Local excitation black blood imaging at 3T: application to the carotid artery wall.

A novel approach for imaging large sections of the carotid artery wall at isotropic spatial resolution is presented. Local excitation by means of 2D excitation pulses was combined with a diffusion-prepared segmented steady-state black-blood gradient echo technique enabling the assessment of the carotid arterial wall over a range of up to 15 cm. The carotid arteries of five healthy volunteers were imaged with the proposed technique. Signal-to-noise ratio (SNR), wall-lumen contrast-to-noise ratio (CNR), and vessel dimensions were assessed and compared to conventional excitation techniques. In all experiments black-blood contrast could be realized over the covered carotid arteries with similar SNR and CNR as the conventional technique covering the region of the bulbus only. The proposed technique enables the time-efficient coverage of the carotid arteries without compromising wall-lumen CNR and geometrical accuracy. Furthermore, the proposed technique appears to be less sensitive to motion and swallowing artifacts due to the local character of the excitation.