Advances in spiral fMRI: A high-resolution study with single-shot acquisition

Area of Science:

• Neuroimaging
• Magnetic Resonance Imaging
• Functional Magnetic Resonance Imaging

Background:

• Rectilinear echo-planar imaging is standard for fMRI but limited in speed.
• Spiral fMRI offers higher k-space acquisition speed and efficiency.
• Field imperfections cause blurring artifacts in spiral fMRI, limiting its application.

Purpose of the Study:

• To evaluate single-shot spiral BOLD fMRI at 0.8 mm resolution at 7 Tesla.
• To demonstrate the feasibility and performance of spiral fMRI for time-series applications.
• To showcase the versatility of spiral fMRI with combined in/out readouts.

Main Methods:

• Utilized an expanded signal model and iterative image reconstruction to correct field imperfections.
• Implemented single-shot 2D spiral imaging at sub-millimeter resolution (0.8 mm).
• Applied combined in/out spiral readout at 1.5 mm resolution for echo combination.

Main Results:

• Achieved high-resolution spiral fMRI at 7 T with excellent image quality and minimal blurring.
• Demonstrated high BOLD sensitivity and spatial specificity in activation maps.
• Showcased improved sensitivity through echo combination with a 1.5 mm resolution spiral readout.

Conclusions:

• High-resolution spiral fMRI at 7 T is feasible and provides superior image quality and BOLD sensitivity.
• The advanced spiral imaging technique overcomes previous limitations, enabling precise laminar/columnar fMRI.
• Spiral fMRI is a versatile and efficient technique for advanced neuroimaging applications.