Diffusion-weighted imaging for the differentiation of Ewing sarcoma from osteosarcoma

Objective The purpose of this study is to assess the ability of apparent diffusion coefficient (ADC) values in differentiating Ewing sarcoma and osteosarcoma. Materials and methods This retrospective cross-sectional observational study included a total of 35 patients with a recent diagnosis of Ewing sarcoma ( n = 13) and osteosarcoma ( n = 22) who underwent conventional MRI and diffusion-weighted imaging (DWI). Three ADC measurements from the areas of the lowest diffusivity in ADC maps (ADC min ), and other areas with low diffusivity (ADC other ), were made independently by two observers on pre-treatment MRI, and the means of these measurements were compared using independent samples t -test. Intraclass correlation coefficient was calculated for inter-observer agreement. Results There was a significant difference between the ADC min ( P