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US of Liver Transplants: Normal and Abnormal¹

¹ From the Department of Diagnostic Imaging, Toronto General Hospital, University of Toronto, 200 Elizabeth St, Toronto, Ontario, Canada M5G 2C4. Recipient of a Magna Cum Laude award for an education exhibit at the 2000 RSNA scientific assembly. Received February 10, 2003; revision requested March 17 and received May 28; accepted May 30. Address correspondence to S.R.W. (e-mail: stephanie.wilson@uhn.on.ca).

View larger version (124K): [in a new window]   Figure 1a.  Normal gray-scale US appearance. (a) Subcostal oblique US image obtained through the hepatic confluence shows the middle and left hepatic veins. The hepatic parenchyma appears homogeneous. (b) Right paramedian sagittal US image obtained through the liver and inferior vena cava (IVC) shows the staples (arrows) of the end-to-end IVC anastomosis, the middle hepatic vein, and normal hepatic parenchyma. (c, d) Intercostal gray-scale US (c) and color Doppler (d) images obtained through the anterior axillary line show the porta hepatis along the long axis. On the gray-scale image (c), the portal vein is easily identified. Often, the hepatic artery (arrows) is identified only with color Doppler imaging.

View larger version (134K): [in a new window]   Figure 1b.  Normal gray-scale US appearance. (a) Subcostal oblique US image obtained through the hepatic confluence shows the middle and left hepatic veins. The hepatic parenchyma appears homogeneous. (b) Right paramedian sagittal US image obtained through the liver and inferior vena cava (IVC) shows the staples (arrows) of the end-to-end IVC anastomosis, the middle hepatic vein, and normal hepatic parenchyma. (c, d) Intercostal gray-scale US (c) and color Doppler (d) images obtained through the anterior axillary line show the porta hepatis along the long axis. On the gray-scale image (c), the portal vein is easily identified. Often, the hepatic artery (arrows) is identified only with color Doppler imaging.

View larger version (133K): [in a new window]   Figure 1c.  Normal gray-scale US appearance. (a) Subcostal oblique US image obtained through the hepatic confluence shows the middle and left hepatic veins. The hepatic parenchyma appears homogeneous. (b) Right paramedian sagittal US image obtained through the liver and inferior vena cava (IVC) shows the staples (arrows) of the end-to-end IVC anastomosis, the middle hepatic vein, and normal hepatic parenchyma. (c, d) Intercostal gray-scale US (c) and color Doppler (d) images obtained through the anterior axillary line show the porta hepatis along the long axis. On the gray-scale image (c), the portal vein is easily identified. Often, the hepatic artery (arrows) is identified only with color Doppler imaging.

View larger version (141K): [in a new window]   Figure 1d.  Normal gray-scale US appearance. (a) Subcostal oblique US image obtained through the hepatic confluence shows the middle and left hepatic veins. The hepatic parenchyma appears homogeneous. (b) Right paramedian sagittal US image obtained through the liver and inferior vena cava (IVC) shows the staples (arrows) of the end-to-end IVC anastomosis, the middle hepatic vein, and normal hepatic parenchyma. (c, d) Intercostal gray-scale US (c) and color Doppler (d) images obtained through the anterior axillary line show the porta hepatis along the long axis. On the gray-scale image (c), the portal vein is easily identified. Often, the hepatic artery (arrows) is identified only with color Doppler imaging.

View larger version (42K): [in a new window]   Figure 2a.  Normal Doppler US appearance. (a) Subcostal oblique color and spectral Doppler image of the right hepatic vein shows normal venous phasicity due to respiration. (b) Intercostal color and spectral Doppler image of the main portal vein shows a normal continuous waveform with mild velocity variations due to respiration. (c) Intercostal color and spectral Doppler image of a normal hepatic artery at the porta hepatis shows a rapid systolic upstroke with continuous low-velocity diastolic flow.

