scholarly journals Simulation study of a coincidence detection system for non-invasive determination of arterial blood time-activity curve measurements

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Yassine Toufique ◽  
Othmane Bouhali ◽  
Pauline Negre ◽  
Jim O’ Doherty
Keyword(s):  
Simulation Study ◽  
Detection System ◽  
Coincidence Detection ◽  
Time Activity ◽  
Time Activity Curve ◽  
Non Invasive ◽  
Arterial Blood ◽  
Activity Curve

scholarly journals Simulation study of a coincidence detection system for non-invasive determination of arterial blood time-activity curve measurements

2020 ◽  
Author(s):  
Yassine Toufique ◽  
Othmane Bouhali ◽  
Pauline Negre ◽  
Jim O Doherty
Keyword(s):  
Activity Concentration ◽  
Detection Efficiency ◽  
Detection System ◽  
Coincidence Detection ◽  
Time Activity ◽  
Time Activity Curve ◽  
Non Invasive ◽  
Arterial Blood ◽  
Arterial Sampling ◽  
Activity Curve

Abstract Background : Arterial sampling in PET studies for the purposes of kinetic modeling remains an invasive, time intensive and expensive procedure. Alternatives to derive the blood time-activity curve (BTAC) non-invasively are either reliant on large vessels in the field of view or are laborious to implement and analyse as well as being prone to many processing errors. An alternative method is proposed in this work by the simulation of a non-invasive coincidence detection unit. Results: We utilized GATE simulations of a human forearm phantom with a blood flow model, as well as a model for dynamic radioactive bolus activity concentration based on clinical measurements. A fixed configuration of 14, and also separately, 8 detectors were employed around the phantom, and simulations performed to investigate signal detection parameters. BGO crystals proved to show the highest detection efficiency and sensitivity to a simulated BTAC with a maximum coincidence rate of 575 cps. Repeatable location of the blood vessels in the forearm allowed a half-ring design with only 8 detectors. Using this configuration, maximum coincident rates of 250 cps and 42 cps were achieved with simulation of activity concentration determined from 15 O and 18 F arterial blood sampling. NECR simulated in a water phantom at 3 different vertical positions inside the 8-detector system (Y=-1 cm, Y=-2 cm and Y=-3 cm) was 8360 cps, 13041 cps and 20476 cps at an activity of 3.5 MBq. Addition of extra axial detection planes to the half-ring configuration provided increases in system sensitivity by a factor of approximately 10. Conclusions: Initial simulations demonstrated that the configuration of a single half-ring 8 detector of monolithic BGO crystals could describe the a simulated BTAC in a clinically relevant forearm phantom with good signal properties, and an increased number of axial detection planes can provide increased sensitivity of the system. The system would find use in the derivation of the BTAC for use in the application of kinetic models without physical arterial sampling or reliance on image-based techniques.

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

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.

scholarly journals Determination of Left Ventricular End Diastolic Pressure Utilizing Non-Invasive Techniques: A Computer Simulation Study

2016 ◽  
Vol 22 (8) ◽  
pp. S43-S44
Author(s):  
Ying Sun ◽  
Toby Steinberg ◽  
Jeremy Rier ◽  
Stewart Benton ◽  
Daniel Steinberg ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Simulation Study ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Computer Simulation Study ◽  
Non Invasive ◽  
Invasive Techniques

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.

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