Time-Resolved Contrast-Enhanced MR Angiography of Spinal Vascular Malformations

Abstract

BACKGROUND AND PURPOSE:The diagnosis of spinal vascular malformations may be challenging on conventional MR imaging because neither the location of the signal abnormality in the spinal cord nor the level of the abnormal flow voids correlates with the level of the fistula. We conducted a retrospective evaluation of the utility of using a time-resolved imaging of contrast kinetics sequence in the diagnosis, characterization, and localization of spinal vascular malformations, comparing it with the criterion standard of spinal DSA.

Impact of non-contrast enhanced volumetric MRI-based feeder localization in the treatment of spinal dural arteriovenous fistula

“…The latter MR method, also known as contrast-enhanced, time-resolved MRA, is a vendor-specific technique recently introduced to investigate vessel flow with the aim of achieving optimal temporal and spatial resolution 19 20. Two studies evaluating the usefulness of this technique have shown that the fistula was localized to one vertebral level in 82% and 85%; however, accurate localization was possible in only 70.2% and 50%, respectively 12 13. Despite the obvious advantages of these techniques, some important limitations must be kept in mind while interpreting the results.…”

Utility of 3D SPACE T2-weighted volumetric sequence in the localization of spinal dural arteriovenous fistula

“…1,2,19 We found good agreement between the 2 observers, achieving more than 80% accuracy in the correct identification of the fistulous site. Accuracy was improved to more than 90% when location within 1 vertebral level was considered.…”

“…Using this technique, Amarouche et al examined 33 patients with SDAVF and accurately determined the level of fistula in 70.2% of patients, which improved to 82% when the fistula was considered within 1 vertebral level. 2 In a similar study, the level of fistula was localized to 1 vertebral level in 85% of patients with SDAVF, although accurate identification was only possible in less than 50% of the cases. 19 Compared with contrast-enhanced MR techniques, there are fewer reports on noncontrast techniques for the as- sessment and localization of the fistula.…”

“…8 Noninvasive imaging methods, such as contrast-enhanced MR angiography (MRA) and CT angiography (CTA), have been shown to have higher sensitivity and specificity in the detection and prediction of the location of the fistula. 1,2,14,17,19,23 Higher magnet strengths, faster imaging techniques due to higher gradient performances, larger field of view (FOV), and robust data-sampling methods have improved the diagnostic performance of MRI. However, such technical specifications may not be available for all MR machines.…”

“…14 The time-resolved MRA technique is increasingly being used to noninvasively study the vascular structures and has also shown improved performance in the detection and localization of SDAVF. 1,2,19 This technique involves preferential rapid sampling of the central k-space region, which is updated continuously to provide a series of timeresolved images of different phases of angiograms. Using this technique, Amarouche et al examined 33 patients with SDAVF and accurately determined the level of fistula in 70.2% of patients, which improved to 82% when the fistula was considered within 1 vertebral level.…”