DOI:10.2214/AJR.05.0611
AJR 2006; 187:W406-W414
© American Roentgen Ray Society
Hepatic Hemangiomas with Arterioportal Shunt: Sonographic Appearances with CT and MRI Correlation
Kyoung Won Kim1,
Ah Young Kim1,
Tae Kyoung Kim1,2,
So Yeon Kim1,
Min-Jeong Kim1,
Mi-Suk Park1,3,
Seong Ho Park1,
Kyung Ho Lee4,
Jeong Kon Kim1,
Pyo-Nyun Kim1,
Hyun Kwon Ha1 and
Moon-Gyu Lee1
1 Department of Radiology, Asan Medical Center, University of Ulsan College of
Medicine, 388-1, Pungnap-2 dong, Songpa-ku, Seoul, South Korea 138-736.
2 Department of Medical Imaging, Toronto General Hospital, Toronto, ON,
Canada.
3 Department of Radiology, YongDong Severance Hospital, Seoul, South
Korea.
4 Department of Radiology, Seoul National University Bundang Hospital, Seong
Nam, South Korea.
Received April 8, 2005;
accepted after revision July 12, 2005.
Address correspondence to K. W. Kim
(kimkw{at}amc.seoul.kr).
WEB This is a Web exclusive article.
Abstract
OBJECTIVE. The purpose of this study was to summarize and illustrate
the sonographic appearance of hepatic hamangiomas with arterioportal shunt and
to correlate them with CT and MRI findings.
CONCLUSION. High-flow hepatic hemangiomas tend to be seen as
hypoechoic lesions at sonography. In the presence of fatty infiltration in the
liver, they may accompany peritumoral low-echoic areas presumably caused by
peritumoral sparing of fatty infiltration similar to a hyperattenuating or
hyperintense peritumoral rim on unenhanced CT or MR chemical shift imaging.
Color Doppler sonography may reveal intratumoral flows, large feeding
arteries, and reversal of portal flow around the tumor. Knowledge of such
sonographic findings may ensure an accurate sonographic diagnosis of these
tumors.
Keywords: arterioportal shunt • CT • genitourinary tract imaging • hepatic hemangiomas • hysterosalpingography • MRI • sonography
Introduction
Hepatic hemangiomas are sometimes associated with arterioportal shunt,
which has been reported with an incidence of up to 26%
[1]. Several investigators have
focused on CT and MRI findings of these tumors. It has been shown that
atypical hepatic hemangiomas with arterioportal shunt tend to show rapid
enhancement on dynamic contrast-enhanced CT scans
[1], and it has been suggested
that the dynamic enhancement pattern of the tumor may histopathologically
correlate with the collective size of its constituent vascular spaces
[2]. However, relatively little
attention has been paid to sonographic appearances of these tumors, even
though sonography is considered the primary screening method for evaluating
focal hepatic lesions. Although sonography may not be settled as the
characterizing imaging technique for liver lesions in most circumstances, it
may, nevertheless, be worthwhile for characterizing these tumors, because they
tend to be found incidentally and are rarely of clinical significance except
to be differentiated from malignant tumors. Thus, in this article, we
summarize and illustrate sonographic appearances of hepatic hemangiomas with
arterioportal shunt and correlate them with CT and MRI findings.
Sonographic Appearances of Hepatic Hemangiomas with Arterioportal Shunt
Sonographic Patterns and Speed of Contrast Enhancement on Dynamic Studies
High-flow hepatic hemangiomas are more likely to accompany arterioportal
shunt than slow-flow hemangiomas
[1]. It has been reported that
histopathologic differences exist between the high-flow and the slow-flow
hemangiomas. Tumors with slow fill-in have relatively large vascular spaces,
whereas those with rapid enhancement have smaller vascular spaces and large
interstitium [2]. Regarding
sonographic appearances of these tumors, it also has been shown that the speed
of contrast enhancement on dynamic studies enables the prediction of the
sonographic pattern and vice versa. Whereas the tumors with rapid enhancement
on dynamic studies tend to have sonographically hypoechoic appearances, those
with slow enhancement tend to have sonographically hyperechoic appearances
[3] (Figs.
1A,
1B,
1C,
2A, and
2B). An associated
arterioportal shunt, however, may not further change sonographic appearances
of the tumor in a healthy liver.
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Fig. 1A —48-year-old woman with high-flow hemangioma with
arterioportal shunt in right lobe of liver. Oblique coronal sonogram shows
well-defined hypoechoic mass (arrowheads) in right lobe of liver.
There is otherwise no remarkable abnormality in hepatic parenchyma.