View larger version (36K): [in a new window]   Figure 2b.  Normal Doppler US appearance. (a) Subcostal oblique color and spectral Doppler image of the right hepatic vein shows normal venous phasicity due to respiration. (b) Intercostal color and spectral Doppler image of the main portal vein shows a normal continuous waveform with mild velocity variations due to respiration. (c) Intercostal color and spectral Doppler image of a normal hepatic artery at the porta hepatis shows a rapid systolic upstroke with continuous low-velocity diastolic flow.

View larger version (35K): [in a new window]   Figure 2c.  Normal Doppler US appearance. (a) Subcostal oblique color and spectral Doppler image of the right hepatic vein shows normal venous phasicity due to respiration. (b) Intercostal color and spectral Doppler image of the main portal vein shows a normal continuous waveform with mild velocity variations due to respiration. (c) Intercostal color and spectral Doppler image of a normal hepatic artery at the porta hepatis shows a rapid systolic upstroke with continuous low-velocity diastolic flow.

View larger version (140K): [in a new window]   Figure 3a.  Hepatic artery thrombosis in a 45-year-old man with worsening results on liver function tests 8 days after orthotopic liver transplantation for alcoholic cirrhosis. (a) Subcostal oblique color Doppler image of the right hepatic lobe shows avascular cystic spaces within the hepatic parenchyma, which represent infarcts. Flow is demonstrated in the adjacent hepatic veins. No hepatic artery flow was seen at the porta hepatis or anywhere in the liver on color or spectral Doppler images. (b) Corresponding contrast material-enhanced CT image shows the infarcts.

View larger version (149K): [in a new window]   Figure 3b.  Hepatic artery thrombosis in a 45-year-old man with worsening results on liver function tests 8 days after orthotopic liver transplantation for alcoholic cirrhosis. (a) Subcostal oblique color Doppler image of the right hepatic lobe shows avascular cystic spaces within the hepatic parenchyma, which represent infarcts. Flow is demonstrated in the adjacent hepatic veins. No hepatic artery flow was seen at the porta hepatis or anywhere in the liver on color or spectral Doppler images. (b) Corresponding contrast material-enhanced CT image shows the infarcts.

View larger version (68K): [in a new window]   Figure 4a.  Hepatic artery stenosis. (a) Color and spectral Doppler image of the main hepatic artery obtained at the anastomosis shows a focal stricture with aliasing in the middle portion of the main hepatic artery (arrow). The Doppler spectrum shows an elevated peak velocity (220 cm/sec) and spectral broadening, findings consistent with turbulence. (b) Superselective digital subtraction angiogram of the main hepatic artery shows the stenosis (arrow). (c) Color and spectral Doppler image of the left intrahepatic artery shows a tardus-parvus waveform with a prolonged acceleration time and decreased resistive index.

View larger version (127K): [in a new window]   Figure 4b.  Hepatic artery stenosis. (a) Color and spectral Doppler image of the main hepatic artery obtained at the anastomosis shows a focal stricture with aliasing in the middle portion of the main hepatic artery (arrow). The Doppler spectrum shows an elevated peak velocity (220 cm/sec) and spectral broadening, findings consistent with turbulence. (b) Superselective digital subtraction angiogram of the main hepatic artery shows the stenosis (arrow). (c) Color and spectral Doppler image of the left intrahepatic artery shows a tardus-parvus waveform with a prolonged acceleration time and decreased resistive index.

View larger version (34K): [in a new window]   Figure 4c.  Hepatic artery stenosis. (a) Color and spectral Doppler image of the main hepatic artery obtained at the anastomosis shows a focal stricture with aliasing in the middle portion of the main hepatic artery (arrow). The Doppler spectrum shows an elevated peak velocity (220 cm/sec) and spectral broadening, findings consistent with turbulence. (b) Superselective digital subtraction angiogram of the main hepatic artery shows the stenosis (arrow). (c) Color and spectral Doppler image of the left intrahepatic artery shows a tardus-parvus waveform with a prolonged acceleration time and decreased resistive index.

