Impact of ECG gating in contrast-enhanced MR angiography for the assessment of the pulmonary veins and the left atrium anatomy.
OBJECTIVE
Implementation of ECG gating in contrast-enhanced MR angiography (ceMRA) for improved visualization of the pulmonary veins, the left atrium, and the thoracic vessels.


METHODS
CeMRA was performed on twelve patients with a history of recurrent atrial fibrillation for the purpose of an intra-individual comparison with and without ECG gating on a 1.5 Tesla MR system (Gyroscan Intera, Philips Medical Systems, Best, NL). Objective image quality parameters such as the signal-to-noise ratio (SNR) of the blood and the contrast-to-noise ratio (CNR) between the blood and myocardium or lung parenchyma were analyzed. The contour sharpness of the pulmonary veins, left atrium, ascending aorta, and pulmonary trunk was also measured. In addition, the artifact level was subjectively assessed by two observers blinded with respect to the sequence parameters. Statistically significant differences (p < 0.05) between the procedures were analyzed using the Wilcoxon test and Pearson Chi-square test.


RESULTS
The use of ECG gating in ceMRA significantly reduced artifacts caused by cardiac motion and vessel pulsation. This in turn lead to a significant increase in the contour sharpness of the left atrium and the thoracic vessels. In addition, higher SNR and CNR were found using ECG-gated ceMRA compared to standard ceMRA.


CONCLUSIONS
The use of ECG gating in ceMRA results in artifact-free and sharper delineation of the structures of the heart and thoracic vessels.
Katoh
M
M
Klinik für Radiologische Diagnostik, Universitätsklinikum RWTH Aachen. katoh@rad.rwth-aachen.de
Bücker
A
A
Mühlenbruch
G
G
Schauerte
P
P
Günther
R W
RW
Spuentrup
E
E
D016477:Artifacts; D001281:Atrial Fibrillation / Q000473:pathology; D003287:Contrast Media; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009068:Movement; D011667:Pulmonary Veins / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method
D003287:Contrast Media