A PHP Error was encountered

Severity: Warning

Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests

Filename: helpers/my_audit_helper.php

Line Number: 143

Backtrace:

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 143
Function: file_get_contents

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 209
Function: simplexml_load_file_from_url

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 994
Function: getPubMedXML

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3134
Function: GetPubMedArticleOutput_2016

File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global

File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword

File: /var/www/html/index.php
Line: 316
Function: require_once

Reliable quantification of F-GE-180 PET neuroinflammation studies using an individually scaled population-based input function or late tissue-to-blood ratio. | LitMetric

AI Article Synopsis

  • The study aimed to explore simplified methods for quantifying microglia activation using F-GE-180 PET, moving away from the complex tracer kinetic modeling that involves arterial blood sampling and metabolite correction.
  • Researchers tested these methods on data from five healthy volunteers and 20 liver transplant patients, creating population-based input function templates for easier analysis.
  • Results showed a high correlation between the traditional reference values and the new population-based input functions, particularly when scaling was based on blood samples, indicating that simplified methods might still retain accuracy in assessing TSPO-related microglia activity.

Article Abstract

Purpose: Tracer kinetic modeling of tissue time activity curves and the individual input function based on arterial blood sampling and metabolite correction is the gold standard for quantitative characterization of microglia activation by PET with the translocator protein (TSPO) ligand F-GE-180. This study tested simplified methods for quantification of F-GE-180 PET.

Methods: Dynamic F-GE-180 PET with arterial blood sampling and metabolite correction was performed in five healthy volunteers and 20 liver-transplanted patients. Population-based input function templates were generated by averaging individual input functions normalized to the total area under the input function using a leave-one-out approach. Individual population-based input functions were obtained by scaling the input function template with the individual parent activity concentration of F-GE-180 in arterial plasma in a blood sample drawn at 27.5 min or by the individual administered tracer activity, respectively. The total F-GE-180 distribution volume (V) was estimated in 12 regions-of-interest (ROIs) by the invasive Logan plot using the measured or the population-based input functions. Late ROI-to-whole-blood and ROI-to-cerebellum ratio were also computed.

Results: Correlation with the reference V (with individually measured input function) was very high for V with the population-based input function scaled with the blood sample and for the ROI-to-whole-blood ratio (Pearson correlation coefficient = 0.989 ± 0.006 and 0.970 ± 0.005). The correlation was only moderate for V with the population-based input function scaled with tracer activity dose and for the ROI-to-cerebellum ratio (0.653 ± 0.074 and 0.384 ± 0.177). Reference V, population-based V with scaling by the blood sample, and ROI-to-whole-blood ratio were sensitive to the TSPO gene polymorphism. Population-based V with scaling to the administered tracer activity and the ROI-to-cerebellum ratio failed to detect a polymorphism effect.

Conclusion: These results support the use of a population-based input function scaled with a single blood sample or the ROI-to-whole-blood ratio at a late time point for simplified quantitative analysis of F-GE-180 PET.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7651670PMC
http://dx.doi.org/10.1007/s00259-020-04810-1DOI Listing

Publication Analysis

Top Keywords

input function
36
population-based input
28
blood sample
16
f-ge-180 pet
12
input
12
input functions
12
tracer activity
12
roi-to-cerebellum ratio
12
function scaled
12
sample roi-to-whole-blood
12

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!

A PHP Error was encountered

Severity: Notice

Message: fwrite(): Write of 34 bytes failed with errno=28 No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 272

Backtrace:

A PHP Error was encountered

Severity: Warning

Message: session_write_close(): Failed to write session data using user defined save handler. (session.save_path: /var/lib/php/sessions)

Filename: Unknown

Line Number: 0

Backtrace: