Abdormal Imaging -Liver
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Transcript of Abdormal Imaging -Liver
Abdominal Imaging of Liver
Chuan LuSchool of Radiology
Taishan Medical University
Anatomy Protocols and Normal
Ultrasound Findings Pathology
Anatomy of the Liver
The Liver occupies all of the right hypochondrium, the greater part of the epigastrium, and left hypochondrium. The ribs cover the greater part of the right lobe .In the epigastric region, the liver extends several centimeters below the xiphoid process. Most of the left lobe of the liver is covered by the rib cage.
Lobes of the Liver
Right lobe: The right lobe of the liver is the largest of the liver’s lobes. It extends the left lobe by a ratio of 6:1. It occupies the right hypochodrium.
Left lobe: The left lobe of the liver lies in the epigastric and left hypochondriac region.
Caudate lobe: The caudate lobe is a small lobe situated on the posterosuperior surface of the left lobe opposite the tenth and eleventh thoracic vertebrae .
Hepatic Nomenclature
Couinaud’s system of hepatic nomenclature provides the anatomic basis for hepatic surgical resection. By using this system , the radiologist may be able to precisely isolate the location of a lesion for the surgical team
Couinaud’s hepatic segments divide the liver into eight segments . The hepatic veins are the longitudinal boundaries . The transverse plane is defined by the right and left portal pedicles .
Hepatic Segmental Anatomy
The caudate lobe (segment ) is Ⅰsituated posteriorly.
Segment includes the caudate Ⅰlobe.
Segment and includes the Ⅱ Ⅲleft superior and inferior lateral segment.
Segment a and b includes Ⅳ Ⅳthe medial segment of the left lobe.
Segment and are caudal to Ⅴ Ⅵthe transverse plane .
Segments and are Ⅶ Ⅷcephalad to the transverse plane.
Superior lateral segment
Inferior lateral segment
Superior anterior segment (right lobe) Caudate lobe
Inferior anterior segment (right lobe)
Superior posterior segment (left lobe)
Superior posterior segment (left lobe)
→
→→
→→
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Medial segment
Anatomy of Liver : Glisson system
Ultrasound can allow us to visualize the portal veins, hepatic veins , intrahepatic bile ducts .
The portal veins carry blood from the bowl to the liver, whereas the hepatic veins drain the blood from the liver into the inferior venal cava . The hepatic arteries carry oxygenated blood from the aorta to the liver. The bile ducts transport bile ,manufactured in the liver , to the duodenum.
The portal venous system is a reliable indicator of various ultrasonic tomographic planes throughout the liver.Main portal veinRight main portal veinLeft main portal vein
Vascular Supply: Portal veins
Intrahepatic Portal Vein Branches Right anterior superior left median superior Right anterior inferior left median inferior Right posterior superior left anterior inferior Right posterior inferior left lateral superior
Vascular Supply: Hepatic veins The hepatic veins are divided into three components: right,middle,and left. The right hepatic veins is the largest and enters the right lateral
Distinguishing Characteristics of Hepatic and Portal Veins
The best way to distinguish the hepatic from the portal vessels is to trace their points of entry to the liver. The hepatic vessels flow into the inferior vena cava, whereas the splenic veins and superior mesenteric vein join together to form the portal venous system.
Distinguishing Characteristics of Hepatic and Portal Veins
The walls of hepatic veins are thin-walled ,and the walls of portal veins are brightly reflective veins
The hepatic veins are easily differentiated from bile ducts and portal veins .
They are not surrounded by an echogenic wall They originate close to the diaphragm , and can
be traced into the inferior vena cava
Sonographic Evaluation of the Liver Evaluation of the hepatic structure is one of
the most important procedures in sonography for many reasons. The normal , basiclly homogenerous parenchyma of the liver allows imaging of the neighboring anatomic structures in the upper abdomen.
The system gain should be adjusted to adequately
penetrate the entire right lobe of the liver as a smooth ,homogeneous echo-texture pattern
The time gain compensation should be adjusted to
balance the far-gain and the near-gain echo signals.
The far time -gain control pods should gradually be increased until the posterior aspect of the liver is well seen.
Sonographic Evaluation of The Liver
The appropriate transducer depends on the patient’s body habitus and size
The average adult abdomen usually requires a 3.5MHz
The basic instrumentation should be adjusted in the following parameters :
Time gain compensation Overall gain Transducer frequency and type Depth and focus
Longitudinal Scan Plane
The longitudinal ,or sagittal, scan offers an excellent window to visualize the hepatic structure . With the patient in full inspiration , the transducer may be swept under the costal margin to record the liver parenchyma from the anterior abdominal wall to the diaphragm.
Longitudinal Scan Plane
Scan Ⅰ Scan Ⅱ Scan Ⅲ Scan , ,Ⅳ Ⅴ Ⅵ
Longitudinal Scan Plane
Scan Ⅰ The initial scan should be made slightly to the
left of the midline to record the left lobe of the liver and the abdominal aorta. The left hepatic and portal veins may be seen as small circular structures in this view.
肝腹主动脉纵切声像图Sagittal image of left lobe of liver, and aorta
The initial scan should be made slightly to the left of the midline to record the left lobe of the liver and the abdominal aorta. The left hepatic and portal veins may be seen as small circular structures in this view.
Sagital image of tip of left lobe of liver
The initial scan should be made slightly to the left of the midline to record the left lobe of the liver and the abdominal aorta. The left hepatic and portal veins may be seen as small circular structures in this view.
Sagittal image of left lobe of liver, and aorta
The initial scan should be made slightly to the left of the midline to record the left lobe of the liver and the abdominal aorta. The left hepatic and portal veins may be seen as small circular structures in this view.
SMA,CA
Longitudinal Scan Plane Scan Ⅱ As the sonographer scans at midline or slightly to the right of
midline , a larger segment of the left lobe and the inferior vena cava may be seen posteriorly . In this view , it is useful to record the inferior vena cana as it is dilated near the end of inspiration. The left or midline hepatic vein may be imaged as it drain into the inferior vena cava near the level of the diaghram. The area of the portal hepatis is shown anterior to the inferior vena cava as the superior mesenteric vein and splenic vein converge to form the main portal vein. The common bile duct may be seen just anterior to the main portal vein. The head of the pancreas may be seen just inferior to the right lobe of the liver and main portal vein and anterior to the inferior vena cava.
Sagittal image of left lobe of liver, portal vein and inferior vena cava
The left or midline hepatic vein may be imaged as it drain into the inferior vena cava near the level of the diaghram. The area of the portal hepatis is shown anterior to the inferior vena cava
Normal IVC and Budd-Charis Syndrome
Longitudinal Scan Plane
Scan Ⅲ The next image should be made slightly
lateral to this saggital plane to record part of the right portal vein and right lobe of liver . The caudate lobe is often seen in this view.
Sagittal image of gallbladder
Gallbladder and Biliary System Normal size of
gallbladder: 7~9cm in length ; 3~4cm in width; Wall thickness : 2~3mm Normal size of bile ducts
: right /left intrahepatic
duct just to proximal CHD: 2-3mm ; CBD:≥8mm =dilated
Longitudinal Scan Plane Scan , ,Ⅳ Ⅴ Ⅵ The nest three scans should be made in small increment through
the right lobe of the liver . The last scan is usually made to show the right kidney and
lateral segment of the right lobe of the liver. The liver texture is compared with the renal parenchyma. The normal liver parenchyma should have a softer , more homogenerous texture than the dense medulla and hypoechoic renal cortex. Liver size may be measured from the tip of the liver to the diaphragm . Generally this measurement is less than 15 cm, with 15 to 20 cm representing the upper limits of normal. Hepatomegaly is present when the liver measurement exceed 20 cm.
肝右肾纵切声像图Sagittal image of liver /right kidney
The normal liver parenchyma should have a softer , more homogenerous texture than the dense medulla and hypoechoic renal cortex
The last scan is usually made to show the right kidney and lateral segment of the right lobe of the liver. The liver texture is compared with the renal parenchyma. The normal liver parenchyma should have a softer , more homogenerous texture than the dense medulla and hypoechoic renal cortex.
Transverse Scan Plane Multiple transverse scans are made across the upper
abdomen to record specific areas of the liver. The transducer should be angled in a steep cephalic direction to be as parallel to the diaphragm as possible.
