Intracranial 4D Flow MRI: Toward Individualized Assessment of Arteriovenous Malformation Hemodynamics and Treatment-Induced Changes

Abstract

BACKGROUND AND PURPOSE:Arteriovenous malformations are an important etiology of hemorrhagic stroke. However, current imaging modalities and risk do not provide insights into individual AVM hemodynamics and its role in pathophysiology. The aims of this study are to determine whether intracranial 4D flow MR imaging can provide insights into arteriovenous malformation hemodynamics independent of the Spetzler-Martin grade and to report the changes in flow observed during staged embolization.

Value of 4D MR Angiography at 3T Compared with DSA for the Follow-Up of Treated Brain Arteriovenous Malformation

“…In addition, temporal and spatial resolution can be further improved up to an acceleration factor of 60 by optimizing the use of intelligent k-space sampling techniques (ie, CENTRA, parallel imaging, and partial Fourier imaging), whereas our examinations had an acceleration factor of 40, equivalent to other recent publications. 17,[19][20][21]28,31 Second, the interobserver agreement for DSA was not as high as expected compared with 4D-MRA, though it was very good ( 0.84, 95% CI .69 -.98 and 0.82, 95% CI .67-.98, respectively) for the reasons explained above.…”

“…Four-dimensional flow MRA techniques provide velocity measures and even color-encoded flow maps to aid in understanding the angioarchitecture. 28,29 In addition, the contribution of selective arterial spinlabeling, in addition to 4D-MRA, provided supplementary functional or anatomic information in 25% of the cases. 30 These techniques have not been evaluated in the posttreatment population.…”

Application of a Novel Brain Arteriovenous Malformation Endovascular Grading Scale for Transarterial Embolization

“…[26][27][28][29][30] In the case of venous egress, a dichotomized variable for the number of venous egress pathways (single ϭ 0, multiple ϭ 1 point) or variations thereof, in addition to or supplanting the number of arterial feeders, might extend the applicability of this grading scale to the transvenous approach. Future studies evaluating the endovascular grading scale in a prospective manner are warranted.…”

Fast 4D Flow MRI Re-Emerges as a Potential Clinical Tool for Neuroradiology

“…In this issue of AJNR, Ansari et al 12 have demonstrated that 4D flow MR imaging may play an important role in neurovascular diseases such as brain AVMs. The report demonstrated that cardiac-gated 4D flow MR imaging of the entire brain can be performed with excellent spatial and temporal resolution.…”