Feasibility of angiographic imaging using fast 3D Magnetic Resonance Spin TomogrAphy in Time-domain (MR-STAT)

To investigate how angiographic information can be obtained from proton density (PD) maps reconstructed with a fast 3D Magnetic Resonance Spin TomogrAphy in Time-domain (MR-STAT) protocol, focusing on intracranial vessels and aneurysms in a clinically relevant population.

This proof-of-concept study consisted of two experiments. First, a healthy volunteer underwent MR-STAT with selective and non-selective excitation to investigate the origin of elevated effective proton density in arteries. Second, ten patients with intracranial aneurysms underwent 3D MR-STAT and time-of-flight MR angiography (TOF MRA). Two neuroradiologists independently assessed vessel visibility, image quality, and aneurysm size. Intraclass correlation coefficients (ICC) were computed for aneurysm size measurements.

Selective excitation amplified inflow effects and yielded increased artery-tissue contrast in PD maps. Major intracranial arteries were visible in all clinical MR-STAT angiographic datasets. Nine out of ten MR-STAT angiographies were rated as at least diagnostically acceptable. Aneurysm measurements showed strong agreement between conventional and MR-STAT angiographic modalities (ICC=0.86/ICC=0.71) and high inter-rater reliability (ICC=0.90/ICC=0.92).

MR-STAT PD maps enable angiographic visualization as an intrinsic component of a single fast quantitative acquisition, demonstrating technical feasibility for vessel depiction. Future work should focus on optimizing MR-STAT acquisition strategies to improve vessel conspicuity and broader clinical validation.