IMAGES Chapter 26 - Liver, Biliary Tree and Gallbladder Flashcards
DIAGNOSIS ? [FIGURE 26.14]
PORTAL VENOUS GAS
A. Noncontrast CT image reveals gas in the portal vein as air-density tubular structures extending to the periphery of the liver. In this case, portal venous gas was associated with the infarction of the small bowel.
DIAGNOSIS ? [FIIGURE 26.24]
HEPATIC CYSTS - CT
Multiple hepatic cysts are an incidental finding on this postcontrast CT in a 78-year-old patient. The cysts are unilocular, well defi ned, and without solid components.
DIAGNOSIS ? [FIGURE 26.5]
FATTY INFILTRATION WITH FOCAL SPARING
A. An US image demonstrates a focal hypoechoic area of normal liver (arrow) near the portal vein (p) in a liver that is heterogeneously but diffusely increased in echogenicity due to fatty deposition.
B. A CT image obtained without contrast enhancement demonstrates the spared area of the normal liver (arrow) to be of high density compared to the lower density of the fatty
liver. Note the characteristic “flip-flop” appearance of fat density between CT and US.
DIAGNOSIS ? [FIGURE 26.16]
CAVERNOUS HEMANGIOMA
Images from a contrast-enhanced helical CT demonstrate the
discontinuous nodular pattern of enhancement from the periphery of the lesion characteristic of cavernous
hemangioma.
DIAGNOSIS? APPEARANCE ? MODALITY USED ?
[FIGURE 26.17]
- *HEPATOCELLULAR CARCINOMA
- SOLITARY MASSIVE APPEARANCE - CT**
Three-phase helical CT demonstrates the enhancement
pattern of a large solitary hepatocellular carcinoma in the right
lobe. The tumor is slightly hyperdense to parenchyma on the unenhanced scan (A) and shows intense enhancement on the early arterial phase (B) scan with contrast washout on delayed portal venous phase (C) scan. The central low density is due to necrosis. Note the satellite lesions (arrowheads).
DIAGNOSIS ? [FIGURE 26.32]
BILIARY DILATION - CT
Scan demonstrates dilated intrahepatic ducts (black arrowheads) easily differentiated from portal
veins (red arrowhead) and hepatic veins by contrast enhancement of the blood vessels. Note that the diameter of the bile ducts clearly exceeds 40% of the diameter of the adjacent portal vein.
Biliary dilatation in this patient was caused by adenocarcinoma of the head of the pancreas.
DIAGNOSIS ? [FIGURE 26.27]
BILIARY CYSTADENOMA - MR
Coronal T2WI shows a large cystic mass (large arrow) with prominent septations. No mural nodules or papillary projections were identified. Surgical removal confi rmed a benign biliary cystadenoma.
Because of the potential of malignant
transformation and the difficulty in differentiating benign from
malignant lesions by imaging, surgical removal is routinely recommended.
Coronal T2WI nicely demonstrates the distal common bile
duct (arrowhead) and pancreatic duct (small arrow) near the ampulla.
DIAGNOSIS ? [FIGURE 26.25]
POLYCYSTIC LIVER DISEASE - MR
Axial T2WI shows near complete replacement of the liver parenchyma by innumerable cysts of varying size. This patient has a variant of autosomal dominant polycystic disease.
IDENTIFY THE RADIOLOGIC FINDING.
[FIGURE 26.14]
PNEUMOBILIA
B. Gas in the biliary tree is central and does not extend into the peripheral 2 cm of the liver. Because gas rises to the highest accessible location, pneumobilia is usually seen on CT only in the anterior portions of the liver
DIAGNOSIS ? [FIGURE 26.6]
MULTIFOCAL FATTY LIVER
Postcontrast CT demonstrates multiple geographic areas of decreased attenuation extending to liver capsule representing multifocal fat deposition. The patient also has ascites.
DIAGNOSIS ? [FIGURE 26.45]
EMPHYSEMATOUS CHOLECYSTITIS - CT
Scan of a patient with diabetes, fever, and sepsis reveals air in the lumen (arrowhead) and wall (fat arrow) of the gallbladder (GB) indicative of emphysematous cholecystitis.
Numerous tiny layering gallstones (skinny arrow)
are present within the gallbladder.
IDENTIFY THE RADIOLOGIC FINDING.
[FIGURE 26.46]
PORCELAIN GALLBLADDER
Conventional radiograph of the right upper quadrant of the abdomen shows calcifi cation (arrows) in the wall of the gallbladder (GB). This finding is indicative of chronic
obstruction of the cystic duct with chronic cholecystitis.
The risk of gallbladder carcinoma is increased.
DIAGNOSIS ? [FIGURE 26.26]
BILIARY HAMARTOMAS - MR
Coronal plane T2WI shows innumerable tiny cysts scattered throughout the liver parenchyma. These von Meyenburg complexes are small benign neoplasms without clinical signifi cance or malignant potential.
DIAGNOSIS ? [FIGURE 26.22]
PRIMARY HEPATIC LYMPHOMA
A poorly marginated hypodense, minimally enhancing mass (arrow) extends from the porta hepatitis occluding blood vessels and causing biliary dilatation (arrowhead).
Initial diagnosis was cholangiocarcinoma, but biopsy
showed B-cell lymphoma.
DIAGNOSIS ? [FIGURE 26.28]
PYOGENIC ABSCESS - CT
Postcontrast scan shows multiple low-density areas separated by enhancing septa and representing abscess locules. Air bubbles (arrowhead) are evident within the lesion.
DIAGNOSIS ? [FIGURE 26.20]
HEPATIC ADENOMA - MR
Postgadolinium, T1-weighted, fat-suppressed MR image shows intense homogeneous enhancement during the arterial phase of a biopsy-proven hepatic adenoma (arrow).
The MR appearance is indistinguishable from a
small hepatocellular carcinoma.
DIAGNOSIS ? [FIGURE 26.30]
TOO SMALL TO CHARACTERIZE
MDCT shows multiple tiny low-attenuation lesions (arrowheads) that are too small to definitively characterize. Even in patients with known malignancy, these
lesions are usually benign. However, on follow-up in some patients, they will prove to be early metastatic lesions. They are usually identifi ed on high-quality postcontrast CT only. Image-guided biopsy can usually not be performed because the lesions cannot be identified on US or noncontrast CT.
DIAGNOSIS ? [FIGURE 26.13]
HEMOCHROMATOSIS - RETICULOENDOTHELIAL PATTERN
T2-weighted MR images demonstrate markedly low-signal intensity in the liver, spleen, and bone marrow of the vertebral body. The low signal is caused by iron deposition in the reticuloendothelial system in this case of secondary hemochromatosis caused by multiple blood transfusions.
DIAGNOSIS ? [FIGURE 26.43]
CHOLELITHIASIS
A. CT reveals numerous subtle low-attenuation floating gallstones (arrow) within the gallbladder. The stones are
close to isodense with bile. Stones may be overlooked on CT because they are isodense with bile or because of small size.
B. Coronal plane T2-weighted MR shows a large gallstone (arrow) as a filling defect within high-signal bile.
DIAGNOSIS ? [FIGURE 26.41]
- *CHOLANGIOCARCINOMA - HILAR
- PERCUTANEOUS TRANSHEPATIC CHOLANGIOGRAM (PTC)**
Percutaneous transhepatic cholangiogram demonstrates abrupt focal narrowing (fat arrow) of the proximal common bile duct (cd) near the bifurcation. The intrahepatic bile ducts are diffusely and markedly dilated. The common bile duct shows normal narrowing at the ampulla of Vater (arrowhead).
The PTC needle (skinny arrow) is evident. D, duodenum.
IDENTIFY THE RADIOLOGIC FINDING.
[FIGURE 26.2]
PERFUSION DEFECT
A common perfusion defect (arrow) is seen in segment IVb adjacent to the fi ssure of the ligamentum teres (arrowhead). This perfusion defect is related to “third inflow” from paraumbilical systemic veins. Focal fatty infiltration is commonly seen in this location. Importantly, this normal variant must not be mistaken for a neoplasm.
