Nerve root infiltration, of the first sacral root with MRI guidance

The purpose of this clinical trial was to describe the methodology and eval uate the accuracy of optical tracking-based magnetic resonance (MR)-guided infiltration of the first sacral (SI), root. Thirty-five infiltrations were performed on 34 patients with a 0.23-T open C-arm magnet installed in a fu lly equipped operation room with large-screen (36 inches) display and optic al navigator utilizing infrared passive tracking. T1 and T2 fast spin-echo (FSE) images were used for localizing the target and fast field echo for mo nitoring, the procedure. Saline as contrast agent in single-shot (SS)FSE im ages gave sufficient contrast-to-noise ratio. Twenty-four patients had unop erated L5/S1 disc herniation, and 10 had S1 root irritation after failed ba ck surgery. Needle placement was successful in 97% of the cases, and no com plications occurred. Outcome was evaluated 1-6 months (mean 2.2 months) aft er the procedure and was comparable to that of other studies using fluorosc opy or computed tomography guidance. MR-guided placement of the needle is a n accurate technique for first sacral root infiltration. (C) 2000 Wiley-Lis s, Inc.