Investigation of the imaging characteristics of the ALBIRA II small animal PET system for 18F, 68Ga and 64Cu

Ali Asgar Attarwala; Yvonne Wanjiku Karanja; Deni Hardiansyah; Chiara Romanó; Mareike Roscher; Björn Wängler; Gerhard Glatting

doi:10.1016/j.zemedi.2017.01.005

Investigation of the imaging characteristics of the ALBIRA II small animal PET system for ¹⁸F, ⁶⁸Ga and ⁶⁴Cu

Z Med Phys. 2017 Jun;27(2):132-144. doi: 10.1016/j.zemedi.2017.01.005. Epub 2017 Apr 13.

Authors

Ali Asgar Attarwala¹, Yvonne Wanjiku Karanja², Deni Hardiansyah³, Chiara Romanó², Mareike Roscher⁴, Björn Wängler⁴, Gerhard Glatting⁵

Affiliations

¹ Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. Electronic address: AliAsgar.Attarwala@medma.uni-heidelberg.de.
² Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
³ Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
⁴ Molecular Imaging and Radiochemistry, Institute for Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
⁵ Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, Ulm, Germany.

PMID: 28412013
DOI: 10.1016/j.zemedi.2017.01.005

Abstract

Aim: In this study the performance characteristics of the Albira II PET sub-system and the response of the system for the following radionuclides ¹⁸F, ⁶⁸Ga and ⁶⁴Cu was analyzed.

Materials and methods: The Albira II tri-modal system (Bruker BioSpin MRI GmbH, Ettlingen, Germany) is a pre-clinical device for PET, SPECT and CT. The PET sub-system uses single continuous crystal detectors of lutetium yttrium orthosilicate (LYSO). The detector assembly consists of three rings of 8 detector modules. The transaxial field of view (FOV) has a diameter of 80mm and the axial FOV is 148mm. A NEMA NU-4 image quality phantom (Data Spectrum Corporation, Durham, USA) having five rods with diameters of 1, 2, 3, 4 and 5mm and a uniform central region was used. Measurements with ¹⁸F, ⁶⁸Ga and ⁶⁴Cu were performed in list mode acquisition over 10h. Data were reconstructed using a maximum-likelihood expectation-maximization (MLEM) algorithm with iteration numbers between 5 and 50. System sensitivity, count rate linearity, convergence and recovery coefficients were analyzed.

Results: The sensitivities for the entire FOV (non-NEMA method) for ¹⁸F, ⁶⁸Ga and ⁶⁴Cu were (3.78±0.05)%, (3.97±0.18)% and (3.79±0.37)%, respectively. The sensitivity based on the NEMA protocol using the ²²Na point source yielded (5.53±0.06)%. Dead-time corrected true counts were linear for activities ≤7MBq (¹⁸F and ⁶⁸Ga) and ≤17MBq (⁶⁴Cu) in the phantom. The radial, tangential and axial full widths at half maximum (FWHMs) were 1.52, 1.47 and 1.48mm. Recovery coefficients for the uniform region with a total activity of 8MBq in the phantom were (0.97±0.05), (0.98±0.06), (0.98±0.06) for ¹⁸F, ⁶⁸Ga and ⁶⁴Cu, respectively.

Conclusion: The Albira II pre-clinical PET system has an adequate sensitivity range and the system linearity is suitable for the range of activities used for pre-clinical imaging. Overall, the system showed a favorable image quality for pre-clinical applications.

Keywords: PET isotopes; PET-Isotope; Positron emission tomography (PET); Positronen-Emissions-Tomographie (PET); Recovery-Koeffizienten; pre-clinical imaging; präklinische Bildgebung; recovery coefficients.

MeSH terms

Animals
Copper Radioisotopes*
Fluorine Radioisotopes*
Gallium Radioisotopes*
Germany
Humans
Phantoms, Imaging
Positron Emission Tomography Computed Tomography / methods*
Positron Emission Tomography Computed Tomography / standards*

Substances

Copper Radioisotopes
Fluorine Radioisotopes
Gallium Radioisotopes
Fluorine-18