The patient should be in full inspiration to maintain detail of the liver parenchyma , vascular architecture, and ductal structures
Transverse Scan Plane Scan Ⅰ Scan Ⅱ Scan Ⅲ Scan Ⅳ Scan ,Ⅴ Ⅵ
Transverse Scan Plane Scan Ⅰ The initial transverse scan is made with the
transducer under the costal margin at a steep angel perpenducular to the diaphragm.
The patient should be in deep inspiration to adequately record the dome of the liver. The sonographer should identify the inferior vena cava and three hepatic veins as they drain into the cava. This pattern has sometimes been referred to as “reindeer sign” or “Playboy bunny” sign.
The sonographer should identify the inferior vena cava and three hepatic veins as they drain into the cava. This pattern has sometimes been referred to as “reindeer sign” or “Playboy bunny” sign.
Transverse Scan Plane Scan Ⅱ The transducer is then directed slightly inferior to the
point described in scan to record the left portal Ⅰvein as it flows into the left lobe of the liver.
Transverse Scan Plane Scan Ⅲ The porta hepatis is seen as a tubular structure
within the central part of the liver. Sometimes the left or right portal vein can be identified . The caudate lobe may be seen just superior to the porta hepatis ; thus , depending on the angel , either the caudate lobe is shown anterior to the inferior vena cava, or as the transducer moves inferior ,the porta hepatis is identified anterior to the inferior vena cava.
Transverse Scan Plane Scan Ⅳ The fourth scan should show the right portal
vein as it divides into the anterior and posterior segments of the right lobe of the liver. The gallbladder may be seen in this scan as an anechoic structure medial to the right lobe and anterior to the right kidney.
肋缘下斜切声像图
The fourth scan should show the right portal vein as it divides into the anterior and posterior segments of the right lobe of the liver. The gallbladder may be seen in this scan as an anechoic structure medial to the right lobe and anterior to the right kidney.
Transverse Scan Plane Scan ,Ⅴ Ⅵ These two scans are made through the lower
segment of the right lobe of the liver . The right kidney is the posterior border. Usually intrahepatic vascular structures are not identified in these views
肝脏右叶最大斜径 测量标准切面:以肝右静脉和肝中静脉汇入下腔静脉的右肋缘下肝脏斜切面为标准测量切面 测量位置:测量点分别置于肝右叶前、后缘之肝包膜处,测量其最大 垂直距离 正常参考值: 12 - 14cm
Lateral Decubitus Scan Plane Left Anterior Oblique The left anterior oblique scan requires that the patient
roll slightly to the left . A 45-degree sponge or pillow may be placed under the right hip to support the patient.
This view allows better visualization of the lower right lobe of the liver, usually diaplacing the duodenum and transverse colon to the midline of the abdomen , out of the field of view. Transverse , oblique, or longitudinal scans may be made in this position.
Lateral Decubitus Scan Plane
Lateral Decubitus Scan Plane
Measurement of main portal vein 1.0 ~ 1.5cm
“Fliying Bird Sign”
Common bile duct
Diameter <0.8cm
Sonographic Evaluation of The Liver
Adequate scanning technique demands that each patient be examined with the following assessment
The size of the liver in the longitudinal plane The attenuation of the liver parenchyma Liver texture The presence of hepatic vascular structures,
ligaments ,and fissures
Pathology of the Live
Evaluation of the liver parenchyma includes the assessment of its size , configuration, homogeneity , and contour.
The Normal attenuation of the liver parenchyma Normal: Liver texture=homogeneous Assessment of its size , configuration, homogeneity , and contour
Abnormal Liver texture-inhomogeneous : The diffuse hepatic lesions Assessment of its size , configuration, homogeneity ,
and contour.
