scholarly journals Estimation of input function from dynamic PET brain data using Bayesian blind source separation

2015 ◽  
Vol 12 (4) ◽  
pp. 1273-1287
Author(s):  
Ondřej Tichý ◽  
Václav Smídl
Keyword(s):  
Blind Source Separation ◽  
Source Separation ◽  
Input Function ◽  
Time Activity ◽  
Probability Modeling ◽  
Arterial Blood ◽  
Positron Emission ◽  
Manual Interaction ◽  
Brain Data ◽  
Estimation Of Time

Selection of regions of interest in an image sequence is a typical prerequisite step for estimation of time-activity curves in dynamic positron emission tomography (PET). This procedure is done manually by a human operator and therefore suffers from subjective errors. Another such problem is to estimate the input function. It can be measured from arterial blood or it can be searched for a vascular structure on the images which is hard to be done, unreliable, and often impossible. In this study, we focus on blind source separation methods with no needs of manual interaction. Recently, we developed sparse blind source separation and deconvolution (S-BSS-vecDC) method for separation of original sources from dynamic medical data based on probability modeling and Variational Bayes approximation methodology. In this paper, we extend this method and we apply the methods on dynamic brain PET data and application and comparison of derived algorithms with those of similar assumptions are given. The S-BSS-vecDC algorithm is publicly available for download.

scholarly journals Kinetic Analysis of the 5-HT2A Ligand [11C]MDL 100,907

2000 ◽  
Vol 20 (6) ◽  
pp. 899-909 ◽  
Author(s):  
Hiroshi Watabe ◽  
Michael A. Channing ◽  
Margaret G. Der ◽  
H. Richard Adams ◽  
Elaine Jagoda ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Specific Binding ◽  
Compartment Model ◽  
Input Function ◽  
Brain Regions ◽  
Time Activity ◽  
Tissue Compartment ◽  
Arterial Blood ◽  
Fixed Parameter ◽  
Mdl 100,907

The goal of this study was to develop a suitable kinetic analysis method for quantification of 5-HT2A receptor parameters with [11C]MDL 100,907. Twelve control studies and four preblocking studies (400 nmol/kg unlabeled MDL 100,907) were performed in isoflurane-anesthetized rhesus monkeys. The plasma input function was determined from arterial blood samples with metabolite measurements by extraction in ethyl acetate. The preblocking studies showed that a two-tissue compartment model was necessary to fit the time activity curves of all brain regions including the cerebellum—in other words, the need for two compartments is not proof of specific binding. Therefore, a three-tissue compartment model was used to analyze the control studies, with three parameters fixed based on the preblocking data. Reliable fits of control data could be obtained only if no more than three parameters were allowed to vary. For routine use of [11C]MDL 100,907, several simplified methods were evaluated. A two-tissue (2T‘) compartment with one fixed parameter was the most reliable compartmental approach; a one-compartment model failed to fit the data adequately. The Logan graphical approach was also tested and produced comparable results to the 2T’ model. However, a simulation study showed that Logan analysis produced a larger bias at higher noise levels. Thus, the 2T' model is the best choice for analysis of [11C]MDL 100,907 studies.

scholarly journals Evaluation of Simplified Kinetic Analyses for Measurement of Brain Acetylcholinesterase Activity Using N-[11C]Methylpiperidin-4-yl Propionate and Positron Emission Tomography

2004 ◽  
Vol 24 (6) ◽  
pp. 600-611 ◽  
Author(s):  
Koichi Sato ◽  
Kiyoshi Fukushi ◽  
Hitoshi Shinotoh ◽  
Shinichiro Nagatsuka ◽  
Noriko Tanaka ◽  
...  
Keyword(s):  
Ache Activity ◽  
Arterial Input Function ◽  
Acetylcholinesterase Activity ◽  
Input Function ◽  
Previous Method ◽  
Target Tissue ◽  
Standard Analysis ◽  
Reference Tissue ◽  
Arterial Blood ◽  
Positron Emission

