scholarly journals Fast direct estimation of the blood input function and myocardial time activity curve from dynamic SPECT projections via reduction in spatial and temporal dimensions

2013 ◽  
Vol 40 (9) ◽  
pp. 092503 ◽  
Author(s):  
Yunlong Zan ◽  
Rostyslav Boutchko ◽  
Qiu Huang ◽  
Biao Li ◽  
Kewei Chen ◽  
...  
Keyword(s):  
Input Function ◽  
Dynamic Spect ◽  
Time Activity ◽  
Time Activity Curve ◽  
Direct Estimation ◽  
Activity Curve ◽  
Temporal Dimensions

Analysis of Myocardial Time-Activity Curves of 123l-Heptadecanoic Acid II. The Acquisition Time

1987 ◽  
Vol 26 (06) ◽  
pp. 248-252 ◽  
Author(s):  
M. J. van Eenige ◽  
F. C. Visser ◽  
A. J. P. Karreman ◽  
C. M. B. Duwel ◽  
G. Westera ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Acquisition Time ◽  
Half Time ◽  
Constant Ratio ◽  
Time Activity ◽  
Time Activity Curve ◽  
Time Value ◽  
Activity Curve ◽  
Low Amplitude ◽  
Parameter Values

Optimal fitting of a myocardial time-activity curve is accomplished with a monoexponential plus a constant, resulting in three parameters: amplitude and half-time of the monoexponential and the constant. The aim of this study was to estimate the precision of the calculated parameters. The variability of the parameter values as a function of the acquisition time was studied in 11 patients with cardiac complaints. Of the three parameters the half-time value varied most strongly with the acquisition time. An acquisition time of 80 min was needed to keep the standard deviation of the half-time value within ±10%. To estimate the standard deviation of the half-time value as a function of the parameter values, of the noise content of the time-activity curve and of the acquisition time, a model experiment was used. In most cases the SD decreased by 50% if the acquisition time was increased from 60 to 90 min. A low amplitude/constant ratio and a high half-time value result in a high SD of the half-time value. Tables are presented to estimate the SD in a particular case.

Impulse-response function of splanchnic circulation with model-independent constraints: theory and experimental validation

2003 ◽  
Vol 285 (4) ◽  
pp. G671-G680 ◽  
Author(s):  
Ole L. Munk ◽  
Susanne Keiding ◽  
Ludvik Bass
Keyword(s):  
Portal Vein ◽  
Impulse Response ◽  
Response Function ◽  
Mean Transit Time ◽  
Impulse Response Function ◽  
Parameter Estimates ◽  
Time Activity ◽  
Time Activity Curve ◽  
Transit Times ◽  
Activity Curve

Modeling physiological processes using tracer kinetic methods requires knowledge of the time course of the tracer concentration in blood supplying the organ. For liver studies, however, inaccessibility of the portal vein makes direct measurement of the hepatic dual-input function impossible in humans. We want to develop a method to predict the portal venous time-activity curve from measurements of an arterial time-activity curve. An impulse-response function based on a continuous distribution of washout constants is developed and validated for the gut. Experiments with simultaneous blood sampling in aorta and portal vein were made in 13 anesthetized pigs following inhalation of intravascular [15O]CO or injections of diffusible 3- O-[11C]methylglucose (MG). The parameters of the impulse-response function have a physiological interpretation in terms of the distribution of washout constants and are mathematically equivalent to the mean transit time ( T̄) and standard deviation of transit times. The results include estimates of mean transit times from the aorta to the portal vein in pigs: T̄ = 0.35 ± 0.05 min for CO and 1.7 ± 0.1 min for MG. The prediction of the portal venous time-activity curve benefits from constraining the regression fits by parameters estimated independently. This is strong evidence for the physiological relevance of the impulse-response function, which includes asymptotically, and thereby justifies kinetically, a useful and simple power law. Similarity between our parameter estimates in pigs and parameter estimates in normal humans suggests that the proposed model can be adapted for use in humans.

Measurement of arterial time-activity curve by monitoring continuously drawn arterial blood with an external detector: Errors and corrections

1988 ◽  
Vol 2 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Michio Senda ◽  
Sadahiko Nishizawa ◽  
Yoshiharu Yonekura ◽  
Takao Mukai ◽  
Hideo Saji ◽  
...  
Keyword(s):  
Time Activity ◽  
Time Activity Curve ◽  
Arterial Blood ◽  
Activity Curve

A simple on-line arterial time-activity curve detector for [O-15] water PET studies

1997 ◽  
Vol 44 (4) ◽  
pp. 1613-1617 ◽  
Author(s):  
S.D. Wollenweber ◽  
R.D. Hichwa ◽  
L.L.B. Ponto
Keyword(s):  
Time Activity ◽  
Time Activity Curve ◽  
Activity Curve ◽  
On Line ◽  
O 15

Development of an instrument for time–activity curve measurements during PET imaging of rodents

2007 ◽  
Vol 571 (1-2) ◽  
pp. 358-361 ◽  
Author(s):  
Jean-Marc Reymond ◽  
David Guez ◽  
Sophie Kerhoas ◽  
Philippe Mangeot ◽  
Raphaël Boisgard ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Time Activity ◽  
Time Activity Curve ◽  
Activity Curve
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