Optimized Inner-Volume 3D TSE for High-Resolution Vessel Wall Imaging of Intracranial Perforating Arteries at 7T

Area of Science:

• Medical Imaging
• Neuroscience
• Biomedical Engineering

Background:

• Microvessel impairment is linked to neurological conditions like stroke and vascular dementia.
• Imaging small perforating arteries, crucial for understanding these diseases, is challenging with current high-resolution techniques.
• Observing the vessel wall of these small arteries remains a significant hurdle in diagnostics.

Purpose of the Study:

• To develop an advanced 3D inner-volume (IV) TSE sequence for high-resolution imaging of perforating arteries.
• To optimize 2D spatially selective excitation (SSE) radiofrequency (RF) pulses for improved imaging of small cerebral vessels.
• To enable simultaneous visualization of both the lumen and vessel wall of small arteries like the lenticulostriate artery (LSA).

Main Methods:

• Development of a 3D inner-volume (IV) TSE (SPACE) sequence.
• Design of optimized 2D spatially selective excitation (SSE) RF pulses using iterative design, trajectory optimization, and Carr-Purcell-Meiboom-Gill (CPMG) phase convention.
• Application of the sequence to image the lenticulostriate artery (LSA) with black-blood imaging.

Main Results:

• Achieved high isotropic resolution of 0.30 mm within 10 minutes for LSA imaging.
• Simultaneous imaging of LSA lumen and vessel wall was successfully demonstrated.
• Optimized RF pulses reduced aliasing artifacts compared to traditional pulses.
• IV-SPACE provided clearer delineation of the LSA vessel wall and lumen than conventional SPACE images.

Conclusions:

• The developed 3D IV-SPACE sequence with optimized SSE RF pulses offers superior imaging of small perforating arteries.
• This technique provides high-resolution, simultaneous visualization of lumen and vessel wall, overcoming limitations of current methods.
• IV-SPACE shows significant promise as a tool for detecting microvasculopathies in cerebral vascular diseases.