Fast, interleaved, Look-Locker-based T₁ mapping with a variable averaging approach: Towards temperature mapping at...

Area of Science:

• Medical Imaging
• Biophysics
• Thermometry

Background:

• Proton resonance frequency shift (PRFS) is the standard for magnetic resonance thermometry but is limited to high-field MRI.
• Low-field MRI offers advantages in accessibility and cost but requires alternative thermometry methods.
• Current alternatives like fat-based thermometry have limitations, especially at low fields.

Purpose of the Study:

• To develop and validate a novel magnetic resonance thermometry technique for low-field (0.1 T) MRI.
• To assess the feasibility of MR-guided thermal therapies at low magnetic field strengths.
• To improve temperature quantification accuracy and precision in low-field MRI settings.

Main Methods:

• An interleaved Look-Locker-based mapping sequence was developed for temperature quantification at 0.1 T.
• A variable averaging scheme was implemented to optimize signal-to-noise ratio during mapping.
• Calibrated samples were used to evaluate the accuracy and precision of the proposed method.

Main Results:

• The proposed method achieved an average accuracy of 85% ± 4% in 10 minutes with a variable averaging scheme.
• This represents an improvement over the 77% ± 7% accuracy obtained with standard averaging.
• Reconstructed temperature maps showed a precision of 3.0°C ± 1.1°C and accuracy of 1.5°C ± 1.0°C between 29.0°C and 41.7°C.

Conclusions:

• The developed low-field MR thermometry technique is accurate and precise, suitable for temperature quantification.
• This method holds promise for applications like MR-guided mild hyperthermia treatments at low-field MRI.
• The findings support the use of low-field MRI for accessible and cost-effective thermal therapies.