title: Monitoring of gustatory stimulation of salivary glands by diffusion-weighted MR imaging: comparison of 1.5T and 3T.
abstract: OBJECTIVE
  Our aim was to compare different field strengths monitoring physiologic changes due to oral stimulation of parotid glands by using diffusion-weighted (DW) echo-planar imaging (EPI).
  
  
  METHODS
  Twenty-seven healthy volunteers were examined with a DW-EPI sequence at 1.5T and 3T before and after oral stimulation with commercially available lemon juice. The b factors used were 0, 500, and 1000 s/mm(2). Apparent diffusion coefficient (ADC) maps were evaluated with a manually placed region of interest including the entire parotid gland. For comparison of results, a Student t test was used on the basis of the mean of the volunteer median values. To compare both field strengths, we calculated the Pearson correlation coefficient (r).
  
  
  RESULTS
  DW-EPI MR imaging visualized the parotid glands of all volunteers. With 1.5T, the mean ADC before stimulation was 1.12 x 10(-3) mm(2)/s +/- 0.08 x 10(-3) mm(2)/s. After stimulation with lemon juice, the ADC increased to 1.18 x 10(-3) mm(2)/s +/- 0.09 x 10(-3) mm(2)/s. For 3T, the ADC before stimulation was 1.14 x 10(-3) mm(2)/s +/- 0.04 x 10(-3) mm(2)/s, with an increase to 1.17 x 10(-3) mm(2)/s +/- 0.05 x 10(-3) mm(2)/s after stimulation. For both field strengths, the increase in ADC after stimulation was significant (P < .001). High correlations between both field strengths were found pre- and poststimulation (r = 0.955, and 0.936, respectively).
  
  
  CONCLUSIONS
  DW-EPI MR imaging allows monitoring of physiologic changes due to oral stimulation of parotid glands by using DW imaging with high correlation between 1.5T and 3T.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. c.habermann@uke.uni-hamburg.de
authors.forename: C R
authors.initials: CR
authors.lastname: Habermann
authors.forename: P
authors.initials: P
authors.lastname: Gossrau
authors.forename: H
authors.initials: H
authors.lastname: Kooijman
authors.forename: J
authors.initials: J
authors.lastname: Graessner
authors.forename: M C
authors.initials: MC
authors.lastname: Cramer
authors.forename: M G
authors.initials: MG
authors.lastname: Kaul
authors.forename: F
authors.initials: F
authors.lastname: Reitmeier
authors.forename: M
authors.initials: M
authors.lastname: Jaehne
authors.forename: G
authors.initials: G
authors.lastname: Adam
mesh_terms: D000328:Adult; D002957:Citrus; D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010306:Parotid Gland / Q000502:physiology*; D012016:Reference Values; D013649:Taste / Q000502:physiology*