Accelerated Time-Resolved Contrast-Enhanced Magnetic Resonance Angiography of Dural Arteriovenous Fistulas Using Highly Constrained Reconstruction of Sparse Cerebrovascular Data Sets.
Time-resolved contrast-enhanced magnetic resonance angiography (MRA) is commonly used to noninvasively characterize vascular malformations. However, the spatial and temporal resolution of current methods often compromises the clinical value of the examinations. Constrained reconstruction is a temporal spatial correlation strategy that exploits the relative sparsity of vessels in space to dramatically reduce the amount of data required to generate fast high-resolution time-resolved contrast-enhanced MRA studies. In this report, we use a novel temporal spatial acceleration method termed HYPRFlow to diagnose and classify dural arteriovenous fistulas (DAVFs). Our hypothesis is that HYPRFlow images are of adequate diagnostic image quality to delineate the arterial and venous components of DAVFs and allow correct classification using the Cognard system.



Eight patients with known DAVFs underwent HYPRFlow imaging with isotropic resolution of 0.68 mm and temporal resolution of 0.75 second and 3-dimensional time-of-flight (3DTOF) MRA. The 3DTOF images and HYPRFlow images were evaluated by 2 readers and scored for arterial anatomic image quality. Digital subtraction angiography (DSA) was available for comparison in 7 subjects, and for these patients, each DAVF was classified according to the Cognard system using HYPRFlow and DSA examinations. Digital subtraction angiography was considered the reference examination or criterion standard.



HYPRFlow imaging classification was concordant with DSA in all but 1 case. There was no difference in the arterial image quality scores between HYPRFlow and 3DTOF MRA (95% confidence interval). Arterial-to-venous separation was rated excellent (n = 3), good (n = 4), or poor (n = 1), and arteriovenous shunting was easily appreciated. Undersampling artifacts were reduced by using a low pass filter and did not interfere with the diagnostic quality of the examinations.



HYPRFlow is a novel acquisition and reconstruction technique that exploits the relative sparsity of intracranial vessels in space to increase temporal and spatial resolution and provides accurate delineation of DAVF vasculature.
From the Departments of *Radiology and †Medical Physics, University of Wisconsin, Madison, WI; and ‡Department of Morphologic and Functional Imaging, Université Paris Descartes, INSERM UMR 894, Hôpital Sainte Anne, Paris, France.
Zachary
Z
Clark
Kevin M
KM
Johnson
Yijing
Y
Wu
Myriam
M
Edjlali
Charles
C
Mistretta
Oliver
O
Wieben
Patrick
P
Turski
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction / Q000379:methods; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D020785:Central Nervous System Vascular Malformations / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013995:Time
D003287:Contrast Media