Conventional and advanced MRI evaluation of brain vascular malformations

Abstract

Vascular malformations (VMs) of the central nervous system (CNS) include a wide range of pathological conditions related to intra and extracranial vessel abnormalities. Although some VMs show typical neuroimaging features, other VMs share and overlap pathological and neuroimaging features that hinder an accurate differentiation between them. Hence, it is not uncommon to misclassify different types of VMs under the general heading of arteriovenous malformations. Thorough knowledge of the imaging findings of each type of VM is mandatory to avoid these inaccuracies. Conventional MRI sequences, including MR angiography, have allowed the evaluation of CNS VMs without using ionizing radiation. Newer MRI techniques, such as susceptibility‐weighted imaging, black blood sequences, arterial spin labeling, and 4D flow imaging, have an added value of providing physiopathological data in real time regarding the hemodynamics of VMs. Beyond MR images, new insights using 3D printed models are being incorporated as part of the armamentarium for a noninvasive evaluation of VMs. In this paper, we briefly review the pathophysiology of CNS VMs, focusing on the MRI findings that may be helpful to differentiate them. We discuss the role of each conventional and advanced MRI sequence for VMs assessment and provide some insights about the value of structured reports of 3D printing to evaluate VMs.

Multimodal MRI diagnosis and transvenous embolization of a basicranial emissary vein dural arteriovenous fistula: A case report

“… 8 , 14 Multimodal MRI has allowed for the evaluation of DAVFs, without ionizing radiation and invasion. 15 TOF-MRA without saturation, due to its high spatial resolution, is important for diagnosing and identifying the feeding artery, fistula location, and venous drainage. 16 , 17 TOF-MRA can describe various DAVF characteristics, including asymmetrically dilated feeding arteries, structural characteristics of vessels surrounding fistulas, abnormal draining veins, and dilated cortical veins and reverse flow with venous thrombosis.…”

Advances in differential diagnosis of cerebrovascular diseases in magnetic resonance imaging: a narrative review

“…The malformation is usually congenital and has abnormal blood flow in the brain. The main symptoms of the vascular malformations include headaches, seizures, strokes, or hemorrhage (88)(89)(90).…”

“…DCE-MRI can quickly acquire image with high specificity for differentiating venous malformation from non-venous malformations, which yields a volumetric dataset of high spatial and temporal resolution. Time-resolved angiography techniques can differentiate high-flow from low-flow lesions based on their hemodynamic based on its assessments of flow direction, feeder arteries and drainage veins (77,89,91,92).…”

Overview of multimodal MRI of intracranial Dural arteriovenous fistulas

“…These include dilated feeding arteries, dilated draining veins, venous sinuses, and the related venous system. 19 , 20 , 21 High-grade DAVFs with venous hypertension, focal angiogenic edema, cytotoxic edema, intracranial hemorrhage, and/or venous obstruction can be detected using T2 weighted imaging (T2WI), fluid attenuated inversion recovery (FLAIR), and diffusion weighted imaging (DWI). 19 , 21 , 22 …”