Benign Versus Malignant Vertebral Compression, Chemical Shift MR Imaging, Is It Useful?

Abstract

Objectives: The aim of this study was to evaluate the diagnostic accuracy of chemical shift imaging in vertebral compression. Patients and Methods: Forty-nine patients with vertebral compression with suspected malignancy or history of trauma were included in this study. MR imaging of the spine with standard conventional MR sequences and additional chemical shift imaging was done with 1.5 Tesla MR Unit. Regions of interest (ROI) were placed on the abnormal marrow of compressed vertebrae both on the opposed phase and on the matching in phase images and signal intensity (SI) ratio values (SI out-phase/SI-in phase) were calculated. Results: Forty-nine patients had 68 spine lesions, consisting of 49 benign and 19 malignant fractures. Student t test, receiver operating characteristic (ROC) analysis and interclass correlation test were used statistically. Mean SI ratio of benign vertebral compression (0. 68 ± 0.29, range 0.13 - 1.53) was significantly lower than malignant SI ratio values (1.06 ± 0.10, range 0.96 - 1.35). With student t-test, there was significant difference between benign compressions compared to malignant compressions (P < 0.001). Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut off value in malignant and benign lesion definition. The optimal SI ratio cut off value was found to be 0.96 for separating benign and malignant vertebral compression. The area under the curve (AUC) value was observed as 0.92 (95% confidence interval [CI] = 0.86 - 0.99). According to that cutoff value, sensitivity was 100% (95% CI = 82.35% - 100%) and the specificity was 86% (95% CI = 72.76% - 94.06%). Interobserver reliability was studied with intraclass correlation and results were statistically significant with intraclass correlation coefficient (ICC) as 0.85 (P < 0.05). Conclusions: There is significant difference in signal values between benign and malignant compression fractures in chemical shift MR imaging. Chemical shift MR imaging has much additive data to conventional MRI in vertebral compression.