title: Gadoxetate-enhanced versus diffusion-weighted MRI for fused Ga-68-DOTANOC PET/MRI in patients with neuroendocrine tumours of the upper abdomen.
abstract: OBJECTIVE
  To compare fused gadoxetate-enhanced Ga-68-DOTANOC PET/MRI and Ga-68-DOTANOC PET/DWI (diffusion-weighted imaging) for the assessment of abdominal neuroendocrine tumours (NETs).
  
  
  METHODS
  Eighteen patients with suspected or histologically proven NETs of the abdomen were enrolled in this retrospective study. All patients underwent Ga-68-DOTANOC PET/CT for a primary search, staging, or restaging, and received an additional MRI, including dynamic gadoxetate-enhanced T1-weighted sequences and DWI (b-values 50, 300 and 600). Co-registered gadoxetate-enhanced PET/MRI and PET/DWI were separately analysed for NET lesions by a nuclear medicine physician and a radiologist in consensus. Sensitivity and specificity were calculated on a per-region, per-organ and per-patient basis.
  
  
  RESULTS
  Eighty-seven out of 684 anatomical regions, and 23 out of 270 organs, were NET-positive in 14 out of 18 patients. Region-based sensitivities and specificities were 97.7 % and 99.7 % for gadoxetate-enhanced PET/MRI and 98.9 % and 99.7 % for PET/DWI. Organ-based sensitivities and specificities were 91.3 % and 99.6 % for gadoxetate-enhanced PET/MRI and 95.7 % and 99.6 % for PET/DWI. Finally, patient-based sensitivities and specificities were 100 % and 100 % for gadoxetate-enhanced PET/MRI and 100 % and 75 % for PET/DWI. Sensitivities and specificities of the two methods did not differ significantly.
  
  
  CONCLUSIONS
  Gadoxetate-enhanced Ga-68-DOTANOC PET/MRI and Ga-68-DOTANOC PET/DWI are equally useful for the assessment of abdominal NETs.
  
  
  CONCLUSIONS
  • Positron emission tomography and magnetic resonance imaging can both assess neuroendocrine tumours. • Fusion of PET/MR imaging provides helpful information. • Gadoxetate-enhanced Ga-68-DOTANOC PET/MRI and Ga-68-DOTANOC PET/DWI assess neuroendocrine tumours equally well. • PET/DWI is inherently simpler than gadoxetate-enhanced PET/MRI. • Only benign hepatic lesions pose a potential diagnostic dilemma for PET/DWI.
authors.affiliation: Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria. marius.mayerhoefer@meduniwien.ac.at
authors.forename: Marius E
authors.initials: ME
authors.lastname: Mayerhoefer
authors.forename: Ahmed
authors.initials: A
authors.lastname: Ba-Ssalamah
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.forename: Markus
authors.initials: M
authors.lastname: Mitterhauser
authors.forename: Harald
authors.initials: H
authors.lastname: Eidherr
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wadsak
authors.forename: Markus
authors.initials: M
authors.lastname: Raderer
authors.forename: Siegfried
authors.initials: S
authors.lastname: Trattnig
authors.forename: Andreas
authors.initials: A
authors.lastname: Herneth
authors.forename: Georgios
authors.initials: G
authors.lastname: Karanikas
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003287:Contrast Media / Q000494:pharmacology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D005710:Gallium Radioisotopes; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging*; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: C504894:68Ga-DOTANOC; D003287:Contrast Media; D005710:Gallium Radioisotopes; D009942:Organometallic Compounds; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA