title: A framework for optimization of diffusion-weighted MRI protocols for large field-of-view abdominal-pelvic imaging in multicenter studies.
abstract: OBJECTIVE
  To develop methods for optimization of diffusion-weighted MRI (DW-MRI) in the abdomen and pelvis on 1.5 T MR scanners from three manufacturers and assess repeatability of apparent diffusion coefficient (ADC) estimates in a temperature-controlled phantom and abdominal and pelvic organs in healthy volunteers.
  
  
  METHODS
  Geometric distortion, ghosting, fat suppression, and repeatability and homogeneity of ADC estimates were assessed using phantoms and volunteers. Healthy volunteers (ten per scanner) were each scanned twice on the same scanner. One volunteer traveled to all three institutions in order to provide images for qualitative comparison. The common volunteer was excluded from quantitative analysis of the data from scanners 2 and 3 in order to ensure statistical independence, giving n = 10 on scanner 1 and n = 9 on scanners 2 and 3 for quantitative analysis. Repeatability and interscanner variation of ADC estimates in kidneys, liver, spleen, and uterus were assessed using within-patient coefficient of variation (wCV) and Kruskal-Wallis tests, respectively.
  
  
  RESULTS
  The coefficient of variation of ADC estimates in the temperature-controlled phantom was 1%-4% for all scanners. Images of healthy volunteers from all scanners showed homogeneous fat suppression and no marked ghosting or geometric distortion. The wCV of ADC estimates was 2%-4% for kidneys, 3%-7% for liver, 6%-9% for spleen, and 7%-10% for uterus. ADC estimates in kidneys, spleen, and uterus showed no significant difference between scanners but a significant difference was observed in liver (p < 0.05).
  
  
  CONCLUSIONS
  DW-MRI protocols can be optimized using simple phantom measurements to produce good quality images in the abdomen and pelvis at 1.5 T with repeatable quantitative measurements in a multicenter study.
authors.affiliation: MRI Unit, Royal Marsden Hospital, Downs Road, Sutton, Surrey SM2 5PT, United Kingdom and Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research, 123 Old Brompton Road, London SW7 3RP, United Kingdom.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Winfield
authors.affiliation: MRI Unit, Royal Marsden Hospital, Downs Road, Sutton, Surrey SM2 5PT, United Kingdom and Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research, 123 Old Brompton Road, London SW7 3RP, United Kingdom.
authors.forename: David J
authors.initials: DJ
authors.lastname: Collins
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge CB2 0QQ, United Kingdom.
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Priest
authors.affiliation: Imperial College Healthcare NHS Trust, Imaging Department, Hammersmith Hospital, Du Cane Road, London W12 0HS, United Kingdom.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Quest
authors.affiliation: Imperial College Healthcare NHS Trust, Imaging Department, Hammersmith Hospital, Du Cane Road, London W12 0HS, United Kingdom.
authors.forename: Alan
authors.initials: A
authors.lastname: Glover
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge CB2 0QQ, United Kingdom.
authors.forename: Sally
authors.initials: S
authors.lastname: Hunter
authors.affiliation: MRI Unit, Royal Marsden Hospital, Downs Road, Sutton, Surrey SM2 5PT, United Kingdom and Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research, 123 Old Brompton Road, London SW7 3RP, United Kingdom.
authors.forename: Veronica A
authors.initials: VA
authors.lastname: Morgan
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge CB2 0QQ, United Kingdom.
authors.forename: Susan
authors.initials: S
authors.lastname: Freeman
authors.affiliation: Imperial College Healthcare NHS Trust, Imaging Department, Hammersmith Hospital, Du Cane Road, London W12 0HS, United Kingdom.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rockall
authors.affiliation: MRI Unit, Royal Marsden Hospital, Downs Road, Sutton, Surrey SM2 5PT, United Kingdom and Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research, 123 Old Brompton Road, London SW7 3RP, United Kingdom.
authors.forename: Nandita M
authors.initials: NM
authors.lastname: deSouza
mesh_terms: D000005:Abdomen; D000273:Adipose Tissue; D000328:Adult; D016477:Artifacts; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004129:Dimethylpolysiloxanes; D005260:Female; D006801:Humans; D008875:Middle Aged; D010388:Pelvis; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio; D013395:Sucrose; D013696:Temperature; D055815:Young Adult
chemical_list: D004129:Dimethylpolysiloxanes; D013395:Sucrose; C013830:baysilon