Digestive system Diagnostic imaging department of xuzhou medical college of xuzhou medical college
liver masses
Characterization of liver masses Liver masses malignant benign Hepatocellular carcinoma Cyst Haemangioma FNH (focal nodular hyperplasia) Hepatic adenoma Liver masses malignant benign
Hepatic cyst precontrast contrast
Hepatocellular carcinoma 1. causes liver cirrhosis hepatitis B and C infection
Hepatocellular carcinoma 2. blood supply come mainly from the hepatic artery portal vein invasion is frequently present whereas hepatic vein occurs more rarely
Hepatocellular carcinoma 3. appearances of CT precontrast CT hypo-or isodense a tumor capsule most HCC appear homogeneous, some HCC appear in heterogeneous intrahepatic biliary duct dilatation
Hepatocellular carcinoma 3. appearances of CT Dynamic contrast enhanced CT arterial phase : homogeneous or heterogeneous enhancement hyperattenuating relative to normal parenchyma portal vein phase: enhancement discreased hypoattenuating relative to normal parenchyma wash-in and wash-out
precontrastArterial phase Portal venous phase HCC
precontrast Arterial phase Portal venous phase tumor vessel
Hepatocellular carcinoma
4. appearances of MRI precontrast MRI T1WI: iso-or hypointense tumor capsule : hypointense T2WI: hyperintense DWI: hyperintense
Hepatocellular carcinoma T 1 WI T 2 WI
Hepatocellular carcinoma 4. appearances of MRI Dynamic contrast enhanced MRI similar to the appearances of dynamic contrast enhanced CT arterial phase : obviously enhancement portal vein phase: enhancement discreased wash-in and wash-out
Hepatocellular carcinoma
Hepatic cavernous haemangioma (CH) a very common benign liver tumor usually small (2cm diameter) and solitary, but 10% cases being multiple CH is composed of blood filled large or tortuous vascular cavities divided by thin, often incomplete, fibrous septa and lined by a single layer of flat endothelium
Hepatic cavernous haemangioma (CH) angiography has been used as the gold standard in the past now several noninvasive imaging methods are available such as US, CT, MRI
Hepatic cavernous haemangioma (CH) angiography
Hepatic cavernous haemangioma (CH) appearances of CT precontrast CT hypo-or isoattenuating homogeneous rounded mass usually smaller than 3cm diameter
Hepatic cavernous haemangioma (CH) appearances of CT dynamic contrast enhanced CT arterial phase :peripheral nodular enhancement pattern portal vein phase: a progressive “ fill- in ” of the lesion from the periphery towards the centre
Hepatic cavernous haemangioma (CH) precontrast arterial phase Portal venous phase
precontrast arterial phase Portal venous phaseequilibrium phase Hepatic cavernous haemangioma (CH)
4. appearances of MRI precontrast MRI T1WI: low signal intensity T2WI: high signal intensity “ light bulb ”
4. appearances of MRI Dynamic contrast enhanced MRI similar to the appearances of dynamic contrast enhanced CT arterial phase :peripheral nodular enhancement portal vein phase: a progressive “ fill- in ” from the periphery towards the centre
bile ducts
gallblader Pancreatic duct the ampulla of Vater Common hepatic duct Common bile duct Right hepatic duct left hepatic duct Normal bile ducts
Imaging investigation of jaundice 1. x-ray ERCP endoscopic retrograde cholangiopancreatography used for suspected distal biliary obstruction PTC percutaneous transhepatic cholangiography assess high biliary obstruction at the level of the porta
Imaging investigation of jaundice 2. ultrasound the initial investigation of choice to identify dilated bile ducts and confirm the presence of mechanical biliary obstruction
Imaging investigation of jaundice 3. computed tomography (CT) identifying dilated bile ducts and confirm the presence of mechanical biliary obstruction suggesting the site and cause of bile duct obstruction
Imaging investigation of jaundice 4. magnetic resonance imaging (MRI) identifying dilated bile ducts and confirm the presence of mechanical biliary obstruction suggesting the site and cause of bile duct obstruction MRCP magnetic resonance cholangiography may replace diagnostic ERCP
T2WIT1WI
Gallstones 1. gallstones are classified in three groups pure cholesterol stones: containing more than 90% cholesterol (胆固醇) mixed cholesterol stones: composed of more than 50% cholesterol pigmented ( 色素性 ) stones: composed mainly of calcium salt
Gallstones 2. x-ray only pigmented stones are visible on the AXR ERCP can present most of gallstones, but it is not used for the detection of gallstones because of the widespread availiability of ultrasound
Stones of the gallbladder
ERCP
Gallstones 3. CT pigmented stones are easily depicted on CT cholesterol stones usually have an attenuation value that is lower than bile and are visible on CT
cholesterol stones
pigmented stones
Mixed cholesterol stones
Stones of CBD
Stones of intrahepatic duct
Gallstones 4. MRI MRI and MRCP are able to visualize gallstones reliably ; presenting low signal intensity in T2WI
Stones of gallbladder
Stones of gallbladder and CBD