AJR 2005; 184:75-81
© American Roentgen Ray Society
CT and MRI of Hepatic Contour Abnormalities
Jafi A. Lipson1,
Aliya Qayyum1,
David E. Avrin2,
Antonio Westphalen1,
Benjamin M. Yeh1 and
Fergus V. Coakley1
1 Department of Radiology, University of California–San Francisco, 505
Parnassus Ave., Rm. M-372, San Francisco, CA 94143-0628.
2 Department of Radiology, University of Utah, 30 N 1900, E #1A71, Salt Lake
City, UT 84132-2140.
Received November 25, 2003;
accepted after revision June 30, 2004.
Address correspondence to A. Qayyum.
Introduction
Hepatic contour abnormalities are seen commonly on CT or MRI but have
received relatively little attention in the radiology literature compared with
parenchymal hepatic disease. The objective of this pictorial essay is to
provide a concise pictorial review of the causes and appearances of hepatic
contour abnormalities on CT and MRI with an emphasis on clinical and imaging
features that facilitate a correct diagnosis. Such a review is timely because
new causes of liver contour abnormalities have been described recently
[1], and the interpretation of
such findings remains controversial. Intrinsic disorders of the liver that may
cause contour abnormalities consist of hepatic tumors, cirrhosis, infarction,
and vascular occlusion; treatment change also may cause contour abnormalities.
Perihepatic diseases also may cause extrinsic alteration of the liver contour.
Depending on the nature and extent of these disorders, the contour abnormality
may be unifocal, multifocal, or diffuse. The mechanism of contour change also
varies and may reflect focal expansion of the liver, capsular retraction,
parenchymal distortion, capsular indentation, or some combination of these
factors. All of these abnormalities should be distinguished from physiologic
irregularity of the hepatic contour, particularly indentation related to
diaphragmatic slips (Fig.
1).
Hepatic Tumors
Although hepatic parenchymal tumors generally are associated with mass
effect resulting in contour bulge, some tumors may result in only capsular
retraction. Cholangiocarcinoma may cause hepatic atrophy and capsular
retraction [2]
(Fig. 2), probably due to
combined venous and biliary occlusion of the atrophic part of the liver.
However, these findings are not specific, and other characteristics such as a
visible mass with delayed enhancement and biliary dilatation should be sought.
Hepatocellular carcinoma may be variably exophytic
[2], causing bulging of the
hepatic contour (Fig. 3). The
tumor typically is hypervascular
[3] and is associated with
cirrhosis.
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Fig. 2. —45-year-old woman with cholangiocarcinoma. Contrast-enhanced
CT scan shows ill-defined hypoattenuating mass (arrow) in left lobe
of liver with associated retraction of liver surface (arrowhead) and
intrahepatic biliary dilatation.
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Fig. 3. —50-year-old man with hepatocellular carcinoma.
Contrast-enhanced CT scan shows exophytic heterogeneously enhancing mass
(arrow) bulging from inferior right lobe of liver. Mass has central
hypoattenuating scar (arrowhead).
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Hepatic hemangioendothelioma can be considered an intermediate between
hemangioma and angiosarcoma. Such tumors include infantile, spindle cell, and
epithelioid hemangioendothelioma. Infantile hemangioendothelioma is a benign
lesion typically presenting as a liver mass, cardiac failure secondary to
arteriovenous shunting, and consumptive coagulopathy and is seen most
frequently in patients before the age of 6 months. Spindle cell
hemangioendothelioma is a low-grade malignant tumor with a propensity for
local recurrence. Epithelioid hemangioendothelioma is a low-grade slowly
progressive malignant vascular tumor that was described first in 1982 and
typically occurs in the liver, bone, skin, or soft tissues of children and
young adults. At imaging, the enhancement pattern of a hemangioendothelioma
may mimic that of a hemangioma. Hepatic epithelioid hemangioendothelioma
usually is multifocal (but may coalesce to become diffuse or infiltrative) and
subcapsular. Capsular retraction has been reported in 25–69% of cases
(Figs. 4A and
4B). A target sign of
concentric zones may be seen on MRI
[4]
(Fig. 5).
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Fig. 4B. —29-year-old woman with hepatic epithelioid
hemangioendothelioma. Contrast-enhanced CT scan shows characteristic
retraction of liver capsule in association with one of the masses
(arrowhead).
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Fig. 5. —24-year-old woman with epithelioid hemangioendothelioma.
Fat-suppressed T2-weighted fast spin-echo image shows high-signal-intensity
mass with slight retraction of liver surface (arrow) at liver dome
with central higher signal intensity or target sign (arrowhead).
