The Application Research Of Magnetic Resonance Imaging And New Techniques Of Diffusion Weighted Imaging In The Diagnosis Of Renal Cell Carcinoma Fuhrman Grade

Part oneThe application research of3T MRI and DWI in diagnosising renal cell carcinoma Fuhrman gradeObjective:To explore the correlation between the conventional Magnetic Resonance Imaging (MRI), diffusion weighted imaging (DWI) with monoexponential model and Fuhrman grade of clear cell renal cancer, assess the diagnostic efficiency of max diameter and ADC values at different b values in differentiating Fuhrman low-and high-grade tumor.Methods:Forty-eight patients with clinically suspected renal masses underwent conventional MRI and DWI exams at3.0T MRI, and33patients with pathologically proved clear cell renal cell cancer (CCRCC) and qualified images were included for the further research. The max diameter, signals on T1WI, T2WI and DWI, pseudocapsules, cystic degeneration degree, enhancement level and patten, and ADC value at different b value was measured and assessed, and the correlation between the Fuhrman grade and those parameters or characteristics were analysed. The diagnostic efficiency of max diameter and ADC values at different b value in differentiating Fuhrman low-(1and2) and high-grade(3and4) tumor ware also assessed.Reasults:The33patients consist one tumor of Fuhrman grade1,14of grade2,16of grade3and2of grade4. A positive correlation was found between the radiological max diameter and Fuhrman grade Fuhrman, correlation coefficient (r) was0.424(p=0.016), while the ADCo-800、ADC0-400-8000、ADCO-600-1200、ADC0-400-800-1200and ADCtotai revealed a negative correlation with Fuhrman grade (r:-0.553、-0.511、-0.603、-0.645、-0.610, respectively)(p<0.05), among which the ADC0-400-800-1200showed the strongest correlation. However, no significantly correlation were observed between the Fuhrman grade and other MRI parameter or characteristic.Conclusion:The max diameter and ADCo-800、ADC0400-800, ADC0-600-1200, ADC0-400-800-1200and ADCtotal revealed significant correlation with the Fuhrman grade of clear cell renal cancer, and providing high diagnostic efficiency in differentiating Fuhrman low-and high-grade tumor. Part TwoBiexponential model DWI for diagnosising renal cell carcinoma Fuhrman grade:Compared with Monoexponential Diffusion Weighted ImagingObjective:To invetstingate the correlation between the parameters of diffusion weighted imaging (DWI) with biexponential model and Fuhrman grade of clear cell renal cancer, assess their diagnostic efficiency for low-and high-grade tumor, and compare them with monoexponential model。Methods:Forty-eight patients with clinically suspected renal mass underwent biexponential and monoexponential model DWI exams at3.0T MRI, and33patients with pathologically proved clear cell renal cell cancer (CCRCC) and qualified images were included for the further research. The correlation between the Fuhrman grade of CCRCC and parameters of biexponential model fast ADC (ADCf), slow ADC (ADCs) and fraction of ADCf (f), the difference of those parameter between low-and high-grade tumor were analysed. The diagnostic efficiency of ADCf, ADCs and f value for low-and high-grade tumor were also assessed and compared by Receiver operator characteristic curve (ROC), and the optimum sensitivity, specificity and accuracy were selected using Youden index. The results were further compared with monoexponential ADC value with different b value.Reasults:A positive correlation were found between the ADCf, f value and the Fuhrman grade of CCRCC(p<0.001), and a negative correlation between the ADCs value and the Fuhrman grade was also observed (p=0.001). The correlation coefficient of ADCf and Fuhman grade was the highest(r=0.779). The ADCf and f value was significantly higher in high grade tumor than low grade tumor (p<0.001), when the ADCs was lower(p=0.005). The AUCs (areas under the ROC curve) of those parameters for differentiating the low-grade and high grade tumor were0.959、0.807、0.833, respectively, among which the ADCf reveal the best result, with a sensitivity of88.9%, specificity of100%, and accuracy of93.94%. The diagnostic efficiency of ADCf for low-and high-grade tumor was also high than that of monoexponential ADC (AUC0.959vs0.794)(p=0.04).Conclusion:A significant correlation were observed between the ADCf, ADCs and f value and the Fuhrman grade of CCRCC, and the biexponential parameters showed high diagnostic efficiency in differentiating Fuhrman low-and high-grade tumor. The ADCf revealed a stronger correlation with Fuhrman grade of CCRCC, and higher diagnostic efficiency in differentiating Fuhrman low-and high-grade tumor comparing to the mostly used monoexponential model.