Characterization of clear cell renal cell carcinoma with diffusion kurtosis imaging: correlation between diffusion kurtosis parameters and tumor cellularity |
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| Authors: | Yongming Dai Qiuying Yao Guangyu Wu Dongmei Wu Lianming Wu Li Zhu Rong Xue Jianrong Xu |
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| Institution: | 1. Magnetic Resonance Imaging Institute for Biomedical Research, Wayne State University, Detroit, MI, USA;2. Department of Radiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China;3. Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, China;4. Department of Urology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China;5. State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Science, Beijing, China;6. Beijing Institute for Brain Disorders, Beijing, China |
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| Abstract: | The aim of this study was to evaluate the role of diffusion kurtosis imaging (DKI) in the characterization of clear cell renal cell carcinoma (ccRCC) and to correlate DKI parameters with tumor cellularity. Fifty‐nine patients with pathologically diagnosed ccRCCs were evaluated by DKI on a 3‐T scanner. Regions of interest were drawn on the maps of the mean diffusion coefficient (MD) and mean diffusion kurtosis (MK). All ccRCCs were histologically graded according to the Fuhrman classification system. Tumor cellularity was measured by the nuclear‐to‐cytoplasm (N/C) ratio and the number of tumor cell nuclei (NTCN). ccRCCs were classified as grade 1 (n = 23), grade 2 (n = 24), grade 3 (n = 10) and grade 4 (n = 3). Both MD and MK could readily discriminate between normal renal parenchyma and ccRCCs (p < 0.001), and receiver operating characteristic (ROC) curve analysis showed that MK exhibited a better performance with an area under the ROC curve of 0.874 and sensitivity/specificity of 68.33%/100% (p < 0.001). Further, MD and MK were significantly different between grade 1 and grades 3 and 4 (p = 0.01, p < 0.001) and between grade 2 and grades 3 and 4 (p = 0.015, p < 0.005), respectively. However, no significant difference was found between grade 1 and grade 2 (p > 0.05) for both MD and MK. With regard to NTCN, no significant difference was found between any two grades (p > 0.05), and the N/C ratio changed significantly with grade (p < 0.01, between any two grades). Negative correlations were found between MK and MD (r = –0.56, p < 0.001), and between MD and N/C ratio (r = –0.36, p < 0.005), whereas MK and the N/C ratio were positively correlated (r = 0.45, p = 0.003). DKI could quantitatively characterize ccRCC with different grades by probing non‐Gaussian diffusion properties related to changes in the tumor microenvironment or tissue complexities in the tumor. Copyright © 2016 John Wiley & Sons, Ltd. |
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| Keywords: | MRI diffusion kurtosis imaging clear cell renal cell carcinoma tumor cellularity |
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