The Accuracy of the TRICKS MRI in Diagnosing and Localizing a Spinal Dural Arteriovenous Fistula: A Feasibility Study.

OBJECTIVE: Spinal vascular malformations (SVMs) are a heterogenous group of vascular abnormalities. The gold standard for diagnosis of SVMs is spinal digital subtraction angiography (DSA), which can be challenging because of the large number of segmental arteries that need to be catheterized and the limitations in term of contrast volume used and fluoroscopy time. We describe and compare the use of the time-resolved imaging of contrast kinetics (TRICKS) sequence and DSA in the diagnosis of spinal dural arteriovenous fistulas (SDAVFs) in our institution. METHODS: This is a retrospective cohort study of 27 patients who had a TRICKS MRI followed by a DSA for the diagnosis of their SDAVFs between November 2003 and November 2021. RESULTS: A total of 19 (70.4%) patients were positive for a SDAVF on both TRICKS MRI and DSA. Out of those 19, 9 (47.4%) were in the exact location on both TRICKS MRI and DSA whereas 10 (52.6%) were in different locations. With respect to the 10 patients who had discrepancies in their SDAVF localization between the 2 modalities, 9 (90%) patients had a 1-level difference and 1 (10%) had a 2-level difference. CONCLUSIONS: TRICKS MRI represents an accurate screening tool to be performed before a spinal DSA in order to guide the interventionalist to focus on the correct level ±2 levels; this extra noninvasive screening tool will decrease the risk of a kidney injury from an overuse of contrast and minimize the fluoroscopy/radiation overexposure.

Advanced imaging applications for endovascular procedures.

Advanced imaging techniques, particularly in CT and MRI, have become state-of-the-art to support the performance of interventional neuroradiologic procedures. Multidetector CT scanners with submillimeter detectors and real-time workstations have allowed the use of a noninvasive study, CT angiography, as a first-line diagnostic study at many institutions to detect and evaluate the morphology of aneurysms. Follow-up for postsubarachnoid spasm now includes transcranial Doppler, CT angiography, and sometimes perfusion to guide therapy. While both intracranial and extracranial stenosis have long been well evaluated by MR and CT angiography, information about the intimal wall and plaque morphology is now possible. In the setting of acute ischemia, CT with perfusion or MR with diffusion and perfusion has increased the ability to separate territory at risk from infarcted tissue, and can help to guide more appropriate intervention. This article addresses current state-of the-art imaging applications as well as a few techniques on the horizon that show great promise in helping to characterize those lesions amenable to endovascular therapy.