肝脏解剖与常见病影像诊断

The Hepatic Lesion: Radiologic Assessment The Affiliatred hospital of NBU Wang JIANHUA ,2014-12-29,CASE,Objectives,Normal liver anatomyImaging techniquesCommon diseases imaging diagnosisDiffuse diseasesFocal diseases,Anatomy of the liver segments,Two different aspects: morphological anatomy and functional anatomy.C. Couinaud (1957) divided the liver into eight functionally indepedent segments.This classification will be presented here with several illustrations.,Couinaud classification,Divides the liver into eight functionally indepedent segments. Each segment has its own vascular inflow, outflow and biliary drainage.In the centre of each segment there is a branch of the portal vein, hepatic artery and bile duct.In the periphery of each segment there is vascular outflow through the hepatic veins.,Right hepatic vein divides the right lobe into anterior and posterior segments.,Cross transverse,Portal vein divides the liver into upper and lower segments.,Middle hepatic vein divides the liver into right and left lobes (or right and left hemiliver). This plane runs from the inferior vena cava to the gallbladder fossa,Left hepatic vein divides the left lobe into a medial and lateral part.,The image on the far left is at the level of the right portal vein. At this level the right portal vein divides the right lobe of the liver into superior segments (7 and 8) and the inferior segments (5 and 6).The level of the right portal vein is inferior to the level of the left portal vein.At the level of the splenic vein, which is below the level of the right portal vein, only the inferior segments are seen (right image).,Counterclockwise,1 Caudate lobe,Segment 1,2 Left lateral upper sagment,8 Right anterior upper sagment,4 Left medial sagment,7 Right posterior upper sagment,Left lateral upper sagment,Left lateral low segment,Left medial segment,Right posterior upper segment,Right anterior upper degment,Right anterior low degment,Right posterior low segment,Liver anatomy,Imaging techniques,US: first choice, screening, difficult to characterize the lesions,CT: important techniqueMRI: problem resolving technique,Good methods of deciding position and predicting the nature of the mass,CT techniques,CT enhanced techniques,The liver has a dual blood supply from the hepatic artery and portal vein.Hepatic artery: 1/3Portal vein: 2/3,3 minutes,Why do we need multiple-phase enhancdment,Increase the contrast between normal parenchyma and the lesion so that increase the detection rate,Understanding the characteristics of blood supply and speculating the pathological changes for the qualitative diagnosis,CASE,Multiple-phase enhancement,MRI advantages,MRI is often used as a problem-solveing technique to give additional information to US and CTExcellent technique foe demonstrating tumoursImages can be obtained in coronal and sagittal planesIntravenuous contrast is used to improve visualization and help charccterize lesions. New liver-specific agents: Some taken by the hepatocytessome by the reticuloendothelial cell,MRI,MRCP,Multiple-phase Enhancement,Arterial phase,Equilibrium phase,Delayed phase 90min,Multihance liver-specific agents: specifically taken by the hepatocytes,Portal vein phase,Hepatocarcinomacant take the agent,multihance,Common liver diseases imaging,Diffuse diseases: fatty liver, cirrhosisFocal diseases: Benign：Liver cyst, absecess, hemangioma Focal nodule hyperplasia(FNH) adenoma Malignant: heptocellular carcinoma cholangiocarcinoma metastasis tumors,Fatty liver,Relatively frequent findingHypercholesterolaemia obesity or diabetes , alcohol addict and patients on chemotherapy or hormonotherapyDiffuse or localFatty infiltration leads to a reduction in the attenuation of the affected parenchyma causing low density on CT scans,局灶性脂肪肝,Fatty liver,Cirrhosis,Pathology: Liver cell degeneration and necrosis, extensive fibrosis nodular regeneration- liver structure and blood circulation system reconstruction Imaging Features:X ray：esophagus, the bottom of the stomach varices,CT、MRIfindings,1/Shape morphology：hepatomegaly /atrophic , liver lobe ratio change, outer concave contour ，parenchymal nodular regeneration 2/Density: Inhomogeneous attenuation 3/ Contrast Enhancement (CE): inhomogeneous degree of enhancement, intrahepatic arterioportal fistulas4/Extrahepatic findings: varices， scites, splenomegaly. 5/The differential diagnosis： Hepatocellular carcinoma,Hepatic Cyst,CT、MRI FeaturesRound and quasi-circular Sharp demarcatationNon enhancingUniform density or signal CT：low density (water density 0-15HU）T1WI：very low signal intensityT2WI： very high signal intensity,Hepatic Cyst,Hepatic Abscess,Bacterial and amebic liver abscessPathology：Pus /Necrosis / Fiber tissue，Inflammatory cells infiltration EdemaImaging FeaturesSingle or multiple low density lesionRound or ovalCircumferential s,kmfrenl wall /enhancement fluild or gas-fluid levelMRI： T1WI: hypo-intensity T2WI: hyper-intensity,Target sign,Target sign,After treatment,Hemangioma,Pathology： Benign lesionCavernous hemangioma (mostly)/ capillary /hemangioendothelioma A type of blood vessel malformation (hemangioma) that has relatively large blood-filled spaces (cavities)No contain tissue of the organ in which they are situated. Imaging Features:Single or multiple low density lesion (CT value: 30-40HU)Round or oval, Sharp margin, no capsule Contrast: early peripheral nodular enhancement, gradually filling in over timeMRI： T1WI: hypo-intensity T2WI: hyper-intensity,Hemangioma,Hemangioma,FNH影像特征,平扫密度信号与肝实质接近强化明显内部瘢痕假包膜少见,肝腺瘤 Hepatocelluar adenoma,女, 1 8岁,增强：强化明显,男, 2