[Whole-heart coronary MR angiography -- initial results].
OBJECTIVE
To evaluate a new coronary MR angiography technique covering the whole coronary artery tree in one data set acquisition.


METHODS
Six healthy volunteers and 15 patients with known CAD were examined with a navigator gated and corrected (NAV) free-breathing 3D steady-state free precession sequence covering the whole heart (WH-MRA) (TR = 5.4, TE = 2.7, SENSE factor = 2, 160 slices, 0.75 mm reconstructed slice thickness, in-plane resolution = 0.99 x 0.99 mm(2), scan time 14 min [50 % NAV efficiency]) and a vessel targeted 3D SSFP MRA sequence (t-MRA) (TR = 5.6 ms, TE = 2.8 ms, 20 slices of 1.5 mm reconstructed slice thickness, in-plane resolution = 0.99 x 0.99 mm(2), scan time = 7 min [50 % NAV efficiency]). Subjective image quality (4-point scale) and objective image quality parameters including vessel sharpness, vessel diameter and CNR were calculated for WH-MRA and t-MRA. In patients, the accuracy for detection of stenosis larger than 50 % was compared to the accuracy of X-ray coronary angiography (XA), which was considered the standard.


RESULTS
WH-MRA demonstrated good vessel visibility in healthy subjects (100 %) whereas vessel visibility in patients was limited (78 % in an 8 segment evaluation). Vessel sharpness was inferior to that of t-MRA in patients (37 vs. 42 %) but equal in healthy subjects (42 %). Vessel diameter did not differ significantly between WH-MRA and t-MRA. CNR was significantly reduced for WH-MRA (CNR 7.4 vs. 11.5). The diagnostic accuracy for the detection of CAD was comparable for both MRA approaches (85.5 vs. 86.2 %).


CONCLUSIONS
WH-MRA allows good coronary artery visualization in healthy subjects and patients and provides a simplified scanning procedure and advantages in 3D post-processing. Regarding image parameters and the detection of CAD, the results are comparable to those acquired with t-MRA. The major disadvantage remains the high number of diagnostically insufficient images.
Ozgun
M
M
Institut für Klinische Radiologie, Universitätsklinikum Münster. murat@uni-muenster.de
Hoffmeier
A
A
Quante
M
M
Fischbach
R
R
Heindel
W
W
Botnar
R
R
Maintz
D
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003331:Coronary Vessels / Q000033:anatomy & histology*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged