GASTROINTESTINAL IMAGING M-2 Lecture Dr. F. Neuffer 2014 GI TRACT Anatomy imaging Pathology Patients OBJECTIVES: Vascular supply and effect on pathology location. Age and site considerations in four major disease groups. Familiarity with imaging findings in Neoplastic, Inflammatory, Vascular and Traumatic diseases relative to the GI Tract. Modality choices based on pathology considerations. UPPER GI – ORAL BARIUM CONTRAST STOMACH WITHOUT CONTRAST COLON BARIUM ENEMA - RECTAL BARIUM CONTRAST NORMAL GAS PATTERN AIR UNDER THE DIAPHRAGM Perforation of GI tract leads to pneumoperitoneum—peritonitis..bleeding Air collecting under the diaphragm on upright x-ray. UPRIGHT ERECT AND DECUBITUS ABDOMEN FILMS SHOW FREE AIR UNDER THE DIAPHRAGM. DECUBITUS Air visible under diaphragm Left lateral decubitus (left side dependent) shows air along liver margin. This is the preferred x-ray if the patient cannot stand. RADIOLOGY DIAGRAM Pathology image X-ray image BARIUM FILLED ESOPHAGUS AORTIC IMPRESSION Pediatric patient Coin often is at site of Aortic impression. ASPIRATION NORMAL SWALLOW ASPIRATION Risk with patients with altered neurological status -post CVA -intoxicated Contrast tracks anteriorly into trachea with aspiration. ZENKER’S DIVERTICULUM source for aspiration Disordered contraction of cricopharyngeus with swallowing leads to diverticulum formation– elderly patients NORMAL ESOPHAGUS HIATAL HERNIA *Note distended distal esophagus with herniation of gastric fundus into chest through esophageal hiatus. DIAPHRAGM DIAPHRAGM This allows reflux of gastric contents into esophagus. ESOPHAGEAL CANCER Distal malignancy may be adenocarcinoma due to Barrett’s esophagus, a dysplastic change caused by chronic reflux of gastric contents. ESOPHAGEAL CANCER Typical squamous cell carcinoma Poor prognosis from local extension into critical mediastinal structures. (esophagus lacks a serosa) . TRACHEO-ESOPHAGEAL FISTULA / ATRESIA Diffuse Esophageal spasm sometimes referred to as: PRESBYESOPHAGUS Elderly patient Disordered contraction Chest pain Cardiac mimic CANDIDA ESOPHAGITIS Extensive nodular filling defects in the esophagus in an immunocompromised patient are typical for Candida esophagitis. ACHALASIA Distended esophagus with distal stricture.-Chronic process Little symptoms. Halitosis Failure of distal sphincter to relax – Nerve damage to sphincter leads to obstruction. Stricture due to CANCER / REFLUX has to be considered first. Barium filled esophagus LOOK ALIKES Scleroderma-smooth muscle -- Skin findings Chagas Disease -Trypanosome infection --Central America ESOPHAGEAL VARICES Linear tubular filling defects represent distended veins from shunting due to cirrhosis and portal hypertension. MALLORY-WEISS TEAR Esophagus shows a linear tear of the distal esophageal mucosa due to vomiting. Barium is seen tracking into the wall. Full thickness tear or rupture (Boerhaave’s syndrome) can lead to mediastinitis and death. Boerhaave’s Syndrome Post emesis – Perforation esophagus into mediastinum— Edema, Effusion and Pneumomediastinum ESOPHAGEAL DISEASE HIATAL HERNIA / ESOPHAGEAL CANCER CANDIDA / SPASM / VARICES MALLORY WEISS TEAR / BOERHAAVE’S SYNDROME ACHALASIA / SCLERODERMA / CHAGAS TE FISTULA / ZENKERS DIVERTICULUM SIGNS / SYMPTOMS CHEST PAIN DIFFICULTY SWALLOWING HOARSENESS FUNDUS NORMAL GASTRIC ANATOMY DUODENUM BODY ANTRUM JEJUNUM C-LOOP Single AP radiograph showing filling of distal esophagus, stomach and proximal small bowel without mass, obstruction or filling defect. GASTRIC ULCER Barium collects in ulcer crater Endoscopic view of ulcer ULCER