MR angiography of the thoracic aorta with an electrocardiographically triggered breath-hold contrast-enhanced sequence

An electrocardiographically (ECG) triggered breath-hold contrast material-e nhanced magnetic resonance (MR) angiography sequence has been developed for imaging the thoracic aorta. A three-dimensional (3D) gradient-echo sequenc e is used with a contrast material bolus. Forty-nine patients with various aortic abnormalities and five healthy volunteers underwent imaging with the sequence. All studies were performed in a single breath hold. ECG-triggere d breath-hold contrast-enhanced MR angiography was tolerated in 48 of the 4 9 patients. The images demonstrated no respiratory motion artifacts and dim inished pulsation artifacts. The cardiac chambers, aortic root, ascending a nd descending aorta, aortic arch, proximal arch vessels, and proximal coron ary arteries were clearly demonstrated and not obscured by ghost artifacts. The 3D data set allowed excellent multiplanar reformation, permitting orth ogonal or oblique views of the vascular anatomy. A variety of congenital an d acquired abnormalities were clearly identified. When this sequence is use d, it is important to evaluate both the maximum-intensity projection and so urce images. Delayed imaging should be performed to detect late filling. In conjunction with cine MR and T1-weighted spin-echo imaging, EGG-triggered breath-hold contrast-enhanced MR angiography should be considered the techn ique of choice for imaging the thoracic aorta.