title: Apparent Diffusion Coefficient of Normal Abdominal Organs and Bone Marrow From Whole-Body DWI at 1.5 T: The Effect of Sex and Age.
abstract: OBJECTIVE
  The objectives of this study were to define the range of apparent diffusion coefficients (ADCs) from whole-body DWI in normal abdominal organs and bone marrow, to identify ADC differences between sexes and changes occurring with age, and to evaluate the effect of the fat fraction (FF) on the ADC of normal liver parenchyma and bone marrow.
  
  
  METHODS
  Fifty-one healthy volunteers (mean age = 38 years; age range = 23-68 years) underwent whole-body DWI using single-shot echo-planar imaging (b = 0, 150, 400, 750, and 1000 s/mm(2)). A two-point Dixon technique was used to evaluate the FF. Perfusion-sensitive ADCs, which we refer to as "ADCALL," and perfusion-insensitive ADCs, which we refer to as "ADCHIGH," of the liver and renal parenchyma, spleen, pancreatic tail, and red and yellow bone marrow were calculated. The relationships between ADC and sex, age, and FF were examined.
  
  
  RESULTS
  ADCALL and ADCHIGH were significantly higher in female volunteers for the pancreatic tail (p = 0.046 and 0.008, respectively), red bone marrow (p = 0.029 and 0.001), and yellow bone marrow (p < 0.001 for both) but with considerable overlap. There were significant negative correlations between ADCALL and ADCHIGH and age in the liver parenchyma (p = 0.008 and 0.01, respectively) and in the yellow bone marrow (p = 0.013 and 0.039) for all subjects. ADCALL and ADCHIGH were also negatively correlated with FF in the liver parenchyma (p = 0.006 and 0.008, respectively) and in yellow bone marrow (p < 0.001 and p = 0.001) in all subjects.
  
  
  CONCLUSIONS
  The ADCs of normal liver parenchyma and bone marrow change significantly with age. The ADCs of bone marrow in women are significantly higher than those of men and correlate strongly with FF. These effects may have an impact on image interpretation when using whole-body DWI to assess disease burden and treatment response.
authors.affiliation: 1 Department of Surgery and Cancer, Comprehensive Cancer Imaging Centre, Imperial College, Hammersmith Campus, DuCane Rd, London W12 0NN, UK.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Lavdas
authors.affiliation: 2 Imaging Department, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: Andrea G
authors.initials: AG
authors.lastname: Rockall
authors.affiliation: 3 Istituto di Radiologia, Policlinico "G. B. Rossi," Verona, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Castelli
authors.affiliation: 2 Imaging Department, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: Ranbir S
authors.initials: RS
authors.lastname: Sandhu
authors.affiliation: 4 Radiological Sciences Unit, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, UK.
authors.forename: Annie
authors.initials: A
authors.lastname: Papadaki
authors.affiliation: 2 Imaging Department, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: Lesley
authors.initials: L
authors.lastname: Honeyfield
authors.affiliation: 2 Imaging Department, Imperial College Healthcare NHS Trust, London, UK.|5 Department of Medicine, Division of Brain Sciences, Imperial College, London, UK.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Waldman
authors.affiliation: 1 Department of Surgery and Cancer, Comprehensive Cancer Imaging Centre, Imperial College, Hammersmith Campus, DuCane Rd, London W12 0NN, UK.
authors.forename: Eric O
authors.initials: EO
authors.lastname: Aboagye
mesh_terms: D034841:Abdominal Cavity / Q000033:anatomy & histology*; D000328:Adult; D000367:Age Factors; D000368:Aged; D001853:Bone Marrow / Q000033:anatomy & histology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors; D051598:Whole Body Imaging / Q000379:methods*
keywords: abdominal organs; bone marrow; normal apparent diffusion coefficient (ADC); sex and age; whole-body DWI