The average calculation times for each ROI size showed little difference. There are two possible reasons for this difference. One is that the calculation did not converge in cases with large error such as the liver or pancreas. Another is that the calculation system involves extra processing other than the displacement calculation, such as outputting of the log for the verification. As manual matching by the radiological technologist took approximately 30–60 s, the current calculation time (approximately 25 s) may be less than the manual matching time. However, we think this is still too long for introduction to clinical sites, and we expect that the calculation time could be reduced to within 10 s by inclusion of preliminary processing and exclusion of the extra processing.