NORMAL or ABNORMAL? [FIGURE 26.31]
NORMAL MR CHOLANGIOPANCREATOGRAPHY (MRCP)
Image from an MRCP in a patient who has had a cholecystectomy shows the cystic duct remnant (red arrowhead), common bile duct (long red arrow), common hepatic duct (fat red arrow), pancreatic duct (small red arrow), left hepatic duct (small blue arrow), anterior branch of the right hepatic duct (small yellow arrow), and posterior branch of the right hepatic (small green arrow). Relatively static fluid
in the stomach, duodenum, and jejunum is high signal on this
maximum-intensity projection T2WI with prolonged acquisition time.
DIAGNOSIS ? [FIGURE 26.42]
CHOLEDOCHODUODENAL FISTULA - UPPER GI (UGI)
A UGI series demonstrates filling of the bile ducts due to a penetrating duodenal ulcer that created a fistula (arrow) between the duodenum (d) and the common hepatic duct (arrowhead).
DIAGNOSIS ? TYPE ?
[FIGURE 26.39]
CHOLEDOCHAL CYST TYPE I
(ERCP)
Radiograph from ERCP demonstrates saccular dilation (arrow) of the common bile duct typical of the most common form of choledochal cyst, type I.
DIAGNOSIS ? [FIGURE 26.21]
FIBROLAMELLAR HEPATOCELLULAR CARCINOMA - CT
Delayed postcontrast image demonstrates a large tumor extending caudally from the right lobe of the liver.
A characteristic enhancing stellate central scar (arrow) is present.
DIAGNOSIS ? [FIGURE 26.15]
METASTASES
A. Hypovascular metastases from adenocarcinoma of the colon appear as numerous low-attenuation nodules of
varying size on this portal venous phase postcontrast CT.
Note how the metastatic disease causes nodularity of the liver contour and the resemblance to regenerative nodules in cirrhosis seen in Figure 26.8.
B. Hypervascular metastasis (arrow) from renal cell carcinoma shows bright enhancement on this arterial phase postcontrast CT image.
DIAGNOSIS ? [FIGURE 26.44]
ACUTE CHOLECYSTITIS - CT
Postcontrast image demonstrates fluid (arrow) around the enhancing mucosa (arrowhead) of the gallbladder and a small high-attenuation gallstone (skinny arrow) within the gallbladder lumen in a patient with acute, severe right upper-quadrant pain.
Surgery confirmed acute cholecystitis.
DIAGNOSIS ? [FIGURE 26.47]
GALLBLADDER CARCINOMA
Postcontrast CT shows an enhancing soft tissue mass (fat arrow) within the lumen of the gallbladder. Direct invasion of tumor into the adjacent liver parenchyma is evident (skinny arrow).
DIAGNOSIS ? [FIGURE 26.37]
CAROLI DISEASE - MR
Sagittal T2WI shows numerous small high-signal cystic lesions scattered throughout the liver.
Careful inspection on this and other images shows connection
(arrows) between the cystic lesions and the biliary tree.
DIAGNOSIS ? [FIGURE 26.36]
ACUTE BACTERIAL CHOLANGTIS - CT
Postcontrast image demonstrates irregular collections of air expanding bile ducts surrounded by low-attenuation edema. Pyogenic cholangitis resulted in necrosis of the bile ducts.
DIAGNOSIS ? LOCATION ?
[FIGURE 26.40]
CHOLANGIOCARCINOMA - PERIPHERAL - MR
Postcontrast, T1-weighted, fat-suppressed MR shows a heterogeneous mass (between arrows) within the liver.
Biopsy confirmed cholangiocarcinoma.
No dilated bile ducts were evident. The mass was centrally
fibrotic.
RADIOLOGIC FINDING? DIAGNOSIS? APPEARANCE?
[FIGURE 26.11]
- *PORTAL VEIN THROMBOSIS
- HEPATOCELLULAR CARCINOMA
- MULTINODULAR APPEARANCE**
Contrast-enhanced CT demonstrates multiple hypodense nodules representing hepatocellular carcinoma that is replacing the right hepatic lobe. The portal vein (pv) is
invaded by tumor (arrow), seen as a filling defect with the vein.
