Emerging clinical imaging techniques for cerebral cavernous malformations: a systematic review

Abstract

Cerebral cavernous malformations (CCMs) are divided into sporadic and familial forms. For clinical imaging, T2-weighted gradient-echo sequences have been shown to be more sensitive than conventional sequences. Recently more advanced imaging techniques such as high-field and susceptibility-weighted MR imaging have been employed for the evaluation of CCMs. Furthermore, diffusion tensor imaging and functional MR imaging have been applied to the preoperative and intraoperative management of these lesions. In this paper, the authors attempt to provide a concise review of the emerging imaging methods used in the clinical diagnosis and treatment of CCMs.

Fig. 1

Subtle changes in appearance of solitary CCM with different MR imaging sequences, reflecting differential sensitivity of blood breakdown products at different ages, and low flow in dilated cavernous channels. The MR imaging appearance of human CCM lesions, including high field ex-vivo image correlations with confocal microscopy are presented in detail by Shenkar et al.

Fig. 2

Multiple MR imaging sequences in a patient presenting with temporal lobe seizures. The T2-weighted sequence (A) illustrates subtle abnormality in the left posterior mesiotemporal region, consistent with non-specific hemosiderin deposition. The Gd-enhanced T1-weighted image (B) delineates a prominent venous structure with “caput medusae” pattern, associated with the T2-weighted signal, likely suggesting an associated DVA. The T2*GRE image (C) reveal much better delineation of multiple foci of CCM.

Fig. 3

A T2*GRE MR image showing multifocal hemorrhagic lesions in an elderly patient with previous strokes, including recent intracerebral hemorrhages associated with untreated hypertension. The T2*GRE MR imaging sequences revealed multifocal occult tiny hemorrhagic lesions, interpreted as hypertensive angiopathy. These are differentiated from familial CCM disease by the clinical setting and by the clustering of lesions in periventricular areas most vulnerable to hypertensive angiopathy. Conversely, CCM disease is associated with lesions in a volume distribution throughout the brain.

Fig. 4

Representative T1-weighted (A), T2*GRE (B), and SW (C) MR images obtained in a patient with a family history of familial CCM disease, who presented for routine MR imaging screening. The T2 sequences (A) reveal 2 suspected CCM lesions, which were better delineated on T2*GRE sequences The T2*GRE sequences (B) also suggesting perhaps 1 or 2 additional subtle lesions. The SW images (C) reveal many additional lesions throughout the brain.

Fig. 5

Representative T1-weighted (A), T2*GRE (B), and SW (C) MR images obtained in a patient with a solitary sporadic CCM that was discovered incidentally in the workup of an unrelated neoplasm. The T1-weighted contrast-enhanced images (A) revealed a suspected CCM in the right frontal cortex (left), and subtle abnormal venous prominence in superior and medial to the lesion (not shown). The T2*GRE images (B) better delineated the same lesion. The SW sequences (C) revealed no additional lesions, although they also demonstrate the suspected venous anomaly.

Fig. 6

Representative CT scan an T2-weighted (B), T1-weighted (C), and functional (D) MR images obtained in a patient who presented with acute onset of left arm and hand paresis. The CT examination (A) revealed focal hemorrhage in the rolandic region. T2-weighted images (B) revealed a hemorrhagic lesion with surrounding edema, consistent with acute hemorrhage. The T1-weighed images (C) did not clearly clarify the location of sensorimotor structures in relation to the lesion. These were easily outlined by functional MR imaging (D), with zones of activation in response to left hand movement shown in red-orange. The region of functional activation on fMR imaging corresponded to reversal of somatosensory median nerve evoked sensory potential recording on the cortical surface, confirming the location of the rolandic sulcus. A more posterior sulcus was chosen for image-guided transsulcal microsurgical resection of the lesion (blue arrow), which proved to be a CCM, and the resection was accomplished without worsening in motor or sensory function.