Two-dimensional XD-GRASP provides better image quality than conventional 2D cardiac cine MRI for patients who cannot suspend respiration

Abstract

Object Residual respiratory motion degrades image quality in conventional cardiac cine MRI (CCMR). We evaluated whether a free-breathing (FB) radial imaging CCMR sequence with compressed sensing reconstruction (eXtra-Dimension (e.g. cardiac and respiratory phases) Golden-angle RAdial Sparse Parallel, or XD-GRASP) could provide better image quality than a conventional Cartesian breath-held (BH) sequence, in an unselected population of patients undergoing clinical CCMR. Material and Methods 101 patients who underwent BH and FB imaging in a mid-ventricular short-axis plane at a matching location were included. Visual and quantitative image analysis was performed by two blinded experienced readers, using a 5-point qualitative scale to score overall image quality and visual signal-to-noise ratio (SNR) grade, with measures of noise and sharpness. End-diastole (ED) and end-systole (ES) left-ventricular areas were also measured and compared for both BH and FB images. Results Image quality was generally better with the BH cines (overall quality grade BH vs FB: 4 vs 2.9, p<0.001; noise 0.06 vs 0.08 p< 0.001; SNR grade: 4.1 vs 3, p<0.001), except for sharpness (p=0.48). There were no significant differences between BH and FB images regarding ED or ES areas (p=0.35 and 0.12). 18 of the 101 patients had impaired BH image quality (grades 1 or 2). In this subgroup, image quality of the FB images was better (p=0.0032), as was the SNR grade (p=0.003), but there were no significant differences regarding noise and sharpness (p=0.45, p=0.47). Conclusion Although FB XD-GRASP CCMR was visually inferior to conventional BH cardiac cine in general, it provided improved image quality in the subgroup of patients presenting respiratory motion-induced artifacts on breath-held images.

Advances in cardiovascular MR imaging

“…Piekarski and colleagues [5] have investigated whether a free-breathing protocol using a radial golden-angle k-space filling strategy and compressed sensing reconstruction can provide improved image quality in such cases. In an unselected patient population, they demonstrated improved image quality with the radial approach when breath-holds failed, although the radial acquisition was visually inferior to the standard CINE protocol when breathholds were successful.…”

Dynamic Contrast-Enhanced MRA of the aorta using a Golden-Angle Radial Sparse Parallel (GRASP) sequence: comparison with conventional time-resolved Cartesian MRA (TWIST)

“…Previous works have successfully proven that GRASP allows for a reliable and robust assessment of dynamic CE liver imaging [21,22] at high acceleration factors. Also, GRASP is known to provide robust imaging in situations with potential image degradation because of respiratory, cardiac or vascular motion artifacts [23]. Because of the above mentioned advantages, GRASP has a potential in improving image quality in body regions subjected to motion and for imaging of high-ow vascular pathologies like peripheral arteriovenous malformations (AVMs), that demand -high temporal resolution while maintaining a decent spatial resolution [24].…”