“…In each subject, the mean ADC over cardiac trigger delays, ADC mean_tds , the SD of the ADC over cardiac trigger delays, ADC SD_tds , and the coefficient of variation across cardiac trigger delays CV tds were also computed for characterizing the variation along the cardiac trigger delay dimension separately for each kidney. A global CV tds_global was finally determined by taking the RMS average over all subjects, from the equation [
47]:
where m is the number of subjects,
is the SD of ADC across trigger delays for subject j and
is the mean ADC across delays for subject j . The global ADC SD_tds_global s were found from the RMS average over all subjects, and the global ADC mean_tds_global s were found from averaging over all subjects.…”