Simultaneous Assessment of Intracranial Artery and Paravascular CSF Pulsation Using 3D Whole-Brain Diffusion-Prepared...

To propose a noninvasive and quantitative MRI approach to simultaneously assessing intracranial artery pulsation and paravascular cerebrospinal fluid (CSF) pulsation in the human brain.

We developed a 3D whole-brain Diffusion-prepared Cine bSSFP (DECAF) MRI technique, with improved motion-sensitized driven-equilibrium providing blood suppression and diffusion weighting. 3D golden-angle radial trajectory, retrospective pulse gating, and GRASP image reconstruction were employed to generate cine images of 25 phases. Semi-automatic image processing pipelines were established to quantify the arterial wall pulsatility index and the paravascular CSF pulsatility index. The ADC quantification was corrected using an analytical approach to remove T1 and T2 effects based on bSSFP. The efficacy of our proposed technique was validated on six healthy participants.

The developed MRI sequence was able to generate high-resolution whole-brain cine images with 25 cardiac phases in approximately 8 min. Reliable arterial wall and paravascular CSF pulsatility indices were quantified in the human brain with good scan-rescan reproducibility. A strong temporal relationship between those two pulsations was observed in the six participants. There is a spatial relationship between CSF pulsation and distance to arteries. In addition, the arterial wall and paravascular CSF pulsation indices are significantly correlated.

We developed and demonstrated a DECAF MR technique, combined with an automatic image processing pipeline, enabling simultaneous quantification of intracranial artery pulsation and paravascular CSF pulsation across the cardiac cycle. This technique can be a noninvasive and quantitative imaging tool for investigating the relationship between vascular or aging-related diseases and glymphatic dysfunction.