acute pancreatitis
DESCRIPTION
Acute pancreatitisTRANSCRIPT
ACUTE PANCREATITIS
Dr.mohamed soliman
Definition
• Acute inflammatory process of pancreas with variable involvement of other regional tissues
or remote organ systems
General Features
• Best diagnostic clue: Enlarged pancreas, fluid
collections & obliteration of fat planes
• Location: Pancreas and peripancreatic tissue
• Size: Pancreas increased in size, focal or diffuse
involvement
Grayscale Ultrasoundo In mild pancreatitis sonographic signs may be subtle or normal
o Enlarged, hypoechoic pancreas: Due to interstitial edema
o Blurred pancreatic outline/margin: Due to pancreatic
edema and peripancreatic exudate
o Enlarged heterogeneous pancreas in patients with
intrapancreatic necrosis or hemorrhage
o Dilated pancreatic duct due to duct compression by
edematous pancreas
o Inflammatory change in soft tissues around
pancreas/kidneys
o Gallstone or intraductal calculi)
Grayscale Ultrasound
o Complications• Pancreatic pseudocyst: Well-circumscribed, unilocularcystic lesion within pancreas or peri-pancreatic tissue• Pancreatic/peri-pancreatic fluid collection• Pancreatic abscess or infected collections:Thick-walled, mostly anechoic with internalechoes and debris• Vascular complications: Pseudoaneurysmformation and porto splenic venous thrombosis,Doppler USG helps for diagnosis• Pancreatic ascites and pleural effusion (usually left –sided)
Radiographic Findings
o Sentinel loop: Mildly dilated, gas-filled segment of small bowel with or without air-fluid levels
o "Colon cutoff" sign
• Markedly distended transverse colon with air
• Absence of gas distal to splenic flexure caused by
colonic spasm due to spread of pancreatic
inflammation to proximal descending colon
CT Findings
• CECT
o Focal or diffuse enlargement of pancreas with ill-defined margino Heterogeneous enhancement: Areas of nonenhancement indicates necrotic element
o Infiltration of peripancreatic fato Detection of complications
• Pancreatic/peripancreatic collection +/- infection:Rim-enhancing fluid density
• Pseudoaneurysm: Cystic vascular lesion, enhances like adjacent blood vessels
• Portal/splenic venous thrombosis: Nonenhancement of thrombosedvein
• Chest: Pleural effusions & basal atelectasis
MR Findings
• T2WI FSo Fluid collections, pseudocyst, necrotic areas: Hyperintenseo Gallstones or intraductal calculi: Hypointense• Tl c+o Heterogeneous enhancement pattern• Non enhancing decreased signal areas (necrosis!fluidcollection/pseudocyst)• Vascular occlusions can be easily demonstrated• MRCP
o All fluid-containing structures: Hyperintenseo Dilated or normal main pancreatic duct (MPD)
Imaging Recommendations• Best imaging tool: CECT, ultrasound• Protocol advice
o Role of ultrasound in acute pancreatitis: Although ultrasound is an ideal initial examination in acutely ill patient, it has certain diagnostic limitations in early acute pancreatitis• Changes of pancreatitis may be quite subtle and the pancreas may initially appear normal
• Transducer pressure cannot be applied on the abdomen as the patient often has severeabdominal pain• Associated distended colon, and small bowel obscures visualization of pancreas and
peri pancreatic soft tissueso Ultrasound is useful in
• Detection of gallstone/choledocholithiasis• Survey of potential complications such as pseudocyst/pancreatic abscess formation
• Provide real time guidance for interventional procedures (e.g., aspiration of peri-pancreatic collection/ abscess)
o CECT helps in better delineation of extent of pancreatitis, detection of pancreatic necrosis and complications, prediction of clinical outcome
DDx: Acute Pancreatitis
Infiltrating Pancreatic Carcinoma
• Irregular, heterogeneous, hypoechoic mass
• Abrupt obstruction & dilatation of pancreatic duct
• Regional nodal metastases: Splenic hilum & porta hepatis
• Contiguous organ invasion
o Duodenum, stomach & mesenteric root
DDx: Acute Pancreatitis
Lymphoma & Metastases
• Nodular, bulky, enlarged pancreas due to infiltration
• Retroperitoneal adenopathy
• Peripancreatic infiltration (obliteration of fat planes)
• Primary may be seen in case of metastatic infiltration
DDx: Acute Pancreatitis
Chronic Pancreatitis
• Atrophic pancreatic parenchyma• Intraductal/parenchymalcalcifications• Lack of peri-pancreatic fluid collection• Functional pancreatic exocrine/endocrineinsufficiency
DDx: Acute Pancreatitis
Perforated Duodenal Ulcer
• Penetrating ulcers may infiltrate anterior pararenal
space, simulating pancreatitis
• Less than 50% of cases have evidence of extraluminal
gas or contrast medium collections
• Pancreatic head may be involved"Shock" Pancreas
• Infiltration of peripancreatic & mesenteric fat planes
following hypotensive episode (e.g., blunt trauma)
• Pancreas itself looks normal or diffusely enlarged
Etiology- Acute Pancreatitis
o Alco h 01/gallstones/ meta bolic/ infection/tra uma/ drugs
o Pathogenesis: Due to reflux of pancreatic enzymes,
bile, duodenal contents & increased ductalpressure
• MPD or terminal duct blockage
• Edema; spasm; incompetence of sphincter of Oddi
Acute Pancreatitis
Gross Pathologic & Surgical Features
• Bulky pancreas, necrosis, fluid collection & pseudocystMicroscopic Features
• Acute edematous pancreatitis
o Edema, congestion, leukocytic infiltrates
• Acute hemorrhagic pancreatitis
o Tissue destruction, fat necrosis & hemorrhage
Staging, Grading or Classification Criteria
• CT classification: Five grades based on severityo Grade A: Normal pancreaso Grade B: Focal or diffuse enlargement of gland, contour irregularities & heterogeneous attenuation,noperipancreatic inflammationo Grade C: Intrinsic pancreatic abnormalities &associated inflammation in peri pancreatic fato Grade D: Small & usually single, ill-defined fluid collectiono Grade E; Two or more large fluid collections, presence of gas in pancreas or retroperitoneum• Most important criterion: Presence & extent of necrotizing pancreatitis (nonenhancing parenchyma)
CLINICAL ISSUES
Presentation• Most common signs/symptomso Acute onset epigastric pain, often radiating to backo Tenderness, fever, nausea, vomiting• Lab datao Increased serum amylase & lipaseo Other: Hyperglycemia, increased lactate dehydrogenase(LDH), leukocytosis, hypocalcemia, fall in hematocrit, rise in blood urea nitrogen (BUN)Demographics• Age: Usually young & middle age group• Gender; Males more than females
Natural History & Prognosis
• Complicationso Pancreatic• Fluid collections, pseudocyst, necrosis, abscess
o Gastrointestinal• Hemorrhage, infarction, obstruction, ileus
o Biliary: Obstructive jaundice
o Vascular: Pseudoaneurysm, porto-splenic vein thrombosis, hemorrhage
o Disseminated intravascular coagulation (DIC), shock, renal failure
• Prognosiso Early detection with minor complications: Goodo Late detection with major complications: Pooro Ranson criteria/APACHE II criteria help predict
prognosiso Infected pancreatic necrosis: Almost 50% mortality even with surgical debridement
Treatment
• Conservative
o Nil by mouth (NPO), gastric tube decompression,
analgesics, antibiotics
• Treat complications of acute pancreatitis
o Infected or obstructing pseudocysts require drainage: Surgical or percutaneous routes
o Infected necrosis needs surgery/catheter drainage
DIAGNOSTIC CHECKLIST
Consider
• Rule out other pathologies which can cause
"peripancreatic infiltration"
Image Interpretation Pearls
• Bulky, irregularly enlarged pancreas with obliteration of peripancreatic fat planes, fluid collections, pseudocyst or abscess formation
Transversetransabdominalultrasound shows a swollen pancreatic body with ill-defined heterogeneous hypoechoic echopattern. The pancreatic head and
tail are less severely affected.
head
body
tail
Transverse transabdominalultrasound shows focal
enlargement of pancreatic head with homogeneous
hypoechoic echo pattern in focal pancreatitis.
Note normal echo pattern of pancreatic body.
body
head
Transverse transabdominalultrasound shows diffuse,hypoechoic,
enlarged pancreatic
parenchyma.
Note the presence of mild pancreatic ductaldilatation
pancreas
Transverse CECTshows an
inflamed pancreas with
peripancreatic stranding . The adjoining duodenum
appears inflamed with an
edematous wall.
Note a calculus in the gallbladder
Gall stone
duodenum
Transverse
transabdominal ultrasound
shows a large heterogeneous
collection involving the
pancreatic head and body
compatible with abscess
formation, resulting from
infected phlegmon.
Transverse transabdominal
ultrasound shows subtle
swelling with hypoechoic
echo pattern of the
pancreatic tail, compatible
with focal pancreatic
necrosis.
Transverse transabdominalultrasound
shows a large, ill-defined,
anechoic/hypoechoic
collection in the
pancreatic body in acute
pancreatitis.
Longitudinal transabdominal
ultrasound shows a large
heterogeneous fluid
collection in the anterior
peripancreatic area. Note the pancreatic body is
compressed by the fluid
collection.
pancreas
Fluid collection
Enhanced ct
Acute pancreatitis .. hypoechoic
Pancreas after resolution
A
B
c