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J Nucl Med. 2016 Apr;57(4):646-52. doi: 10.2967/jnumed.115.159723. Epub 2015 Dec 23.

National Electrical Manufacturers Association and Clinical Evaluation of a Novel Brain PET/CT Scanner.

Author information

1
The Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts.
2
Photo Diagnostic Systems, Inc., Boxborough, Massachusetts; and.
3
Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts.
4
The Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts elfakhri.georges@mgh.harvard.edu.

Abstract

The aim of this study was to determine the performance of a novel mobile human brain/small-animal PET/CT system. The scanner has a 35.7-cm-diameter bore and a 22-cm axial extent. The detector ring has 7 modules each with 3 × 4 cerium-doped lutetium yttrium orthosilicate crystal blocks, each consisting of 22 × 22 outer-layer and 21 × 21 inner-layer crystals, each layer 1-cm thick. Light is collected by 12 × 12 silicon photomultipliers. The integrated CT can be used for attenuation correction and anatomic localization. The scanner was designed as a low-cost device that nevertheless produces high-quality PET images with the unique capability of battery-powered propulsion, enabling use in many settings.

METHODS:

Spatial resolution, sensitivity, and noise-equivalent counting rate were measured based on the National Electrical Manufacturers Association NU2-2012 procedures. Reconstruction was done with tight energy and timing cuts-400-650 keV and 7 ns-and loose cuts-350-700 keV and 10 ns. Additional image quality measurements were made from phantom, human, and animal studies. Performance was compared with a reference scanner with comparable imaging properties.

RESULTS:

The full width at half maximum transverse resolution at a 1-cm (10-cm) radius was 3.2 mm (5.2-mm radial, 3.1-mm tangential), and the axial resolution was 3.5 mm (4.0 mm). A sensitivity of 7.5 and 11.7 kcps/MBq at the center for tight and loose cuts, respectively, increased to 8.8 and 13.9 kcps/MBq, respectively, at a 10-cm radial offset. The maximum noise-equivalent counting rate of 19.5 and 22.7 kcps for tight and loose cuts, respectively, was achieved for an activity concentration of 2.9 kBq/mL. Contrast recovery for 4:1 hot cylinder to warm background was 76% for the 25-mm-diameter cylinder but decreased with decreasing cylinder size. The quantitation agreed within 2% of the known activity distribution and concentration. Brain phantom and human scans have shown agreement in SUVs and image quality with the reference scanner.

CONCLUSION:

We characterized the performance of the NeuroPET/CT and showed images from the first human studies. The study shows that this scanner achieves good performance when spatial resolution, sensitivity, counting rate, and image quality along with a low cost and unique mobile capabilities are considered.

KEYWORDS:

NEMA standard; PET/CT; instrumentation

PMID:
26697961
PMCID:
PMC4818715
DOI:
10.2967/jnumed.115.159723
[Indexed for MEDLINE]
Free PMC Article

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