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Hemangiomas may be exophytic, causing a focal bulge of the hepatic contour
(Fig. 6). Large hemangiomas may
develop central thrombosis, leading to fibrotic retraction of the adjacent
capsule [2]. Metastatic
neuroendocrine tumor is one of the few secondary cancers that commonly causes
contour abnormality (Fig. 7),
possibly because the indolent nature of the tumor allows the slow development
of hepatic enlargement and surface expansion. Rarely, untreated metastases
from adenocarcinoma of the colon, stomach, breast, lung, pancreas, and
gallbladder cause focal capsular retraction, probably due to internal necrosis
and desmoplasia [2]
(Fig. 8).
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Fig. 8. —60-year-old man with untreated metastatic colon cancer.
Contrast-enhanced CT scan shows hypoattenuating liver masses. There is focal
retraction (arrowhead) of liver surface adjacent to one of the
metastases. Bland thrombus is present incidentally within inferior vena cava
(arrow).
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Cirrhosis and Confluent Hepatic Fibrosis
Cirrhosis is a diffuse progressive process of ongoing hepatic necrosis
resulting in nodular regenerative hyperplasia and fibrosis
[1]. Imaging characteristics
include surface nodularity, atrophy of the right lobe and medial segment of
the left lobe, enlargement of the caudate lobe and lateral segment of the left
lobe, increased porta hepatis fat, and expansion of the gallbladder fossa
[3]
(Fig. 9). Liver surface
nodularity has been attributed to regenerative nodules
[3].
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Fig. 9. —54-year-old man with cirrhosis. Fat-suppressed T1-weighted
gradient-echo image with gadolinium enhancement shows shrunken liver with
diffusely nodular contour and recanalized paraumbilical vein
(arrowhead).
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Confluent hepatic fibrosis is a masslike atrophic region occasionally seen
in cirrhosis, and it typically affects the anterior and medial segments (Figs.
10A and
10B). On CT, confluent hepatic
fibrosis appears as a wedge-shaped region of iso- or hypoattenuation with
associated atrophy and capsular retraction
[2]. On MRI, focal confluent
hepatic fibrosis is hypointense on T1-weighted images and usually is
hyperintense on T2-weighted images
[3]. Possible explanations for
the observed hyperintense signal of confluent fibrosis on T2-weighted imaging
may be a relative reduction in the signal of the remaining liver parenchyma
due to increased iron deposition or edema associated with areas of confluent
fibrosis due to venous thrombosis in this region; however, these explanations
are speculative.
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Fig. 10A. —48-year-old man with cirrhosis. Fat-suppressed T1-weighted
gradient-echo image with early gadolinium enhancement shows diffusely nodular
liver contour with associated retraction (arrowhead) of liver surface
involving medial segment of left lobe and anterior segment of right lobe.
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Fig. 10B. —48-year-old man with cirrhosis. Fat-suppressed T2-weighted
fast spin-echo image shows wedge-shaped region of slightly increased signal
intensity (arrowhead) involving medial segment of left lobe and
anterior segment of right lobe with associated retraction of liver
surface.
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Infarction and Vascular Occlusion
Hepatic infarction is uncommon due to the dual vascular supply of the
liver, but recognized causes include liver transplantation, laparoscopic
cholecystectomy, profound shock, sepsis, arterial embolism, vasculitis,
preeclampsia, and oral contraceptives. Infarcts appear as peripheral
nonenhancing geographic regions that may change in shape over time and that
may be associated with necrosis, bile lakes, and atrophic capsular retraction
[5] (Figs.
11A and
11B). Hepatic vein thrombosis
(Budd-Chiari syndrome) may be spontaneous secondary to prothrombotic
conditions (e.g., myeloproliferative disorders, paroxysmal nocturnal
hemoglobinuria, coagulation disorders, and oral contraceptives) or may be
caused by malignant venous occlusion
[1]
(Fig. 12). Portal vein
thrombosis may be due to pancreatitis, cholangitis, peritonitis,
lymphadenopathy, pancreatic cancer, or cirrhosis. Both chronic Budd-Chiari
syndrome and chronic portal vein thrombosis may result in venous collateral
formation and hepatic atrophy with lobulated capsular irregularity
[1,
3].
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Fig. 11A. —29-year-old woman with liver infarct after having undergone
liver transplantation. Fat-suppressed T1-weighted gradient-echo image with
gadolinium enhancement shows small geographic area of low signal intensity
(arrow).
