title: [An approximation for improving the accuracy of compartmental analysis after intravenous 133Xe].
abstract: Perfusion of transplanted kidneys is studied in our clinic by intravenous injection of 133Xe with subsequent graphic compartmental analysis of time-activity curves. Where there is poor perfusion of the renal cortex, it is not possible to obtain a half-value time for the first compartment--which is the significant measure for specific blood flow -- since few points are available for the tail end of the curve. A correction is described which produces an approximation to a bolus, based on the time-activity curve of the expired air. If this is applied to the proximal part of the time-activity curve, with respect to background activity, compartmental analysis can be performed with a higher degree of accuracy in the calculation of renal perfusion.
mesh_terms: D000388:Air; D006207:Half-Life; D006801:Humans; D007668:Kidney / Q000098:blood supply* / Q000378:metabolism; D016030:Kidney Transplantation; D011868:Radioisotopes; D012039:Regional Blood Flow; D012119:Respiration; D013997:Time Factors; D014184:Transplantation, Homologous; D014978:Xenon / Q000378:metabolism
chemical_list: D011868:Radioisotopes; D014978:Xenon
vernacular_title: Näherungsverfahren zur Erhöhung der Genauigkeit der Kompartmentanalyse nach i.v. 122Xe-Applikation