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Fig. 1B —48-year-old woman with high-flow hemangioma with
arterioportal shunt in right lobe of liver. Dynamic T1-weighted image during
hepatic artery phase after gadopentetate dimeglumine administration shows
rapid homogeneous enhancement of tumor (arrow) with peritumoral
wedge-shaped parenchymal enhancement (arrowheads), which suggests
high-flow hemangioma with arterioportal shunt.
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Fig. 1C —48-year-old woman with high-flow hemangioma with
arterioportal shunt in right lobe of liver. Dynamic T1-weighted image during
the equilibrium phase shows persistent homogeneous enhancement of tumor
(arrow). However, wedge-shaped hyperintense peritumoral enhancement
during hepatic artery phase is no longer seen.
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Fig. 2B —51-year-old man with slow-flow hemangioma in right lobe of
liver. Contrast-enhanced CT scan of liver during portal venous phase shows
dotlike enhancement (arrowhead) in periphery of lesion, suggesting
diagnosis of slow-flow hemangioma.
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Sonographic Appearances in Hepatic Steatosis
It is well known that fatty infiltration of surrounding hepatic parenchyma
may result in an atypical echo-poor appearance of the hepatic hemangioma. In
addition, in highflow hepatic hemangiomas with arterioportal shunt in the
presence of fatty infiltration in the liver, an associated arterioportal shunt
may result in peritumoral sparing of fatty infiltration. As the cause of the
focal sparing of fatty infiltration, some investigators have speculated that
the regional alteration of intrahepatic portal flow (dilution of portal blood
flow by non-lipid-rich arterial blood through an arterioportal shunt) may be
an important factor [4]. It has
been well documented that the peritumoral sparing of fatty infiltration is
seen as a hyperattenuating rim on unenhanced CT
[5] and hyperintense
peritumoral rim on MR chemical shift imaging
[6]. However, to our knowledge,
the sonographic appearance of hemangiomas with peritumoral fat sparing has not
been well described. We have seen several cases of highflow hemangiomas in the
presence of hepatic steatosis in which sonographic findings were correlated
with those on CT scans or MR chemical shift imaging. In our experience, the
tumors were seen as hypoechoic masses with or without a thin hyperechoic rim
and were surrounded by a geographic peritumoral hypoechoic area. The size and
shape of the peritumoral hypoechoic area were variable, but invariably
corresponded to a hyperattenuating rim on unenhanced CT (Figs.
3A,
3B,
3C,
3D,
4A,
4B,
4C, and
4D) and a hyperintense
peritumoral rim on MR chemical shift imaging (Figs.
5A,
5B,
5C,
5D, and
5E). This supports the
evidence of peritumoral fat sparing in these tumors.
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Fig. 3A —44-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma is seen with arterioportal
shunt. Transverse sonogram shows increased liver echogenicity, suggestive of
hepatic steatosis, and also shows well-defined mass with echo-poor appearance
(arrow) and small geographic peritumoral hypoechoic area
(arrowheads) in lateral segment of left hepatic lobe.
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Fig. 3B —44-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma is seen with arterioportal
shunt. Contrast-enhanced CT during hepatic artery phase shows strong
homogeneous enhancement of tumor (long arrow), peritumoral
wedge-shaped parenchymal enhancement (arrowheads), and early
opacification of portal vein branch (short arrow) in that area,
suggestive of high-flow hemangioma with arterioportal shunt.
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Fig. 3C —44-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma is seen with arterioportal
shunt. Contrast-enhanced CT during portal venous phase shows persistent
homogeneous enhancement of tumor (arrow) and faint wedge-shaped
peritumoral enhancement.
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Fig. 3D —44-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma is seen with arterioportal
shunt. Unenhanced CT scan shows decrease of hepatic attenuation, suggestive of
hepatic steatosis, and also shows thin hyperdense peritumoral rim
(arrowheads), which corresponds to geographic peritumoral hypoechoic
area at sonography, suggesting peritumoral sparing of fatty infiltration.
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Fig. 4A —24-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma with arterioportal shunt is
seen. Oblique sagittal sonogram shows slightly increased liver echogenicity,
suggestive of mild hepatic steatosis, and also shows well-defined hypoechoic
mass with hyperechoic rim (arrow) and peritumoral hypoechoic area
(arrowheads) in posterior segment of right hepatic lobe.
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Fig. 4B —24-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma with arterioportal shunt is
seen. Contrast-enhanced CT scan during hepatic arterial phase shows strong
homogenous enhancement of tumor (arrow) and peritumoral wedge-shaped
parenchymal enhancement (arrowheads), suggestive of high-flow
hemangioma with arterioportal shunt.
