title: Feasibility of navigator setting on the left diaphragm for whole-heart coronary MRA: a study in healthy volunteers.
abstract: OBJECTIVE
  We prospectively compared the quality of images obtained by navigator setting on the left and right diaphragm on whole-heart coronary magnetic resonance angiography (WHCMRA).
  
  
  METHODS
  In 10 healthy volunteers, we performed free-breathing, 3-dimensional segmented true fast imaging with steady-state precession (trueFISP) WHCMRA by setting the navigator on the left and right diaphragm in random order. For the left diaphragm, we set the navigator outside the scope of the heart to avoid the influence on coronary arteries. We compared image acquisition time and visible length of coronary arteries using paired t-test and subjective image quality on a 4-point scale (1, poor; 4, excellent) using Wilcoxon signed-rank test.
  
  
  RESULTS
  Mean overall subjective image quality was significantly better in the left diaphragm than the right (3.3+/-0.7 versus 2.9+/-0.9, P=0.02). Mean overall visible length of the coronary arteries was significantly better in the left diaphragm than the right (115.4+/-31.1 vs. 112.6+/-29.9 mm, P=0.02). Mean acquisition time between the left and right diaphragm was not significantly different (15.6+/-5.0 versus 16.0+/-5.7 min, P=0.79).
  
  
  CONCLUSIONS
  In this small group of healthy volunteers, navigator setting for WHCMRA was superior on the left diaphragm than the right; however, feasibility of the technique requires additional consideration in a larger group of actual patients.
authors.affiliation: Department of Radiology, Saitamaken Saiseikai Kurihashi Hospital, kitakatsushika-gun, Saitama, Japan. watanabesaikuri@yahoo.co.jp
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Watanabe
authors.forename: Satoru
authors.initials: S
authors.lastname: Morita
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Maruyama
authors.forename: Mayumi
authors.initials: M
authors.lastname: Noda
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Fujita