The applicability of two reference tissue-based analyses without arterial blood sampling for the measurement of brain regional acetylcholinesterase (AChE) activity using N-[11C]methylpiperidin-4-yl propionate ([11C]MP4P) was evaluated in 12 healthy subjects. One was a linear least squares analysis derived from Blomqvist's equation, and the other was the analysis of the ratio of target-tissue radioactivity relative to reference-tissue radioactivity proposed by Herholz and coworkers. The standard compartment analysis using arterial input function provided reliable quantification of k3 (an index of AChE activity) estimates in regions with low (neocortex and hippocampus), moderate (thalamus), and high (cerebellum) AChE activity with a coefficient of variation (COV) of 12% to 19%. However, the precise k3 value in the striatum, where AChE activity is the highest, was not obtained. The striatum was used as a reference because its time-radioactivity curve was proportional to the time integral of the arterial input function. Reliable k3 estimates were also obtained in regions with low-to-moderate AChE activity with a COV of less than 21% by striatal reference analyses, though not obtained in the cerebellum. Shape analysis, the previous method of direct k3 estimation from the shape of time-radioactivity data, gave k3 estimates in the cortex and thalamus with a somewhat larger COV. In comparison with the standard analysis, a moderate overestimation of k3 by 9% to 18% in the linear analysis and a moderate underestimation by 2% to 13% in the Herholz method were observed, which were appropriately explained by the results of computer simulation. In conclusion, simplified kinetic analyses are practical and useful for the routine analysis of clinical [11C]MP4P studies and are nearly as effective as the standard analysis for detecting regions with abnormal AChE activity.

scholarly journals Arterial Input Function Derived from Pairwise Correlations Between PET-image Voxels

2013 ◽  
Vol 33 (7) ◽  
pp. 1058-1065 ◽  
Author(s):  
Martin Schain ◽  
Simon Benjaminsson ◽  
Katarina Varnäs ◽  
Anton Forsberg ◽  
Christer Halldin ◽  
...  
Keyword(s):  
Arterial Input Function ◽  
Pearson Correlation ◽  
Invasive Procedure ◽  
Compartmental Analysis ◽  
Input Function ◽  
Time Activity ◽  
Pairwise Correlation ◽  
Positron Emission ◽  
Using Data ◽  
Suitable Reference

A metabolite corrected arterial input function is a prerequisite for quantification of positron emission tomography (PET) data by compartmental analysis. This quantitative approach is also necessary for radioligands without suitable reference regions in brain. The measurement is laborious and requires cannulation of a peripheral artery, a procedure that can be associated with patient discomfort and potential adverse events. A non invasive procedure for obtaining the arterial input function is thus preferable. In this study, we present a novel method to obtain image-derived input functions (IDIFs). The method is based on calculation of the Pearson correlation coefficient between the time-activity curves of voxel pairs in the PET image to localize voxels displaying blood-like behavior. The method was evaluated using data obtained in human studies with the radioligands [ 11 C]flumazenil and [ 11 C]AZ10419369, and its performance was compared with three previously published methods. The distribution volumes ( VT) obtained using IDIFs were compared with those obtained using traditional arterial measurements. Overall, the agreement in VT was good (~3% difference) for input functions obtained using the pairwise correlation approach. This approach performed similarly or even better than the other methods, and could be considered in applied clinical studies. Applications to other radioligands are needed for further verification.

scholarly journals Comparison of Eight Methods for the Estimation of the Image-Derived Input Function in Dynamic [18F]-FDG PET Human Brain Studies

2009 ◽  
Vol 29 (11) ◽  
pp. 1825-1835 ◽  
Author(s):  
Paolo Zanotti-Fregonara ◽  
El Mostafa Fadaili ◽  
Renaud Maroy ◽  
Claude Comtat ◽  
Antoine Souloumiac ◽  
...  
Keyword(s):  
Blood Sample ◽  
Rate Constants ◽  
Fdg Pet ◽  
Input Function ◽  
Blood Samples ◽  
Arterial Blood ◽  
Positron Emission ◽  
Phantom Studies ◽  
The Individual ◽  
Individual Rate

The aim of this study was to compare eight methods for the estimation of the image-derived input function (IDIF) in [18F]-FDG positron emission tomography (PET) dynamic brain studies. The methods were tested on two digital phantoms and on four healthy volunteers. Image-derived input functions obtained with each method were compared with the reference input functions, that is, the activity in the carotid labels of the phantoms and arterial blood samples for the volunteers, in terms of visual inspection, areas under the curve, cerebral metabolic rates of glucose (CMRglc), and individual rate constants. Blood-sample-free methods provided less reliable results as compared with those obtained using the methods that require the use of blood samples. For some of the blood-sample-free methods, CMRglc estimations considerably improved when the IDIF was calibrated with a single blood sample. Only one of the methods tested in this study, and only in phantom studies, allowed a reliable calculation of the individual rate constants. For the estimation of CMRglc values using an IDIF in [18F]-FDG PET brain studies, a reliable absolute blood-sample-free procedure is not available yet.