View larger version (119K): [in a new window]   Figure 5a.  Hepatic artery pseudoaneurysm in a 58-year-old woman with worsening results on liver function tests 23 days after orthotopic liver transplantation. (a) Gray-scale US image obtained through the porta hepatis shows a focal cystic structure (arrow) alongside the hepatic artery. (b) Color Doppler image shows that the cystic structure (arrow) is vascular, an appearance consistent with a pseudoaneurysm. (c) Color and spectral Doppler image of the right intrahepatic artery shows a tardus-parvus waveform. (d) Corresponding contrast-enhanced CT image shows the pseudoaneurysm (arrow).

View larger version (131K): [in a new window]   Figure 5b.  Hepatic artery pseudoaneurysm in a 58-year-old woman with worsening results on liver function tests 23 days after orthotopic liver transplantation. (a) Gray-scale US image obtained through the porta hepatis shows a focal cystic structure (arrow) alongside the hepatic artery. (b) Color Doppler image shows that the cystic structure (arrow) is vascular, an appearance consistent with a pseudoaneurysm. (c) Color and spectral Doppler image of the right intrahepatic artery shows a tardus-parvus waveform. (d) Corresponding contrast-enhanced CT image shows the pseudoaneurysm (arrow).

View larger version (51K): [in a new window]   Figure 5c.  Hepatic artery pseudoaneurysm in a 58-year-old woman with worsening results on liver function tests 23 days after orthotopic liver transplantation. (a) Gray-scale US image obtained through the porta hepatis shows a focal cystic structure (arrow) alongside the hepatic artery. (b) Color Doppler image shows that the cystic structure (arrow) is vascular, an appearance consistent with a pseudoaneurysm. (c) Color and spectral Doppler image of the right intrahepatic artery shows a tardus-parvus waveform. (d) Corresponding contrast-enhanced CT image shows the pseudoaneurysm (arrow).

View larger version (160K): [in a new window]   Figure 5d.  Hepatic artery pseudoaneurysm in a 58-year-old woman with worsening results on liver function tests 23 days after orthotopic liver transplantation. (a) Gray-scale US image obtained through the porta hepatis shows a focal cystic structure (arrow) alongside the hepatic artery. (b) Color Doppler image shows that the cystic structure (arrow) is vascular, an appearance consistent with a pseudoaneurysm. (c) Color and spectral Doppler image of the right intrahepatic artery shows a tardus-parvus waveform. (d) Corresponding contrast-enhanced CT image shows the pseudoaneurysm (arrow).

View larger version (144K): [in a new window]   Figure 6a.  Portal vein thrombosis. (a) Subcostal oblique US image shows the bifurcation of the portal vein into right and left branches. Echogenic material is seen in the vessel lumen (arrows). An acute thrombus may be anechoic and identified only at color flow imaging as a flow defect. (b) Subcostal right paramedian US image shows the long axis of the main portal vein (MPV) with a distal thrombus (T).

View larger version (155K): [in a new window]   Figure 6b.  Portal vein thrombosis. (a) Subcostal oblique US image shows the bifurcation of the portal vein into right and left branches. Echogenic material is seen in the vessel lumen (arrows). An acute thrombus may be anechoic and identified only at color flow imaging as a flow defect. (b) Subcostal right paramedian US image shows the long axis of the main portal vein (MPV) with a distal thrombus (T).

View larger version (40K): [in a new window]   Figure 7.  Portal vein stenosis. Gray-scale US (top left), color Doppler (top right), and spectral Doppler (bottom) images of the long axis of the main portal vein show focal color aliasing (second arrow) at the vascular anastomosis. The waveforms show a greater than sixfold velocity in the poststenotic segment (first arrow) relative to the velocity in the prestenotic segment (third arrow), a finding consistent with a significant stenosis.

View larger version (166K): [in a new window]   Figure 8a.  IVC thrombosis. (a) Subcostal oblique US image obtained through the hepatic confluence shows an echogenic thrombus (arrows) that fills the lumen of the right hepatic vein and extends into the IVC. (b) Right paramedian sagittal US image shows the IVC thrombus (arrows).

View larger version (159K): [in a new window]   Figure 8b.  IVC thrombosis. (a) Subcostal oblique US image obtained through the hepatic confluence shows an echogenic thrombus (arrows) that fills the lumen of the right hepatic vein and extends into the IVC. (b) Right paramedian sagittal US image shows the IVC thrombus (arrows).

