title: Triggering in quantitative diffusion imaging with single-shot EPI.
abstract: OBJECTIVE
  The aim of this study was to evaluate any possible effects of brain motion, CSF pulsations and other possible sources of physiological motion in electrocardiographic (ECG) triggered and non-triggered single-shot echo-planar imaging (EPI) measurements of diffusion.
  
  
  METHODS
  Three different triggering protocols were evaluated in 6 healthy volunteers: 1) ECG triggering with time delay (TD) 100 ms; 2) ECG triggering with TD 400 ms; and 3) no triggering at all.
  
  
  RESULTS
  The results obtained showed that white matter mean apparent diffusion coefficient (ADC) values were similar for all triggering protocols and that the reproducibility in ADC measurements using diffusion-weighted (DW) EPI was good. The average standard deviation of the ADC values was, however, higher for ADC maps obtained without ECG triggering.
  
  
  CONCLUSIONS
  The use of prospective diastolic ECG triggering significantly improves the accuracy of quantitative diffusion measurements but for routine clinical diffusion imaging, where quantitative data is of less importance, the accuracy obtained without ECG triggering can be considered adequate.
authors.affiliation: Department of Radiation Physics, University Hospital, Lund, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Brockstedt
authors.forename: M
authors.initials: M
authors.lastname: Borg
authors.forename: B
authors.initials: B
authors.lastname: Geijer
authors.forename: R
authors.initials: R
authors.lastname: Wirestam
authors.forename: C
authors.initials: C
authors.lastname: Thomsen
authors.forename: S
authors.initials: S
authors.lastname: Holtås
authors.forename: F
authors.initials: F
authors.lastname: Ståhlberg
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology; D017352:Echo-Planar Imaging / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results