eMedicine Specialties > Radiology > Brain/Spine
Brain, Cavernous Angiomas: Imaging
Updated: May 20, 2009
Radiography
Findings
Plain radiography is not indicated in the diagnosis of cavernous angioma.
Computed Tomography
Large, right frontal and left occipital cavernous angiomas (same patient as in Images 2-4 in Multimedia). Axial nonenhanced CT image demonstrates a large heterogeneous-appearing lesion in the right frontal region. The lesion is primarily hyperattenuating in its central region, with a more diffuse, peripheral area of increased density resulting from calcification and small areas of hemorrhage.
Large right frontal and left occipital cavernous angiomas (same patient as in Images 1-4 in Multimedia). Nonenhanced axial CT image demonstrates findings of a large primarily hyperattenuating mass in the left occipital region. Note the relative lack of mass effect on the surrounding parenchyma on both CT images (see also Image 1 in Multimedia) and subsequent MRIs (see also Images 3 and 4 in Multimedia).
Typical nonspecific appearance of a left frontal-lobe cavernous angioma on a nonenhanced CT scan in this young adult who presented with new-onset seizures. Note the lack of mass effect or surrounding vasogenic edema.
Findings
With all relative imaging methods, dividing cavernomas into 3 components is helpful. These include (1) the peripheral pseudocapsule composed of gliotic hemosiderin-laden tissue, (2) the irregular intersecting connective tissue septa separating the sinusoidal spaces, and (3) the central vascular area composed of slow-flowing sinusoidal spaces.
Nonenhanced CT scans demonstrate cavernomas as focal oval or nodular-appearing lesions that demonstrate mild-to-moderate increased attenuation, without mass effect on the surrounding brain parenchyma. Areas of calcification and hemosiderin deposits in the walls of the fibrous septa, combined with the increased blood pool within the lesion, are responsible for hyperattenuation on nonenhanced images. CT scans demonstrate calcifications in as many as 33% of cavernomas. If the lesions are older, they can contain central hypoattenuating nonenhancing areas, which correspond to cystic cavities from resorbed hematomas.
Contrast enhancement can vary from minimal to striking, although 70-94% of cavernous malformations demonstrate mild-to-moderate enhancement after the intravenous administration of contrast agent. In large part, this enhancement results from the increased blood pool within the vascular component. The slightly heterogeneous and mottled enhancement results from the fibrous intravascular septa, and the peripheral rim of decreased attenuation results from the pseudocapsule of gliotic tissue surrounding the lesion.
Mass effect is not common unless the lesion is associated with recent hemorrhage. Cavernomas may not be detected when they present as acute intracerebral hematomas on nonenhanced CT images. After the administration of contrast material, cavernomas may be identified as areas of nodular enhancement adjacent to the hematoma.
Degree of Confidence
The degree of confidence is low.
Magnetic Resonance Imaging
Large, right frontal and left occipital cavernous angiomas (same patient as in Images 1-4 in Multimedia). T1-weighted axial MRI obtained at a slightly different angle from the CT scan (see Image 2 in Multimedia). The image demonstrates both cavernomas on the same image. These 2 heterogeneous masses have a reticulated core of high and low signal intensities surrounded by a hypointense rim of hemosiderin.
Gradient-echo axial MRI demonstrates increased conspicuity in large right frontal and left occipital cavernous angiomas (same patient as in Images 1-3 in Multimedia). The hemosiderin rim demonstrates a blooming artifact as a result of its increased magnetic susceptibility effects.
This image and those that follow (see Images 5-7 in Multimedia) demonstrate increased sensitivity of gradient-echo sequences compared with T1- and T2-weighted sequences in the detection of smaller lesions. This T1-weighted MRI fails to demonstrate the multiple, tiny cavernomas demonstrated on the gradient-echo image (see Image 7 in Multimedia).
Same patient as in Images 5-7 in Multimedia. A corresponding T2-weighted axial MRI does not demonstrate well the multiple tiny cavernomas seen with a gradient-echo sequence (see Image 7 in Multimedia).
