IVER Normal Sonographic Anatomy

1 25 THELIVERC hapter 2:The LiverDUNSTAN ABRAHAMN ormal Sonographic Anatomy Homogeneous, echogenic texture (Figure 2-1) Measures approximately 15 cm in length and10 cm anterior to posterior; measurementtaken at mid clavicular in longitudinal section Divisions right, left, and caudate lobes (Figure 2-2) Main lobar fissure Echogenic line extending to gallbladder fossa(Figure 2-3) Separates right and the left lobes Falciform ligament (contains ligamentum teres) Round, hyperechoic area in left lobe (Figure 2-3) Divides left lobe into medial and lateralsegments Fissure for ligamentum venosum Echogenic line anterior to caudate lobe(Figure 2-4)

2 Separates caudate from left lobeHepatic Vessels Portal veins Main portal vein enters liver at hilum (Figure 2-5). Divides into right and left branches Right branch divides into anterior andposterior branches. Left branch divides into medial and lateralbranches (Figure 2-6). Walls are thick and echogenic. Hepatic veins Right, middle, and left branches drain intoinferior vena cava (Figure 2-7). Walls are thin compared with thick-walledportal vein (Figure 2-8). 7/27/09 3:03 PM Page 25 Jones and Bartlett Publishers, LLC.

3 NOT FOR SALE OR DISTRIBUTION. 26 Chapter 2: The LiverFigure 2-1 Normal longitudinal sonogramdemonstrates a homogeneous liver with midlevel structures (white arrows) represent diaphragm (black arrow) is seen 2-2 Lobes of the view showsright (RT), left (LT), and caudate (CL) lobes of the inferior vena cava (C) is seen posterior to the cau-date lobe (CL). L main lobar 7/27/09 3:03 PM Page 26 Jones and Bartlett Publishers, LLC. NOT FOR SALE OR DISTRIBUTION. Normal Sonographic Anatomy27 LLRLRKF igure 2-3 Main lobar fissure and falciform transverse sonogram shows main lobar fissure (1) sep-arating the right lobe (RL) from the left lobe (LL).

4 The fal-ciform ligament (2) is seen within the left rightkidney (RK) is seen posterior to the right 2-4 Fissure for ligamentum longi-tudinal scan shows fissure for ligamentum venosum(arrow) anterior to the caudate lobe (C).The left hepaticvein (H) is seen joining the inferior vena cava (ivc). 7/27/09 3:03 PM Page 27 Jones and Bartlett Publishers, LLC. NOT FOR SALE OR DISTRIBUTION. 28 Chapter 2: The LiverHPIF igure 2-5 Main portal longitudinal sonogramshows main portal vein (P) as it enters hilum of the inferior vena cava (I) and hepatic vein (H) are 2-6 Branches of the portal transverseimage showing the right branch of the portal vein (RT)dividing into anterior (A) and posterior (P) branch (LT) divides into medial (M) and lateral (L) inferior vena cava (I) is seen the echogenic borders of the portal 7/27/09 3:03 PM Page 28 Jones and Bartlett Publishers, LLC.

5 NOT FOR SALE OR DISTRIBUTION. Normal Sonographic Anatomy29 Figure 2-7 Hepatic transverse sonogramshowing right (2), middle (3), and left (4) hepatic veinsdraining into the inferior vena cava (1).GBSTF igure 2-8 Portal and hepatic transverse sono-gram showing a section of portal vein (PV) with its hyper-echoic borders adjacent to a section of hepatic vein (HV),which has thin border (not hyperechoic).The gallbladder(GB) and fluid-filled stomach (ST) are also 7/27/09 3:03 PM Page 29 Jones and Bartlett Publishers, LLC.

6 NOT FOR SALE OR DISTRIBUTION. Hepatic artery Generally seen between the common bile ductand the portal vein as small, rounded,anechoic structure Linear and anechoic when demonstrated inoblique long axis view (Figure 2-9) Intrahepatic bile ducts Are anechoic and seen anterior to portal vein Measure less than 2 mm in anterior toposterior dimensions Diaphragm seen as curvilinear hyperechoicstructure abutting liver superiorly Reidel s lobe Downward projection of right lobe (Figure 2-10) May give false appearance of hepatomegaly30 Chapter 2.

7 The LiverHCPIF igure 2-9 Hepatic longitudinal oblique viewdemonstrates the hepatic artery (H) between the mainportal vein (P) and common bile duct (C) as it enters theliver. I inferior vena 7/27/09 3:03 PM Page 30 Jones and Bartlett Publishers, LLC. NOT FOR SALE OR DISTRIBUTION. Liver PathologyDiffuse DiseasesHepatomegaly Liver measures more than 15 cm in length(Figure 2-11) Commonly seen with infiltrative diseases andmasses in the liverFatty Liver Mild (early stage) Minimal increase in liver echogenicity Intrahepatic vessels and diaphragm wellvisualized (Figure 2-12A) Moderate (mid stage) Moderate increase in liver echogenicity Intrahepatic vessels and diaphragmsuboptimally visualizedLiver Pathology31 RLRKF igure 2-10 Reidel s longitudinal image showsa Reidel s lobe (RL)

8 Projecting from the right lobe of right kidney (RK) is seen 7/27/09 3:03 PM Page 31 Jones and Bartlett Publishers, LLC. NOT FOR SALE OR DISTRIBUTION. 32 Chapter 2: The LiverRKPF igure 2-11 measurement in alongitudinal section shows enlargement of the organ(RK right kidney, P pleural effusion).RKFigure 2-12A Mild fatty infiltration of the lon-gitudinal image showing generalized increased echogenici-ty of the liver. Note that the diaphragm (black arrow) andsection of an intrahepatic vessel (white arrow) are wellvisualized.

9 Right kidney (RK) is posterior to the 7/27/09 3:03 PM Page 32 Jones and Bartlett Publishers, LLC. NOT FOR SALE OR DISTRIBUTION. Severe (late stage) Significant increase in liver echogenicity Poor visualization of posterior aspect of liver Poor or nonvisualization of intrahepaticvessels and diaphragm (Figure 2-12B) Focal fat infiltration Hyperechoic area within an otherwise normalliver; commonly seen in right lobe and mayresolve over time (Figure 2-13) Focal fat sparing Area of Normal liver within fatty liver;commonly seen anterior to portal vein andgallbladder (Figure 2-14) Focal fat infiltration and sparing may mimic livertumorLiver Pathology33 Figure 2-12B Severe fatty infiltration of the image showing increased echogenicity of theliver in the anterior segment { }.

10 The posterior segment[ ] is hypoechoic because of poor penetration of diaphragm (arrow) is poorly demonstratedand the intrahepatic vessels are not 7/27/09 3:03 PM Page 33 Jones and Bartlett Publishers, LLC. NOT FOR SALE OR DISTRIBUTION. 34 Chapter 2: The LiverLONGF igure 2-13 Focal fatty longitudinalimage showing hyperechoic area (M) consistent withfocal fatty 2-14 Focal fatty longitudinal imagedemonstrates Normal liver (M) surrounded by liver withincreased echogenicity caused by fatty 7/27/09 3:03 PM Page 34 Jones and Bartlett Publishers, LLC.