After that, the mean value and standard deviation for each parameter were S-adenosylhomocysteine hydrolase calculated for each group at each time point for statistical analysis. T2 weighted and contrast enhanced-T1 weighted MRI: The residual viable tumor or rim after treatment was visualized as contrast-enhanced, high signal region on the CE-T1W-MRI. The tumor necrotic areas were contoured on CE-T1W-MRI based on the unenhanced, low-signal areas within the tumors that were observed after injection of a contrast agent. Relative volumes (%) of tumor necrosis were calculated by normalizing them to the entire tumor volume. For each lesion, the tumor areas were delineated at T2W-MRI on all slices and automatically combined into the total tumor volume. The tumor volume change (%) was calculated using the following formula: [(volumepost - volumepre)/volumepre] �� 100.

Separate calculation of tumor ADC: For calculating different ADC values, the first step was to measure the entire tumor signal intensity (SI) from original DW-MRI images of 10 b values, respectively. Briefly, for each tumor, freehand delineations were performed on all slices of the original DW-MRI at a b value of 1000 s/mm2. These delineations were merged to form one 3D volume of interest per lesion. The volume of interest was then automatically copied to all images with different b values and the average SI of each lesion per b value was determined. The second step was to obtain separate ADC values according to a monoexponential model using all 10 b values[14].

To differentiate the individual contributions of tissue microcapillary perfusion and pure tissue diffusivity, the ADC values of each tumor were obtained separately for low b values (b = 0, 50, and 100 s/mm2; ADClow) and high b values (b = 500, 750, and 1000 s/mm2; ADChigh) from the average SI per tumor and per b value. Each ADC value was calculated by using a least squares solution of the following system of equations: ADCall: Sk = S0 �� exp (-bk �� ADClow), for k = 0, 50, 100; 150, 200, 250, 300, 500, 750, 1000; ADClow: Si = S0 �� exp (-bi �� ADClow), for i = 0, 50, 100; ADChigh: Sj = S0 �� exp (-bj �� ADChigh), for j = 500, 750, 1000; where Sk, Si, and Sj are the SI measured on the DW-MRI acquired with the corresponding b values bk, bi and bj, S0 represents the exact SI (without the influence of noise induced by the MR measurement) with b value equal to 0 s/mm2.

ADClow is perfusion sensitive, while ADChigh is perfusion insensitive. Although ADClow is perfusion sensitive, it is also affected by diffusion effects in tissue[15]. Therefore, an approximate indicator, ADCperf, Anacetrapib for the tissue perfusion contribution can be calculated as ADClow-ADChigh[7]. Imaging software (MeVisLab 2.2.1, MeVis Medical Solutions AG, Bremen, Germany) was used to generate the maps of ADCall, ADChigh, ADClow and ADCperf.