Gradient-echo MRI demonstrates multiple, bilateral punctate and rounded areas of hypointensity within the periventricular and subcortical white matter (same patient as in Images 5-6 in Multimedia). The largest lesion in the periventricular frontal white matter just anterior to the frontal horn of the left lateral ventricle near the genu of the corpus callosum. Multiple smaller lesions are seen both anteriorly and posteriorly.
T1-weighted MRI demonstrates a small hyperintense lesion in the left temporal cortex with a hypointense rim. This smaller lesion is demonstrated better and is more apparent on a T2-weighted image (see Image 9 in Multimedia) and on a gradient-echo image (see Image 10 in Multimedia).
T2-weighted MRI demonstrates the hypointense blooming artifact within the lesion in the left temporal lobe, although the blooming is not nearly as marked as seen on a gradient-echo image (see Image 10 in Multimedia).
The lesion becomes obvious on this gradient-echo image (see also Image 9 in Multimedia). Even this relatively small temporal-lobe lesion is detected easily with this pulse sequence. Because cavernous angiomas are often multiple, a gradient-echo sequence should be performed in addition to standard T1- and T2-weighted sequences to carefully identify all concomitant lesions, as clinically indicated.
T1-weighted MRI demonstrates a pontine cavernous angioma. Note the slightly hypointense lesion located centrally and to the right near the middle cerebellar peduncle. Given its location, a significant hemorrhage can have a clinically devastating result. This lesion demonstrates that location, more than size, is a critical factor in predicting outcome or sequelae of future hemorrhage.
T2-weighted MRI of a pontine cavernoma (same patient as in Image 11 in Multimedia).
Minor amounts of hemosiderin can make smaller lesions evident on gradient-echo MRIs, as seen in this pontine cavernoma.
T1-weighted MRI of the classic popcornlike appearance of a large left-sided cavernous angioma, which primarily affects the temporal lobe.
T2-weighted MRI of a large cavernoma (same patient as in Image 14 in Multimedia). Note the minimal mass effect of this large lesion.
Gradient-echo MRI demonstrates the large amount of blood-breakdown products within this large lesion. Repeated hemorrhage is believed to contribute to the slow growth of some cavernomas over time.
T2-weighted MRI of a left frontal cavernoma (same patient as in Image 17 in Multimedia).
On this T1-weighted MRI, the lesion begins to take on the more characteristic mixed-signal-intensity appearance of a cavernoma (same patient as in Image 18 in Multimedia). Hyperintense bilateral arclike artifact from the patient's metallic dental braces is seen centrally over the basal ganglia and thalamic regions.
Findings
MRI findings of parenchymal cavernous angiomas demonstrate typical, popcornlike, smoothly circumscribed, well-delineated complex lesions. The core is formed by multiple foci of mixed signal intensities, which represents hemorrhage in various stages of evolution.5,6,7,8
Acute hematoma containing deoxyhemoglobin is isointense on T1-weighted images and markedly hypointense on T2-weighted images. Subacute hematoma, which contains extracellular methemoglobin, displays hyperintensity on both T1- and T2-weighted images because of the paramagnetic effect of the methemoglobin.
The interspersed fibrous-containing elements demonstrate mild hypointensity on both T1- and T2-weighted images because they contain a combination of calcification and hemosiderin. The heterogeneous core typically is surrounded completely by a low-signal-intensity hemosiderin rim on T1-weighted images. The hypointensity of this rim becomes more prominent, or blooms, on T2-weighted and gradient-refocused images because of the magnetic susceptibility effects.
Smaller cavernomas may appear as focal hypointense nodules with both T1- and T2-weighted sequences. The small lesions are depicted more clearly and are more numerous on gradient-echo images because of the increased susceptibility effects of the sequences. Sequential gradient-echo images also have been shown to define these punctate lesions further when the echo time is lengthened; this finding suggests that such lesions contain paramagnetic substances.
When imaged with time-of-flight techniques, the methemoglobin in the central core of a cavernous malformation may mimic flowing blood. However, a subsequent phase-contrast magnetic resonance angiogram obtained with low-velocity encoding (10-20 cm/s) should not demonstrate flow or abnormal vascularity; this finding helps exclude a vascular lesion.
Typically, cavernous angiomas are not associated with mass effect or edema and do not demonstrate a feeding artery or draining vein, except when associated with other vascular malformations with similar features. Cavernous angiomas are reported to be associated with venous malformations, which typically demonstrate a draining vein. Often, conventional angiography can be helpful for further characterization in these mixed cases.
