DOES QUANTIFICATION OF DIFFUSION (ADC VALUE) AID IN IDENTIFYING MALIGNANT VERTEBRAL LESIONS? A CROSS SECTIONAL OBSERVATIONAL STUDY.

Abstract

Background: Characterization of vertebral pathologies as benign or malignant is a frequent dilemma that often requires invasive procedures for diagnosis. Today, imaging is sufcient for diagnosis of most benign vertebral pathologies with further conrmation on response to therapy. With better understanding of diffusion characteristics of tissues, attempt is being made to assess various imaging characteristics to make a denite diagnosis of malignant lesions as well. In this study we quantied apparent diffusion coefcient (ADC) of lesions in an effort to determine whether ADC values are different for benign or malignant vertebral body lesions. Consecutive patients that reported to the department of Radiodiagnosis, during 1st November 2017 to 31st March 2019, were included in the study. In this cross sectional observational study, for 32, that is, 22 benign and ten malignant vertebral lesions, diffusion weighted (DW) MRI sequence was done and ADC values were recorded. Conrmation was done with post treatment follow up or wherever feasible, tissue diagnosis. All malignant cases had histopathology conrmation from the site of primary lesion. Quantitative variables using independent t-test were used for comparison of ADC values between two groups. Results: The difference in mean ADC values of benign and malignant lesions were statistically signicant (P<0.0001). The optimal cutoff of ADC -3 2 value for differentiating benign from malignant vertebral body lesion was 0.950 x 10 mm /s with sensitivity of 80% and specicity of 95.45%. Conclusion:In all cases, DWI/ ADC, along with routine MR sequences, were able to characterize the lesion either as benign or malignant except in two cases of tubercular infection of spine and one each of spindle cell sarcoma & metastasis from cancer lung where there was overlap of ADC values.