Figure 4:
Comparison of ADC (ADCtot) computed using different sets of b values and of Dt derived from a biexponential fit. A, ADC values obtained with b = 0 and 400 sec/mm2 were markedly higher than when computed from, C, b = 0 and 800 sec/mm2. B, By using 17 b values between 0 and 800 sec/mm2 with interval of 50 sec/mm2, the obtained ADC values fell between those in A and C. It is seen that ADC values depend heavily on the sets of b values being used. D, Image shows Dt determined by using a biexponential model (Eq [1]) that separates out the IVIM contribution to diffusion. ADC values calculated using a monoexponential model (A–C) were all considerably higher than Dt. High Dt values in upper pole cyst are likely due to unrestricted diffusion.