Enhanced Blood Suppression in Magnetic Resonance Vessel Wall Imaging Using Toggled DANTE (tDANTE).

PURPOSE: To develop a method capable of effectively suppressing blood flow signals in arbitrary directions, thereby improving the black-blood contrast in head-neck vessel wall imaging (VWI). METHODS: The polarities of gradients in the conventional delay alternating with nutation for tailored excitation (DANTE) module were toggled at each TR, forming three linearly independent black-blood gradient vectors with a cycle of three TRs, and this proposed technique was named tDANTE. The proposed sequence was applied for head-neck VWI in healthy volunteers and patients with aneurysms. The imaging performance was comparatively analyzed among the proposed tDANTE-prepared VWI sequence, standalone VWI sequence and conventional DANTE-prepared VWI sequence. RESULTS: In volunteer imaging, the tDANTE sequence achieved further attenuation of blood flow signals, with an overall vessel wall-to-lumen contrast-to-noise ratio (CNR) of 24.11 ± 9.20. Compared with the standalone VWI sequence and conventional DANTE-prepared VWI sequence, the CNR increased by 7.3% and 5.9% respectively (p < 0.001). More prominent black-blood improvement was observed in tortuous intracranial vessels, compared with straight extracranial vessels. Aneurysm imaging demonstrated that tDANTE significantly reduced luminal signal intensity without causing additional attenuation of aneurysm wall signals. The aneurysm wall CNR increased by 15.9% and 6.3% relative to the two control sequences, enabling clear delineation of aneurysm wall boundaries. CONCLUSION: The tDANTE method achieves superior blood suppression performance in head-neck VWI.