CT Imaging of Acute Pancreatitis Erin Rikard Radiology December 2007 Outline • • • • • Definition Epidemiology Causal Factors Pathophysiology CT Evaluation and Findings – Normal and abnormal • Complications • Management • Prognosis Definition Definition Ac Pa ute n Inf crea l am t i t pa i sm nc a rea tion po t en s w of co mp tial f ith let or eh ea ling Epidemiology Epidemiology • 79.8/100,000 per year → 185,000 new cases annually in U.S • Peak incidence in 6th decade Causal Factors Causal Factors Etiology Incidence Cholelithiasis 30-60% Alcohol 15-30% Iatrogenic 2-5% Trauma/Surgery Metabolic Disorders Viral Infection Pathophysiology Pathophysiology • Pancreatic autodigestion, with activated pancreatic enzymes escaping the ductal system and lysing tissue of pancreas and adjacent structures • Lack of capsule facilitates spread Pancreatic abscess containing gas in 54-year-old man Demos, T C et al Am J Roentgenol 2002;179:1375-1388 Copyright © 2006 by the American Roentgen Ray Society Large fluid collection containing gas bubbles in pancreatic bed due to abscess complicating acute pancreatitis Note infiltration of peripancreatic fat and calcified gallstones Hemorrhagic Pancreatitis • Rare • Noted clinically by ↓ in hematocrit 70 year-old woman with hemorrhagic pancreatitis Urban, Bruce A., et al Radiographics 2000; 20: 725-749 Copyright © 2000 by RSNA CT scan demonstrates hemorrhagic pancreatitis as a heterogeneous mass in the area of the pancreatic bed (*) Arrow indicates active extravasation (hemorrhage) Splenic Artery Pseudoaneurysm • Presents similarly to hemorrhagic pancreatitis with a ↓ in hematocrit Pseudoaneurysm Tang, Linda J J Vasc Interv Radiol 2005; 16: 863-866 Copyright © 2005 by The Society of Interventional Radiology Axial CT scan with intravenous contrast material reveals a pseudoaneurysm (arrow) projecting from the splenic artery Management Management • Acute pancreatitis usually self-limited  Inflammation ↓ within 3-7 days in 90% of cases • Medical therapy  Analgesics  IV hydration  Decrease PO intake → Decreased pancreatic secretion Antimicrobials in severe necrotizing pancreatitis Management • Presence of abscess or necrosis indicates need for intervention • Percutaneous drainage of abscess • Surgical debridement (necrosectomy) of infected necrotic tissue when conservative treatment has failed Prognosis Prognosis • Mortality ↓ over last 20 years  5% for all cases 20% for severe cases Reasons for Reduced Mortality • • Initially - Recognition and application of severity signs 1990s – More selective endoscopic or surgical debridement of infected tissue, endoscopic cyst drainage, and angiographic control of GI bleeding • Later – Improved nutritional support by jejunal feeding, earlier use of antibiotic therapy, gut sterilization, early ERCP for common bile duct stones, and necrosectomy for necrotic tissue Resources Resources • Balthazar, Emil J “Acute Pancreatitis: Assessment of Severity With Clinical and CT Evaluation.” Radiology 2002; 223: 603-613 • Banu, S., P Singh, N Pooran, and B Stark “Evaluation of Factors That Have Reduced Mortality from Acute Pancreatitis Over the Past 20 Years.” Journal of Clinical Gastroenterology 2002 July; 35: 50-60 • Bennett, William F., Kuldeep Vaswani, and Kenneth Vitellas “Case 1: Parenchymal Lymphoma.” American Journal of Roentgenology 2000; 175: 882-883 • Cohen-Scali, Frank, et al “Discrimination of Unilocular Macrocystic Serous Cystadeoma from Pancreatic Pseudocyst and Mucinous Cystadenoma with CT: Initial Observations.” Radiology 2003; 228: 727-733 • Demos, Terrence C., et al “Cystic Lesions of the Pancreas.” American Journal of Roentgenology 2002; 179: 1375-1388 • Gore, Richard M., et al “ Helical CT in the Evaluation of the Acute Abdomen.” American Journal of Roentgenology 2000; 174: 901-913 Resources Continued • Gunderman, Richard B Essential Radiology 1998 • Greenberger, Norton J and Phillip P Toskes “Acute and Chronic Pancreatitis.” Harrison’s Internal Medicine • Mitchell, RM, MF Byrne, and J Baillie “Pancreatitis.” Lancet 2003 Apr 26; 361: 1447-1455 • Novelline, Robert A Squire’s Fundamentals of Radiology 6th ed 2004 • Pretorius, E Scott and Jeffrey A Solomon Radiology Secrets 2nd ed 2006 • Ranson, JH, et al “Prognostic Signs and the Role of Operative Management in Acute Pancreatitis.” Surgery, Gynecology, and Obstetrics • Tang, Linda J., Stan Zipser, and Young S Kang “Temporary Spontaneous Thrombosis of a Splenic Artery Pseudoaneurysm in Chronic Pancreatitis During Intravenous Octreotide Administration.” Journal of Vascular Interventional Radiology 2005; 16: 863-866 Resources Continued • Urban, Bruce A and Elliot K Fishman “Tailored Helical CT Evaluation of Acute Abdomen.” Radiographics 2000; 20: 725749 • West, Jeffrey H., Stephen B Vogel, and Walter E Drane “Gallium Uptake in Complicated Pancreatitis.” American Journal of Roentgenology 2002; 178: 841-846 ... Kidney R Kidney ea s Liver cr Pa n Stomach Evaluation by CT Evaluation of Acute Pancreatitis • Contrast-enhanced CT is imaging modality of choice • Oral and IV contrast differentiate pancreatic... mm in adults (5 mm in elderly)  Empties into ampulla of Vater, along medial aspect of 2nd portion of duodenum 50 year-old woman A CT scans of normal kidneys and pancreas Bennett, W F et al Am... Infection Pathophysiology Pathophysiology • Pancreatic autodigestion, with activated pancreatic enzymes escaping the ductal system and lysing tissue of pancreas and adjacent structures • Lack of