Vol 5, No 2 (2002)
Submitted: 2012-01-23
Published online: 2002-06-07
Optimal time window for measurement of renal output parameters
Jacob D. Kuyvenhoven, Hamphrey R. Ham, Amy Piepsz
Nucl. Med. Rev 2002;5(2):105-108.
Vol 5, No 2 (2002)
Submitted: 2012-01-23
Published online: 2002-06-07
Abstract
Although normalised residual activity (NORA) and output efficiency
(OE) are usually measured at a fixed time t, their dependency
on t may affect the prediction of mean transit time (MTT).
This study aimed to evaluate their degree of dependency on t
and to determine an optimal time of measurement by assessment
of their relationship with MTT for various times t. A simulation
model generated 232 cortical renograms by convolving one
plasma disappearance curve with 232 created cortical retention
functions. The results show that considerable changes are observed for
NORA and OE , depending on the time of measurement t. The
choice of this time significantly influences the predictive value
of these parameters for estimating MTT. The optimal time for
measurement of NORA and OE should be close to the MTT, at
the moment when emptying takes place. In the clinical practice,
it should be adapted to the clinical problem under investigation.
Abstract
Although normalised residual activity (NORA) and output efficiency
(OE) are usually measured at a fixed time t, their dependency
on t may affect the prediction of mean transit time (MTT).
This study aimed to evaluate their degree of dependency on t
and to determine an optimal time of measurement by assessment
of their relationship with MTT for various times t. A simulation
model generated 232 cortical renograms by convolving one
plasma disappearance curve with 232 created cortical retention
functions. The results show that considerable changes are observed for
NORA and OE , depending on the time of measurement t. The
choice of this time significantly influences the predictive value
of these parameters for estimating MTT. The optimal time for
measurement of NORA and OE should be close to the MTT, at
the moment when emptying takes place. In the clinical practice,
it should be adapted to the clinical problem under investigation.
Keywords
renography; output efficiency; NORA; simulation study
Title
Optimal time window for measurement of renal output parameters
Journal
Nuclear Medicine Review
Issue
Vol 5, No 2 (2002)
Pages
105-108
Published online
2002-06-07
Page views
517
Article views/downloads
1192
Bibliographic record
Nucl. Med. Rev 2002;5(2):105-108.
Keywords
renography
output efficiency
NORA
simulation study
Authors
Jacob D. Kuyvenhoven
Hamphrey R. Ham
Amy Piepsz