the stomach and the gastroesophageal junction are both above the diaphragm (99%) This ring is visible radiographically with this condition May be related to reflux Schatzki’s Ring

Bowel Obstructions

Mechanical Bowel Obstruction Large dilated colon Little small bowel gas

Mechanical Bowel Obstruction Occurs from a blockage of the bowel lumen Bowel sounds are _______________ & high pitched Vomiting _________

Gallstone Ileus X-ray show air-fluid levels or air in biliary tree Gallstone may also be visible in the TI where it causes the obstruction

Gallstone Ileus A type of mechanical obstruction Gallstone can erode & create a fistula in the SB Obstruction occurs when stone reaches ileocecal valve

Paralytic Ileus Gas distributed throughout both LG & SB Normal bowel sounds are absent

Paralytic Ileus Results from failure of peristalsis Absent bowel sounds

Volvulus X-ray shows collection of air conforming to the shape of affected bowel

Volvulus Twisting of bowel loop Identifiable with x-ray Usually at the sigmoid or ileocecal junction Identifiable with x-ray Usually happens in elderly Volvulus

Intussusception X-ray looks like a coiled spring Air fluid levels LG bubble within mid abdomen

Intussusception Is a kind of mechanical obstruction Segment of bowel telescopes into distal segment and is driven further into distal bowel by peristalsis Intussusception

Neurogenic Diseases

Achalasia X-ray shows dilated esophagus with little or no peristalsis

Achalasia Failure of the esophageal sphincter to relax causing dysphasia Distal esophagus open intermittently

Diverticular Diseases

Esophageal Diverticula Occurs when mucosal outpouchings penetrate through the muscular layer of the esophagus

Esophageal Diverticula (traction) Involves all layers of esophagus and results in adjacent scar tissue that pulls esophagus toward area of involvement

Zenker’s Diverticulum

Zenker’s Diverticulum Involves mucosa only & results from a __________ disorder Allows esophagus to _________ outwardly Found at pharyngealesophageal junction

Colonic Diverticula Appear as round – oval Outpouchings of BA projecting beyond bowel lumen Vary in size 2cm or more Tend to occur in clusters

Colonic Diverticula

Colonic Diverticula The presence of diverticula _________inflammation Diverticula are associated with hypertrophy of the muscular layer of the bowel Most common in _____________ (95%) Most patients are asymptomatic

Diverticulitis Inflammation of the diverticulum Exacerbated by feces lodging in the diverticulum Signs and symptoms: fever, LLQ pain, tenderness and increased WBC count BA shows diverticulum Treatment centers on reduction of inflammation and infection

Neoplastic Diseases

Leimyomas Appear as intramural defects in the barium outlined esophageal wall

Leimyomas of Esophagus __________ tumors Have smooth muscular tumors Exact location can be determined on CT

Gastroesophageal Adenocarcinomas Appears as mucosal destruction, ulceration, narrowing and sharp demarcation between normal Tissue & malignant tumor

Occur in the lower esophagus around the gastroesophageal junction Some believe there is a direct link between Barrett’s esophagus & adenocarcinoma 90% have been found to arise from Barrett’s mucosa Adenocarcinomas

Small Bowel Neoplasms Most common means of identifying is through endoscopy with biopsy Can be seen on CT & with SBS

Small Bowel Neoplasms Most occur in the duodenum & proximal jejunum Some predisposing factors include: Polyposis Kaposi’s sarcoma Crohn’s disease

Colonic Polyps BE is exam of choice, showing rounded filling defects Proctosigmoidoscopy and colonoscopy are critical in evaluation and removal of polyps

Colonic Polyps Small masses of tissue arising from the bowel wall to project inward in the lumen More frequently in the left colon Most cancers of the colon & rectum usually arise from previous benign polyps

Colon Cancer 2nd most common cause of cancer mortality Adenocarcinoma is the most common type of colorectal cancer

Colon Cancer

Colon Cancer “Apple-Core lesion” X-ray shows “napkin ring” or “apple core” lesions Double contrast BE more accurate than single contrast CT colonoscopy also useful

CT of Abdomen & GI Clearly demonstrates abdominal organs that are normally not apparent on x-ray w/o contrast Recommended for bowel obstruction diagnosis Virtual colonoscopy can be done to see areas not seen during a regular colonoscopy

MRI imaging of Abdomen & GI Still limited due to bowel motion Useful in demonstrating retroperitoneal masses impinging on GI system Can differentiate between pathology & normal tissue

US imaging of Abdomen & GI Not useful in imaging of the GI system Extensively used to image the retroperitoneum because of the flexibility of angling the transducer With this modality it is possible to image behind the bowel & assess for abnormalities

Nuclear Medicine imaging for Abdomen & GI Useful is detecting: GI bleeds Gastric emptying time Presence of H. Pylori Infection from gastric ulcers PET has been known to demonstrate 20% of esophageal cancer undetected by CT

Endoscopic Procedures Fiberoptic tube device to look inside hollow organs or cavities Upper endoscopy can see esophagus, stomach, duodenum & proximal jejunum Colonoscopy to the terminal ileum Small bowel is still out of reach Capsule endoscopy is a camera pill that is swallowed and takes pictures of the GI tract Drawbacks include inability to biopsy area and locate pathology Insurance reimbursement Also used for several therapeutic applications Biopsies Stent placement Polyp removal Stone removal