Ryogo Minamimoto MD, PhD, Presenter: Nothing to Disclose

Andrei Iagaru MD, Abstract Co-Author: Advisory Board, Cytogen Corporation Advisory Board, Spectrum Pharmaceuticals, Inc Researcher, General Electric Company

Mehran Jamali, Abstract Co-Author: Nothing to Disclose

Dawn Holley, Abstract Co-Author: Nothing to Disclose

Anne-Marie Sawyer, Abstract Co-Author: Nothing to Disclose

Shreyas Shreenivas Vasanawala MD, PhD, Abstract Co-Author: Research collaboration, General Electric Company Stockholder, Morpheus Imaging, Inc

Robert J. Herfkens MD, Abstract Co-Author: Nothing to Disclose

Amir Barkhodari, Abstract Co-Author: Nothing to Disclose

Gary H. Glover PhD, Abstract Co-Author: Nothing to Disclose

Sanjiv Sam Gambhir MD, PhD, Abstract Co-Author: Research Grant, Bayer AG Research Grant, General Electric Company Research Grant, sanofi-aventis Group Research Consultant, Bracco Group Research Consultant, CytomX Therapeutics Research Consultant, Spectrum Dynamics Ltd Research Consultant, Enlight Biosciences Research Consultant, ImaginAb, Inc Stockholder, CellSight Technologies, Inc Stockholder, Endra, Inc Stockholder, Enlight Biosciences Stockholder, ImaginAb, Inc Stockholder, Lumen Therapeutics, LLC Stockholder, MagArray, Inc Stockholder, NinePoint Medical, Inc Stockholder, Prolume, Ltd Stockholder, RefleXion Medical Inc Stockholder, Spectrum Dynamics Ltd Advisory Board, Enlight Biosciences Advisory Board, ImaginAb, Inc Spouse, Employee, CellSight Technologies, Inc Stockholder, FUJIFILM Holdings Corporation Advisory Board, FUJIFILM Holdings Corporation Research Consultant, FUJIFILM Holdings Corporation Advisory Board, SiteOne Therapeutics, Inc Research Consultant, SiteOne Therapeutics, Inc

Greg Zaharchuk MD, PhD, Abstract Co-Author: Research Grant, General Electric Company

Recently, a whole-body, simultaneous positron emission tomography-magnetic resonance imaging (PET-MRI) system combing MRI with time-of-flight (TOF) PET has been developed. We present our first experience with human clinical studies with 18F-fluorodeoxyglucose (FDG) with this scanner.

All patients underwent a single-injection of FDG, dual-imaging protocol consisting of a PET-CT followed by PET-MR scan. Standard diagnostic PET-CT examination performed on a Discovery 600 or 690 PET-CT scanner, 2 min/bed position. Patients were then transferred to the PET-MRI scanner. Two radiologist evaluated MRI image quality, focusing on whole body coronal short-tau inversion recovery (STIR) images (TR/TI/TE 4300/190/44.2 ms; FOV 44-46 cm; matrix 384 x 224; slice thickness/skip: 8/0 mm) using the following scale (0 non-diagnostic; 1 poor; 2 good; 3 excellent). Two nuclear medicine physicians compared the image quality of the PET image obtained from PET-CT and PET-MRI (1 worse than PET-CT; 2 almost equal; 3 better than PET-CT). PET-MR and PET-CT were compared visually by two observers (radiologists and nuclear physician) for identifying the location of a maximum of three lesions per patient with most intense FDG uptake.

Nineteen patients (average: 64±14 yrs) with clinically indicated oncologic (n=17), neurologic (n=2) and cardiologic (n=1) were enrolled in the study. PET-CT occurred 71±16 min after injection of 10.2 ± 1.10 mCi of FDG. The PET-MRI scan occured 52±16 minutes (range 23 to 84 minutes) after PET-CT scan. The average length of the PET-MRI scan from head to thigh was 51±14 minutes. PET image quality from PET-MRI was rated consistently higher than the PET image quality from PET-CT. All MRI images were rated to be diagnostic; 59% were rated excellent, 35% were rated good, and 6% were rated poor; lower scores were related to motion, with no specific artifacts attributable to the PET hardware. 64% of the 3 most FDG intense lesions were observed in the same location for both PET-CT and PET-MRI. 

TOF PET-MRI provided comparable image quality and diagnostic ability with PET-CT, despite imaging at a later time point. However, PET-MRI scanning took long at least initially.

PET-MRI provide acceptable MRI quality and equal PET quality with that of PET-CT. The diagnostic performance of PET-MRI regarding the identification of lesion with intense FDG uptake was equivalent to PET-CT.  

Minamimoto, R, Iagaru, A, Jamali, M, Holley, D, Sawyer, A, Vasanawala, S, Herfkens, R, Barkhodari, A, Glover, G, Gambhir, S, Zaharchuk, G, Whole-body Simultaneous Time-of-Flight PET-MRI: Initial Clinical Experience.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14009042.html