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Fig. 4C —24-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma with arterioportal shunt is
seen. Contrast-enhanced CT during portal venous phase shows persistent
homogeneous enhancement of tumor (arrow). Also, wedge-shaped
peritumoral enhancement during hepatic arterial phase is still seen as
hyperattenuation (arrowheads).
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Fig. 4D —24-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma with arterioportal shunt is
seen. Unenhanced CT scan shows decrease of hepatic attenuation, suggestive of
hepatic steatosis, and also shows geographic hyperdense area
(arrowheads) around tumor (arrow), which corresponds to
geographic peritumoral hypoechoic area at sonography, suggesting peritumoral
sparing of fatty infiltration.
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Fig. 5A —31-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma with arterioportal shunt is
seen. Oblique sagittal sonogram shows slightly increased liver echogenicity,
suggestive of mild hepatic steatosis, and also shows well-defined hypoechoic
mass with hyperechoic rim (arrow) and peritumoral hypoechoic area
(arrowheads) in right lobe of liver.
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Fig. 5B —31-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma with arterioportal shunt is
seen. Contrast-enhanced CT scan during hepatic arterial phase shows strong
globular enhancement of tumor (arrow) and small peritumoral
wedge-shaped parenchymal enhancement (arrowheads), suggestive of
high-flow hemangioma with arterioportal shunt.
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Fig. 5C —31-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma with arterioportal shunt is
seen. Contrast-enhanced CT during portal venous phase shows centripetal
fill-in enhancement of tumor (arrow). However, wedge-shaped
peritumoral enhancement during hepatic arterial phase is no longer seen.
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Fig. 5D —31-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma with arterioportal shunt is
seen. In-phase gradient-echo T1-weighted image shows mass with hypointensity
(arrow).
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Fig. 5E —31-year-old woman with hepatic steatosis. Peritumoral sparing
of fatty infiltration around high-flow hemangioma with arterioportal shunt is
seen. Out-of-phase gradient-echo T1-weighted image shows signal decrease of
hepatic parenchyma, suggesting hepatic steatosis. It also shows thin
peritumoral hyperintense rim (arrowheads), which corresponds to
geographic peritumoral hypoechoic area at sonography, suggesting peritumoral
sparing of fatty infiltration.
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However, the presence of peritumoral sparing of fatty infiltration in
hepatic steatosis may not necessarily indicate that the diagnosis of the tumor
is high-flow hemangioma; this finding may also be seen in hepatocellular
carcinomas (Figs. 6A,
6B,
6C,
6D, and
6E) or metastases (Figs.
7A,
7B,
7C,
7D, and
7E), although the mechanisms
differ. In those cases, the venous drainage area of hepatocellular carcinomas
or peritumoral hepatic parenchyma compressed by metastatic tumors is presumed
as the cause of peritumoral sparing of fatty infiltration
[7]. Therefore, a further
investigation is warranted regarding the differential diagnosis of focal
hepatic lesions with peritumoral fat sparing at sonography.
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Fig. 6A —58-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatocellular carcinoma is seen. Oblique
sagittal sonogram shows increased liver echogenicity, suggestive of hepatic
steatosis, and also shows large hypoechoic mass (arrows) surrounded
by peritumoral hypoechoic area (arrowheads) in posterior segment of
right hepatic lobe.
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Fig. 6B —58-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatocellular carcinoma is seen. In-phase
gradient-echo T1-weighted image shows large mass with hypointensity
(arrows).
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Fig. 6C —58-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatocellular carcinoma is seen. Out-of-phase
gradient-echo T1-weighted image shows signal decrease of hepatic parenchyma,
suggesting hepatic steatosis. It also shows large mass with hypointensity
(arrows) and peritumoral hyperintense area (arrowheads),
which corresponds to peritumoral hypoechoic area at sonography, suggesting
peritumoral sparing of fatty infiltration.
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Fig. 6D —58-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatocellular carcinoma is seen. Dynamic
T1-weighted image during hepatic arterial phase after gadopentetate
dimeglumine administration shows intense peripheral enhancement of tumor.
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Fig. 6E —58-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatocellular carcinoma is seen. Dynamic
T1-weighted image during the equilibrium phase shows isointense enhancement of
tumor periphery compared with hepatic parenchyma, irregular necrotic cavity in
center, and thin peritumoral enhancement (arrowheads), suggesting
encapsulated hepatocellular carcinoma. Diagnosis of hepatocellular carcinoma
was made by histopathologic examination of percutaneous biopsy specimen.
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Fig. 7A —67-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatic metastasis from rectal cancer is seen.
Oblique sagittal sonogram shows increased liver echogenicity, suggestive of
hepatic steatosis. It also shows hypoechoic mass (arrows) surrounded
by peritumoral hypoechoic area (arrowheads).
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Fig. 7B —67-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatic metastasis from rectal cancer is seen.
Contrast-enhanced CT scan during hepatic arterial phase shows thin peripheral
rimlike enhancement (arrowheads).
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Fig. 7C —67-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatic metastasis from rectal cancer is seen.
Tumor is seen as hypoattenuation on contrast-enhanced CT scan during portal
venous phase.
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Fig. 7D —67-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatic metastasis from rectal cancer is seen.
In-phase gradient-echo T1-weighted image shows mass with hypointensity
(arrow).
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Fig. 7E —67-year-old man with hepatic steatosis. Peritumoral sparing
of fatty infiltration around hepatic metastasis from rectal cancer is seen.
Out-of-phase gradient-echo T1-weighted image shows signal decrease of hepatic
parenchyma, suggesting hepatic steatosis. It also shows thin peritumoral
hyperintense rim (arrowheads), which corresponds to geographic
peritumoral hypoechoic area at sonography, suggesting peritumoral sparing of
fatty infiltration. Hepatic metastasis was proven by histopathologic
examination of percutaneous biopsy specimen.
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Color Doppler Sonographic Findings
Color Doppler sonography is now widely used as part of a routine
examination for liver tumors. Although hepatic hemangiomas are vascular
lesions consisting of blood-filled channels, their evaluation with color
Doppler imaging has been unsuccessful in most typical cases. The lack of
apparent flow is presumably related to the fact that the intratumoral flow is
multidirectional and its velocity is below the sensitivity limits of the color
Doppler technique. However, it is assumed that atypical high-flow hepatic
hemangiomas with arterioportal shunt may show different findings from those of
typical slow-flow hemangiomas. Also, if a considerable amount of transtumoral
arterioportal shunt is seen, it may result in a variable amount of retrograde
flow through the portal vein, which can be sufficiently shown by color Doppler
sonography. Although few consecutive studies have focused on the efficacy of
color Doppler sonography for evaluating high-flow hemangiomas with
arterioportal shunt, one study reported that these tumors may show the
presence of intratumoral flows, large feeding arteries, and reversal of portal
flow around the tumor [8]
(Figs. 8A,
8B,
8C,
8D,
8E,
8F, and
8G).
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Fig. 8A —34-year-old man with hepatic steatosis. High-flow hemangioma
with arterioportal shunt is seen. Oblique sagittal sonogram shows increased
liver echogenicity, suggestive of hepatic steatosis. It also shows hypoechoic
mass (arrow) with hyperechoic rim surrounded by geographic
peritumoral hypoechoic area (arrowheads).
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Fig. 8C —34-year-old man with hepatic steatosis. High-flow hemangioma
with arterioportal shunt is seen. Color Doppler sonogram shows large feeding
artery (arrow) and reversal of portal flow (arrowheads),
seen as blue color, in proximity of tumor.
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Fig. 8E —34-year-old man with hepatic steatosis. High-flow hemangioma
with arterioportal shunt is seen. Contrast-enhanced CT during hepatic artery
phase shows strong enhancement of tumor (large arrow), peritumoral
wedge-shaped parenchymal enhancement (arrowheads), and early
opacification of portal vein branch (short arrow) in that area,
suggestive of high-flow hemangioma with arterioportal shunt.
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Fig. 8F —34-year-old man with hepatic steatosis. High-flow hemangioma
with arterioportal shunt is seen. Contrast-enhanced CT during portal venous
phase shows persistent homogeneous enhancement of tumor (arrow).
However, wedge-shaped peritumoral enhancement during hepatic artery phase is
no longer seen.
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Fig. 8G —34-year-old man with hepatic steatosis. High-flow hemangioma
with arterioportal shunt is seen. Unenhanced CT scan shows decrease of hepatic
attenuation, suggestive of hepatic steatosis. It also shows hyperdense area
(arrowheads) around tumor (arrow), which corresponds to
geographic peritumoral hypoechoic area at sonography, suggesting peritumoral
sparing of fatty infiltration.
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Conclusion
High-flow hepatic hemangiomas tend to be seen as hypoechoic lesions at
sonography. In the presence of fatty infiltration in the liver, they may
accompany a geographic peritumoral low echoic area, presumably caused by
peritumoral sparing of fatty infiltration similar to a hyperattenuating or
hyperintense peritumoral rim on unenhanced CT or MR chemical shift imaging.
Color Doppler sonography may reveal intratumoral flows, large feeding
arteries, and reversal of portal flow around the tumor. Knowledge of such
sonographic findings may ensure an accurate sonographic diagnosis of these
tumors.
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Abstract
Introduction
