Cavernous Venous Malformation

40F with headache • Xray of the Week

Figure 1. What is the important finding on these images.

Figure 2. CT and MRI of cavernous venous malformation. Arterial venous malformation in the left posterior periventricular region with draining veins extending to the internal cerebral veins.

A. Axial non contrast CT showing subtle density in left frontal lobe (red arrow).

B. Axial T1WI showing cavernous venous malformation (green arrow).

C. Axial T1WI with contrast showing cavernous venous malformation with no significant enhancement (green arrow).

D. Axial FLAIR showing cavernous venous malformation (green arrow).

E. coronal GRE showing cavernous venous malformation with peripheral hemosiderin ring (green arrow).

F. Axial GRE showing cavernous venous malformation with peripheral hemosiderin ring (green arrow).

Introduction:

Cavernous venous malformations (CVM; or cavernomas, cavernous hemangiomas) are clusters of abnormal hyalinized capillaries most commonly located supratentorially and can be found incidentally or present with focal neurological deficits, headaches, and most often seizures (1). CVMs have an incidence of 0.4%-0.8% in the general population (2). They can be seen in adults or children and are either familial (multiple CVMs) or sporadic (usually a single CVM) (1). According to the ISSVA classification of vascular anomalies, these CVMs have been termed slow flow venous malformations. Rupture causing hemorrhage can occur with an average annual rate of 0.7%-1.1% (2), although less common compared to arteriovenous malformations due to their low pressure and flow (1).

Discussion:

CVMs are difficult to diagnose on cerebral angiography due to their low flow profile and lack of arteriovenous shunting (3). CT has higher sensitivity and shows hyperdense lesions without contrast (Figure 1A), although they can be difficult to visualize since they do not enhance. MRI is more sensitive and specific for detecting CVMs, and is the imaging modality of choice. On T2w and T1w-MR, a rim of hypointensity may be seen (Figure 1D). Using the Zabramski classification, CVMs can be grouped into four types based on appearance on MRI (5). Susceptibility-weighted MR imaging can also be very useful since it can recognize deoxyhemoglobin and hemosiderin deposits which are characteristically associated with CVMs. Blood breakdown products may appear different depending on the MR sequence and the age of the products. Gradient-echo (GRE) MRI offers optimal detection of CVMs, especially if missed by conventional spin echo sequences (4, 6) and can appear as a blooming pattern (Figure 1E).

Treatment:

Diffusion tensor (DT) imaging (Figure 1F) may be used intraoperatively along with fMRI to better visualize the CVM. DT tractography allows the surgeon to visualize white matter tracts which may cross through or near the hemosiderin rim of the CVM (1,7). Generally, symptomatic CVMs or ones that are in sensitive areas undergo microsurgical resection. If surgical risk is high, stereotactic radiosurgery may be done to prevent progression of CVMs (1). Follow-up MRIs are recommended due to high risk of re-bleeding of CVM remnants (1).

References:

1. Mouchtouris N, Chalouhi N, Chitale A, et al. Management of cerebral cavernous malformations: from diagnosis to treatment. ScientificWorldJournal. 2015;2015:808314. doi:10.1155/2015/808314

2. Ene C, Kaul A, Kim L. Natural history of cerebral cavernous malformations. Handb Clin Neurol. 2017;143:227-232. doi:10.1016/B978-0-444-63640-9.00021-7

3. Wang, K. Y., Idowu, O. R., & Lin, D. (2017). Radiology and imaging for cavernous malformations. In Handbook of Clinical Neurology (Vol. 143, pp. 249-266). (Handbook of Clinical Neurology; Vol. 143). Elsevier B.V.. doi:10.1016/B978-0-444-63640-9.00024-2

4. Lehnhardt FG, von Smekal U, Rückriem B, et al. Value of gradient-echo magnetic resonance imaging in the diagnosis of familial cerebral cavernous malformation. Archives of Neurology. 2005 Apr;62(4):653-658. doi:10.1001/archneur.62.4.653

5. Zabramski JM, Wascher TM, Spetzler RF, et al. The natural history of familial cavernous malformations: results of an ongoing study. J Neurosurg. 1994;80(3):422-432. doi:10.3171/jns.1994.80.3.0422

6. Campbell PG, Jabbour P, Yadla S, Awad IA. Emerging clinical imaging techniques for cerebral cavernous malformations: a systematic review. Neurosurg Focus. 2010;29(3):E6. doi:10.3171/2010.5.FOCUS10120

7. Cauley KA, Andrews T, Gonyea JV, Filippi CG. Magnetic resonance diffusion tensor imaging and tractography of intracranial cavernous malformations: preliminary observations and characterization of the hemosiderin rim. J Neurosurg. 2010;112(4):814-823. doi:10.3171/2009.8.JNS09586

Neal Joshi is a medical student and aspiring diagnostic radiologist at Rowan University School of Osteopathic Medicine in New Jersey. Prior to medical school, he did research with mouse models for Parkinson’s disease and L-DOPA induced dyskinesias. He also did an internship at Kessler Institute for Rehabilitation in a stroke lab analyzing MR images in ischemic stroke patients with hemispatial neglect. During his time at Rowan, he did research with animal models for traumatic brain injury with an emphasis on electrophysiology of neurons. He graduated from William Paterson University where he completed his studies in biology and biopsychology. Apart from medical school, Neal loves to read, skateboard, go on hikes, and spend time with his friends.

Follow Neal Joshi on Twitter @NealJoshi

All posts by Neal Joshi

Kevin M. Rice, MD is the president of Global Radiology CME

Dr. Rice is a radiologist with Renaissance Imaging Medical Associates and is currently the Vice Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.

Follow Dr. Rice on Twitter @KevinRiceMD

All posts by Kevin M. Rice, MD