title: Techniques for measuring renal transit time.
abstract: A variety of techniques have been used for quantitative estimation of renal transit time. We compared different indices of transit time in a group of 30 patients having baseline and ACE inhibitor technetium-99m mercaptoacetyltriglycine (MAG3) renography prior to arteriography: peak time, mean transit time, and the ratio of background-subtracted counts at 20 min to those at 3 min. Each index was calculated from whole-kidney ROI, cortical ROI, and cortical factor (by factor analysis). The strongest correlations between angiographic percent of stenosis and transit time index were observed for the peak time (Spearman p=0.469, n=53, P <0.005) and for the R20/3 (again p=0.469, n=53, P <0.005) using the whole-kidney ROI and using only the baseline data without captopril. (Spearman's p is simply the correlation coefficient calculated from rank in list, which allows for nonlinear correlation.) Thus simple indices of transit time (whole-kidney peak time and R20/3) correlated as well with the observed pathology as did more complicated methods that required deconvolution, factor analysis, or selection of a cortical ROI.
authors.affiliation: Division of Nuclear Medicine and Nuclear Medicine Service, University of Alabama at Birmingham Medical Center, Birmingham, Alabama, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Russell
authors.forename: M
authors.initials: M
authors.lastname: Japanwalla
authors.forename: S
authors.initials: S
authors.lastname: Khan
authors.forename: J W
authors.initials: JW
authors.lastname: Scott
authors.forename: E V
authors.initials: EV
authors.lastname: Dubovsky
mesh_terms: D000328:Adult; D002216:Captopril / Q000008:administration & dosage; D006801:Humans; D006977:Hypertension, Renal / Q000000981:diagnostic imaging / Q000378:metabolism; D007668:Kidney / Q000000981:diagnostic imaging / Q000378:metabolism*; D016030:Kidney Transplantation; D012372:ROC Curve; D011859:Radiography; D011866:Radioisotope Renography; D012077:Renal Artery / Q000000981:diagnostic imaging; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging / Q000378:metabolism; D017263:Technetium Tc 99m Mertiatide; D013997:Time Factors
chemical_list: D017263:Technetium Tc 99m Mertiatide; D002216:Captopril