Cross-calibration of the Siemens mMR: easily acquired accurate PET phantom measurements, long-term stability and reproducibility.
EJNMMI Phys
; 3(1): 11, 2016 Dec.
Article
em En
| MEDLINE
| ID: mdl-27387738
ABSTRACT
BACKGROUND:
We present a quick and easy method to perform quantitatively accurate PET scans of typical water-filled PET plastic shell phantoms on the Siemens Biograph mMR PET/MR system. We perform regular cross-calibrations (Xcal) of our PET systems, including the PET/MR, using a Siemens mCT water phantom. LONG-TERM STABILITY The mMR calibration stability was evaluated over a 3-year period where 54 cross-calibrations were acquired, showing that the mMR on average underestimated the concentration by 16 %, consistently due to the use of MR-based µ-maps. The mMR produced the narrowest calibration ratio range with the lowest standard deviation, implying it is the most stable of the six systems in the study over a 3-year period. MMR ACCURACY WITH PREDEFINED µ-MAPS With the latest mMR software version, VB20P, it is possible to utilize predefined phantom µ-maps. We evaluated both the system-integrated, predefined µ-map of the long mMR water phantom and our own user-defined CT-based µ-map of the mCT water phantom, which is used for cross-calibration. For seven scans, which were reconstructed with correctly segmented µ-maps, the mMR produced cross-calibration ratios of 1.00-1.02, well within the acceptance range [0.95-1.05], showing high accuracy.CONCLUSIONS:
The mMR is the most stable PET system in this study, and the mean underestimation is no longer an issue with the easily accessible µ-map, which resulted in correct cross-calibration ratios in all seven tests. We will share the user-defined µ-map of the mCT phantom and the protocol with interested mMR users.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
EJNMMI Phys
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Dinamarca
País de publicação:
ALEMANHA
/
ALEMANIA
/
DE
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DEUSTCHLAND
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GERMANY