MR coronary vessel wall imaging:: Comparison between radial and spiral k-space sampling

Purpose: To compare radial and spiral k-space sampling in navigator-gated ECG-triggcred three-dimensional (3D) coronary vessel wall imaging. Materials and Methods: The right coronary artery (RCA) vessel walls of eight healthy subjects were imaged using a modifled double-inversion prepulse in concert with radial and spiral data acquisition. For data analysis, two investigators blinded to the sequence parameters subjectively assessed image quality in terms of artifacts and vessel wall visualization. Objective measures of the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and vessel wall definition were also determined. Results: Radial k-space sampling demonstrated fewer artifacts and led to improved visualization of the coronary vessel wall compared to spiral imaging (P < 0.05). This finding was also reflected in a better vessel wall definition using radial data acquisition (P < 0.05). SNR and CNR were found to be higher when spiral k-space sampling was used (n.s.). Conclusion: Radial k-space sampling in concert with freebreathing navigator-gated cardiac-triggered MRI of the coronary vessel wall resulted In fewer motion artifacts and improved vessel wall definition compared to spiral k-space sampling. The proposed approach therefore appears to be preferable.