Mirizzi syndrome
Common bile duct narrowing and fibrosis due to chronic gallstone disease Stone usually impacted in gall bladder neck, cystic duct or cystic duct remnant Fistula can develop between gall bladder or cystic duct and common duct, stone may partially or totally pass into common duct Stricture commonly in upper and middle common duct Difficult to…
Primary sclerosing cholangitis
70% patients have history of inflammatory bowel disease – ulcerative colitis Multiple segments of stricture involving intra- and/or extra-hepatic ducts Bile duct wall thickening at sites of structuring Small diverticula-like outpouchings Cholangiocarcinoma in 10% cases Imaging Cholangiography: multifocal strictures, areas of distension, pruning of ducts, areas of ductal isolation CT-IVC and MRCP: thickened biliary epithelium…
Angiosarcoma (spleen)
Rare, poor prognosis Multiple nodules of varying size Solitary solid mass with cystic components, variable enhancement Well-defined hemorrhagic nodules Diffuse spleen involvement Imaging CT: hypodense on plain with areas of increased attenuation due to hemorrhage. Enhancement similar to hemangioma (liver) and often not diagnosed without metastases. MR: nodular masses with hypo intense T1 and T2…
Portal hypertension
Normal pressure difference between wedged hepatic vein and IVC = 4-8 mm Hg Higher pressures suggest portal hypertension Ascites Distended mesenteric veins Distended walls of gall bladder Stomach and small bowel are edematous Splenomegaly not always present Portal vein diameter > 15 mm suggests hypertension but a normal diameter does not rule out hypertension Porto-systemic…
Epithelioid hemangioendothelioma
Tumor of vascular origin Adult women Consists of epithelioid endothelial cells Occasionally contains punctate calcification Multiple peripheral nodules that coalesce, cause capsular retraction, with compensatory hypertrophy of uninvolved liver segments Can cause hepatic vein occlusion Imaging CT: multiple peripheral heterogeneous areas of low attenuation. Enhancement of rim of nodules with low attenuation halo outside ring…
Fibrolamellar carcinoma (liver)
5-35 years age Arise spontaneously Solitary, lobulated, well-defined tumor with central scar Punctuate calcification within scar in >50% cases Contains fibrotic lamellae and numerous eosinophilic hepatocytes Resection when possible 5-year survival 60% Imaging CT: well-defined lobulated, low attenuation mass with even lower attenuation central scar with radial linear components and punctate calcification. Shows non-specific enhancement…
Focal fat (liver)
Regional or focal Causes confusion if there is any underlying mass Common sites: either side of falciform ligament, around gall bladder fossa, posterior aspect of segment IV Variations in local blood supply and venous drainage responsible for difference in fat distribution Imaging Unenhanced US and CT: angular margins, geographic appearance. Lack of mass effect, preservation…
Hemangioma (liver)
Commonest benign hepatic tumor 4-20% post-mortem prevalence Vascular channels of varying size, lined with endothelium, has intervening fibrous tissue Asymptomatic incidental findings Lesions 2-4 cm in size show typical imaging findings Imaging US: well defined, lobular, homogeneous, increased echo reflectivity. No doppler flow due to slow flow MRI: most sensitive and specific. Extended ECHO time…
Portal venous gas
Always abnormal Present when intestinal permeability increases or when there is increase in intestinal luminal pressure Neonatal necrotising enterocolitis, adults with gastric emphysema, intestinal obstruction, infection, Crohn disease Blunt abdominal trauma, invasive malignancies (colon, ovarian carcinoma) Duodenal perforation at ERCP Colitis following barium enema Gas radiates out of hilum Less gravity dependence than pneumobilia, more…
Hepatic steatosis
Increased triglyceride loading of hepatocytes Acute and chronic alcohol abuse Obesity Diabetes mellitus Insulin resistance Cystic fibrosis Malnourishment Total parenteral nutrition Tetracyclines, steroids, ileal bypass Imaging US: increased parenchymal reflectivity, obscures portal vein margins CT: helps quantify. Fat reduces 1.6 HU for every mg of triglyceride increase per gram of liver substance. Preserved liver architecture…
Hepatic encephalopathy
Patients with liver dysfunction Cirrhosis, portal hypertension, portal systemic shunts, acute liver failure MRI demonstrates CNS increase in certain substances that are normally metabolized by the liver Imaging MRI T1 high signal in globus pallidum due to excess manganese Elevated glutamate/glutamine peak with decreased myo-inositol and choline on spectroscopy. This is due to hyperammonemia T1…
Porcelain gall bladder
0.2% of cholecystectomy specimens Complete or scattered mural calcification <5% chance of carcinoma of gall bladder Prophylactic cholecystectomy recommended Imaging Calcification follows contour of gall bladder Focal or diffuse Mimics emphysematous cholecystitis on ultrasound. ‘Double-arc shadow’ sign of stones is absent Read more Stephen, Antonia E., and David L. Berger. “Carcinoma in the porcelain gallbladder:…
Acute calculous cholecystitis
Ultrasound is best initial investigation – definitive in 80% cases 90-95% of cases of cholecystitis due to stones Imaging USG Gall bladder wall thickness > 3 mm has 95% positive predictive value Gall bladder distension (diameter >5 cm) Pericholecystic fluid Gall bladder wall striations Wall hyperemia occasionally on Doppler If labs show signs of cholestasis,…
Transplant pancreas imaging
Graft rejection is best demonstrated by MRI T1 drop in signal to similar to skeletal muscle T2 signal similar to fluid Perfusion studies will demonstrate decreased blood flow Acute rejection: Gland will be swollen with patchy areas of decreased attenuation Chronic rejection: gland is diffusely hyper echoic and reduced in size Tc 99m DTPA is…
Multi-system disease involving pancreas
Cystic fibrosis Autosomal recessive Defects of serous and mucous secretion 85% have exocrine pancreatic insufficiency, steatorrhea Main duct and branch ducts obstructed by inspissated secretions Acinar and ductal dilatation Atrophy of pancreas Fatty replacement, dystrophic calcification, pancreatic cysts Autosomal dominant polycystic kidney disease 10% patients show pancreatic cysts Von Hippel-Lindau disease Autosomal dominant Renal cell…
Metastasis to pancreas
Rare, occur late in disease Lung, breast, kidney and melanoma 3 patterns described: multiple small nodules, diffuse infiltration, solitary mass Kidney origin lesions may appear hyper enhancing and mimic neuroendocrine tumors
Intraductal papillary mucinous tumor of pancreas (IPMT)
Most common cystic pancreatic neoplasm Arise from epithelial cells of main duct or side branches Produces large amount of mucin 4 histological types: dysplasia, borderline, carcinoma in situ, IPMT with invasive cancer Based on location: main duct type, branch duct type or mixed type Diffuse or segmental duct dilatation Mixed type shows diffuse and segmental…
Serous cystic neoplasms of pancreas
Mass consisting of numerous tiny cysts, at least 6 in number, each cyst <2 cm in diameter May show central scar or stellate calcification If cysts too small to discern, it will appear as a solid mass. MRI clearly depicts the microcystic nature Very rarely it can appear in a macrocystic form and be difficult to distinguish…
Mucinous cystic neoplasms of pancreas
Benign to malignant, eventually turn malignant Mass consisting of few >2 cm sized cysts Any accompanying solid component suggests malignancy
Neuroendocrine tumors of pancreas
Functioning or non-functioning depending on hormonal hyper secretion Functioning tumors produce a peptide hormone and has a clinical syndrome Non-functioning tumors have a better prognosis Insulinoma, gastrinoma, glucagonoma, VIPoma, somatostatinoma 20% NETs are partially cystic, 3% purely cystic Insulinoma Hypoglycemic episodes Solitary, benign 80% cases <2 cm size Treated by surgical resection Gastrinoma Second most…
Ductal adenocarcinoma of pancreas
Aggressive Early advanced local or distant spread Perivascular, perineurial and lymphatic spread Early spread to liver and peritoneum At time of diagnosis, only 10% cases surgically resectable 5 year survival rate <5% Radical pacreaticoduodenectomy – severe morbidity and mortality Weight loss, anorexia common symptoms Obstructive jaundice seen in tumors involving head of pancreas CA 19-9…
Autoimmune pancreatitis
No history of alcohol use or biliary stone disease Immune-mediated Gland infiltrated by CD4 positive lymphocytes and plasma cells Serum IgG4 sometimes elevated Responds to steroids Focal form difficult to distinguish from malignancy May be associated with other IgG4 issues: cholangitis, renal, salivary gland or lacrimal gland inflammation, lymphadenopathy Imaging 3 types in imaging: diffuse,…
Chronic pancreatitis
Irreversible inflammation and fibrosis Multiple prior attacks of acute disease Abdominal pain Loss of exocrine and endocrine function Weight loss, steatorrhea, diabetes Diagnosis made when 3 of the following 4 is present Parenchymal calcifications Intraductal calcifications Parenchymal atrophy Cystic lesions Focal pancreatitis and malignancy in chronic pancreatitis are hard to distinguish on imaging. One sign…
Acute pancreatitis
Some etiologies Alcohol, cholelithiasis, trauma, iatrogenic, hyperlipidemia, hypercalcemia, viral infections (CMV, mumps), drugs, idiopathic Clinical diagnosis Needs at least 2 of the 3 below: Abdomen pain strongly pointing to acute pancreatitis Serum amylase and or lipase at least 3 times upper limit Characteristic imaging findings Revised Atlanta Classification (2008) Two morphological types: interstitial edematous and…
Annular pancreas
Second most common congenital anomaly Failure of normal rotation during development Pancreas partially or completely encircles duodenum Sometimes causes symptomatic duodenal narrowing Barium studies show narrowing at level of major papilla Quite often asymptomatic CT, MRI shows the tissue around second part of duodenum ERCP or MRCP will show the duct encircling the duodenum
Pancreas divisum
Commonest congenital pancreatic abnormality Failure of normal fusion of dorsal and ventral anlage Dorsal and ventral ducts don’t fuse Wirsung (ventral duct) drains head of pancreas via major papilla Santorini (dorsal duct) drains body and tail via minor papilla Can cause functional stenosis of minor papilla and secondary pancreatitis Higher prevalence in patients with recurrent…
Chronic calcific pancreatitis
Clinical presentation 38 year old gentleman presented with recurrent upper abdominal pain. CT https://www.youtube.com/watch?v=ovCmHfb3Q5c https://www.youtube.com/watch?v=aLXdvn284JM Findings and discussion https://www.youtube.com/watch?v=W1QzJ2E7a-Y Read more Chronic pancreatitis – Radiopaedia Busireddy, Kiran K., et al. “Pancreatitis-imaging approach.” World journal of gastrointestinal pathophysiology 5.3 (2014): 252.
Polycystic liver disease
Clinical presentation 45 year old gentleman, with family history of polycystic disease developed epigastric discomfort and came to assess present status of hepatic cysts. MRI Liver https://www.youtube.com/watch?v=vsvB_X5tIog https://www.youtube.com/watch?v=IvMAvG9yTrI https://www.youtube.com/watch?v=au-zg6CiXXU Key images Findings Multiple simple cysts of varying sizes are seen in both lobes of liver left > right, largest measuring 11 x 8.5 cm…
Flash hemangioma of the liver
30 year old gentleman went for a routine health check up as a part of his job health clearance and was detected to have a heteroechoic focal lesion in right lobe of liver. A multiphase contrast enhanced CT study was requested to identify the nature of the lesion. Triphasic CT Arterial phase https://www.youtube.com/watch?v=Oc_3XL4Typs Portal phase…