More Accurate Volume and ADC Measurements of Heterogeneous Tumor in Diffusion-Weighted MR Imaging: With Correlation to PET/CT

Nan-Jie Gong¹, Chun-Sing Wong¹, Yiu-Ching Chu², Bingsheng Huang¹, Queenie Chan³

To more precisely segment high-cellularity tumor tissues in heterogeneous lesions and therefore more accurately measure volumes and ADCs, we proposed a semi-automatic method based on thresholding both the b0 images and the ADC maps. Using k-means clustering algorithm, B0 images and ADC maps in the contoured regions were separately classified into three clusters (with low, intermediate and high value). The pixels with low intensities on b0 images and those with high ADC values on ADC maps were excluded, leaving only the probable high-cellularity tumor tissues. The volumes measured using the proposed method had perfect concordance with those in PET/CT. Furthermore, stronger correlations between ADC values and SUV values were achieved using this method.