Low-Field Magnetic Resonance Imaging Appearance of Postarthroscopic Magnetic Susceptibility Artifacts in Horses.

The study aims to understand how commonly magnetic resonance imaging (MRI) can detect artifacts created by surgical tools after arthroscopy in horses, and how these artifacts change over time and with different types of MRI scans.

Study Objectives

• The study’s main objective was to identify the prevalence of magnetic susceptibility artifacts following arthroscopy in non-lame horses.
• The researchers also aimed to describe how the time elapsed post-operation and the type of MRI pulse sequence affected the intensity of the MRI signal and the visibility of these artifacts.

Methodology

• The study involved ten non-lame Standardbred horses, which were subjected to arthroscopy in both metacarpophalangeal joints for unrelated reasons.
• These horses underwent a series of low-field MRI scans on each joint at three different points in time—before surgery and six and twelve weeks after surgery.
• Two of the ten horses had additional MRI scans for a more detailed longitudinal assessment.

Findings

• Results from the study revealed that eight of the scanned metacarpophalangeal joints displayed magnetic susceptibility artifacts at the arthroscopy access sites at both the six and twelve-week post-operation marks (a 40% prevalence).
• The MRI scans of the two longitudinally followed horses did not display any artifacts at any point in time.
• Artifacts were only detectable on gradient echo (GRE) sequences of the MRI scans.
• The observations indicated that magnetic susceptibility artifacts can be found in horses’ post-arthroscopy MRIs and can persist until 12 weeks after the arthroscopy.
• For the sample of horses used in this study, these detected artifacts did not affect the evaluation of the joint.

Implications

• This research underscores the importance of being aware of magnetic susceptibility artifacts when interpreting pre-purchase and post-operative MRI studies in horses.
• It suggests the necessity for further longitudinal studies to understand the full duration of these artifacts’ persistence in affected tissues.