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Fig. 11B. —29-year-old woman with liver infarct after having undergone
liver transplantation. Contrast-enhanced CT scan obtained 4 months after
A shows interval development of focal liver retraction at site of
infarction (arrowhead).
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Fig. 12. —25-year-old woman with antiphospholipid antibody and
Budd-Chiari syndrome. Fat-suppressed T1-weighted gradient-echo image with
gadolinium enhancement shows lobulated liver contour (arrowheads),
heterogeneous reduced signal intensity in liver periphery, and caudate
enlargement.
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Treatment Change
Resection, chemoembolization, radiofrequency ablation, and chemotherapy may
cause cystic change, focal atrophy, and capsular retraction within and
adjacent to treated tumors [2].
An increasingly recognized entity is the phenomenon known as pseudocirrhosis,
the development of diffuse hepatic nodularity, segmental volume loss, and
enlargement of the caudate lobe in patients receiving chemotherapy for breast
cancer metastatic to the liver
[1,
3]
(Fig. 13). This condition
actually may be a type of true cirrhosis, because changes of portal
hypertension can be seen in these patients. The pathologic basis of this
process has not been well established
[6].
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Fig. 13. —68-year-old woman with pseudocirrhosis secondary to
chemotherapy treatment for breast cancer metastatic to liver.
Contrast-enhanced CT scan shows diffusely lobulated liver contour and
ascites.
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Perihepatic Disease
Peritoneal spread of tumor may result in biconvex perihepatic implants that
indent the hepatic contour, particularly in the intersegmental fissure, the
superior recess of the lesser sac, subphrenic space, and Morison's pouch.
Tumors that commonly spread within the peritoneal cavity are cancer of the
ovary, colon, stomach, pancreas, and breast
(Fig. 14).
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Fig. 14. —65-year-old woman with metastatic ovarian cancer.
Contrast-enhanced CT scan shows biconvex perihepatic implants
(arrowheads) that indent hepatic contour. Metastatic involvement of
spleen also is depicted.
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Pseudomyxoma peritonei is a type of peritoneal neoplasia characterized by
the progressive accumulation of mucinous ascites ("jelly belly")
that usually is caused by rupture of an ovarian or appendiceal mucinous
adenoma or adenocarcinoma [7].
In practice, the primary site is often unclear. On CT or MRI, the condition is
distinguished from simple ascites by the masslike nodular nature of the
gelatinous material that results in suggestive findings such as hepatic,
splenic, and mesenteric scalloping and visible septations or locules
[7]
(Fig. 15).
Perihepatic hematoma is another condition that may indent the hepatic
contour and can be recognized by the typical imaging characteristics of blood
on CT and MRI. Causes include trauma; bleeding disorders; and rupture of a
hepatic tumor, cyst, or abscess. Preeclampsia and the "HELLP"
syndrome (hemolysis, elevated liver enzymes, and low platelet count) appear to
have a particular predilection to cause perihepatic hematoma
[8].
Summary
Hepatic contour abnormalities commonly are seen on CT and MRI; although
these findings are not specific, awareness of the possible causes and their
imaging appearances may facilitate recognition of the underlying
diagnosis.
References
- Ros PR, Mortele KF. Diffuse liver disease. Clin Liver
Dis 2002;6:181
-201[Medline]
- Yang DM, Kim HS, Cho SW. Various causes of hepatic capsular
retraction: CT and MR findings. Br J Radiol2002; 75:994
-1002[Abstract/Free Full Text]
- Danet IM, Semelka RC, Braga L. MR imaging of diffuse liver disease.
Radiol Clin North Am2003; 41:67
-87[Medline]
- Lyburn ID, Torreggiani WC, Harris AC, et al. Hepatic epithelioid
hemangioendothelioma: sonographic, CT, and MR imaging appearances.
AJR 2003;180:1359
-1364[Free Full Text]
- Tzakis A, Gordon R, Shaw B Jr, et al. Clinical presentation of
hepatic artery thrombosis after liver transplantation in the cyclosporine era.
Transplantation1985; 40:667
-671[Medline]
- Shirkhoda A, Baird S. Morphologic changes of the liver following
chemotherapy for metastatic breast carcinoma: CT findings. Abdom
Imaging 1994;19:39
-42[Medline]
- Coakley FV. Staging ovarian cancer: role of imaging.
Radiol Clin North Am2002; 40:609
-636[Medline]
- Barton JR, Sibai BM. Hepatic imaging in HELLP syndrome (hemolysis,
elevated liver enzymes, and low platelet count). Am J Obstet
Gynecol 1996;174:1820
-1825[Medline]
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Introduction
Hepatic Tumors
