With PSF, the maximum-based measures, RC50bg and RCmax, converged slower than RCavg (compare Fig. 5a b) probably because the maximum voxel value is more dependent on higher-frequency features, voxel noise and edge artifacts in the image.
Within this contour, the maximum voxel value was recorded.
The maximum voxel error for at an SNR = 19.5 (estimated SNR level) is voxels; however using a in this case results in a more threefold increase of the accuracy as the maximum error is reduced to voxels.
Similarly 2 up to 4 demonstrate the appearance of a marker when its centre coincides with the middle of a voxel face, the middle of a voxel edge and a voxel corner, respectively.
Finally, the immediate neighborhood of the maximum voxel determines the magnitude of the potential interpolation effect.
Fixed threshold of 50% and 70% of maximum voxel value (VOI50, VOI70) [18].
The liver VOI was then thresholded at values between 0 and the maximum voxel value.
The threshold value was set to 42% of the maximum voxel value in the initialization VOI.
Adaptive threshold range of 41-70% of maximum voxel value (VOIA41, VOIA50, VOIA70).
For a large homogeneous lesion, the difference of maximum voxel and neighboring voxel is just noise and the interpolation effects essentially lead to noise reduction (assuming trilinear interpolation).