The hepatic artery (arrowhead) is enlarged because of cirrhosis and portal hypertension.
DIAGNOSIS? APPEARANCE? MODALITY USED?
- *HEPATOCELLULAR CARCINOMA
- SOLITARY MASSIVE APPEARANCE - MR**
T1-weighted MR image shows the typical mosaic pattern of large hepatocellular carcinomas.
Note the heterogeneous enhancement most pronounced in the periphery of the tumor.
DIAGNOSIS ? [FIGURE 26.3]
DIFFUSE FATTY LIVER - CT
CT reveals the density of the enhanced liver parenchyma (L) to be significantly less than the density of the enhanced splenic parenchyma (S). Portal (p) and hepatic (h) veins run their normal courses without displacement or distortion. V, inferior vena cava; Ao, aorta.
DIAGNOSIS ? [FIGURE 26.33]
OBSTRUCTING STONE IN COMMON BILE DUCT
- CT
Serial CT images obtained from a jaundiced patient demonstrate dilatation of the common bile duct (red arrows) due to an obstructing high density gallstone (green arrow) impacted in the distal common bile duct. This stone is high attenuation, indicating calcium content.
On CT, stones vary from fat density to calcium density.
The bile duct above the calcific stone is low attenuation due to its bile content. Note the course of the common bile duct in relationship to the head of the pancreas (p) and descending duodenum (d).
DIAGNOSIS ? [FIGURE26.9]
SMALL HEPATOCELLULAR CARCINOMA
MR images show findings characteristic of a small HCC
(arrows).
A. Axial T2WI shows a hyperintense, poorly marginated, 1.8 cm nodule in the left hepatic lobe. Hyperintensity on T2WI is rare for dysplastic or regenerative nodules but is highly characteristic of HCC.
B. T1-weighted in-phase image shows the low-signal
ill-defined nodule.
C. T1-weighted out-of-phase image shows distinct loss of signal indicating the presence of intracellular fat, a finding seen in HCC and hepatic adenomas.
D. Postcontrast arterial phase image shows a ring-like peripheral enhancement of the lesion. Arterial phase enhancement is a key finding in the imaging diagnosis of HCC.
Prominent early enhancement of a tangle of portosystemic collateral vessels (curved arrow) is also present in this patient with advanced cirrhosis and in hepatic arterioportal shunting. E. Portal venous phase postcontrast image shows early washout of contrast from the nodule, which has become slightly hypointense to the enhanced hepatic parenchyma. This is another key finding of HCC on postcontrast images. Also noted is the enhancement of paraumbilical collateral vessels (arrowhead), a specific sign of advanced portal hypertension.
Using the American Association for the Study of Liver Diseases standard HCC was diagnosed on the basis of its imaging characteristics, and the nodule was successfully treated with transcatheter arterial chemoembolization.
IDENTIFY THE RADIOLOGIC FINDING.
[FIGURE 26.10]
CONFLUENT FIBROSIS
Portal venous phase postcontrast CT image shows a mass-like enhancing lesion (straight arrows) extending from the portal hepatis to a prominent area of parenchymal
atrophy with overlying retraction (curved arrow) of the liver capsule.
This is an example of the minority of cases of confluent fibrosis that show contrast enhancement. Most cases (80%) of confluent fibrosis are hypoattenuating on noncontrast images and show no enhancement.
DIAGNOSIS ? [FIGURE 26.34]
CHOLEDOCHOLITHIASIS - MR
MR cholangiopancreatography image demonstrates two stones ( arrow ) seen as filling defects in the distal common bile duct. Ascites (a) outlines the liver. A normal gallbladder (gb) is evident.
CLASSIFICATION OF CONGENITAL BILIARY CYSTS
[FIGURE 26.38]
Type I choledochal cysts (80% to 90% of cases) are focal, saccular, or fusiform dilatations of the common bile duct.
Type II cysts (2%) are true diverticula of the common bile duct.