Spatiotemporal Clustering Method for Automatic Estimation of the FDG Input Function for Small-Animal PET

2010 ◽  
Vol 143-144 ◽  
pp. 358-363
Author(s):  
Li Sun ◽  
Yan Ning Zhang ◽  
Miao Ma ◽  
Guang Jian Tian
Keyword(s):  
Small Animal ◽  
Input Function ◽  
Small Animal Pet ◽  
Image Clustering ◽  
Dynamic Pet ◽  
Clustering Methods ◽  
Spatial And Temporal Patterns ◽  
Time Activity ◽  
Arterial Blood ◽  
Activity Curve

The plasma time-activity curve is often required as the input function for dynamic quantitative FDG PET studies to estimate the metabolic rate of glucose. The invasive gold standard arterial blood sampling has been suggested, however, it has many inconveniences and challenges in clinical and pre-clinical settings. Thus, the image-derived input function has been proposed to obtain the input function from dynamic images non-invasively. This method often needs a manual drawing of one or two regions of interest (ROIs), which is an operator-dependent and time-consuming task. The aim of the presented study was to capture the spatial and temporal patterns of dynamic PET images for automatic ROI extraction. Our proposed approach tries to overcome the main limitation of image clustering methods: the loss of temporal information for dynamic PET ROI definition. The experiments showed that the proposed automatic ROI method can be used for dynamic PET parameter estimation.

scholarly journals Serotonin 5HT2 Receptor Imaging in the Human Brain Using Positron Emission Tomography and a New Radioligand, [18F]Altanserin: Results in Young Normal Controls

1995 ◽  
Vol 15 (5) ◽  
pp. 787-797 ◽  
Author(s):  
B. Sadzot ◽  
C. Lemaire ◽  
P. Maquet ◽  
E. Salmon ◽  
A. Plenevaux ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
High Specific Activity ◽  
Emission Tomography ◽  
Binding Potential ◽  
Receptor Imaging ◽  
Time Activity ◽  
Arterial Blood ◽  
Positron Emission

Changes in serotonin-2 receptors have been demonstrated in brain autopsy material from patients with various neurodegenerative and affective disorders. It would be desirable to locate a ligand for the study of these receptors in vivo with positron emission tomography (PET). Altanserin is a 4-benzoylpiperidine derivative with a high affinity and selectivity for S2 receptors in vitro. Dynamic PET studies were carried out in nine normal volunteers with high-specific activity (376–1,680 mCi/μmol) [18F]altanserin. Arterial blood samples were obtained and the plasma time–activity curves were corrected for the presence of labeled metabolites. Thirty minutes after injection, selective retention of the radioligand was observed in cortical areas, while the cerebellum, caudate, and thalamus had low radioactivity levels. Specific binding reached a plateau between 30 and 65 min postinjection at 1.8% of the injected dose/L of brain and then decreased, indicating the reversibility of the binding. The total/nonspecific binding ratio reached 2.6 for times between 50 and 70 min postinjection. The graphical analysis proposed by Logan et al. allowed us to estimate the binding potential ( Bmax/ KD). Pretreatment with ketanserin was given to three volunteers and brain activity remained uniformly low. An additional study in one volunteer showed that [18F]altanserin can be displaced from the receptors by large doses of ketanserin. At the end of the study, unchanged altanserin was 57% of the total plasma activity. These results suggest that [18F]altanserin is selective for S2 receptors in vivo as it is in vitro. They indicate that [18F]altanserin is suitable for imaging and quantifying S2 receptors with PET in humans.

scholarly journals Plasma L-[18F]6-Fluorodopa Input Function: A Simplified Method

1992 ◽  
Vol 12 (5) ◽  
pp. 881-884 ◽  
Author(s):  
Grace L.-Y. Chan ◽  
K. Scott Morrison ◽  
James E. Holden ◽  
Thomas J. Ruth
Keyword(s):  
Time Course ◽  
Input Function ◽  
Blood Analysis ◽  
Arterial Blood ◽  
Positron Emission ◽  
Straight Line ◽  
Simplified Method ◽  
Straight Line Method ◽  
Single Plasma

This article describes a simplified method for the determination of the l-[18F]6-fluorodopa (FDOPA) fraction time course that takes advantage of the strong correlation between the radioactivity ratio (metabolites/FDOPA) and time. Serial arterial blood samples are collected for assay of plasma total radioactivities following an intravenous injection of FDOPA into carbidopa-pretreated subjects. In addition, a single plasma sample, collected late in the study and analyzed for FDOPA fraction, is sufficient to determine accurately the time course of the FDOPA concentration in plasma. The validated straight-line method greatly simplifies blood analysis for routine positron emission tomography FDOPA studies.

scholarly journals Automated Reference Region Extraction and Population-Based Input Function for Brain [11C]TMSX PET Image Analyses

2014 ◽  
Vol 35 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Eero Rissanen ◽  
Jouni Tuisku ◽  
Pauliina Luoto ◽  
Eveliina Arponen ◽  
Jarkko Johansson ◽  
...  
Keyword(s):  
Arterial Input Function ◽  
Input Function ◽  
Population Based ◽  
Reference Region ◽  
Automated Method ◽  
Arterial Blood ◽  
Positron Emission ◽  
Using Data ◽  
Multiple Sclerosis Patients ◽  
Image Analyses

[11C]TMSX ([7- N-methyl-11C]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine) is a selective adenosine A2A receptor (A2AR) radioligand. In the central nervous system (CNS), A2AR are linked to dopamine D2 receptor function in striatum, but they are also important modulators of inflammation. The golden standard for kinetic modeling of brain [11C]TMSX positron emission tomography (PET) is to obtain arterial input function via arterial blood sampling. However, this method is laborious, prone to errors and unpleasant for study subjects. The aim of this work was to evaluate alternative input function acquisition methods for brain [11C]TMSX PET imaging. First, a noninvasive, automated method for the extraction of gray matter reference region using supervised clustering (SCgm) was developed. Second, a method for obtaining a population-based arterial input function (PBIF) was implemented. These methods were created using data from 28 study subjects (7 healthy controls, 12 multiple sclerosis patients, and 9 patients with Parkinson's disease). The results with PBIF correlated well with original plasma input, and the SCgm yielded similar results compared with cerebellum as a reference region. The clustering method for extracting reference region and the population-based approach for acquiring input for dynamic [11C]TMSX brain PET image analyses appear to be feasible and robust methods, that can be applied in patients with CNS pathology.

ntPET: A New Application of PET Imaging for Characterizing the Kinetics of Endogenous Neurotransmitter Release

2005 ◽  
Vol 4 (4) ◽  
pp. 7290.2005.05130 ◽  
Author(s):  
Evan D. Morris ◽  
Karmen K. Yoder ◽  
Chunzhi Wang ◽  
Marc D. Normandin ◽  
Qi-Huang Zheng ◽  
...  
Keyword(s):  
Neurotransmitter Release ◽  
Small Animal Imaging ◽  
Small Animal ◽  
Input Function ◽  
Rat Striatum ◽  
Time Varying ◽  
Imaging Data ◽  
Endogenous Dopamine ◽  
Arterial Blood ◽  
Positron Emission

We present a new application of positron emission tomography (“ntPET” or “neurotransmitter PET”) designed to recover temporal patterns of neurotransmitter release from dynamic data. Our approach employs an enhanced tracer kinetic model that describes uptake of a labeled dopamine D2/D3 receptor ligand in the presence of a time-varying rise and fall in endogenous dopamine. Data must be acquired during both baseline and stimulus (transient dopamine release) conditions. Data from a reference region in both conditions are used as an input function, which alleviates the need for any arterial blood sampling. We use simulation studies to demonstrate the ability of the method to recover the temporal characteristics of an increase in dopamine concentration that might be expected following a drug treatment. The accuracy and precision of the method—as well as its potential for false-positive responses due to noise or changes in blood flow—were examined. Finally, we applied the ntPET method to small-animal imaging data in order to produce the first noninvasive assay of the time-varying release of dopamine in the rat striatum following alcohol.

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