Determination of T1 relaxation time of normal equine tendons using magic angle magnetic resonance imaging.

This research article focuses on the use of magic angle magnetic resonance imaging to determine the normal T1 relaxation time in the tendons and ligaments of equine front limbs. This is a potentially valuable tool for identifying chronic tendinopathy in horses, given that increased T1 values may signify such conditions.

Objective and Methodology

• The investigation explores the use of ‘magic angle’ MRI, a special imaging technique where the subject, in this case, the equine limbs, is positioned at a precise angle (55°) relative to the magnetic field. Spin-echo proton density and inversion recovery images were obtained, allowing the researchers to calculate the T1 relaxation times.
• Seven isolated equine front limbs were used for this research to determine the normal T1 relaxation time (a measure of how quickly individual protons realign with the magnetic field after the radiofrequency pulse is turned off) in three specific structures – the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and the suspensory ligament (SL).

Findings

• The results yielded T1 relaxation times for SDFT, DDFT, and SL as 288 (± 17), 244 (± 14), and 349 (± 16) milliseconds, respectively. These times were noticeably different, which was statistically significant.
• Through the use of magic angle imaging on a clinical MR system, these T1 values can be determined in less than 10 minutes of total scan time, indicating efficiency and practicality of this imaging approach in a clinical setting.

Conclusion and Implications

• The findings could prove instrumental in disease detection, especially in chronic tendinopathy – a common condition in sport horses which often results in poor performance and extended rest periods. This prediction is based on human medical literature, wherein an increased T1 value is expected in similar conditions.
• With the established range of normal T1 values in equine tendons, practitioners can now compare these with values from affected horses, aiding in early and accurate diagnosis.