Dynamic contrast-enhanced magnetic resonance perfusion compared with digital subtraction angiography for the evaluation of extradural spinal metastases: a pilot study.
Academic Article
Overview
abstract
STUDY DESIGN: This was a retrospective study comparing dynamic contrast-enhanced magnetic resonance (DCE-MR) perfusion with digital subtraction angiography (DSA) in determining the vascularity of spinal tumors. OBJECTIVE: To report on the efficacy of DCE-MR perfusion as a potential noninvasive surrogate for measuring vascularity and thus determine the need for preoperative embolization. SUMMARY OF BACKGROUND DATA: Although primary spinal tumors are rare, spine metastases are relatively common and symptomatic in approximately 14% of patients. Symptomatic patients require palliation with radiotherapy and/or surgery, with possible preoperative endovascular embolization of the tumor. METHODS: A retrospective review revealed 10 patients with 11 diseased vertebral bodies who had received spine DCE-MR perfusion studies and subsequently underwent spinal DSA. Processed MR data were used to calculate a blood flow ratio comparing blood flow with a diseased and an adjacent normal vertebral body. Spinal tumor vascularity was graded on the basis of angiographic tumor blush from 0 (decreased enhancement compared with a normal vertebral body) to 4 (marked tumor blush with early arteriovenous shunting). RESULTS: Eight vertebral bodies demonstrated increased vascularity on DSA with blood flow ratios of greater than 1.8, 2 vertebral bodies demonstrated normal enhancement on DSA with cerebral blood flow (CBF) ratio of 0.55 to 1.14, and 1 vertebral body level had decreased enhancement on DSA, with a CBF ratio of 0.43. There was a strong correlation between CBF ratio and DSA score, with Spearman ρ = 0.87 (P = 0.00012). CONCLUSION: These data show a statistically significant correlation between CBF ratio and DSA and suggest that DCE-MR perfusion can serve as a surrogate to DSA for determining tumor vascularity in patients with extramedullary spinal metastases.
