RESUMO
Renal transit time usually refers to tubular transit time, as introduced by Taplin, but other measures of renal transit have been proposed. Here we examine the vascular transit time (VTT, following Rutland) and the standard deviation of tubular transit time (SDTT, following Britton) in a group of 30 patients having baseline and ACE-inhibitor 99Tcm-MAG3 renography prior to arteriography. A same-day, low-dose/high-dose protocol was used for renography; only the post-captopril dose was high enough to measure VTT. Pre-captopril, the Spearman rank correlation coefficient for SDTT was rho = 0.52 (n = 53 kidneys; P < 0.0002); post-captopril, rho = 0.54 (n = 49 kidneys; P < 0.0002). For VTT, the post-captopril value was rho = 0.24 (n = 30 kidneys; N.S.). For comparison, the same statistics were calculated for Taplin's original measure of transit time: the time from injection to maximum count rate (peak time). Pre-captopril, for peak time, rho was 0.47 (n = 53 kidneys; P < 0.001); post-captopril, rho was 0.39 (n = 50 kidneys, P < 0.01). These findings confirm the diagnostic value of SDTT but not of VTT. SDTT correlated better than peak time with the arteriographic findings.
Assuntos
Rim/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Mertiatida , Adulto , Inibidores da Enzima Conversora de Angiotensina , Captopril , Humanos , Túbulos Renais/diagnóstico por imagem , Túbulos Renais/metabolismo , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Obstrução da Artéria Renal/diagnóstico por imagem , Circulação Renal , Tecnécio Tc 99m Mertiatida/farmacocinéticaRESUMO
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.
Assuntos
Rim/metabolismo , Renografia por Radioisótopo , Adulto , Captopril/administração & dosagem , Humanos , Hipertensão Renal/diagnóstico por imagem , Hipertensão Renal/metabolismo , Rim/diagnóstico por imagem , Transplante de Rim , Curva ROC , Radiografia , Artéria Renal/diagnóstico por imagem , Obstrução da Artéria Renal/diagnóstico por imagem , Obstrução da Artéria Renal/metabolismo , Tecnécio Tc 99m Mertiatida , Fatores de TempoRESUMO
Early ischemic bowel disease may be apparent on In-111 WBC scan before endoscopic changes of the mucosa. This may indicate a subacute process. The case in point did have angiographic findings of ileocolitis despite repeated colonoscopy.