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  • Meeting abstract
  • Open Access

Whole-body simultaneous time-of-flight PET-MRI: early experience with clinical studies

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EJNMMI Physics20152 (Suppl 1) :A64

  • Published:


  • Positron Emission Tomography
  • Image Quality
  • Computational Mathematic
  • Technical Physic
  • Attenuation Correction

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 initial experience with human clinical studies using 18Ffluorodeoxyglucase (FDG) with this scanner, in comparison to PET-CT. All patients underwent a single-injection of 18F-FDG, with a dual-imaging protocol consisting of PET-CT followed by PET-MRI scan. PET-MR attenuation correction used a two point Dixon fat-water separated method for the body, combined with registration to an atlas for the head. Two radiologists evaluated MRI image quality using the following scale (0 non-diagnostic; 1 poor; 2 good; 3 excellent). PET-MRI and PET-CT images were reviewed for FDG uptake thought to be consistent with malignancy by two readers independently, and categorized into 5 groups (1 both PETMRI and PET-CT positive, 2 PET-MRI positive, PET-CT positive in retrospect; 3 PET-CT positive, PET-MRI positive in retrospect; 4: PET-MRI positive, PET-CT negative; 5: PET-MRI negative, PET-CT positive) by consensus.


Twenty-six oncologic patients (average age: 63±14 yrs) with were enrolled in the study. PET-CT and PETMRI scan started 71±14 and 144±22 minutes after injection of 10Å}1 mCi FDG, respectively. The average length of the PET-CT and PET-MRI scan was 20±7, and 55±15 minutes, respectively. All MRI images were rated to be diagnostic; 64% were rated excellent, 32% were rated good, and 4% were rated poor. 64% (34/53) of 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.

Authors’ Affiliations

Stanford University, Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, USA


© Minamimoto et al; licensee Springer. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.