Type III cysts (1.4% to 5%) are termed choledochoceles and are dilatations of the terminal intraduodenal portion of the common bile duct.
Type IV cysts (19%) refers to multiple intrahepatic and extrahepatic bile duct cysts.
Caroli disease is classified Type V.
DIAGNOSIS ?
[FIGURE 26.4]
DIFFUSE FATTY LIVER - MR
A. In-phase gradient recall MR.
B. Out-of-phase gradient recall MR. The out-of-phase image shows distinct loss of signal (darkening) of the entire liver parenchyma compared to the in-phase image. The out-of-phase MR image is easily recognized by the black line surrounding the soft tissue structures at the interface with abdominal fat.
DIAGNOSIS ? [FIGURE 26.23]
- *HEREDITARY HEMORRHAGIC TELANGIECTASIA
- CT**
Arterial phase image reveals a nodular contour to the liver (pseudocirrhosis), multiple enhancing confluent vascular masses, and tortuous enlarged hepatic arteries.
DIAGNOSIS ? [FIGURE 26.19]
FOCAL NODULAR HYPERPLASIA - MR
The lesion (arrows), consisting of liver elements, is isointense with the hepatic parenchyma on T1WI (A) and gradient recall two-dimensional timeof- flight image ( B ). The lesion is clearly depicted by intense enhancement during the arterial phase (C) postgadolinium administration. This lesion lacks a central scar.
DIAGNOSIS ? [FIGURE 26.35]
- *PRIMARY SCLEROSING CHOLANGITIS
- ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY (ERCP)**
Radiograph from an ERCP demonstrates the focal irregular strictures and focal mild dilatation of intrahepatic bile ducts typical of early-stage sclerosing cholangitis.
IDENTIFY THE RADIOLOGIC FINDING.
[FIGURE 26.8]
REGENERATIVE NODULES IN CIRRHOSIS
CT image filmed at a narrow window shows innumerable low-density small nodules evident throughout the liver in this patient with cirrhosis. Needle biopsy confirmed benign regenerative nodules.
DIAGNOSIS ? [FIGURE 26.12]
BUDD-CHIARI SYNDROME
Early-phase CT images show the markedly heterogeneous liver with prominent central and weak peripheral enhancement that is characteristic of Budd–Chiari syndrome.
Tumor invasion from a right adrenal carcinoma is seen as tumor thrombus (arrow) within the inferior vena cava.
COUINAUD LIVER SEGMENTS
A. Superior portion of the liver.
B. Inferior portion of the liver.
[FIGURE 26.1]
CT scans illustrate the Couinaud classification of the numbering of liver segments.
The longitudinal plane of the right hepatic vein divides VIII from VII in the superior portion of the liver and V from VI in the inferior portion of the liver.
The longitudinal plane of the middle hepatic vein through the gallbladder fossa separates IVa from VIII in the superior liver and IVb from V in the inferior liver.
The longitudinal plane of the left hepatic vein and fissure of the ligamentum teres separates IVa from II in the superior liver and IVb from III in the inferior liver.
The axial plane of the left portal vein separates IVa superiorly from IVb inferiorly and II superiorly from III inferiorly in the left
lobe.
The axial plane of the right portal vein separates VIII and VII superiorly from V and VI inferiorly in the right lobe.
The caudate lobe (segment I) extends between the fissure of the ligamentum venosum anteriorly and the inferior vena cava posteriorly.
DIAGNOSIS ? [FIGURE 26.7]
CIRRHOSIS and PORTAL HYPERTENSION
A CT scan reveals atrophy of the liver with diffuse nodularity of its surface (fat arrow) and splenomegaly (S). Numerous enhancing portosystemic collateral vessels are evident including gastrohepatic (skinny arrow) and gastric
varices. A dilated periumbilical vein (arrowhead) is seen coursing out of the fissure of the ligamentum teres into the falciform ligament.
DIAGNOSIS [FIGURE 26.29]
AMEBIC ABSCESS - CT
Postcontrast CT image reveals a thick-walled fl uid collection in the right hepatic lobe. Differentiation of amebic from pyogenic liver abscess is made by history, serology, or image-guided aspiration.