Assessment of its size , configuration,
homogeneity , and contour
Assessment of its size , configuration, homogeneity , and contour
The size of the liverThe changes of the size and shape
Assessment of its size , configuration, homogeneity , and contour
The changes of the hepatic contour
Assessment of its size , configuration, homogeneity , and contour The focal hepatic lesions
hyperechoic , hypoechoic, anechioc , mixed pattern
Assessment of its size , configuration, homogeneity , and contour The vascular disorganization
Assessment of its size , configuration, homogeneity , and contour Dilated intrahepatic bile ducts
Pathology of the LiveSubsequent sections discuss the pathology of liver
disease in the following categories : Diffuse disease Hepatic Tumors Benign disease Malignant disease Abscess formation Functional disease Tranplantation Vascular problems
Pathology of the Live
Diffuse Fatty Infiltration US increased sound attenuation =poor definition of
posterior aspect of liver ( bright liver) fine/coarsened hyperechogenicity (compared with kidney) impaired visualization of borders of hepatic
vessels Attenuation of sound beam
increased sound attenuation =poor definition of posterior aspect of liver ( bright liver)
Fatty Infiltration
impaired visualization of borders of hepatic vessels
Diffuse Fatty Infiltration—CT
Areas of lower attenuation than normal portal vein/IVC density
Reversal of liver spleen density relationship (liver density is normal 6-12HU greater than spleen)
Hyperdense intrahepatic vessels
Diffuse Fatty Infiltration—CT
Areas of lower attenuation than normal portal vein/IVC density
Hyperdense intrahepatic vessels
Reversal of liver spleen density relationship (liver density is normal 6-12HU greater than spleen)
Hepatic Cirrhosis
Surface irregularity Increased echogenicity Heterogeneous coarse echotexture Ascites
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Regenerating nodules
Regenerating nodules
AscitesPortal hypertension
Heterogeneous coarse echotextureSurface irregularityAscitesDecreased definition of walls of portal venules
Heterogeneous coarse echotextureSurface irregularityAscitesDecreased definition of walls of portal venules
Ascites, even in very small qualities, can cause a thick gallbladder wall
Ascites
Surface irregularity
Pathology of the Live
Focal Hepatic Disease Cystic Lesions Hepatic cysts may be congenital or
acquired ,solitary , or multiple. Patients are often asymptomatic, except patients who have large cysts , which can compress the hepatic vasculature or ductal system.
Pathology of the Live
Focal Hepatic Disease Cystic Lesions within the liver include the following : Simple or congenital hepatic cysts Traumatic cysts Parasitic cysts Inflammatory cysts Polycystic disease Pseudo-cysts
Ultrasound Findings of Cystic Lesions
On ultrasound examination the cyst walls are thin , with well-defined borders, and anechoic with distal posterior enhancement.
Sonographic FeaturesOf hepatic cyst: No internal echoes Smooth borders Regular /irregular outline Acoustic enhancement Septum may be seen
Hepatic cyst 1
Hepatic cyst 2
Hepatic cyst Second most common benign hepatic
lesion(22%) Acquired hepatic cyst: second to trauma,
inflammation , parasitic infection Associated tuberous necrosis polycystic kidney disease(25-33%have liver cyst); polycystic liver disease(50%have polycystic
kidney disease)
Polycystic liver disease
Hepatic abscess
Types pyogenic(88%) amebic(10%) fungal(2%)
Hepatic abscess-
Hypoechoic round lesion with well-defined –mildly
echogenic rim Distal acoustic enhancement Coarse clumpy debris /low-level echoes/fluid-debris level Intensely echogenic reflections with reverberations
Hypoechoic round lesion with well-defined –mildly
echogenic rim Distal acoustic enhancement Coarse clumpy debris /low-level echoes/fluid-debris level Intensely echogenic reflections with reverberations
Hepatic abscess-CT
Pathology of the Live
Hepatic Tumors Benign disease Malignant disease
Pathology of Liver
Primary Hepatic Carcinoma (PHC) Metastases to liver Hepatic hemangioma
Etiology: cirrhosis, hepatitis B and C infection and carcinogens
Solitary, multifocal or more rarely diffusely infiltrating
Hepatocellular Carcinoma(HCC) Primary Hepatic Carcinoma (PHC)
Growth pattern: solitary massive (27-59%):
