Diagnostic Accuracy of Diffusion Weighted Magnetic Resonance Imaging in Differentiation Between Benign and Malignant Soft Tissue Tumors Keeping Histopathology as Gold Standard

Abstract

Background & Objective: To determine diagnostic accuracy of Diffusion Weighted Magnetic Resonance Imaging in
differentiation between benign and malignant soft tissue tumors keeping histopathology as gold standard.
Methodology: Atotal of 176 patients meeting inclusion criteria underwent MRI, including DWI sequences at b-values of
0, 50, and 1000 s/mm² and ADC values were calculated from corresponding maps. ROI was placed on the solid tumor
component of mass. Post-contrast imaging was also performed. All MRIs were interpreted by blinded, qualified
radiologists to ensure unbiased results. Definitive diagnoses were confirmed through histopathological analysis by
certified pathologists.
Results: 98 (55.69%) were aged 13–40 years and 78 (44.1%) were 41–75 years, with a mean age of 40.62±10.13 years.
There were 94 males (53.5%) and 82 females (46.5%). Tumor sizes ranged from 3.1 cm to 11.5 cm, with a mean size of
6.3 cm. The average ADC value of benign masses (1.50 × 10⁻³ mm²/s) was higher than that of malignant masses (0.83 ×
10⁻³ mm²/s). A cutoff ADC value of 1.1 × 10⁻³ mm²/s provided sensitivity of 85.51%, specificity of 86.84%, PPV of
88.89%, NPV of 82.50%, and diagnostic accuracy of 85.88%. Histopathology showed 97 masses (55.3%) were malignant
and 79 (44.7%) were benign.
Conclusion: Diffusion-weighted MRI (DWI) is a non-invasive, cost-effective imaging tool with 85.5% sensitivity and
86.8% specificity for evaluating soft tissue masses. It can aid early detection of malignant tumors, improving patient
outcomes through timely diagnosis.