Joint Program in Nuclear Medicine
Imaging Workup of Hepatic Hemangiomas
Jac D. Scheiner, MD
Kevin J. Donohoe, MD
September 10, 1996
Presentation
A 53 year old woman with a history of a messencymal tumor of the thigh
presented with hepatomegally.
Imaging Findings
The ultrasound of the liver showed a hyperechoic mass in the dome of the
right lobe (seen a sagital and an
oblique images; arrows show lesions on sagital
and on transverse images). In addition there
was a complex lession at the inferior tip of the
right lobe of the liver (shown by arrow). First
past images from the blood pool study (above) show no areas of increased
flow. Planar delayed images show two areas
of increase uptake (the lesion in the dome of the right lobe corresponding
to the hyperechoic lesion is shown by
arrow heads; the lesion at the tip of the right lobe is shown by arrows;
also seen are the blood pools of the heart, H, and the spleen, S). Coronal
SPECT images show these two areas of increased blood pool.
Discussion
Hemangiomas are the most common benign tumor of the liver, noted in up
to 7% of patients on autopsy series. Up to 20% are multiple. Histology
demonstrates an overgrowth of enlarged endothelial lined vascular spaces.
While almost always asymptomatic, these tumors have been associated with
abdominal pain, fullness, and belching. Complications are similarly rare,
but have included bleeding, infarction, necrosis, and thrombocytopenia.
The clinical importance of these incidentally discovered tumors relates
to distinguishing them from malignancies.
Among the most common imaging modalities used to evaluate hemangiomas
are ultrasonography (US), computed tomography (CT), magnetic resonance
imaging (MRI) and technetium-99m labeled red blood cell single photon emission
computed tomography (Tc-99m RBC SPECT).
Ultrasonography
The classic finding of hemangioma on US is that of a well defined, echogenic
mass. This is seen in approximately 50-60% of hemangiomas (1). However,
this appearance can also be seen in adenomas, hepatocellular carcinomas,
and metastatic disease. The specificity of US findings for hemangioma is
increased if one also sees increased through transmission, although this
is not always seen. Stable finding over several US exams can be used to
suggest the lesion is benign. In a study of 21 hemangiomas in 21 patients
seen on US or CT, follow-up imaging in 5-84 months (mean = 26 months) demonstrated
size stability in 90% (19/21) (2). Of the 2 that had increased in size,
one had increased by 1 cm in 3 months and then remained stable at 3 year
follow-up, while the other had increased by 2 cm in 10 months. In the latter
case, the patient developed thrombocytopenia (an extremely rare complication)
and the hemangioma was resected.
Computed Tomography
The classic finding of hemangioma on CT is that of a round, low attenuation
lesion with slight lobulations on the non-contrast images. Following contrast
injection, "peripheral puddling" of contrast (of an attenuation matching
the aorta) is seen. The classic findings are not always evident, however.
A study of 58 hemangiomas in 47 patients who prospectively underwent CT
with and without contrast, using a more stringent criteria which required
the lesion to have an attenuation greater than or equal to the liver on
delayed images, demonstrated classic findings in only 55% (32/58) of the
hemangiomas (3).
Tc-99m Labeled RBC SPECT
The classic findings of hemangioma on Tc-99m labeled RBC SPECT are a lesion
that is undetectable or demonstrates decreased intensity compared to the
liver on the flow images, and increased intensity to the liver on the 30-60
minute delayed images. These findings are nearly 100% specific for
hemangioma. In the literature, there have been only 8 reported false positive
cases of hemangioma (4-9). Two of these were cases of hepatocellular carcinoma
in which there was increased tracer localization on the flow images. Another
2 were cases of hepatocellular carcinoma in patients with chronic liver
disease. The remaining 4 were in cases of intrahepatic extramedullary hematopoiesis,
metastatic gastric carcinoid, metatstatic colon cancer, and angiosarcoma.
Of these 8 cases, only one (metastatic colon cancer) had characteristic
hemangioma features (on both flow and delayed images) and could be considered
a common tumor.
