RT Journal Article
SR Electronic
T1 Comparison of PET/CT with Sequential PET/MRI Using an MR-Compatible Mobile PET System
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 846
OP 851
DO 10.2967/jnumed.117.197665
VO 59
IS 5
A1 Nakamoto, Ryusuke
A1 Nakamoto, Yuji
A1 Ishimori, Takayoshi
A1 Fushimi, Yasutaka
A1 Kido, Aki
A1 Togashi, Kaori
YR 2018
UL http://jnm.snmjournals.org/content/59/5/846.abstract
AB The current study tested a newly developed flexible PET (fxPET) scanner prototype. This fxPET system involves dual arc-shaped detectors based on silicon photomultipliers that are designed to fit existing MRI devices, allowing us to obtain fused PET and MR images by sequential PET and MR scanning. This prospective study sought to evaluate the image quality, lesion detection rate, and quantitative values of fxPET in comparison with conventional whole-body (WB) PET and to assess the accuracy of registration. Methods: Seventeen patients with suspected or known malignant tumors were analyzed. Approximately 1 h after intravenous injection of 18F-FDG, WB PET/CT was performed, followed by fxPET and MRI. For reconstruction of fxPET images, MRI-based attenuation correction was applied. The quality of fxPET images was visually assessed, and the number of detected lesions was compared between the 2 imaging methods. SUVmax and maximum average SUV within a 1 cm3 spheric volume (SUVpeak) of lesions were also compared. In addition, the magnitude of misregistration between fxPET and MR images was evaluated. Results: The image quality of fxPET was acceptable for diagnosis of malignant tumors. There was no significant difference in detectability of malignant lesions between fxPET and WB PET (P > 0.05). However, the fxPET system did not exhibit superior performance to the WB PET system. There were strong positive correlations between the 2 imaging modalities in SUVmax (ρ = 0.88) and SUVpeak (ρ = 0.81). SUVmax and SUVpeak measured with fxPET were approximately 1.1-fold greater than measured with WB PET. The average misregistration between fxPET and MR images was 5.5 ± 3.4 mm. Conclusion: Our preliminary data indicate that running an fxPET scanner near an existing MRI system provides visually and quantitatively acceptable fused PET/MR images for diagnosis of malignant lesions.