Technical Note: Transconvolution based equalization of positron energy effects for the use of 68 Ge/68 Ga phantoms in determining 18 F PET recovery.

Prenosil, George A; Hentschel, Michael; Fürstner, Markus; Krause, Thomas Michael; Weitzel, Thilo; Klaeser, Bernd (2017). Technical Note: Transconvolution based equalization of positron energy effects for the use of 68 Ge/68 Ga phantoms in determining 18 F PET recovery. Medical physics, 44(7), pp. 3761-3766. American Association of Physicists in Medicine AAPM 10.1002/mp.12330

[img]
Preview
Text
Prenosil_et_al-2017-Medical_Physics.pdf - Published Version
Available under License Creative Commons: Attribution-Noncommercial-No Derivative Works (CC-BY-NC-ND).

Download (297kB) | Preview

PURPOSE Avoiding measurement variability from 18 F phantom preparation by using 68 Ge/68 Ga phantoms for the determination of 18 F recovery curves (RC) in clinical quality assurance measurements and for PET/CT site qualification in multicentre clinical trials. METHODS RCs were obtained from PET/CT measurements of seven differently sized phantom spheres filled either with 18 F or with 68 Ga. RCs for the respective other isotope were then determined by two different methods: In the first method, images were convolved with positron range transconvolution functions derived from positron annihilation distributions found in literature. This method generated recasted images matching images using the respective other isotope. In the second method, the PET/CT system's isotope independent (intrinsic) point spread function was determined from said phantom measurements and convolved with numerical representations simulating hot spheres filled with the respective other isotope. These simulations included the isotope specific positron annihilation distributions. Recovered activity concentrations were compared between recasted images, simulated images, and the originally acquired images. RESULTS 18 F and 68 Ga recovery was successfully determined from image acquisitions of the respective opposite isotope as well as from the simulations. 68 Ga RCs derived from 18 F data had a normalized root-mean-square deviation (NRMSD) from real 68 Ga measurements of 0.019% when using the first method and of 0.008% when using the second method. 18 F RCs derived from 68 Ga data had a NRMSD from real 18 F measurements of 0.036% when using the first method and of 0.038% when using the second method. CONCLUSIONS Applying the principles of transconvolution, 18 F RCs can be recalculated from 68 Ga phantom measurements with excellent accuracy. The maximal additionally introduced error was below 0.4% of the error currently accepted for RCs in the site qualification of multicentre clinical trials by the EARL program of the European Association of Nuclear Medicine (EANM). Therefore, our methods legitimately allow for the use of long-lived solid state 68 Ge/68 Ga phantoms instead of manually prepared 18 F phantoms to characterize comparability of 18 F measurements across different imaging sites or of longitudinal 18 F measurements at a single PET/CT system.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Department of Radiology, Neuroradiology and Nuclear Medicine (DRNN) > Clinic of Nuclear Medicine
04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > Forschungsbereich Pavillon 52 > Forschungsgruppe Klinische Radiopharmazie
04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > Forschungsbereich Pavillon 52 > Forschungsgruppe Klinische Radiopharmazie

UniBE Contributor:

Prenosil, George; Hentschel, Michael; Fürstner, Markus; Krause, Thomas Michael; Weitzel, Thilo and Klaeser, Bernd

Subjects:

600 Technology > 610 Medicine & health

ISSN:

0094-2405

Publisher:

American Association of Physicists in Medicine AAPM

Language:

English

Submitter:

Franziska Nicoletti

Date Deposited:

06 Mar 2018 13:35

Last Modified:

20 Mar 2018 13:23

Publisher DOI:

10.1002/mp.12330

PubMed ID:

28494090

Uncontrolled Keywords:

PET/CT partial volume effect positron range function quantitative imaging recovery curve transconvolution

BORIS DOI:

10.7892/boris.109338

URI:

https://boris.unibe.ch/id/eprint/109338

Actions (login required)

Edit item Edit item
Provide Feedback