View larger version (150K): [in a new window]   Figure 9a.  IVC stenosis. (a, b) Right paramedian sagittal gray-scale US (a) and color Doppler (b) images show focal narrowing of the IVC lumen with associated flow turbulence secondary to a stricture at the distal IVC anastomosis (arrows). (c) Spectral Doppler image shows a twofold increase in velocity between the prestenotic (right arrow) and poststenotic (left arrow) IVC segments with turbulent flow in the poststenotic segment. A satisfactory waveform could not be obtained at the stenosis due to artifact from the surgical sutures. Although the stenosis was significant at gray-scale and Doppler US, the patient was asymptomatic and the referring clinicians decided to monitor the stenosis with US follow-up.

View larger version (144K): [in a new window]   Figure 9b.  IVC stenosis. (a, b) Right paramedian sagittal gray-scale US (a) and color Doppler (b) images show focal narrowing of the IVC lumen with associated flow turbulence secondary to a stricture at the distal IVC anastomosis (arrows). (c) Spectral Doppler image shows a twofold increase in velocity between the prestenotic (right arrow) and poststenotic (left arrow) IVC segments with turbulent flow in the poststenotic segment. A satisfactory waveform could not be obtained at the stenosis due to artifact from the surgical sutures. Although the stenosis was significant at gray-scale and Doppler US, the patient was asymptomatic and the referring clinicians decided to monitor the stenosis with US follow-up.

View larger version (95K): [in a new window]   Figure 9c.  IVC stenosis. (a, b) Right paramedian sagittal gray-scale US (a) and color Doppler (b) images show focal narrowing of the IVC lumen with associated flow turbulence secondary to a stricture at the distal IVC anastomosis (arrows). (c) Spectral Doppler image shows a twofold increase in velocity between the prestenotic (right arrow) and poststenotic (left arrow) IVC segments with turbulent flow in the poststenotic segment. A satisfactory waveform could not be obtained at the stenosis due to artifact from the surgical sutures. Although the stenosis was significant at gray-scale and Doppler US, the patient was asymptomatic and the referring clinicians decided to monitor the stenosis with US follow-up.

View larger version (104K): [in a new window]   Figure 10a.  Anastomotic stricture of the bile duct. (a) Right paramedian sagittal US image shows focal narrowing of the middle portion of the common bile duct (arrow) at the surgical anastomosis. (b) Corresponding image from endoscopic retrograde cholangiopancreatography shows the narrowing (arrow). (c) Color and spectral Doppler image of the main hepatic artery shows a normal waveform.

View larger version (127K): [in a new window]   Figure 10b.  Anastomotic stricture of the bile duct. (a) Right paramedian sagittal US image shows focal narrowing of the middle portion of the common bile duct (arrow) at the surgical anastomosis. (b) Corresponding image from endoscopic retrograde cholangiopancreatography shows the narrowing (arrow). (c) Color and spectral Doppler image of the main hepatic artery shows a normal waveform.

View larger version (109K): [in a new window]   Figure 10c.  Anastomotic stricture of the bile duct. (a) Right paramedian sagittal US image shows focal narrowing of the middle portion of the common bile duct (arrow) at the surgical anastomosis. (b) Corresponding image from endoscopic retrograde cholangiopancreatography shows the narrowing (arrow). (c) Color and spectral Doppler image of the main hepatic artery shows a normal waveform.

View larger version (111K): [in a new window]   Figure 11a.  Sloughing of biliary epithelium in a liver transplant recipient with known hepatic artery thrombosis and biliary necrosis. (a) Transverse US image shows distention of the common bile duct by echogenic intraluminal material (arrows), which represents sloughed biliary epithelium. (b) Coronal MR image of the porta hepatis, obtained after administration of a biliary excreting agent, shows a filling defect within the biliary tree confluence (arrows), which represents the sloughed epithelium. (c) Contrast-enhanced CT image shows the "cutoff" of the main hepatic artery (large arrow). Short arrows = surgical sutures of the hepatic artery anastomosis. (d) Color Doppler image obtained at the porta hepatis shows no flow in the hepatic artery. Only portal vein flow is seen (red areas). (Fig 11b courtesy of K. Khalili, MD, Princess Margaret Hospital, Toronto, Ontario, Canada.)

View larger version (156K): [in a new window]   Figure 11b.  Sloughing of biliary epithelium in a liver transplant recipient with known hepatic artery thrombosis and biliary necrosis. (a) Transverse US image shows distention of the common bile duct by echogenic intraluminal material (arrows), which represents sloughed biliary epithelium. (b) Coronal MR image of the porta hepatis, obtained after administration of a biliary excreting agent, shows a filling defect within the biliary tree confluence (arrows), which represents the sloughed epithelium. (c) Contrast-enhanced CT image shows the "cutoff" of the main hepatic artery (large arrow). Short arrows = surgical sutures of the hepatic artery anastomosis. (d) Color Doppler image obtained at the porta hepatis shows no flow in the hepatic artery. Only portal vein flow is seen (red areas). (Fig 11b courtesy of K. Khalili, MD, Princess Margaret Hospital, Toronto, Ontario, Canada.)

View larger version (184K): [in a new window]   Figure 11c.  Sloughing of biliary epithelium in a liver transplant recipient with known hepatic artery thrombosis and biliary necrosis. (a) Transverse US image shows distention of the common bile duct by echogenic intraluminal material (arrows), which represents sloughed biliary epithelium. (b) Coronal MR image of the porta hepatis, obtained after administration of a biliary excreting agent, shows a filling defect within the biliary tree confluence (arrows), which represents the sloughed epithelium. (c) Contrast-enhanced CT image shows the "cutoff" of the main hepatic artery (large arrow). Short arrows = surgical sutures of the hepatic artery anastomosis. (d) Color Doppler image obtained at the porta hepatis shows no flow in the hepatic artery. Only portal vein flow is seen (red areas). (Fig 11b courtesy of K. Khalili, MD, Princess Margaret Hospital, Toronto, Ontario, Canada.)

View larger version (147K): [in a new window]   Figure 11d.  Sloughing of biliary epithelium in a liver transplant recipient with known hepatic artery thrombosis and biliary necrosis. (a) Transverse US image shows distention of the common bile duct by echogenic intraluminal material (arrows), which represents sloughed biliary epithelium. (b) Coronal MR image of the porta hepatis, obtained after administration of a biliary excreting agent, shows a filling defect within the biliary tree confluence (arrows), which represents the sloughed epithelium. (c) Contrast-enhanced CT image shows the "cutoff" of the main hepatic artery (large arrow). Short arrows = surgical sutures of the hepatic artery anastomosis. (d) Color Doppler image obtained at the porta hepatis shows no flow in the hepatic artery. Only portal vein flow is seen (red areas). (Fig 11b courtesy of K. Khalili, MD, Princess Margaret Hospital, Toronto, Ontario, Canada.)

View larger version (163K): [in a new window]   Figure 12a.  Biliary stone. (a) Right paramedian sagittal US image shows a distended common bile duct and a focal echogenic calculus (arrow) with distal acoustic shadowing. (b) Corresponding CT image shows the calculus (arrow).

View larger version (138K): [in a new window]   Figure 12b.  Biliary stone. (a) Right paramedian sagittal US image shows a distended common bile duct and a focal echogenic calculus (arrow) with distal acoustic shadowing. (b) Corresponding CT image shows the calculus (arrow).

View larger version (146K): [in a new window]   Figure 13a.  Recurrent sclerosing cholangitis 1 years after orthotopic liver transplantation. (a) Right paramedian sagittal US image shows mural thickening of the common bile duct (arrows). However, the arterial Doppler waveform was normal. (b) Magnified view shows the abnormality (arrows).

View larger version (155K): [in a new window]   Figure 13b.  Recurrent sclerosing cholangitis 1 years after orthotopic liver transplantation. (a) Right paramedian sagittal US image shows mural thickening of the common bile duct (arrows). However, the arterial Doppler waveform was normal. (b) Magnified view shows the abnormality (arrows).

View larger version (152K): [in a new window]   Figure 14a.  Recurrent hepatocellular carcinoma in a 49-year-old man 10 months after transplantation for alcoholic cirrhosis. Pathologic analysis of the liver explant at the time of transplantation revealed previously undiagnosed multiple microscopic foci of hepatocellular carcinoma. (a) Median sagittal US image shows a large mass of mixed echogenicity in the right hepatic lobe (arrows). (b) Corresponding contrast-enhanced CT image shows the mass (arrows).

View larger version (155K): [in a new window]   Figure 14b.  Recurrent hepatocellular carcinoma in a 49-year-old man 10 months after transplantation for alcoholic cirrhosis. Pathologic analysis of the liver explant at the time of transplantation revealed previously undiagnosed multiple microscopic foci of hepatocellular carcinoma. (a) Median sagittal US image shows a large mass of mixed echogenicity in the right hepatic lobe (arrows). (b) Corresponding contrast-enhanced CT image shows the mass (arrows).

View larger version (134K): [in a new window]   Figure 15a.  Posttransplantation lymphoproliferative disease. (a) Transverse US image shows a large, heterogeneous, echogenic mass (arrows) that effaces and displaces the porta hepatis. Biopsy demonstrated posttransplantation lymphoproliferative disease. (b) Contrast-enhanced CT image obtained at a different level shows the mass (arrows), which encases the vasculature at the porta hepatis.

View larger version (169K): [in a new window]   Figure 15b.  Posttransplantation lymphoproliferative disease. (a) Transverse US image shows a large, heterogeneous, echogenic mass (arrows) that effaces and displaces the porta hepatis. Biopsy demonstrated posttransplantation lymphoproliferative disease. (b) Contrast-enhanced CT image obtained at a different level shows the mass (arrows), which encases the vasculature at the porta hepatis.

View larger version (107K): [in a new window]   Figure 16.  Infarct in a 56-year-old woman with hepatic artery thrombosis 9 days after orthotopic liver transplantation. US (top left) and CT (top right) images show a peripheral parenchymal infarct (*) in segment 6 of the liver. Doppler spectrum for the intrahepatic artery (bottom) shows an abnormal tardus-parvus waveform (arrow); this flow originates from collateral pathways.

View larger version (111K): [in a new window]   Figure 17a.  Infarct in a 42-year-old woman with fatigue 5 years after liver transplantation. The fatigue was secondary to delayed hepatic artery thrombosis, which led to extensive infarction of the liver. (a) Transverse US image of the liver shows a large area of heterogeneous parenchyma with central hypoechoic areas (arrows), which represent necrosis. (b) Corresponding contrast-enhanced CT image shows the infarct (arrows).

View larger version (141K): [in a new window]   Figure 17b.  Infarct in a 42-year-old woman with fatigue 5 years after liver transplantation. The fatigue was secondary to delayed hepatic artery thrombosis, which led to extensive infarction of the liver. (a) Transverse US image of the liver shows a large area of heterogeneous parenchyma with central hypoechoic areas (arrows), which represent necrosis. (b) Corresponding contrast-enhanced CT image shows the infarct (arrows).

View larger version (175K): [in a new window]   Figure 18a.  Biopsy-proved infarct in a 35-year-old patient 4 months after orthotopic liver transplantation for fibrolamellar carcinoma. (a) Midline transverse US image shows an echogenic focus with a hypoechoic rim (arrow) in the left hepatic lobe. (b) Corresponding contrast-enhanced CT image shows the lesion (arrow).

View larger version (128K): [in a new window]   Figure 18b.  Biopsy-proved infarct in a 35-year-old patient 4 months after orthotopic liver transplantation for fibrolamellar carcinoma. (a) Midline transverse US image shows an echogenic focus with a hypoechoic rim (arrow) in the left hepatic lobe. (b) Corresponding contrast-enhanced CT image shows the lesion (arrow).

