title: Respiratory-triggered MRCP applying parallel acquisition techniques.
abstract: OBJECTIVE
  To evaluate the influence of parallel imaging on the image quality of respiratory triggered magnetic resonance cholangiopancreatography (MRCP).
  
  
  METHODS
  A total of 30 consecutive patients underwent MRCP applying a respiratory triggered T2-weighted (T2w) turbo spin-echo (TSE) sequence without and with parallel imaging (acceleration factor of 2). Acquisition times of both sequences were recorded. Quantitative evaluation included measurement of a contour sharpness index of two segments of the pancreaticobiliary tree as well as calculation of the relative contrast between ductal structures and organ parenchyma at four different segments. The qualitative evaluation was performed by two independent radiologists who graded overall image quality, depiction of eight segments of the pancreaticobiliary tree, and the frequency of artifacts.
  
  
  RESULTS
  The application of parallel imaging significantly (P<0.05) reduced the acquisition time of the respiratory triggered MRCP sequence by 37.7% (six minutes and two seconds+/-one minute and 26 seconds vs. three minutes and 46 seconds+/-58 seconds). The quantitative and qualitative evaluation revealed no statistically significant differences between the two sequences (P>0.05). The frequency of artifacts was at the same level for both sequences as well.
  
  
  CONCLUSIONS
  The application of parallel imaging for respiratory triggered MRCP significantly reduces the acquisition time without relevant influence on image quality.
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany. patrick.asbach@charite.de
authors.forename: Patrick
authors.initials: P
authors.lastname: Asbach
authors.forename: Marc
authors.initials: M
authors.lastname: Dewey
authors.forename: Christian
authors.initials: C
authors.lastname: Klessen
authors.forename: Alto
authors.initials: A
authors.lastname: Stemmer
authors.forename: Johann
authors.initials: J
authors.lastname: Ockenga
authors.forename: Alexander
authors.initials: A
authors.lastname: Huppertz
authors.forename: Bernhard
authors.initials: B
authors.lastname: Sander
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.forename: Matthias
authors.initials: M
authors.lastname: Taupitz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016477:Artifacts; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods; D008297:Male; D008875:Middle Aged; D009068:Movement; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D012680:Sensitivity and Specificity