Pancreas Flashcards
USF of acute pancreatitis
Enlarged, hypo echoic pancreas: Due to interstitial oedema.
Blurred pancreatic outline/margin
• Enlarged heterogeneous pancreas in patients with intra pancreatic necrosis or hemorrhage
• Dilated pancreatic duct due to duct compression by edematous pancreas
Inflammatory change in soft tissues around pancreas/kidneys
• Gallstone or intraductal calculi
• Pancreatic pseudocyst
• Pancreatic/peri-pancreatic fluid collection
• Pancreatic abscess or infected collections: Thick-walled, mostly anechoic with internal echoes and deb
Checklist for acute pancreatitis
Exclude other causes of perpancreatic infiltration
Bulky irregular enlarged pancreas with obliteration or peri pancreatic fat planes, fluid collections, pseudocyst or abscess formation
USF of pancreatic pseudocyst
Well-circumscribed, smooth-walled, unilocular anechoic mass with posterior acoustic enhancement
• Most common in pancreatic body and tail
• Multilocular in 6% of cases
• Fluid-debris level, internal echoes and septations (due to hemorrhage/infection)
• Solid or complex in morphology (during initial phase of cyst formation)
• Wall calcification: May make it difficult to assess details of pseudocyst
Dilated pancreatic duct & common bile duct (CBD) may be seen due to compression by pseudocyst
• Pseudocyst formation usually takes about 6-8 weeks to mature which is the best time for detection
• Apart from pancreas and peri-pancreatic spaces, anatomical locations such as peritoneal space, intra-abdominal parenchyma or even intrathoracic cavity should also be evaluated
• Follow-up: US helps to monitor serial change in size and to select patients requiring decompression
Checklist of pancreatic pseudocyst
Rule out other cystic lesions of pancreas
UsF of chronic pancreatitis
Atrophic gland: Gland may be enlarged in early part of chronic pancreatitis & during an acute on chronic episode, enlargement may be focal or diffuse
• Patchy hypoechoic (due to inflammatory change) and hyperechoic (combination of fibrosis and calcification) echo pattern
• Irregular pancreatic contour
• Dilated MPD (irregular, smooth or beaded)
• Pancreatic calcifications
• Focal mass/enlargement in 40%
• Pseudocyst: 25-40%, intra/peri pancreatic
• Dilatation of common bile duct: 5-10%
Portosplenic venous thrombosis: 5%
• Arterial pseudoaneurysm formation
• Ascites/pleural effusion
• Peripancreatic inflammatory change
• Areas of focal intraparenchymal necrosis
Checklist for chronic pancreatitis
Glandular atrophy, dilated MPD and ductal calculi/parenchymal calcifications are best signs for chronic pancreatitis
USF of mucinous cystic pancreatic tumour
Best diagnostic clue: Multiseptated mass in body or tail of pancreas, particularly in women
• Cyst contents may be clearly anechoic, echogenic with debris +/- solid component
Solid papillary tissue protruding into tumor suggests malignancy cysts
• May contain mural calcification
• Has a tendency to invade adjacent structures
• Hypovascular mass, scant vascularity
• May encase splenic vein
Checklist for mucinous cystic pancreatic tumour
Large, multiloculated cystic mass with enhancing septa & cyst wall in pancreatic body or tail
USF of serous cystadenoma
Well-demarcated mass with externallobulations
• Appearances depend on size of individual cysts
• Slightly echogenic, solid-appearing mass (small cysts depicted as interfaces)
• Partly solid-looking mass with anechoic cystic areas: Cysts usually in periphery
• Multicystic mass with septae and solid component
• Central stellate scar: Characteristic feature
• Amorphous central calcification
• Pancreatic and common bile duct dilatation is rare
• In patients with thin body habitus, higher frequency transducer help to depict small cysts within the mass
Careful examination for presence of subtle pancreatic calcification
Checklist for serious cysteadenoma
Rule out other “cystic pancreatic masses” such as pseudocysts, congenital cysts and cystic malignant neoplasms
• Large, well-demarcated, lobulated cystic lesion composed of innumerable small cysts (1-20 mm) separated by thin septa located in head of pancreas
USF of ductal pancreatic carcinoma
Best diagnostic clue: Irregular, heterogeneous pancreatic mass with abrupt obstruction of pancreatic and/or common bile duct (“double duct sign”)
• Location: Head (60-70%), body (20%), diffuse (15%), tail (5%)
• Ill-defined tumor with extensive local invasion into soft tissues, duodenum, stomach, left adrenal, spleen
• Metastatic involvement of liver, portal hilar nodes, peritoneum, lungs, pleura, bone
• Poorly-defined, homogeneous/heterogeneous, hypoechoic mass in the pancreas or pancreatic fossa
• Pancreatic ductal dilatation distal to tumor
Bile duct dilatation
• Displacement/encasement of adjacent vascular structures (superior mesenteric artery, splenic artery, hepatic artery, gastroduodenal artery)
• Mild increase in color flow within the tumor
• Best imaging tool: CECT,US+/- endoscopic US
• CECThelps predict resectability better than US
Checklist for ductal pancreatic carcinoma
Irregular heterogeneous mass in head of pancreas with eccentric ductal obstruction/dilatation & extensive local invasion & regional metastases
USF of islet cell tumours
Best diagnostic clue: Hypervascular mass(es) in pancreas (primary) & liver (metastases)
• Pancreas (85%); ectopic (15%)
• Most common appearances: Small, solid, hypoechoic pancreatic mass, lack of calcification or necrosis
• Occasional isoechoic mass: Seen as focal bulge of contour
• Large tumor (mostly non-functional): May be echogenic and contain calcification and internal necrosis
• Liver and regional lymph node metastases: 60-90% at clinical presentation
• Hyperechoic hepatic metastases are suggestive of islet cell tumors rather than adenocarcinoma
Checklist for islet cell tumours
Hypervascular pancreatic tumor & liver metastases suggests islet cell tumor
• Contrast-enhanced CT and endoscopic US offers better diagnostic accuracy
• Intra-operative has highest sensitivity and is useful to ensure complete resection of tumor
USF of solid and papillary neoplasm
Well-defined heterogeneous mass in pancreatic tail
• Solid and cystic components
• Hypoechoic center due to tumor necrosis, hemorrhage
• Cystic portion may show fluid level
• Dystrophic calcification occasionally seen
• No pancreatic ductal dilatation
• Color Doppler: Hypovascular pattern
Checklist of solid and papillary neoplasm
Well-demarcated encapsulated pancreatic tail mass with mixed cystic and solid components and low malignant potential
