Phase Shift MRI in Assessement of Vertebral Compression Fracture: Trial for a New Scoring System

Abstract

PurposeTo assess the value of in /opposed-phase quantitative chemical shift MRI in differentiating malignant from benign vertebral compression fractures (VCF).Patients and methodsTwenty patients (8 men), mean age 56 years, with low back and radiological proof of VCF were included in the study. MRI of spine with standard conventional sequences and special chemical shift sequence (in/opposed phase) as well as diffusion weighted imaging were performed (at 1.5 Tesla). Quantitative image analysis of regions of interest (ROI) on the abnormal marrow in the compressed (study group) and related normal vertebra in same patient (control group) was done in each patient. The signal intensity ratio (SIR) of the marrow was determined by dividing the mean signal intensity on the opposed-phase and in-phase images was performed.ResultsMean SIR of benign VCF [0.6 ± 0.27 (range 0.23–1.1)] was significantly lower than malignant VCF values [1.115 ± 0.14 (range 0.87–1.45)] (p < 0.0001, ROC 0.97). The optimal SIR cutoff value for separating benign and malignant VCF was found to be 0.9 with a calculated sensitivity of 91.5%, specificity of 87.5% and accuracy of 90%. We also found a cut-off value of 0.9, to be a statistically significant in differentiating benign from malignant causes of VCF. If SIR of 0.91 as a cutoff is applied, with >0.91 indicating malignant result and <0.91 defined as a benign result.ConclusionQuantitative chemical shift MR imaging could be a valuable addition to standard MR imaging techniques in differentiating benign from malignant vertebral compression fracture. We designed a new scoring system based on conventional MRI, in/opposed phase chemical shift and diffusion weighted imaging. The new scoring system may be a useful tool and add value in the diagnosis of compression vertebral fractures.