复旦大学上海医学院：《医学影像学》PPT教学课件_肝脏超声检查 Ultrasound of the liver.pdf

Content Content........................................................................................................................1 Topographic Remarks......................................................... ........................................2 Liver anatomy..............................................................................................................3 Ultrasound Examination technique..............................................................................4 Patient Preparation...................................................................................................4 Examination.............................................................................................................4 Liver pathology - diffuse liver disease...................................................................... ..8 Hepatic steatosis......................................................................................................8 Liver cirrhosis......................................................................................................... 9 Chronic viral hepatitis C......................................................................................... 10 Primary biliary cirrhosis (PBC)...............................................................................10 Doppler ultrasound techniques in the evaluation of liver disease................................11 Anatomy, blood supply of hepatic vessels............................................................ . 11 Arterial flow........................................................................................................12 Portal venous system...........................................................................................12 Venous outflow............................................................................................ ..... .13 Vascular (Doppler) indices.......................................................................... .. ... 13 Examination of the portal vein in patients with diffuse liver disease.............. . ..13 Normal and pathological portal venous blood flow................................... ... ... 13 Portal hypertension..............................................................................................14 No portal venous blood flow................................................................................14 Retrograde portal venous blood flow...................................................................14 Portal vein thrombosis..........................................................................................15 Examination of the hepatic veins in patients with diffuse liver disease...................16 Hepatic venous outflow obstruction (Budd Chiari-syndrome, BCS).............. ....16 Liver pathology - detection and characterisation of focal liver lesions (FLL).............16 Liver tumour detection.................................................................................... ........17 Differentiation of benign and malignant lesions......................................... ............18 Focal liver lesion (liver tumour) characterisation....................................................19 Liver cyst..............................................................................................................18 Haemangioma.......................................................................................................19 Hepatocellular carcinoma (HCC)........................................................................ 20 Metastases............................................................................................................21 Abscess.................................................................................................................21 Clinical importance of liver ultrasound in daily routine........................................... ..24 References....................................................................................................................25

Topographic Remarks The liver is located intraperitonealy, and under the right hemi-diaphragm but also extend across the midline reach to the left hemi-diaphragm and to the spleen in some cases. The liver is fixed to the diaphragm by the pars affixa and to the ventral abdominal wall by the ligamentum falciforme(falciform ligament)and its strong margin, the ligamentum teres hepatis. The minor omentum consists of the ligamentum hepatogastricum and of the ligamentum hepatoduodenale. The hepatoduodenal ligament carries three vessels-two containing blood(the portal vein and hepatic artery), and one carrying bile(common bile duct). The further courses of these three vessels is mainly parallel( Glisson's triad) The structures of the liver hilum(porta hepatis)are panied by a number of (in relation to the portal vein) ventrally and dorsally lymph nodes which can routinely be demonstrated by ultrasound (US). The liver has three main veins(hepatic veins)- left, middle and right one which drain the liver blood to the retroperitoneally located inferior vena cava. The inferior vena cava is variably surrounded by liver parenchyma The organs and structures surrounding the liver are the organs of the peritoneal cavity and but also pleural and pericardial structures. Neighbourhood structures adjacent to the liver are numerous, including(clockwise) basal lung proportions separated by the muscular layers of the right diaphragm(and more or less extensively also of the left diaphragm too), heart, stomach, intestine(e.g, upper duodenal loop and right colonic flexure), abdominal aorta, inferior vena cava, right adrenal gland and right kidney Interposition of the colon between liver and the anterior abdominal wall can prevent the sonographic approach to the right liver lobe in case of Chilaiditi's syndrome. In the case of complete or incomplete situs inversus the topographic relations are inverted Liver anatomy Anatomic orientation Liver anatomy is defined by ligaments and fissures as well as by the vascular architecture: branches of the hepatic artery, portal vein, and bile ducts in their parallel course define the centers of liver segment anatomy Liver segment anatom A simplified anatomy divides into the larger right lobe(including segment V, VI, VIl VIID), the left lobe with its medial(IVa, b) and lateral segments(Il, III), and the caudate lobe D) Couinaud classification Liver segment anatomy is explained by the widely accepted architecture described by Couinaud [(16, 17)]. The Couinaud classification, modified by Bismuth(segment IVa b), is based on 8 segments, each of which has its own arterial and portal venous vessel

Topographic Remarks The liver is located intraperitonealy, and under the right hemi-diaphragm but also extend across the midline reach to the left hemi-diaphragm and to the spleen in some cases. The liver is fixed to the diaphragm by the pars affixa and to the ventral abdominal wall by the ligamentum falciforme (falciform ligament) and its strong margin, the ligamentum teres hepatis. The minor omentum consists of the ligamentum hepatogastricum and of the ligamentum hepatoduodenale. The hepatoduodenal ligament carries three vessels – two containing blood (the portal vein and hepatic artery), and one carrying bile (common bile duct). The further courses of these three vessels is mainly parallel (Glisson`s triad). The structures of the liver hilum (porta hepatis) are accompanied by a number of (in relation to the portal vein) ventrally and dorsally located lymph nodes which can routinely be demonstrated by ultrasound (US). The liver has three main veins (hepatic veins) – left, middle and right one – which drain the liver blood to the retroperitoneally located inferior vena cava. The inferior vena cava is variably surrounded by liver parenchyma. The organs and structures surrounding the liver are the organs of the peritoneal cavity and but also pleural and pericardial structures. Neighbourhood structures adjacent to the liver are numerous, including (clockwise) basal lung proportions separated by the muscular layers of the right diaphragm (and more or less extensively also of the left diaphragm too), heart, stomach, intestine (e.g., upper duodenal loop and right colonic flexure), abdominal aorta, inferior vena cava, right adrenal gland and right kidney. Interposition of the colon between liver and the anterior abdominal wall can prevent the sonographic approach to the right liver lobe in case of Chilaiditi’s syndrome. In the case of complete or incomplete situs inversus the topographic relations are inverted. Liver anatomy Anatomic orientation Liver anatomy is defined by ligaments and fissures as well as by the vascular architecture: branches of the hepatic artery, portal vein, and bile ducts in their parallel course define the centers of liver segment anatomy. Liver segment anatomy A simplified anatomy divides into the larger right lobe (including segment V, VI, VII, VIII), the left lobe with its medial (IVa,b) and lateral segments (II, III), and the caudate lobe (I). Couinaud classification Liver segment anatomy is explained by the widely accepted architecture described by Couinaud [(16;17)]. The Couinaud classification, modified by Bismuth (segment IVa, b), is based on 8 segments, each of which has its own arterial and portal venous vessel

architecture( Glisson's triad) indicating vascular inflow, outflow, and biliary drainag [9; 10)1. Because of this division into self-contained units, each can be resected (alone or in groups) without damaging those remaining as the vascular inflow, outflow and biliary drainage is preserved. Depending on the 3D volume orientation of the liver (longitudinal or oblique orientated) interpretation of Couinaud classification unfortunately finds some inconsistency in literature. While the portal vein plane has often been described as transverse, it may be oblique since the left branch runs superiorly and the right branch runs inferiorly. In addition to forming an oblique transverse plane between segments, the left and right portal veins branch superiorly and inferiorly to project into the centre of each segment Ultrasound Examination technique Patient Preparation It is recommended that a patient undergo a period of fasting prior to upper abdominal imaging to maximise the distension of the gall bladder and to reduce food residue and gas in the upper GI tract which may reduce image quality or precluded liver imaging This is essential for full imaging of the liver and related biliary tree but may not be required in an acute situation such as trauma where imaging of the gall bladder is not immediately essential. a patient may take small amounts of still water by mouth prior to scan, particularly for taking any medications. There is some evidence that smoking can reduce image quality when scanning upper abdominal structures and it is good practice to encourage a patient not to smoke for 6-8 hours prior to US scan. Smoking increases gas intake into upper GI tract and may reduce image quality. Also, some chemicals in tobacco are known to cause contraction of the smooth muscle of the gi tract and this can cause contraction of the gall bladder, even when fasting has occurred, and the gall bladder cannot be scanned E The liver is a large, pyramidal shaped organ and liver sectional anatomy may be best described imaged and defined using by real time ultrasound imaging. Conventional eal time ultrasound produces images of thin slices of the liver on the screen, and so it is essential that the operator scans the entire organ systematically/ritually, in at least two anatomical planes, to be entirely convinced that the entire volume of the liver tissue and structures has been imaged. The operator must then synthesise this 2 dimensional information in their brain to develop a 3 dimensional map of the individual patients liver anatomy and pathology. This requires good hand-eye-brain coordination For orientation, three levels of the central portion of the liver can be differentiated Level of the Confluences of the liver veins [Figure 1] Level of the Pars umbilicalis of the(left) portal vein branch [Figure 2] Level of the gall bladder Figure 3 Figure 1 Confluences of the liver veins. This "junction" level is the first one in ultrasound examination of the right liver lobe by subcostal scanning sections steeply looking"upwards, preferably in deep inspiration [video]. VCI: inferior vena cava. LLV: Left liver vein. MLV. Middle liver vein. C: Confluens of the llv and MLV RLV: Right liver vein. The rlv often separately joins the inferior