CAN PERFORATE INTO PANCREAS AND LEAD TO PANCREATITIS Silva, A. C. et al. Radiographics 2004;24:677-687 GASTRIC CARCINOMA PYLORIC STENOSIS PYLORIC STENOSIS ULTRASOUND GASTROPARESIS DIABETIC NEUROPATHY EFFECT GASTRIC DISEASE ULCER CANCER PYLORIC STENOSIS GASTROPARESIS SIGNS / SYMPTOMS PAIN ANEMIA HEMATEMESIS / MELENA EMESIS WEIGHT LOSS NORMAL SMALL BOWEL JEJUNUM Early contrast is predominantly in jejunum and later predominately in ileum. (note difference in mucosal fold pattern) ILEUM COLON SMALL BOWEL OBSTRUCTION Ng tube ERECT Note dilated small bowel centrally placed with air/fluid levels on upright exam. POST – OP COLON ADYNAMIC ILEUS LARGE AND SMALL BOWEL SM. BOWEL SUTURES Symmetric dilation of large and small bowel is seen normally as a post operative ileus. SMALL BOWEL BARIUM STUDY HERNIA CT Note hernia in right lower quadrant on both exams accounting for obstruction. Hernia is likely cause if there is no history of prior surgery. CROHN'S DISEASE Narrowed distal ileum due to chronic inflammation is typical for Crohn’s disease. SMALL BOWEL DISEASE ULCER OBSTRUCTION POST-OPERATIVE ILEUS CROHN’S DISEASE SIGNS / SYMPTOMS PAIN HEMATEMESIS DISTENTION DIARRHEA SPLENIC FLEXURE NORMAL COLON HEPATIC FLEXURE TERMINAL ILEUM CECUM Normal air contrast barium enema (double contrast-air and barium per rectum) shows filling of colon with air and barium retrograde to the cecum with reflux into the terminal ileum. COLON DISEASE APPENDICITIS / DIVERTICULITIS POLYP / CANCER VOLVULUS GI HEMORRHAGE SIGNS / SYMPTOMS RIGHT / LEFT LOWER QUADRANT PAIN FEVER / ELEVATED WBC’s DISTENSION / OBSTRUCTION WEIGHT LOSS HEMOCULT POSITIVE STOOL / ANEMIA MELENA / HEMATOCHEZIA ACUTE APPENDICITIS NORMAL DISTENDED APPENDIX WITH LOCAL INFLAMMATION. ABSCESS Catheter has been placed by radiologist using CT guidance draining abscess collection. DRAINAGE (DESCENDING COLON) stalk on polyp--pedunculated PEDUNCULATED COLON POLYP COLON CANCER Barium enema showing apple-core type constricting lesion with proximal dilation of colon—”APPLE - CORE” constricting lesion SMALL BOWEL Ng tube vs COLON OBSTRUCTION COLON SIGMOID VOLVULUS Dilated horse-shoe shaped sigmoid colon due to volvulus. “COFFEE BEAN SIGN” COLON VOLVULUS “BEAK SIGN” Barium fills to point of obstruction -- twist of sigmoid colon ULCERATIVE COLITIS Normal PSEUDOPOLYPS with ulcerative colitis CHROHN’S COLITIS Segmental distribution commonly referred to as “skip lesions” CROHN’S VS ULCERATIVE COLITIS Skip Continuous Fistula Colon cancer DIVERTICULOSIS Balloon in rectum to Help control barium. Barium extends from lumen outward into diverticulum. DIVERTICULITIS Extensive inflammation, wall thickening and spasm can simulate carcinoma. Colonoscopy required to confirm. PSEUDOMEMBRANOUS COLITIS ANTIBIOTIC ASSOCIATED CLOSTRIDIUM DIFFICILIS PAIN DIARRHEA FEVER GI HEMORRHAGE Catheter is placed in superior mesenteric artery. NORMAL BLEEDING NUCLEAR MEDICINE Technetium-labeled RBCs Labeled red blood cells are imaged over 1 hour showing extravasation in Rt. colon steadily increasing indicating active bleeding. ISCHEMIC COLITIS Watershed area-----Splenic flexure Elderly---Embolic----Fibrillation Blood in stool----Pain SMA IMA Stomach MECKEL‘S DIVERTICULUM Yolk sac remnant at distal small bowel. Usually asymtomatic but can bleed. Technetium 99m labels gastric Mucosa --Ectopic gastric mucosa Diverticulum Bladder Pediatric patient <2yrs old SUMMARY PLAIN X-RAY---BOWEL GAS PATTERN BARIUM---OUTLINES LUMEN CT---PROBLEM SOLVING NUCLEAR MED ULTRA SOUND SPECIAL SITUATIONS ANGIOGRAPHY MR---LITTLE USE RADIOLOGY VACATION SPOT The end!