Prospective navigator correction of image position for coronary MR angiography.
OBJECTIVE
To determine the potential benefit of prospective navigator correction of image position for coronary magnetic resonance (MR) angiography.


METHODS
Two-dimensional MR angiograms were obtained with free breathing in 12 adult subjects. Navigator gating was used with and without prospective correction and with gating windows set at 3, 5, and 7 mm. MR angiograms were compared with those obtained with conventional, end-expiratory breath holding.


RESULTS
Navigator gating with correction resulted in image quality equivalent to that obtained with breath holding, even with the 7-mm gating window. In contrast, navigator gating without correction allowed only maintenance of image quality similar to that obtained with breath holding for the 3- and 5-mm windows and resulted in decreased image quality with the 7-mm window (P < .05). Use of navigator gating with correction and the 7-mm window resulted in a 28% decrease in imaging time compared with breath holding and a 33% decrease compared with the 3-mm gating window (P < .05 for both comparisons).


CONCLUSIONS
Prospective, adaptive navigator correction of image position for free-breathing coronary MR angiography is a promising, novel approach to compensate for respiratory motion.
Danias
P G
PG
Charles A. Dana Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
McConnell
M V
MV
Khasgiwala
V C
VC
Chuang
M L
ML
Edelman
R R
RR
Manning
W J
WJ
D000328:Adult; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009068:Movement; D011446:Prospective Studies; D012119:Respiration; D013997:Time Factors