Ultrafast Blood T₁ Measurement Using Golden Angle Rotated Spiral k-t Sparse Parallel Imaging (GASSP): Evaluations in...

Area of Science:

• Medical Imaging
• Biophysics
• Cardiovascular Imaging

Background:

• Blood T1 is crucial for hemodynamic quantification in various imaging techniques.
• Current methods for measuring blood T1 require approximately one minute, limiting dynamic assessments.
• There is a need for faster methods to capture dynamic changes in blood T1.

Purpose of the Study:

• To develop and validate an ultrafast blood T1 measurement technique using Golden Angle rotated Spiral k-t Sparse Parallel imaging (GASSP).
• To enable blood T1 measurement in a single 10-second scan with high spatial resolution.
• To assess the feasibility of GASSP for both non-contrast and contrast-enhanced imaging.

Main Methods:

• A single-shot GASSP pulse sequence was developed for T1 measurement in the internal jugular vein (IJV) at 1x1 mm2 resolution.
• The GASSP method was compared against a segmented EPI readout in nine healthy volunteers for accuracy and reproducibility.
• Dynamic T1 changes were assessed in three patients following Gadolinium administration using the 10-second GASSP scan.

Main Results:

• GASSP-derived blood T1 values strongly correlated with multi-shot EPI measurements (r=0.83) and showed high reproducibility (r=0.88).
• Baseline IJV T1 values ranged from 1700-2000 ms.
• Post-Gadolinium T1 values in IJVs recovered from 300-400 ms to approximately 500 ms within 10-15 minutes.

Conclusions:

• Ultrafast blood T1 measurement is feasible within a single 10-second shot using GASSP with high spatial resolution.
• This method is applicable to both pre- and post-contrast imaging scenarios.
• The technique allows for rapid hemodynamic quantification and assessment of dynamic contrast changes.