Stroud John, Hao Yu, Read Tim S, Hankiewicz Janusz H, Bilski Pawel, Klodowski Krzysztof, Brown Jared M, Rogers Keegan, Stoll Josh, Camley Robert E, Celinski Zbigniew, Przybylski Marek
UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States.
UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States.
Magn Reson Imaging. 2023 Jul;100:43-54. doi: 10.1016/j.mri.2023.03.004. Epub 2023 Mar 16.
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 T relaxation time at low-fields, MRI scanners operating at 0.2 T can use shorter repetition times and achieve a significant T 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 °C at 37 °C for a 90 μg/mL concentration of magnetic particles.
本研究深入探讨了将嵌入琼脂凝胶体模中的铁氧体颗粒用作低磁场扫描仪的MRI温度指示器的优缺点。我们将低场（0.2 T）下MR图像的温度依赖性强度与高场（3.0 T）下的进行比较。由于在低场时T弛豫时间较短，工作在0.2 T的MRI扫描仪可以使用更短的重复时间并实现显著的T加权，从而在短采集时间内使MR图像亮度产生强烈的温度依赖性变化。尽管0.2 T MR时MR图像的信噪比远低于3.0 T时，但对于90 μg/mL浓度的磁性颗粒，在37 °C时足以实现约±1.0 °C的温度测量不确定度。
