Temperature-induced tissue susceptibility changes lead to significant temperature errors in PRFS-based MR thermometry...

Area of Science:

• Biomedical Engineering
• Magnetic Resonance Imaging
• Medical Physics

Background:

• Proton resonance frequency shift-based MR thermometry (MRT) is susceptible to errors from temporal magnetic field changes.
• Temperature variations alter the magnetic volume susceptibility of tissues, affecting magnetic field homogeneity.
• Fatty tissues, such as the human breast, exhibit temperature-dependent susceptibility that can compromise MRT accuracy.

Purpose of the Study:

• To quantify the impact of temperature-dependent magnetic susceptibility on proton resonance frequency shift-based MRT.
• To evaluate the accuracy of MRT in fatty tissues under thermal variations.
• To assess the clinical implications of susceptibility-induced errors in breast MR thermometry.

Main Methods:

• Performed heating experiments in a controlled phantom setup to observe susceptibility changes.
• Utilized simulations on a 3D breast model to assess clinical relevance.
• Quantified temperature errors by calculating magnetic field changes due to susceptibility variations in heated regions.

Main Results:

• Temperature-induced susceptibility changes in water and fat significantly impact MRT.
• Experiments demonstrated errors in proton resonance frequency shift-based temperature maps due to these susceptibility changes.
• Simulations indicated substantial temperature errors in a 3D breast model.

Conclusions:

• Temperature-dependent magnetic susceptibility is a critical source of error in proton resonance frequency shift-based MRT.
• Accurate temperature mapping in fatty tissues requires accounting for these susceptibility-related artifacts.
• Further research is needed to mitigate these errors for reliable clinical application of MRT.