Development and evaluation of mini-EXPLORER

A long axial field-of-view PET scanner for nonhuman primate imaging

Eric Berg, Xuezhu Zhang, Julien Bec, Martin S. Judenhofer, Brijesh Patel, Qiyu Peng, Maciej Kapusta, Matthias Schmand, Michael E. Casey, Alice F Tarantal, Jinyi Qi, Ramsey D Badawi, Simon R Cherry

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

We describe a long axial field-of-view (FOV) PET scanner for high-sensitivity and total-body imaging of nonhuman primates and present the physical performance and first phantom and animal imaging results. Methods: The mini-EXPLORER PET scanner was built using the components of a clinical scanner reconfigured with a detector ring diameter of 43.5 cm and an axial length of 45.7 cm. National Electrical Manufacturers Association (NEMA) NU-2 and NU-4 phantoms were used to measure sensitivity and count rate performance. Reconstructed spatial resolution was investigated by imaging a radially stepped point source and a Derenzo phantom. The effect of the wide acceptance angle was investigated by comparing performance with maximum acceptance angles of 14°–46°. Lastly, an initial assessment of the in vivo performance of the mini-EXPLORER was undertaken with a dynamic18F-FDG nonhuman primate (rhesus monkey) imaging study. Results: The NU-2 total sensitivity was 5.0%, and the peak noise-equivalent count rate measured with the NU-4 monkey scatter phantom was 1,741 kcps, both obtained using the maximum acceptance angle (46°). The NU-4 scatter fraction was 16.5%, less than 1% higher than with a 14° acceptance angle. The reconstructed spatial resolution was approximately 3.0 mm at the center of the FOV, with a minor loss in axial spatial resolution (0.5 mm) when the acceptance angle increased from 14° to 46°. The rhesus monkey18F-FDG study demonstrated the benefit of the high sensitivity of the mini-EXPLORER, including fast imaging (1-s early frames), excellent image quality (30-s and 5-min frames), and late-time-point imaging (18 h after injection), all obtained at a single bed position that captured the major organs of the rhesus monkey. Conclusion: This study demonstrated the physical performance and imaging capabilities of a long axial FOV PET scanner designed for high-sensitivity imaging of nonhuman primates. Further, the results of this study suggest that a wide acceptance angle can be used with a long axial FOV scanner to maximize sensitivity while introducing only minor tradeoffs such as a small increase in scatter fraction and slightly degraded axial spatial resolution.

Original languageEnglish (US)
Pages (from-to)993-998
Number of pages6
JournalJournal of Nuclear Medicine
Volume59
Issue number6
DOIs
StatePublished - Jun 1 2018

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Primates
Macaca mulatta
Imaging Phantoms
Haplorhini
Noise
Injections

Keywords

  • High sensitivity
  • Long axial field of view
  • Positron emission tomography
  • Rhesus monkey
  • Total-body imaging

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

Development and evaluation of mini-EXPLORER : A long axial field-of-view PET scanner for nonhuman primate imaging. / Berg, Eric; Zhang, Xuezhu; Bec, Julien; Judenhofer, Martin S.; Patel, Brijesh; Peng, Qiyu; Kapusta, Maciej; Schmand, Matthias; Casey, Michael E.; Tarantal, Alice F; Qi, Jinyi; Badawi, Ramsey D; Cherry, Simon R.

In: Journal of Nuclear Medicine, Vol. 59, No. 6, 01.06.2018, p. 993-998.

Research output: Contribution to journalArticle

Berg, Eric ; Zhang, Xuezhu ; Bec, Julien ; Judenhofer, Martin S. ; Patel, Brijesh ; Peng, Qiyu ; Kapusta, Maciej ; Schmand, Matthias ; Casey, Michael E. ; Tarantal, Alice F ; Qi, Jinyi ; Badawi, Ramsey D ; Cherry, Simon R. / Development and evaluation of mini-EXPLORER : A long axial field-of-view PET scanner for nonhuman primate imaging. In: Journal of Nuclear Medicine. 2018 ; Vol. 59, No. 6. pp. 993-998.
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