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 vesselTopographic 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