Multiparametric approach with diffusion-weighted imaging and dynamic contrast-enhanced MRI: a comparison study for differentiating between benign and malignant bone lesions in adults.

Aim: To evaluate and compare the diagnostic performance of quantitative parameters derived from diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in differentiating benign and malignant bone tumours.
Materials and Methods: Fifty-five patients (age range, 21-82 years; mean age, 55 years) underwent pretreatment MRI. Apparent diffusion coefficient (ADC) values were calculated by DWI. The DCE-MRI data were analysed for the volume transfer constant (K ^trans ), extravascular extracellular volume fraction (V _e ), and volume rate constant (K _ep ), and K ^trans /ADC ratio. Each parameter's performance was evaluated using the area under the receiver operating characteristic (ROC) curv (AUC), and their AUCs were compared. ROC curves were analysed and each parameter's optimal cut-off value was determined, from which each parameter was evaluated for sensitivity, specificity, accuracy, and positive and negative predictive values. The odds ratio (OR) with 95% confidence interval for detecting malignant bone lesions after adjusting the age factor of each parameter was estimated.
Results: All parameter values (except V _e ) were significantly different between benign and malignant bone tumours (p<0.05). The K ^trans had a significantly greater AUC than V _e (p=0.03). The K ^trans /ADC and K _ep had the best sensitivity (0.917) and specificity (0.632), respectively. The K _ep and K ^trans /ADC had the best positive (0.811) and negative (0.769) predictive values, respectively. The OR was highest for K ^trans /ADC (17.38; p=0.0013).
Conclusion: The K ^trans , K _ep , ADC, and K ^trans /ADC could help to detect malignant lesions from bone tumours and K ^trans /ADC appears to be the superior variable among them.
(Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)