History: An elderly woman presents with memory loss and confusion.
CT images are shown below.
Here are some panels of fluid-attenuated inversion-recovery (FLAIR) and gradient-recalled echo (GRE) images.
CT: CT shows a 5-mm focus of hyperattenuation with surrounding hypoattenuation within the superior right cerebellar hemisphere. Diffuse sulcal and ventricular prominence, compatible with diffuse cerebral volume loss. Scattered geographic regions of relative hypoattenuation within the bilateral periventricular white matter, compatible with small-vessel ischemic disease.
MRI: MRI shows numerous small, rounded areas of signal dropout, best appreciated on axial GRE, within the cerebellum, right paracentral pons, left posterior and ventral thalamus, and corona radiata.
- Multiple cavernous malformations
- Multiple hypertensive hemorrhages
- Sequelae of prior trauma
- Diffuse axonal injury
- Parenchymal contusions
- Amyloid angiopathy
- Multiple hemorrhagic telangiectasia
Diagnosis: Multiple cavernous malformations (presumed, given the distribution and lack of inciting trauma or hypertension)
Cavernous malformations (also known as cavernomas) are benign vascular hamartomas that are comprised of sinusoids of endothelial-lined, immature blood vessels without intervening normal brain tissue. They demonstrate a wide range of behavior and may progress, regress, or enlarge. Cavernous malformations are the most common angiographically occult CNS vascular malformation, with a prevalence of approximately 0.5%. About 75% of cases are solitary (sporadic), with 10% to 30% of cases being multiple or familial. The average age of onset is age 40 to 60, but they can be seen in children. They occur in equal frequency in men and women, and they are seen in all ethnicities.
Cavernous malformations vary in size and may range from microscopic to giant (> 6 cm), averaging 0.5 to 4 cm. They frequently contain blood products of varying ages and often demonstrate a complete hemosiderin rim. Three gene loci are associated with cavernous malformations: CCM1, CCM2, and CCM3. There is a disease entity known as multiple familial cavernous malformations syndrome.
海绵状血管畸形大小不等，从微小的到巨大的（> 6 cm），平均0.5-4cm。病变包含不同时期的血液产物，常可见一完整的含铁血黄素环。
三个基因位点与海绵状血管畸形相关: CCM1, CCM2, CCM3。有一种病为：多发性家族性脑海绵状血管畸形综合症。
Cavernous malformations are associated with developmental venous anomaly (DVA), superficial siderosis, and cutaneous abnormalities, including café-au-lait spots and hyperkeratotic capillary venous malformations (“cherry angiomas”). They most commonly present clinically with seizures (50%), and 25% of patients with cavernous malformations will have neurologic deficits. However, it is important to note that 20% of these patients will be completely asymptomatic.
Radiologic overview of the diagnosis
In terms of radiologic workup of cavernous malformations, noncontrast-enhanced CT (NECT) is frequently the first imaging modality employed. Interestingly, 30% to 50% of the time, NECT is negative. When demonstrated on NECT, cavernomas are typically well-delineated round to ovoid, hyperdense lesions, typically less than 3 cm. Approximately 40% to 60% of these lesions demonstrate calcification. They do not demonstrate mass effect, unless there has been recent hemorrhage. It is important to note that the adjacent brain parenchyma appears normal. On contrast-enhanced CT (CECT), cavernomas demonstrate minimal, if any, enhancement. The exception arises in the setting of associated DVA. CT angiography is typically negative.
The single best imaging modality for evaluating cavernous malformations is MRI. On T1-weighted imaging, cavernous malformations demonstrate a variable appearance, which depends on the stage of blood products. Most commonly, they have a “popcorn ball” appearance of heterogenous hyper- and hypointense blood-containing locules. Uncommonly, acute, nonspecific hemorrhage is identified. On T2-weighted imaging, cavernomas most commonly demonstrate a reticulated, “popcorn” lesion of heterogenous signal with complete, hypointense hemosiderin rim. They may or may not demonstrate locules of blood with fluid-fluid levels. These lesions have a rounded appearance, with a matrix preventing collapse. Uncommonly, these lesions are hypointense on T2-weighted imaging. FLAIR may show a small geographic region of surrounding edema in acute lesions. The single best sequence for evaluation of cavernous malformations is the T2* GRE sequence, which is characterized by its marked susceptibility artifact, or “blooming.” If more than three lesions are present, the most common presentation is numerous, punctuate hypointense foci on GRE. Contrast-enhanced T1-weighted imaging demonstrates minimal, if any, enhancement, but it is useful in evaluating for associated DVA. MRA is typically unremarkable, except in cases of associated DVA.