A resistive heating system for homeothermic maintenance in small animals

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Animal Research

Background:

• Maintaining stable body temperature in anesthetized animals is crucial for accurate physiological monitoring and Magnetic Resonance Imaging (MRI).
• Conventional heating methods can interfere with MRI data acquisition, causing artifacts and compromising image quality.

Purpose of the Study:

• To develop and evaluate an MR-compatible resistive heater for precise temperature maintenance in anesthetized animals.
• To assess the heater's impact on MRI image and spectral quality.

Main Methods:

• A resistive electrical heater was constructed using tightly-wound twisted pair wire and connected to a homeothermic controller.
• MRI scans (fat-suppressed images and localized spectra) were performed with the twisted pair heater and a single-strand wire heater.
• Data were acquired with and without current to assess MR insensitivity to heater-induced distortions.

Main Results:

• The twisted pair wire heater produced no discernible interference with MRI images or spectra.
• In contrast, a single-strand wire heater caused significant field shifts and lineshape distortions.
• Rectal temperature was effectively maintained, with lost temperature recovered within 10-20 minutes post-anesthesia induction.

Conclusions:

• The developed twisted pair wire heater is compatible with MRI environments.
• It effectively maintains animal body temperature without compromising MR image or spectral quality.
• This technology enables reliable physiological monitoring during MR studies.