Dynamic pseudo-continuous arterial spin labeling angiography using a 3D-radial multi-spoke spoiled gradient-recalled...

Area of Science:

• Neuroradiology
• Medical Imaging
• Vascular Imaging

Background:

• Accurate identification of arterial feeders and draining veins is crucial for managing intracranial high-flow vascular lesions.
• Existing MRI sequences often lack the necessary temporal and spatial resolution for comprehensive assessment.
• Novel imaging techniques are needed to improve diagnostic capabilities.

Purpose of the Study:

• To develop and assess a novel time-resolved pseudo-continuous arterial spin labeling (ASL) angiography sequence.
• To evaluate its image quality metrics for clinical performance in identifying intracranial high-flow vascular lesions.
• To compare its resolution and efficiency against standard-of-care sequences.

Main Methods:

• A novel time-resolved ASL sequence with multi-spoke readouts and dynamic, sliding-window reconstruction was implemented.
• Image quality was assessed using Likert scales, SNR, and SNR efficiency in ten volunteers and eight patients.
• Spatial/temporal resolution and acquisition time were compared with time-of-flight (TOF) MRA and contrast-enhanced (CE)-MRA.

Main Results:

• The novel ASL sequence achieved high isotropic spatial resolution (0.68 mm³) and temporal resolution (200 ms).
• It demonstrated superior spatial and temporal resolution compared to CE-MRA and comparable spatial resolution to TOF MRA.
• Multi-spoke acquisitions significantly increased SNR and SNR efficiency, reducing scan time by 31% compared to single-spoke.

Conclusions:

• The study confirms the clinical feasibility of the novel time-resolved ASL sequence.
• The sequence provides sufficient SNR, superior resolution to CE-MRA, and comparable resolution to TOF MRA.
• This technique offers a promising tool for evaluating intracranial high-flow vascular lesions within a clinically practical timeframe.