Degree of Confidence
The degree of confidence is high.
Ultrasonography
Findings
Ultrasonography is not indicated in the diagnosis of cavernous angioma.
Nuclear Imaging
Findings
Nuclear medicine studies are not indicated in the diagnosis of cavernous angioma.
Angiography
Findings
In general, cavernous malformations are considered angiographically occult, and when they are evident on angiographic studies, the findings are nonspecific. MRI has largely replaced conventional angiography in the diagnosis of cavernomas. However, when the lesions occur in combination with other types of vascular malformations, as they do in as many as 30% of patients with venous angiomas, MRI characteristics become more complicated and less specific. In these patients, angiography can help further define the lesions.
Most cavernous malformations (37-48%) correspond to avascular masses on conventional angiograms. Because of the extremely slow flow of blood through these lesions, cerebral arteriographic findings are often normal. If the lesions are large enough or associated with hematomas, mass effect on adjacent vessels can be appreciated. The avascular appearance is the result of compression or destruction of vascular channels by hemorrhage, thrombosis, and generalized slow flow because of the small size of the connecting sinusoidal vessels with the peripheral normal parenchymal vessels.
When lesions are smaller and not associated with hematomas, 20-27% of angiograms demonstrate normal findings. Capillary blush is demonstrated at 12-20%. The capillary blush may not be visualized during the first injection; if the injection is repeated a few minutes later with a larger volume and over a longer period, the blush can be demonstrated better. Capillary blush is by no means a specific finding, and it can be seen in a variety of other processes and entities.
Degree of Confidence
The degree of confidence is low.
More on Brain, Cavernous Angiomas |
| Overview: Brain, Cavernous Angiomas |
 Imaging: Brain, Cavernous Angiomas |
| Follow-up: Brain, Cavernous Angiomas |
| Multimedia: Brain, Cavernous Angiomas |
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| Further Reading |
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References
Liquori CL, Berg MJ, Siegel AM, et al. Mutations in a gene encoding a novel protein containing a phosphotyrosine-binding domain cause type 2 cerebral cavernous malformations. Am J Hum Genet. Dec 2003;73(6):1459-64. [Medline].
Craig HD, Gunel M, Cepeda O, et al. Multilocus linkage identifies two new loci for a mendelian form of stroke, cerebral cavernous malformation, at 7p15-13 and 3q25.2-27. Hum Mol Genet. Nov 1998;7(12):1851-8. [Medline].
Maraire JN, Awad IA. Intracranial cavernous malformations: lesion behavior and management strategies. Neurosurgery. Oct 1995;37(4):591-605. [Medline].
Hauck EF, Barnett SL, White JA, Samson D. Symptomatic brainstem cavernomas. Neurosurgery. Jan 2009;64(1):61-70; discussion 70-1. [Medline].
Hallam DK, Russell EJ. Imaging of angiographically occult cerebral vascular malformations. Neuroimaging Clin N Am. May 1998;8(2):323-47. [Medline].
Hoang TA, Hasso AN. Intracranial vascular malformations. Neuroimaging Clin N Am. Nov 1994;4(4):823-47. [Medline].
Ide C, De Coene B, Baudrez V. MR features of cavernous angioma. JBR-BTR. Dec 2000;83(6):320. [Medline].
Novak V, Chowdhary A, Abduljalil A, et al. Venous cavernoma at 8 Tesla MRI. Magn Reson Imaging. Nov 2003;21(9):1087-9. [Medline].
Tarnaris A, Fernandes RP, Kitchen ND. Does conservative management for brain stem cavernomas have better long-term outcome?. Br J Neurosurg. Dec 2008;22(6):748-57. [Medline].
Bernotas G, Rastenyte D, Deltuva V, Matukevicius A, Jaskeviciene V, Tamasauskas A. Cavernous angiomas: an uncontrolled clinical study of 87 surgically treated patients. Medicina (Kaunas). 2009;45(1):21-8. [Medline].
Tasic GM, Djurovic BM, Jovanovic VT, Nikolic IM, Nestorovic BD, Radulovic DV, et al. [Surgical treatment of brain stem cavernoma--current approaches]. Acta Chir Iugosl. 2008;55(2):141-9. [Medline].
