Separate calculation of DW-MRI in assessing therapeutic effect in liver tumors in rats

Figure 2 Apparent diffusion coefficient maps for tumors. A: Representative maps of apparent diffusion coefficient (ADC)_all and ADC_high for liver tumors (solid arrow) in three groups. The area of therapy-induced necrosis (dotted arrow) was significantly larger in the ZDTHA group than those observed in both the ZD6126 and control groups; B: The dynamic change of ADC_all during the experiment (^aP < 0.05, ^bP < 0.01 vs control; respectively); C: The dynamic change of ADC_high during the experiment. Compared to the ADC_all, the increased diffusion due to therapeutic necrosis was better reflected with ADC_high in both the ZDTHA and ZD6126 groups on day 2 (^bP < 0.01 vs control; ^cP < 0.05 vs ZD6126); D: Representative maps of ADC_low and ADC_perf for liver tumors (arrow) in the three groups. The signal intensities observed on ADC_low maps were always higher than those observed on ADC_perf maps at each time point in each group, because ADC_low combines both the perfusion and diffusion effects; E: The dynamic change of ADC_low during the experiment (^aP < 0.05 vs control; ^cP < 0.05 vs ZD6126); F: The dynamic change of ADC_perf during the experiment. Compared to the ADC_low, the perfusion reduction due to the shutdown of tumor vessels was better reflected with ADC_perf in both the ZDTHA and ZD6126 groups at 4 h (^aP < 0.05 vs control). Furthermore, the ADC_perf in the ZDTHA group was even lower compared to the ZD6126 group at 4 h (^cP < 0.05 vs ZD6126).