Silent T₂^* and T₂ encoding using ZTE combined with BURST

To obtain T₂^* and T₂ -weighted images as well as quantitative T₂^* , T₂ , and susceptibility maps with a novel, silent 3D imaging method, which combines zero-echo-time (ZTE) imaging with gradient- and spin-echo BURST encoding.

After a segment of standard ZTE encoding with multiple 3D radial k-space spokes, the direction of traversing k-space is reversed while excitation is switched off. This recalls gradient echoes for each spoke/excitation. This results in multiple images: one FID image from ZTE and multiple BURST echo images at different echo times weighted by a T₂^* decay. By adding a pair of 180° pulses with an appropriate wait period, it is also possible to obtain spin echoes, leading to T₂ -weighted images. Data is reconstructed using standard 3D gridding and Fourier transformation. In vivo feasibility was demonstrated by imaging the brain of multiple healthy volunteers.

It is possible to acquire high-quality T₂^* - and T₂ -weighted brain images in a silent manner. From images acquired with gradient-echo ZTE-BURST, it is possible to extract quantitative T₂^* and magnetic susceptibility maps, whereas the spin echo version yields T₂ maps.

ZTE combined with BURST enables silent acquisition of T₂^* - and T₂ -weighted images with good image quality.