Harmonization of [11C]raclopride brain PET images from the HR+ and HRRT: method development and validation in human subjects

Abstract Background There has been an ongoing need to compare and combine the results of new PET imaging studies conducted with [11C]raclopride with older data. This typically means harmonizing data across different scanners. Previous harmonization studies have utilized either phantoms or human subj...

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Main Authors: Jocelyn Hoye, Takuya Toyonaga, Yasmin Zakiniaeiz, Gelsina Stanley, Michelle Hampson, Evan D. Morris
Format: Article
Language:English
Published: SpringerOpen 2022-04-01
Series:EJNMMI Physics
Subjects:
Online Access:https://doi.org/10.1186/s40658-022-00457-z
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author Jocelyn Hoye
Takuya Toyonaga
Yasmin Zakiniaeiz
Gelsina Stanley
Michelle Hampson
Evan D. Morris
author_facet Jocelyn Hoye
Takuya Toyonaga
Yasmin Zakiniaeiz
Gelsina Stanley
Michelle Hampson
Evan D. Morris
author_sort Jocelyn Hoye
collection DOAJ
description Abstract Background There has been an ongoing need to compare and combine the results of new PET imaging studies conducted with [11C]raclopride with older data. This typically means harmonizing data across different scanners. Previous harmonization studies have utilized either phantoms or human subjects, but the use of both phantoms and humans in one harmonization study is not common. The purpose herein was (1) to use phantom images to develop an inter-scanner harmonization technique and (2) to test the harmonization technique in human subjects. Methods To develop the harmonization technique (Experiment 1), the Iida brain phantom was filled with F-18 solution and scanned on the two scanners in question (HRRT, HR+, Siemens/CTI). Phantom images were used to determine the optimal isotropic Gaussian filter to harmonize HRRT and HR+ images. To evaluate the harmonization on human images (Experiment 2), inter-scanner variability was calculated using [11C]raclopride scans of 3 human subjects on both the HRRT and HR+ using percent difference (PD) in striatal non-displaceable binding potential (BPND) between HR+ and HRRT (with and without Gaussian smoothing). Finally, (Experiment 3), PDT/RT was calculated for test–retest (T/RT) variability of striatal BPND for 8 human subjects scanned twice on the HR+. Results Experiment 1 identified the optimal filter as a Gaussian with a 4.5 mm FWHM. Experiment 2 resulted in 13.9% PD for unfiltered HRRT and 3.71% for HRRT filtered with 4.5 mm. Experiment 3 yielded 5.24% PDT/RT for HR+. Conclusions The PD results show that the variability of harmonized HRRT is less than the T/RT variability of the HR+. The harmonization technique makes it possible for BPND estimates from the HRRT to be compared to (and/or combined with) those from the HR+ without adding to overall variability. Our approach is applicable to all pairs of scanners still in service.
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spelling doaj.art-888fdc113f7743a8a8f0a651962be0882022-12-22T00:10:07ZengSpringerOpenEJNMMI Physics2197-73642022-04-01911910.1186/s40658-022-00457-zHarmonization of [11C]raclopride brain PET images from the HR+ and HRRT: method development and validation in human subjectsJocelyn Hoye0Takuya Toyonaga1Yasmin Zakiniaeiz2Gelsina Stanley3Michelle Hampson4Evan D. Morris5Department of Radiology and Biomedical Imaging, Yale School of MedicineDepartment of Radiology and Biomedical Imaging, Yale School of MedicineDepartment of Psychiatry, Yale School of MedicineDepartment of Radiology and Biomedical Imaging, Yale School of MedicineDepartment of Radiology and Biomedical Imaging, Yale School of MedicineDepartment of Radiology and Biomedical Imaging, Yale School of MedicineAbstract Background There has been an ongoing need to compare and combine the results of new PET imaging studies conducted with [11C]raclopride with older data. This typically means harmonizing data across different scanners. Previous harmonization studies have utilized either phantoms or human subjects, but the use of both phantoms and humans in one harmonization study is not common. The purpose herein was (1) to use phantom images to develop an inter-scanner harmonization technique and (2) to test the harmonization technique in human subjects. Methods To develop the harmonization technique (Experiment 1), the Iida brain phantom was filled with F-18 solution and scanned on the two scanners in question (HRRT, HR+, Siemens/CTI). Phantom images were used to determine the optimal isotropic Gaussian filter to harmonize HRRT and HR+ images. To evaluate the harmonization on human images (Experiment 2), inter-scanner variability was calculated using [11C]raclopride scans of 3 human subjects on both the HRRT and HR+ using percent difference (PD) in striatal non-displaceable binding potential (BPND) between HR+ and HRRT (with and without Gaussian smoothing). Finally, (Experiment 3), PDT/RT was calculated for test–retest (T/RT) variability of striatal BPND for 8 human subjects scanned twice on the HR+. Results Experiment 1 identified the optimal filter as a Gaussian with a 4.5 mm FWHM. Experiment 2 resulted in 13.9% PD for unfiltered HRRT and 3.71% for HRRT filtered with 4.5 mm. Experiment 3 yielded 5.24% PDT/RT for HR+. Conclusions The PD results show that the variability of harmonized HRRT is less than the T/RT variability of the HR+. The harmonization technique makes it possible for BPND estimates from the HRRT to be compared to (and/or combined with) those from the HR+ without adding to overall variability. Our approach is applicable to all pairs of scanners still in service.https://doi.org/10.1186/s40658-022-00457-zHarmonizationBrain PETBinding Potential[11C]RacloprideInter-scannerTest–retest Variability
spellingShingle Jocelyn Hoye
Takuya Toyonaga
Yasmin Zakiniaeiz
Gelsina Stanley
Michelle Hampson
Evan D. Morris
Harmonization of [11C]raclopride brain PET images from the HR+ and HRRT: method development and validation in human subjects
EJNMMI Physics
Harmonization
Brain PET
Binding Potential
[11C]Raclopride
Inter-scanner
Test–retest Variability
title Harmonization of [11C]raclopride brain PET images from the HR+ and HRRT: method development and validation in human subjects
title_full Harmonization of [11C]raclopride brain PET images from the HR+ and HRRT: method development and validation in human subjects
title_fullStr Harmonization of [11C]raclopride brain PET images from the HR+ and HRRT: method development and validation in human subjects
title_full_unstemmed Harmonization of [11C]raclopride brain PET images from the HR+ and HRRT: method development and validation in human subjects
title_short Harmonization of [11C]raclopride brain PET images from the HR+ and HRRT: method development and validation in human subjects
title_sort harmonization of 11c raclopride brain pet images from the hr and hrrt method development and validation in human subjects
topic Harmonization
Brain PET
Binding Potential
[11C]Raclopride
Inter-scanner
Test–retest Variability
url https://doi.org/10.1186/s40658-022-00457-z
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