Logan Plot

2020 ◽  
Author(s):  
Keyword(s):  
Logan Plot

scholarly journals Modified Regression Model for the Logan Plot

2002 ◽  
Vol 22 (2) ◽  
pp. 240-244 ◽  
Author(s):  
József Varga ◽  
Zsolt Szabo
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Graphical Model ◽  
Logan Plot ◽  
Positron Emission ◽  
Straight Line ◽  
Binding Data ◽  
Data Points ◽  
Voxel Data

Logan's graphical model is a robust estimation of the total distribution volume (DVt) of reversibly bound radiopharmaceuticals, but the resulting DVt values decrease with increasing noise. The authors hypothesized that the noise dependence can be reduced by a linear regression model that minimizes the sum of squared perpendicular rather than vertical ( y) distances between the data points and fitted straight line. To test the new method, 15 levels of simulated noise (repeated 2,000 times) were added to synthetic tissue activity curves, calculated from two different sets of kinetic parameters. Contrary to the traditional method, there was no ( P > 0.05) or dramatically decreased noise dependence with the perpendicular model. Real dynamic 11C (+) McN5652 serotonin transporter binding data were processed either by applying Logan analysis to average counts of large areas or by averaging the Logan slopes of individual-voxel data. There were no significant differences between the parameters when the perpendicular regression method was used with both approaches. The presented experiments show that the DVt calculated from the Logan plot is much less noise dependent if the linear regression model accounts for errors in both the x and y variables, allowing fast creation of unbiased parametric images from dynamic positron-emission tomography studies.

Cortisol plasma levels are associated with serotonin - 1A receptor binding in postmenopausal women

2011 ◽  
Vol 26 (S2) ◽  
pp. 933-933
Author(s):  
G. Kranz ◽  
A. Hahn ◽  
J. Ungersböck ◽  
U. Kaufmann ◽  
P. Stein ◽  
...  
Keyword(s):  
Postmenopausal Women ◽  
Receptor Binding ◽  
Plasma Levels ◽  
Hormone Replacement ◽  
Binding Potential ◽  
Serotonin 1A Receptor ◽  
Strong Negative Correlation ◽  
Logan Plot ◽  
Increased Risk ◽  
Relationship Of

IntroductionAlterations of the serotonin-1A receptor (5-HT1A) and the hypothalamic-pituitary-adrenal (HPA) axis have been reported in depression and anxiety disorders. We previously showed a strong negative correlation between cortisol plasma levels and 5-HT1A receptor binding potential (BP) in patients with social anxiety disorder but not in healthy controls using PET [1].ObjectivesTo investigate the relationship of cortisol and the 5-HT1A BP in postmenopausal women, a population that is at increased risk of suffering from depressive symptoms.MethodsSubjects: 19 postmenopausal women, aged 55.26 ± 4.98, medication free, no current substance abuse or hormone replacement therapy.PETDynamic measurements (50 frames, 90 min) were performed using the radioligand [carbonyl-11C]WAY100635 and a GE-Advance scanner. PET data were normalized to a ligand-specific template [2]. Regions-of-interest (ROI) were defined as given in [3]. TACs within ROIs were averaged and the 5-HT1A receptor BP was quantified using Logan-plot and PMOD 3.1. Measurement of total cortisol plasma levels was done using electrochemoluminescence.ResultsWe found negative correlations between cortisol and 5-HT1A BP in the midbrain (Spearman's rs = −0.54, p = 0.02), the median raphe nucleus (rs = −0.47, p = 0.04) and the nucleus accumbens (rs = −0.505, p = 0.03).ConclusionsIn line with our previous findings [1], the observed negative association between cortisol plasma levels and 5-HT1A BP might reflect an increased vulnerability for mood disorders in postmenopausal women.

scholarly journals Building a database for brain 18 kDa translocator protein imaged using [11C]PBR28 in healthy subjects

2018 ◽  
Vol 39 (6) ◽  
pp. 1138-1147 ◽  
Author(s):  
Soumen Paul ◽  
Evan Gallagher ◽  
Jeih-San Liow ◽  
Sanche Mabins ◽  
Katharine Henry ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
High Performance ◽  
Patient Characteristics ◽  
Brain Regions ◽  
Distribution Volume ◽  
Translocator Protein ◽  
Blood Samples ◽  
Arterial Blood ◽  
Logan Plot ◽  
Translocator Protein 18 Kda

Translocator protein 18 kDa (TSPO) has been widely imaged as a marker of neuroinflammation using several radioligands, including [11C]PBR28. In order to study the effects of age, sex, and obesity on TSPO binding and to determine whether this binding can be accurately assessed using fewer radio high-performance liquid chromatography (radio-HPLC) measurements of arterial blood samples, we created a database of 48 healthy subjects who had undergone [11C]PBR28 scans (23 high-affinity binders (HABs) and 25 mixed-affinity binders (MABs), 20 F/28 M, age: 40.6 ± 16.8 years). After analysis by Logan plot using 23 metabolite-corrected arterial samples, total distribution volume ( VT) was found to be 1.2-fold higher in HABs across all brain regions. Additionally, the polymorphism plot estimated nondisplaceable uptake ( VND) as 1.40 mL · cm−3, which generated a specific-to-nondisplaceable ratio ( BPND) of 1.6 ± 0.6 in HABs and 1.1 ± 0.6 in MABs. VT increased significantly with age in nearly all regions and was well estimated with radio-HPLC measurements from six arterial samples. However, VT did not correlate with body mass index and was not affected by sex. These results underscore which patient characteristics should be accounted for during [11C]PBR28 studies and suggest ways to perform such studies more easily and with fewer blood samples.

scholarly journals Equilibrium versus Compartmental Analysis for Assessment of the Vesicular Monoamine Transporter Using (+)-α-[11C]Dihydrotetrabenazine (DTBZ) and Positron Emission Tomography

1997 ◽  
Vol 17 (9) ◽  
pp. 919-931 ◽  
Author(s):  
Robert A. Koeppe ◽  
Kirk A. Frey ◽  
Akito Kume ◽  
Roger Albin ◽  
Michael R. Kilbourn ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Steady State ◽  
Close Agreement ◽  
Compartmental Analysis ◽  
Distribution Volume ◽  
Emission Tomography ◽  
Vesicular Monoamine Transporter ◽  
Monoamine Transporter ◽  
Logan Plot ◽  
Positron Emission

This work compares equilibrium to kinetic analysis of positron emission tomography data for the assessment of vesicular monoamine transporter (VMAT2) binding density using (+)-α-[11C]dihydrotetrabenazine ((+)-α-[11C]DTBZ). Studies were performed for 80 minutes after intravenous administration of 18 ± 1 mCi (+)-α-[11C]DTBZ on 9 young control subjects, 20 to 45 years of age. A 9-mCi bolus was injected over the first minute of the study, whereas the remaining 9 mCi were infused at a constant rate over the following 79 minutes. Steady-state was reached in both blood and brain by approximately 30 minutes after initiation of the study. Nonlinear least-squares analysis using two- and three-compartment models, weighted integral analysis using a two-compartment configuration, and Logan plot analysis all yielded kinetic estimates of the total tissue distribution volume, DVtot(kin). These results were compared with equilibrium distribution volume estimates, DVtot(eq), calculated from the tissue to metabolite corrected arterial plasma concentration ratio after 30 minutes. Kinetic modeling results from this study were in close agreement with prior bolus-injection (+)-α-[11C]DTBZ studies. In the current study, coefficients of variation in DVtot(kin) (19% to 23% across regions) and DVtot(eq) (18% to 22%) were nearly identical. Equilibrium estimates of DVtot were slightly lower than kinetic estimates, averaging 5% ± 9% lower ( P = 0.04, paired t test) in regions of high binding density (caudate and putamen), but only 2% ± 6% ( P = 0.09) in lower binding density regions (cortex, thalamus, cerebellum). DVtot(eq) estimates, however, still correlated highly with DVtot(kin) estimates ( r = 0.977−0.989). Steady-state conditions can be achieved in both tissue and blood by 30 minutes, and the tissue-to-blood ratios of (+)-α-[11C]DTBZ at equilibrium yield DVtot(eq) measures that are in close agreement with DVtot(kin) estimates. Thus, a simple, easily tolerated protocol using a loading bolus followed by continuous infusion can provide excellent measures of VMAT2 binding.

scholarly journals [18F]Fallypride dopamine D2 receptor studies using delayed microPET scans and a modified Logan plot