architecture (Glisson`s triad) indicating vascular inflow, outflow, and biliary drainage [(9;10)]. Because of this division into self-contained units, each can be resected (alone or in groups) without damaging those remaining as the vascular inflow, outflow and biliary drainage is preserved. Depending on the 3D volume orientation of the liver (longitudinal or oblique orientated) interpretation of Couinaud classification unfortunately finds some inconsistency in literature. While the portal vein plane has often been described as transverse, it may be oblique since the left branch runs superiorly and the right branch runs inferiorly. In addition to forming an oblique transverse plane between segments, the left and right portal veins branch superiorly and inferiorly to project into the centre of each segment. Ultrasound Examination technique Patient Preparation It is recommended that a patient undergo a period of fasting prior to upper abdominal imaging to maximise the distension of the gall bladder and to reduce food residue and gas in the upper GI tract which may reduce image quality or precluded liver imaging. This is essential for full imaging of the liver and related biliary tree but may not be required in an acute situation such as trauma where imaging of the gall bladder is not immediately essential. A patient may take small amounts of still water by mouth prior to scan, particularly for taking any medications. There is some evidence that smoking can reduce image quality when scanning upper abdominal structures and it is good practice to encourage a patient not to smoke for 6-8 hours prior to US scan. Smoking increases gas intake into upper GI tract and may reduce image quality. Also, some chemicals in tobacco are known to cause contraction of the smooth muscle of the GI tract and this can cause contraction of the gall bladder, even when fasting has occurred, and the gall bladder cannot be scanned. Examination The liver is a large, pyramidal shaped organ and liver sectional anatomy may be best described imaged and defined using by real time ultrasound imaging. Conventional real time ultrasound produces images of thin slices of the liver on the screen, and so it is essential that the operator scans the entire organ systematically/ritually, in at least two anatomical planes, to be entirely convinced that the entire volume of the liver tissue and structures has been imaged. The operator must then synthesise this 2 dimensional information in their brain to develop a 3 dimensional map of the individual patient`s liver anatomy and pathology. This requires good hand-eye-brain coordination. For orientation, three levels of the central portion of the liver can be differentiated: • Level of the Confluences of the liver veins [Figure 1]. • Level of the Pars umbilicalis of the (left) portal vein branch [Figure 2]. • Level of the gall bladder [Figure 3]. Figure 1 Confluences of the liver veins. This “junction” level is the first one in ultrasound examination of the right liver lobe by subcostal scanning sections steeply “looking” upwards, preferably in deep inspiration [video]. VCI: inferior vena cava. LLV: Left liver vein. MLV: Middle liver vein. C: Confluens of the LLV and MLV. RLV: Right liver vein. The RLV often separately joins the inferior