SPECT significantly improves the sensitivity for hemangioma detection
over planar imaging, especially for lesions less than 5.0 cm. A study of
77 hemangiomas in which planar imaging and single head SPECT were performed
showed the sensitivity of these 2 techniques for different size lesions
to be as follows (10):
| Size (cm) |
Planar (%) |
SPECT (%) |
| <=2.0 |
6/31 (19) |
9/26 (35) |
| 2.1-3.0 |
12/21 (57) |
16/19 (84) |
| 3.1-5.0 |
13/16 (81) |
15/15 (100) |
| >5.0 |
9/9 (100) |
9/9 (100) |
Another study of 108 hemangiomas less than 5.0 cm, in which planar imaging
and single head SPECT was performed, gave the following sensitivities (11):
| Size (cm) |
Planar (%) |
SPECT (%) |
| <=1.0 |
0/20 (0) |
0/20 (0) |
| 1.1-2.0 |
3/29 (10) |
11/29 (38) |
| 2.1-3.0 |
15/35 (43) |
29/35 (83) |
| 3.1-4.0 |
8/13 (62) |
12/13 (92) |
| 4.1-5.0 |
10/11 (91) |
11/11 (100) |
This same study also looked at 45 hepatocellular carcinomas sized 1.5-5.0
cm. None of these malignancies met the scintigraphic criteria for hemangioma.
Two headed SPECT study of 56 hemangiomas resulted in slightly improved
sensitivities (13):
| Size (cm) |
Planar(%) |
SPECT1(%) |
SPECT2(%) |
| <=1.0 |
1/11 (9) |
2/11 (18) |
9/11 (92) |
| 1.1-2.0 |
3/14 (21) |
7/14 (50) |
13/14 (93) |
| 2.1-3.0 |
6/11 (55) |
9/11 (82) |
11/11 (100) |
| 3.1-4.0 |
5/6 (83) |
6/6 (100) |
6/6 (100) |
| >=4.1 |
14/14 (100) |
14/14 (100) |
14/14 (100) |
SPECT1 refers to conventional SPECT images, whereas SPECT2 refers to SPECT
images interpreted on a 3-D digital display.
A study in which 3 headed SPECT was performed on 34 hemangiomas (0.5-6.8
cm, mean = 2.2 cm) gave the following sensitivity results (14):
| Size (cm) |
SPECT (%) |
| <=0.8 cm |
1*/5 (20) |
| 0.9-1.3 cm |
3/9 (33) |
| >=1.4 cm |
20/20 (100) |
| * this was a 5 mm hemangioma |
False negative exams most commonly occur because of small hemangioma size.
Other reported causes include the hemangioma being adjacent to a vascular
structure (such as the heart, portal vein, or IVC) (13), perceived increased
activity on the flow images (reported in 6% and 8% of cases in 2 studies)
(10,15), and extensive fibrosis within the tumor itself (15).
MRI
The classic findings of hemangioma on MRI are that of a homogeneous, well
defined lesion with slight lobulations that is low signal relative to liver
on the T1 weighted images, becomes progressively brighter (greater than
or equal to cerebral spinal fluid) on the T2 weighted images as the time
to echo (TE) is lengthened, and demonstrates peripheral puddling of contrast
on the enhanced images (of a signal intensity matching the aorta). Approximately
5% of malignant tumors mimic hemangiomas on these long TE images, with
the most common mimics being sarcomas, endocrine tumors, and cystadenocarcinomas
(16). The common liver metastases (colon, lung, pancreas) are poor mimics
on MRI.
One of the useful distinguishing features on MRI is that, whereas both
hemangiomas and malignancies tend to have high signal on conventional T2
weighted images, the signal from malignancies tends to decrease as the
TE is lengthened, whereas the signal from hemangiomas tends to increase.
MRI was compared to Tc-99m RBC SPECT in 69 lesions seen on CT and/or
US ranging in size from 1.0 to 13.0 cm (12). All patients underwent Tc-99m
RBC SPECT (single head) and 0.5 Tesla MRI (TR/TE = 2000/50 and 2000/100).
The final diagnosis was hemangioma in 64 of these cases. The sensitivity
results were as follows:
| Size (cm) |
SPECT (%) |
MRI (%) |
| 1.0 - 1.9 cm |
14/24 (58) |
20/24 (83) |
| 2.0 - 2.9 cm |
12/13 (92) |
11/13 (85) |
| 3.0-13.0 cm |
24-27*/27 (89-100) |
27/27 (100)... |
the 3 false negatives on SPECT were ‘hot’ on the
delayed images and the flow images. |
Summary
Tc-99m RBC SPECT is a highly specific examination in the diagnosis of hemangioma,
with only 8 reported false positive cases in the literature. While the
sensitivity of MRI is greater than that of SPECT, it lacks SPECT’s high
specificity.
-
For possible hemangiomas greater than 2.0 cm, where the sensitivity of
SPECT has been reported to range from 83% to 100%, Tc-99m RBC SPECT is
the study of choice.
-
For possible hemangiomas < 1.0 cm, the sensitivity of SPECT has been
reported to range from 0% to 20%. Since small size often prohibits diagnostic
characterization on MRI, biopsy or follow-up imaging to document stability
are the recommended.
