Assessment of Magnetic Resonance Imaging Artefacts Caused by Equine Anaesthesia Equipment: A Cadaver Study

Abstract

Acquisition of magnetic resonance images of the equine limb is still sometimes conducted under general anaesthesia. Despite low-field systems allow the use of standard anaesthetic equipment, possible interferences of the extensive electronic componentry of advanced anaesthetic machines on image quality is unknown. This prospective, blinded, cadaver study investigated the effects of seven standardised conditions (Tafonius positioned as in clinical cases, Tafonius on the boundaries of the controlled area, anaesthetic monitoring only, Mallard anaesthetic machine, Bird ventilator, complete electronic silence in the room (negative control), source of electronic interference [positive control]) on image quality through the acquisition of 78 sequences using a 0.31T equine MRI scanner. Images were graded with a 4-point scoring system, where 1 denoted absence of artefacts and 4 major artefacts requiring repetition in a clinical setting. A lack of STIR fat suppression was commonly reported (16/26). Ordinal logistic regression showed no statistically significant differences in image quality between the negative control and either the non-Tafonius or the Tafonius groups (P = 0.535 and P = 0.881, respectively), and with the use of Tafonius compared to the other anaesthetic machines (P = 0.578). The only statistically significant differences in scores were observed between the positive control and the non-Tafonius (P = 0.006) and the Tafonius groups (P = 0.017). Our findings suggest that anaesthetic machines and monitoring do not appear to affect MRI scan quality and support the use of Tafonius during acquisition of images with a 0.31T MRI system in a clinical context.