Diagnostic value of 3 T MR spectroscopy, diffusion-weighted MRI, and apparent diffusion coefficient value for distinguishing benign from malignant myometrial tumours

Abstract

To further verify the effectiveness of diffusion-weighted (DWI) magnetic resonance imaging (MRI) and 1H magnetic resonance spectroscopy (MRS) using a 3 T MRI system to differentiate benign leiomyomas from uterine sarcoma; to investigate the benefit of adding MRS to the apparent diffusion coefficient (ADC) for improving the specificity of the benign/malignant classification. The dataset included 21 uterine sarcoma from 14 patients and 84 benign leiomyomas from 51 patients. T1-and T2-weighted images as well as DWI were obtained using a 3-T MRI system. Approximately 60% of patients also underwent MRS. The chi-square test was used to compare the percentage of malignant lesions that showed choline peaks, lipid peaks, and restricted diffusion to the corresponding percentage of benign masses. Using the area under a receiver operating characteristic (AUC) curve, the efficacy of different parameters for distinguishing uterine sarcomas from leiomyomas was measured. The visual assessment of DWI images showed that 100% of malignant lesions exhibited restricted diffusion while the corresponding figure for benign leiomyomas was only 5%. The mean ADC of malignant tumours differed significantly from that of benign ones (p<0.001). The percentage of malignant lesions for which choline and lipid peaks were present was significantly higher than that of benign lesions. By combining the ADC and MRS findings, an accuracy of 98.3 (95.1-100) was achieved. The findings suggested that a combination of DWI and MRS could be useful in the preoperative assessment of uterine masses to differentiate benign leiomyomas from leiomyosarcoma.