Superior Metal Artifact Reduction With MAVRIC-SL Versus STIR in Lumbar Spine Instrumentation: A Retrospective Analysis of 84 Patients.

Abstract

Study DesignRetrospective Comparative Study.ObjectivesTo evaluate Multi-Acquisition Variable-Resonance Image Combination Selective (MAVRIC-SL) versus conventional Short-Tau Inversion Recovery (STIR) sequences for metal artifact reduction and diagnostic capability in patients with lumbar titanium instrumentation.Methods84 patients with implants in lumbar spine (mean age 54.3 ± 14.7 years; 52.4% male), who underwent both STIR and MAVRIC-SL MRI at 1.5 T. A neuroradiologist and spine surgeon independently measured signal loss areas and evaluated geometric distortion and neural structure visibility using standardized scales. Statistical analysis included paired t-tests and Wilcoxon signed-rank tests with Bonferroni correction (<i>P</i> < 0.01).ResultsMAVRIC-SL reduced signal loss area by 39.1% compared to STIR (0.809 ± 0.205 cm² vs 1.356 ± 0.266 cm², <i>P</i> < 0.001, Cohen's d = 2.04). Neural structure visibility showed substantial improvement: axial neural foramina (96.4% vs 0%), sagittal neural foramina (96.4% vs 7.1%), and sagittal spinal cord (98.8% vs 14.3%), all <i>P</i> < 0.001. Posterior vertebral border clarity improved from 33.3% to 94.0% (<i>P</i> < 0.001).ConclusionsMAVRIC-SL provides superior metal artifact reduction and significantly improves neural structure visualization in lumbar spine instrumentation, with effect sizes among the largest reported in spine imaging studies. These improvements justify the longer acquisition time for symptomatic patients requiring detailed evaluation.