-
In the 1.0 to 2.0 cm category, the sensitivity of SPECT has been reported
to range from 33% - 58%, whereas the sensitivity of MRI has been reported
to be approximately 83%. If the possible hemangioma is adjacent to a highly
vascular structure (i.e. the heart, portal vein, or IVC), it may ‘blend’
into the activity of the adjacent high activity and not be distinguished.
For lesions adjacent to a highly vascular structure lesions, MRI will probably
have a better diagnostic yield. The main false positive MRI exams result
from metastases from hypervascular or cystic primary tumors. In patients
with a history of such primary tumors, Tc-99m RBC SPECT will probably have
a higher diagnostic yield. In cases in which Tc-99m RBC SPECT is equivocal,
MRI can be a useful adjunctive study.
References
1. Prakash R, Gupta RK, Narayyanan R, et al. Tc-99m radiocolloid scintigraphy,
planar, and SPECT red blood cell imaging and ultrasonography in the diagnosis
of hepatic hemangioma. Austr Radiol, 1989;33:237-244.
2. Mungovan JA, Cronan JJ, Vacarro J. Hepatic cavernous hemangiomas:
lack of enlargement over time. Radiology,1994;191:115-117.
3. Freeny PC and Marks WM. Hepatic hemangioma: dynamic bolus CT. AJR;
1986:147:711-719.
4. Tamm EP, Rabushka LS, Fishman EK, et al. Intrahepatic extramedullary
hematopoiesis mimicking hemangioma on Tc-99m red blood cell SPECT examination.
Clin Imag 1995;19:88-91.
5. Ginsberg F, Slavin JD and Spencer RP. Hepatic angiosarcoma: mimicking
of angioma on three-phase Tc-99m red blood cell scintigraphy. JNM 1986;27:1861-1863.
6. Swayne LC, Diehl WL, Brown TD and Hunter NJ. False-positive hepatic
blood pool scintigraphy in metastatic colon carcinoma. Clin Nucl Med 1991;16:630-632.
7. Farlow DC, Little JM, Gruenewald SM, et al. A case of metastatic
malignancy masquerading as a hepatic hemangioma on labelled red blood cell
scintigraphy. JNM 1993;34:1172-1174.
8. Rabinowitz SA, McKusik KA, Strauss HW. Tc-99m red blood cell scintigraphy
in evaluating focal liver lesions. AJR 1984;143:63-68.
9. Intenzo C, Kim S, Madsen M, et al. Planar and SPECT Tc-99m red blood
cell imaging in hepatic cavernous hemangiomas and other hepatic lesions.
Clin Nucl Med 1988;13:237-240.
10. Bonanno N, Baldari S, Cerrito A, et al. Diagnosis of hepatic hemangiomas
with Tc-99m labelled red blood cell scanning: value of SPECT. J of N Biology
and Medicine, 1991;35:135-140.
11. Kudo M, Ikekubo K, Yamamoto K, et al. Distinction between hemangioma
of the liver and hepatocellular carcinoma: value of labelled RBC - SPECT
scanning. AJR 1989;152:977-983.
12. Birnbaum BA, Weinreb JC, Megibow AJ, et al. Definitive Diagnosis
of Hepatic Hemangiomas: MR Imaging versus Tc-99m - labeled red blood cell
SPECT. Radiology 1990;176:95-101.
13. Krause T, Hauenstein K, Studier-Fisher B, et al. Improved evaluation
of Tc-99m RBC SPECT in hemangioma of the liver. JNM, 1993;34:375-380.
14. Zeissman HA, Silverman PM, Petterson J, et al. Improved detection
of small cavernous hemangiomas of the liver with high resolution 3 headed
SPECT. JNM 1991;32:2086-2091.
15. Rabinowitz SA, McKusick KA, Strauss HW. Tc-99m red blood cell imaging
in evaluating focal liver lesions. AJR 1984;143:63-68.
16. Weissleder R and Stark DD. Magnetic resonance imaging of liver tumors.
Seminars in US, CT, and MRI. 1989;10:63-77.
17. Egglin TK, Rummeny E, Stark DD, et al. Hepatic Tumors: Quantitative
tissue characterization with MRI. Radiology, 1990:176;107-110.
18. Choi BI, Han MC, Kim CW. Small hepatocellular carcinoma versus small
cavernous hemangioma: differentiation with MR imaging at 2.0 T. Radiology
1990;176:103-106.
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J. Anthony Parker, MD PhD, Tony_Parker@bidmc.harvard.edu