View larger version (144K): [in a new window]   Figure 19a.  Abscess in a 57-year-old man with fever and rigor 6 months after orthotopic liver transplantation for primary sclerosing cholangitis. (a) Transverse US image shows a focal mass in the left hepatic lobe. The mass demonstrates highly echogenic air (arrows) and posterior dirty shadowing, which could easily be mistaken for gas in an adjacent bowel loop. (b) Corresponding CT image shows the lesion (arrows).

View larger version (141K): [in a new window]   Figure 19b.  Abscess in a 57-year-old man with fever and rigor 6 months after orthotopic liver transplantation for primary sclerosing cholangitis. (a) Transverse US image shows a focal mass in the left hepatic lobe. The mass demonstrates highly echogenic air (arrows) and posterior dirty shadowing, which could easily be mistaken for gas in an adjacent bowel loop. (b) Corresponding CT image shows the lesion (arrows).

View larger version (143K): [in a new window]   Figure 20a.  Preexisting lesion in a liver implant. Transverse US images show a round hematoma in segment 4b as a focal, well-defined cystic structure with dependent internal echoes, which delineate a fluid-fluid level (arrowheads in b). The donor had been in a motor vehicle accident.

View larger version (154K): [in a new window]   Figure 20b.  Preexisting lesion in a liver implant. Transverse US images show a round hematoma in segment 4b as a focal, well-defined cystic structure with dependent internal echoes, which delineate a fluid-fluid level (arrowheads in b). The donor had been in a motor vehicle accident.

View larger version (194K): [in a new window]   Figure 21a.  Acute and subacute fluid collections. (a) Transverse US image shows an isoechoic acute hematoma as an echogenic mass (arrows) with echogenicity similar to that of adjacent liver tissue. Acute hematomas can be difficult to detect, as they are often isoechoic relative to adjacent liver tissue. (b, c) Subacute hematoma in a 52-year-old man 10 days after orthotopic liver transplantation. Right paramedian sagittal (b) and corresponding transverse (c) US images show a complex, septated, avascular fluid collection (arrows in b) in the hepatorenal space. The fluid collection extends to the bare area of the liver (B in b), a location not identified in the native liver.

View larger version (157K): [in a new window]   Figure 21b.  Acute and subacute fluid collections. (a) Transverse US image shows an isoechoic acute hematoma as an echogenic mass (arrows) with echogenicity similar to that of adjacent liver tissue. Acute hematomas can be difficult to detect, as they are often isoechoic relative to adjacent liver tissue. (b, c) Subacute hematoma in a 52-year-old man 10 days after orthotopic liver transplantation. Right paramedian sagittal (b) and corresponding transverse (c) US images show a complex, septated, avascular fluid collection (arrows in b) in the hepatorenal space. The fluid collection extends to the bare area of the liver (B in b), a location not identified in the native liver.

View larger version (163K): [in a new window]   Figure 21c.  Acute and subacute fluid collections. (a) Transverse US image shows an isoechoic acute hematoma as an echogenic mass (arrows) with echogenicity similar to that of adjacent liver tissue. Acute hematomas can be difficult to detect, as they are often isoechoic relative to adjacent liver tissue. (b, c) Subacute hematoma in a 52-year-old man 10 days after orthotopic liver transplantation. Right paramedian sagittal (b) and corresponding transverse (c) US images show a complex, septated, avascular fluid collection (arrows in b) in the hepatorenal space. The fluid collection extends to the bare area of the liver (B in b), a location not identified in the native liver.

View larger version (167K): [in a new window]   Figure 22a.  Adrenal hemorrhage. (a) Transverse US image shows a hypoechoic nodule (arrow) in the hepatorenal space. The nodule represents focal adrenal hemorrhage secondary to intraoperative venous infarction. (b) Corresponding CT image shows the nodule (arrow).

View larger version (166K): [in a new window]   Figure 22b.  Adrenal hemorrhage. (a) Transverse US image shows a hypoechoic nodule (arrow) in the hepatorenal space. The nodule represents focal adrenal hemorrhage secondary to intraoperative venous infarction. (b) Corresponding CT image shows the nodule (arrow).