Evaluation of a 0.05 T low-field MRI system for canine brain imaging via comparison with images acquired at 1.5 T field strength: a pilot cadaver study

Magnetic resonance imaging (MRI) systems continue to grow in number in veterinary and human medicine with higher field strength magnets increasingly available; however, the associated high costs have created healthcare inequities. This technical feasibility study aimed to evaluate a low-cost, portable, and permanent magnet-based 0.05 T low-field system (LF), originally designed for human neuroimaging, for assessing the canine brain. By using 23 canine cadavers, a scanning protocol was developed, consisting of transverse T1-weighted (T1w) and T2-weighted (T2w) sequences, and compared to a 1.5 T (HF) protocol for the visibility of 22 anatomical features. For the purpose of hydrocephalus evaluation, the LF system showed non-inferior detection of the lateral ventricles (LV) and mesencephalic aqueduct on T2w sequences with >90% conditional probability for detecting these features on the LF, given they were present on the HF. For T1w sequences, the LF system had inconclusive non-inferiority for detection of LV with 76.6% conditional probability. In summary, a canine brain scanning protocol was successfully developed for a 0.05 T MRI with preliminary evaluation suggestive that this device can aid with the detection of hydrocephalus. Future in vivo studies are required to evaluate the device's true clinical application.