Magnetic particle based MRI thermometry at 0.2 T and 3 T

This study provides insight into the advantages and disadvantages of using ferrite particles embedded in agar gel phantoms as MRI temperature indicators for low-magnetic field scanners. We compare the temperature -dependent intensity of MR images at low-field (0.2 T) to those at high-field (3.0 T). Due to a shorter T1 relax-ation time at low-fields, MRI scanners operating at 0.2 T can use shorter repetition times and achieve a significant T2* weighting, resulting in strong temperature-dependent changes of MR image brightness in short acquisition times. Although the signal-to-noise ratio for MR images at 0.2 T MR is much lower than at 3.0 T, it is sufficient to achieve a temperature measurement uncertainty of about +/- 1.0 degrees C at 37 degrees C for a 90 mu g/mL concentration of magnetic particles.

Automated summary

This study explores the pros and cons of using ferrite particles embedded in agar gel phantoms as MRI temperature indicators for low-field scanners. The researchers compare the temperature-dependent intensity of MR images at low-field (0.2 T) and high-field (3.0 T). Despite the lower signal-to-noise ratio, MRI scanners operating at 0.2 T can achieve a temperature measurement uncertainty of about +/- 1.0 degrees C at 37 degrees C for a 90 mu g/mL concentration of magnetic particles.