2009 ◽  
Vol 36 (8) ◽  
pp. 931-940 ◽  
Author(s):  
Mohammed N. Tantawy ◽  
Carrie K. Jones ◽  
Ronald M. Baldwin ◽  
M. Sib Ansari ◽  
P. Jeffrey Conn ◽  
...  
Keyword(s):  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
Dopamine D2 ◽  
Logan Plot

scholarly journals Evaluating the In Vivo Specificity of [18F]UCB-H for the SV2A Protein, Compared with SV2B and SV2C in Rats Using microPET

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1705 ◽  
Author(s):  
Maria Elisa Serrano ◽  
Guillaume Becker ◽  
Mohamed Ali Bahri ◽  
Alain Seret ◽  
Nathalie Mestdagh ◽  
...  
Keyword(s):  
Synaptic Vesicle ◽  
Brain Structures ◽  
Input Function ◽  
Population Based ◽  
The Other ◽  
Sprague Dawley ◽  
Logan Plot ◽  
Sprague Dawley Rats ◽  
Inferior Colliculi

The synaptic vesicle protein 2 (SV2) is involved in synaptic vesicle trafficking. The SV2A isoform is the most studied and its implication in epilepsy therapy led to the development of the first SV2A PET radiotracer [18F]UCB-H. The objective of this study was to evaluate in vivo, using microPET in rats, the specificity of [18F]UCB-H for SV2 isoform A in comparison with the other two isoforms (B and C) through a blocking assay. Twenty Sprague Dawley rats were pre-treated either with the vehicle, or with specific competitors against SV2A (levetiracetam), SV2B (UCB5203) and SV2C (UCB0949). The distribution volume (Vt, Logan plot, t* 15 min) was obtained with a population-based input function. The Vt analysis for the entire brain showed statistically significant differences between the levetiracetam group and the other groups (p < 0.001), but also between the vehicle and the SV2B group (p < 0.05). An in-depth Vt analysis conducted for eight relevant brain structures confirmed the statistically significant differences between the levetiracetam group and the other groups (p < 0.001) and highlighted the superior and the inferior colliculi along with the cortex as regions also displaying statistically significant differences between the vehicle and SV2B groups (p < 0.05). These results emphasize the in vivo specificity of [18F]UCB-H for SV2A against SV2B and SV2C, confirming that [18F]UCB-H is a suitable radiotracer for in vivo imaging of the SV2A proteins with PET.

scholarly journals Noninvasive Measurement of [11C]PiB Distribution Volume Using Integrated PET/MRI

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 993
Author(s):  
Hidehiko Okazawa ◽  
Masamichi Ikawa ◽  
Tetsuya Tsujikawa ◽  
Akira Makino ◽  
Tetsuya Mori ◽  
...  
Keyword(s):  
Standardized Uptake Value ◽  
Input Function ◽  
Distribution Volume ◽  
Mri Segmentation ◽  
Reference Tissue ◽  
Pittsburgh Compound B ◽  
Quantitative Measurements ◽  
Logan Plot ◽  
Static Data ◽  
Early Alzheimer’S Disease

A noninvasive image-derived input function (IDIF) method using PET/MRI was applied to quantitative measurements of [11C] Pittsburgh compound-B (PiB) distribution volume (DV) and compared with other metrics. Fifty-three patients suspected of early dementia (71 ± 11 y) underwent 70 min [11C]PiB PET/MRI. Nineteen of them (68 ± 11 y) without head motion during the scan were enrolled in this study and compared with 16 age-matched healthy controls (CTL: 68 ± 11 y). The dynamic frames reconstructed from listmode PET data were used for DV calculation. IDIF with metabolite correction was applied to the Logan plot method, and DV was normalized into DV ratio (DVR) images using the cerebellar reference (DVRL). DVR and standardized uptake value ratio (SUVR) images were also calculated using the reference tissue graphical method (DVRr) and the 50–70 min static data with cerebellar reference, respectively. Cortical values were compared using the 3D-T1WI MRI segmentation. All patients were assigned to the early Alzheimer’s disease (eAD) group because of positive [11C]PiB accumulation. The correlations of regional values were better for DVRL vs. DVRr (r2 = 0.97) than for SUVR vs. DVRr (r2 = 0.88). However, all metrics clearly differentiated eAD from CTL with appropriate thresholds. Noninvasive quantitative [11C]PiB PET/MRI measurement provided equivalent DVRs with the two methods. SUVR images showed acceptable results despite inferior variability and image quality to DVR images.

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