title: Diffusion-weighted MR imaging of the normal pancreas: reproducibility and variations of apparent diffusion coefficient measurement at 1.5- and 3.0-Tesla.
abstract: OBJECTIVE
  To evaluate reproducibility and variations in apparent diffusion coefficient (ADC) measurement in normal pancreatic parenchyma at 1.5- and 3.0-Tesla and determine if differences may exist between the four pancreatic segments.
  
  
  METHODS
  Diffusion-weighted MR imaging of the pancreas was performed at 1.5-Tesla in 20 patients and at 3.0-Tesla in other 20 patients strictly matched for gender and age using the same b values (0, 400 and 800s/mm(2)). Two independent observers placed regions of interest within the four pancreatic segments to measure ADC at both fields. Intra- and inter-observer agreement in ADC measurement was assessed using Bland-Altman analysis and comparison between ADC values obtained at both fields using non-parametrical tests.
  
  
  RESULTS
  There were no significant differences in ADC between repeated measurements and between ADC obtained at 1.5-Tesla and those at 3.0-Tesla. The 95% limits of intra-observer agreement between ADC were 2.3%-22.7% at 1.5-Tesla and 1%-24.2% at 3.0-Tesla and those for inter-observer agreement between 1.9%-14% at 1.5-Tesla and 8%-25% at 3.0-Tesla. ADC values were similar in all pancreatic segments at 3.0-T whereas the tail had lower ADC at 1.5-Tesla.
  
  
  CONCLUSIONS
  ADC measurement conveys high degrees of intra- and inter-observer reproducibility. ADC have homogeneous distribution among the four pancreatic segments at 3.0-Tesla.
authors: Department of Radiology, Groupe Henri-Mondor Albert-Chenevier, 51 avenue du Maréchal-de-Lattre-de-Tassigny, Créteil cedex, France.
authors: M
authors: M
authors: Barral
authors: P
authors: P
authors: Soyer
authors: W
authors: W
authors: Ben Hassen
authors: E
authors: E
authors: Gayat
authors: M
authors: M
authors: Aout
authors: M
authors: M
authors: Chiaradia
authors: A
authors: A
authors: Rahmouni
authors: A
authors: A
authors: Luciani
mesh_terms: D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010179:Pancreas / Q000473:pathology*; D010182:Pancreatic Diseases / Q000175:diagnosis; D012016:Reference Values; D015203:Reproducibility of Results; D055815:Young Adult