Evaluation of apparent diffusion coefficient measurements and magnetic resonance imaging findings in benign and malignant gynecologic masses

Aim: This study aimed to investigate the differences in magnetic resonance imaging (MRI) findings and various apparent diffusion coefficient (ADC) measurements between benign and malignant gynecologic masses. Methods: MRI images of 102 patients with pelvic masses, examined between June 2016 and November 2018, were retrospectively reviewed. Patients were categorized histopathologically as benign or malignant, by lesion composition (cystic, solid, mixed), and according to anatomical location (ovary, uterus, tube, cervix). Three ADC measurement methods were applied: diffuse ADC (dADC) from large ROIs covering the entire lesion, focal ADC (fADC) from small ROIs placed on the darkest regions of each slice, and specific ADC (sADC) calculated as the mean of the three lowest fADC values. Results: According to lesion composition, solid lesions demonstrated lower ADC values than mixed lesions, yet no differences were observed between benign and malignant categories within each lesion composition. In ovarian and uterine masses, the value of ADCs showed no significant differences between benign and malignant groups. For cervical masses, the mean ADCs were higher in benign masses compared to malignant masses (dADC: 2.4±0.2 vs. 1.1±0.3, p=0.002; fADC : 2.3±0.2 vs. 0.7±0.1, p=0.001; sADC: 2.2±0.2 vs. 0.6±0.02, p=0.001). Conclusion: Among various ADC measurement strategies, focal and specific ADC values more clearly reflected diffusion differences between benign and malignant gynecologic masses, particularly in cervical lesions. ADC values were affected by lesion composition, yet within each composition subgroup, benign and malignant lesions exhibited comparable values.