Simultaneous multislice MRI thermometry with a single coil using incoherent blipped-controlled aliasing.

Area of Science:

• Medical Physics
• Magnetic Resonance Imaging
• Ultrasound Therapy

Background:

• Real-time MR thermometry is crucial for guiding transcranial MR-guided focused ultrasound (tcMRgFUS) ablation.
• Increasing volume coverage without multiple receive coils presents a significant technical challenge.

Purpose of the Study:

• To develop and validate a simultaneous multi-slice (SMS) imaging technique for enhanced volumetric coverage in tcMRgFUS.
• To enable accurate real-time temperature mapping without requiring additional receive coils.

Main Methods:

• Implementation of multiband excitation and incoherent blipped-controlled aliasing in a 2D Fourier Transform (2DFT) pulse sequence.
• Development of an extended k-space hybrid reconstruction for slice-separated temperature map recovery.
• In vivo and phantom experiments using a single receive coil to assess temperature precision and heating accuracy.

Main Results:

• Simulations demonstrated accurate reconstruction of up to three simultaneous slices with minimal temperature error ($$ C RMSE) for focal heating.
• Robustness against slice-phase k-space permutations was confirmed, with 86% yielding $$ C error.
• In vivo and phantom studies showed no degradation in temperature precision and accurate tracking of focal heating without aliasing.

Conclusions:

• Incoherent controlled aliasing SMS is effective for accurate focal heating reconstruction in tcMRgFUS.
• The method enables simultaneous imaging of two to three slices using a single receive coil.
• Sparsity-promoting temperature reconstruction further enhances the accuracy of thermal mapping.