Reduced field-of-view diffusion-weighted imaging of the brain at 7 T

Area of Science:

• Neuroimaging
• Radiology
• Medical Physics

Background:

• Ventral and rostral brain regions are crucial for diagnosing neurological conditions like dementia, traumatic brain injury, and epilepsy.
• Standard diffusion-weighted imaging at high magnetic fields (7 Tesla) suffers from severe artifacts near air-tissue interfaces, hindering visualization of these critical areas.
• Existing methods struggle to provide clear images of the temporal and frontal lobes, which are vital for early disease detection.

Purpose of the Study:

• To mitigate imaging artifacts in the ventral and rostral brain regions at 7 Tesla.
• To enhance the visualization of the temporal and frontal lobes using advanced magnetic resonance imaging (MRI) techniques.
• To improve the characterization of early-stage neurological disorders through clearer MRI data.

Main Methods:

• Implementation of a reduced field-of-view strategy.
• Utilization of outer volume suppression (OVS) with novel quadratic phase radiofrequency (RF) pulses.
• Combination of partial Fourier and parallel imaging techniques to further reduce artifacts and acquisition time.

Main Results:

• The novel acquisition strategy significantly reduced imaging artifacts in the targeted brain regions.
• Improved visualization of the temporal and frontal lobes was achieved in all six human subjects scanned.
• The technique demonstrated effectiveness in four patients presenting with early symptoms of dementia.

Conclusions:

• The developed reduced field-of-view MRI technique effectively minimizes artifacts in high-field imaging of the ventral and rostral brain.
• This method enhances the clarity of temporal and frontal lobe imaging, offering a valuable tool for diagnosing early neurological conditions.
• The combination of OVS, partial Fourier, and parallel imaging presents a promising advancement for clinical neuroimaging at 7 Tesla.