bulk in one (most often right) lobe with satellite nodules
multifocal small nodular (15-25%): small foci of usually <2 cm (up to 5 cm) in both
hepatic lobes diffuse microscopic infiltrating form (10-26%):
tiny indistinct nodules closely resembling cirrhosis Vascular supply: hepatic artery, portal vein in 6%
Hepatocellular Carcinoma(HCC)
Metastases to: lung (most common = 8%), adrenal, lymph nodes, bone
portal vein invasion (25-48%) arterioportal shunting (4-63%) invasion of hepatic vein (16%)/IVC (= Budd-Chiari syndrome) occasionally invasion of bile ducts calcifications in ordinary HCC (2-25%); however, common in fibrolamellar (30-40%) and sclerosing HCC hepatomegaly and ascites tumor fatty metamorphosis (2-17%)
HCC
Sonographic Features of HCC
86-99% sensitivity; 90-93% specificity; 65-94% accuracy; Hyperechoic HCC(13%)due to fatty metamophosis
or marked dilatation of sinusoids Hypoechoic HCC(26%)due to solid tumor HCC of mixed echogenicity (61%)due to
nonliquefactive tumor necrosis
HCC of mixed echogenicity (61%)due to nonliquefactive tumor necrosis
Hypoechoic HCC(26%)due to solid tumor
Hyperechoic HCC(13%)due to fatty metamophosis or marked dilatation of sinusoids
Vascular supply: hepatic artery, portal vein in 6%
portal vein invasion (25-48%)
HCC- CT sensitivity of 63% in cirrhosis, 80% without cirrhosis) hypodense mass/rarely isodense/hyperdense in fatty
liver: dominant mass with satellite nodules mosaic pattern = multiple nodular areas with differing
attenuation on CECT (up to 63%) diffusely infiltrating neoplasm
encapsulated HCC = circular zone of radiolucency surrounding the mass (12-67%) False-positive: confluent fibrosis, regenerative nodule
Biphasic CECT: enhancement during hepatic arterial phase (80%) decreased attenuation during portal venous phase
with inhomogeneous areas of contrast accumulation isodensity on delayed scans (10%) thin contrast-enhancing capsule (50%) due to rapid
washout wedge-shaped areas of decreased attenuation
(segmental/lobar perfusion defects due portal vein occlusion by tumor thrombus)
Biphasic CECT:
enhancement during hepatic arterial phase (80%)
Biphasic CECT:
decreased attenuation during portal venous phase with inhomogeneous areas of contrast accumulation
Biphasic CECT:
isodensity on delayed scans (10%)
HCC- CT : Unenhanced CT and Contrast enhanced CT
Unenhanced CT :hypodense mass/rarely isodense/hyperdense in fatty liver
Biphasic CECT:
enhancement during hepatic arterial phase (80%)
Biphasic CECT:
decreased attenuation during portal venous phase with inhomogeneous areas of contrast accumulation
Biphasic CECT:
isodensity on delayed scans (10%)
After 1st TACE
Therapy of HCC: Interventional radiology - transcatheter arterial chemoembolization(TACE)
After 2nd TACE
Therapy of HCC: Interventional radiology - transcatheter arterial chemoembolization(TACE)
Metastases to liver Organ of origin: colon(42%); stomach(23%); pancreas(21%); breast(14%); lung(13%) Number : multiple(98%); solitary(2%) “Bullseye”: An echogenic center with a surrounding echopenic area Echopenic : Less echogenic than the surrounding liver Echogenic More echogenic than the surrounding liver
所指为肝内多发低回声结节,呈
“Bullseye” : An echogenic center with a surrounding echopenic area“牛眼征”
“Bullseye” : An echogenic center with a surrounding echopenic area
Metastases to liver
Metastases to liver
(bulls eye sign)
Hepatic hemangioma / Cavernous hemangioma of liver CH of the liver is composed of blood-filled
fairly large or tortuous vascular cavities divided by thin, often incomplete, fibrous septa and lined by a single layer of flat endothelium
The blood flow in the vascular spaces is slow and nondirectional which is predisposed to thrombosis
Ultrasonic features of Hepatic hemangioma
Uniformly hyperechoic mass(60-70%) Inhomogeneous hypoechoic mass (up to 40%) Homogeneous(58-73%) /heterogeneous May show acoustic enhancement(37-77%) Unchanged in size/appearance(82)on 1-to-6 year
follow-up No Doppler signals/signals with peak velocity of
<50cm/cm
。
Uniformly hyperechoic mass(60-70%)
Cavernous hemangioma of liver
Markedly hyperechoic lesion without dorsal acoustic shadowing.
A slightly hypoechoic lesion with sharply delineated borders, oval shape and no dorsal acoustic enhancement.
hypoechoic mass (up to 40%)
多发肝海绵状血管瘤
谢 谢