title: PET/MRI with diagnostic MR sequences vs PET/CT in the detection of abdominal and pelvic cancer.
abstract: OBJECTIVE
  Integrated positron emission tomography/magnetic resonance imaging (PET/MRI) scanners provide combined MR-based anatomic and metabolic image information. The aim of this study was to evaluate qualitative and quantitative diagnostic performance of PET/MR with (18)fluoro-2-deoxyglucose ((18)F-FDG) using a diagnostic MR sequence in patients with abdominal and pelvic tumors, compared to positron emission tomography/computed tomography (PET/CT).
  
  
  METHODS
  Forty five patients underwent a single-injection ((18)F-FDG), dual-imaging protocol including whole-body PET/CT and subsequent regional PET/MR hybrid imaging. A regional PET/MR scan followed the PET/CT. Images from both modalities were analyzed using a 3-point scale for PET/CT and PET/MR image quality, image alignment, and lesion visibility on PET images. PET-CT/PET-MR functional and anatomical correlation was analyzed.
  
  
  RESULTS
  A total of 66 lesions were studied, from which 63 were identified using PET/CT and 59 were identified using PET/MR. The (18)F-FDG PET images had good diagnostic quality (P<0.001); alignment was found to be excellent in PET/MR data as well as PET/CT data (P=0.102), and there was no difference in lesion visibility (P=0.18). The average rating score regarding anatomical correlation for PET-positive lesions was 2.75 for combined MR sequence images and 2.04 for CT, with a significant difference (P=0.317), Standard uptake value (SUV) for focal lesions had excellent correlation (SUVmax/mean: R=0.948/0.948); furthermore, the SUVmean of background organs combined, bone marrow and the muscle tissue showed good correlation (R=0.329/0.398/0.298). No correlations were found in the liver and spleen.
  
  
  CONCLUSIONS
  PET/MR with diagnostic MR sequence was able to detect abdominal and pelvic lesions and had good image quality compared to PET/CT. SUVmax and SUVmean values in focal lesions, and the SUVmean of background organs generally correlated well in abdominal and pelvic oncology patients examined using PET/CT and PET/MRI.
authors.affiliation: Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China. Electronic address: xinjun69@189.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Xin
authors.affiliation: Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China. Electronic address: quanmeima@qq.com.
authors.forename: Quanmei
authors.initials: Q
authors.lastname: Ma
authors.affiliation: Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China. Electronic address: guoqy@sj-hospital.org.
authors.forename: Qiyong
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Department of Nuclear Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China. Electronic address: sunhongzan@sina.com.
authors.forename: Hongzan
authors.initials: H
authors.lastname: Sun
authors.affiliation: Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China. Electronic address: zhangshaomin@gmail.com.
authors.forename: Shaomin
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Nuclear Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China. Electronic address: liucp@sj-hospital.org.
authors.forename: Changping
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Nuclear Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China. Electronic address: zhaiw@sj-hospital.org.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhai
mesh_terms: D000008:Abdominal Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods* / Q000592:standards; D010386:Pelvic Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography / Q000379:methods* / Q000592:standards; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000592:standards; D051598:Whole Body Imaging / Q000379:methods; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 3.0-T MR imaging; Abdominal neoplasms; Hybrid imaging; PET/CT; PET/MR; Pelvic neoplasms