TY - JOUR T1 - Whole-body Simultaneous Time-of-flight PET-MRI: Clinical Comparison with PET-CT JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1853 LP - 1853 VL - 56 IS - supplement 3 AU - Ryogo Minamimoto AU - Andrei Iagaru AU - Mehran Jamali AU - Amir Barkhodari AU - Dawn Holley AU - Shreyas Vasanawala AU - Greg Zaharchuk Y1 - 2015/05/01 UR - http://jnm.snmjournals.org/content/56/supplement_3/1853.abstract N2 - 1853 Objectives Recently, a whole-body simultaneous system with time-of-flight (TOF) PET has been developed. We have compared the results of this new system with PET-CT in a cohort of clinical patients scanned with 18F-fluorodeoxyglucose (FDG).Methods All patients underwent a single-injection of FDG, with a dual-imaging protocol consisting of a PET-CT followed by PET-MRI scan. After standard diagnostic PET-CT examination, patients were then transferred to the TOF PET-MRI scanner, where whole body imaging was performed. Two radiologists evaluated MRI image quality on a 4 point scale (0 non-diagnostic; 1 poor; 2 good; 3 excellent). On both PET-MRI and PET-CT images, regions of FDG uptake suspicious for malignancy were identified by two readers independently, and categorized into 3 groups (identified on both PET-MRI and PET-CT, on PET-MRI but not on PET-CT, and on PET-CT but not PET-MRI) by consensus.Results Twenty-five oncologic patients (average age 64±15 yrs) were enrolled in the study. PET-CT occurred 72±14 min after injection of 10±1 mCi of FDG. The PET-MRI scan occurred 146±24 min after injection of FDG. The average length of the PET-CT scan was 21±7 min, while the average length of the PET-MRI scan was 56±19 min. All MRI images were rated as diagnostic; 64% as excellent, 32% as good, and 4% as poor; lower scores were related to motion and body size, with no specific artifacts attributable to the PET hardware. 82% of suspicious FDG lesions were observed prospectively in the same location for both PET-CT and PET-MRI. We also observed that TOF reconstruction improved conspicuity of FDG avid lesions.Conclusions TOF PET-MRI provided comparable image quality and diagnostic ability as PET-CT, despite imaging at a later time point. However, current PET-MRI protocols required longer acquisition times compared with PET-CT. TOF PET-MRI demonstrates great promise for clinical imaging.Research Support Research Grant, General Electric Company ER -