Zada G, Day JD, Giannotta SL. The extradural temporopolar approach: a review of indications and operative technique. Neurosurg Focus. 2008;25(6):E3. [Medline].
Attar A, Ugur HC, Savas A, et al. Surgical treatment of intracranial cavernous angiomas. J Clin Neurosci. May 2001;8(3):235-9. [Medline].
Flemming KD, Goodman BP, Meyer FB. Successful brainstem cavernous malformation resection after repeated hemorrhages during pregnancy. Surg Neurol. Dec 2003;60(6):545-7; discussion 547-8. [Medline].
Pollock BE, Garces YI, Stafford SL, et al. Stereotactic radiosurgery for cavernous malformations. J Neurosurg. Dec 2000;93(6):987-91. [Medline].
Shalek PA, Vinogradov BM, Pozdniakov AV, Stukov LA, Garmashov IuA. [Methods and results of stereotactic radiosurgery for cavernous angiomas]. Vopr Onkol. 2008;54(4):525-8. [Medline].
Flickinger JC, Kondziolka D, Pollock BE, Lunsford LD. Radiosurgical management of intracranial vascular malformations. Neuroimaging Clin N Am. May 1998;8(2):483-92. [Medline].
Awad IA, Robinson JR Jr, Mohanty S, Estes ML. Mixed vascular malformations of the brain: clinical and pathogenetic considerations. Neurosurgery. Aug 1993;33(2):179-88; discussion 188. [Medline].
Chaloupka JC, Huddle DC. Classification of vascular malformations of the central nervous system. Neuroimaging Clin N Am. May 1998;8(2):295-321. [Medline].
Escott EJ, Rubinstein D, Cajade-Law AG, Sze CI. Suprasellar cavernous malformation presenting with extensive subarachnoid hemorrhage. Neuroradiology. Apr 2001;43(4):313-6. [Medline].
Grossman RI, Yousem DM. Vascular diseases of the brain. In: Neuroradiology: The Requisites. St Louis: Mosby-Year Book;. 1994: 121-6, 141-2.
Mulliken JB, Young AE, eds. Classification of vascular birthmarks. In: Vascular Birthmarks: Hemangiomas and Malformations. Philadelphia: WB Saunders Co;1988: 24-37.
Osborne AG. Intracranial vascular malformations. In: Diagnostic Neuroradiology. Mosby-Year Book;1994:284, 311-4.
Rapacki TF, Brantley MJ, Furlow TW Jr, et al. Heterogeneity of cerebral cavernous hemangiomas diagnosed by MR imaging. J Comput Assist Tomogr. Jan-Feb 1990;14(1):18-25. [Medline].
Sage MR, Blumbergs PC. Cavernous haemangiomas (angiomas) of the brain. Australas Radiol. May 2001;45(2):247-56. [Medline].
TerBrugge KG, Rao KC. Intracranial aneurysms and vascular malformations. In: Lee SH, Zimmerman RA, Rao KC, eds. Cranial MRI and CT. 4th ed. New York: McGraw-Hill;1999: 530-7.
Voigt K, Yasargil MG. Cerebral cavernous haemangiomas or cavernomas. Incidence, pathology, localization, diagnosis, clinical features and treatment. Review of the literature and report of an unusual case. Neurochirurgia (Stuttg). Mar 1976;19(2):59-68. [Medline].
Yasargil MG. Microneurosurgery. New York: Theime Medical Publishers;1987.
Further Reading
Clinical guidelines
Stereotactic radiosurgery for patients with intracranial arteriovenous malformations (AVM).
IRSA - Professional Association. 2003 Sep. 10 pages. NGC:003285
Clinical trials
Influence of MMP on Brain AVM Hemorrhage
Genetic Basis of Hemangiomas
Related eMedicine topics
Brain, Capillary Telangiectasia
Intracranial Arteriovenous Malformation
Temporal Lobe Epilepsy
Brain, Venous Vascular Malformations
Keywords
cavernous angiomas, cavernous malformation, cavernous hemangioma, cavernomas, occult cerebrovascular malformation, intracranial vascular malformations
