UC San Diego

Purpose

This cross-sectional study investigates the utility of the quantitative ultrashort echo time (UTE) adiabatic T_1ρ (UTE-Adiab-T_1ρ) magnetic resonance imaging (MRI) in detecting potential differences in Achilles tendons and entheses of patients with psoriatic arthritis disease (PsA) compared with asymptomatic volunteers.

Material and method

The Achilles tendons of forty-four PsA patients (59 ± 15 years old, 38 % female) and thirty-seven asymptomatic volunteers (32 ± 10 years old, 51 % female) were scanned on a 3 T clinical scanner in the sagittal plane using a 3-inch surface coil. The 3D UTE-Adiab-T_1ρ sequences with fat saturation (FS) were used to measure UTE-Adiab-T_1ρ. Tenderness of the tendons, the SF-12 health survey, and visual analog scale (VAS) were recorded for the patients. The Kruskal Wallis test was used to examine the differences in UTE-Adiab-T1_ρ values between asymptomatic volunteers and patients, as well as subgroups of patients with pain in the Achilles tendon region and those treated with Biologics. Spearman's correlation coefficients were calculated between UTE-Adiab-T_1ρ and patient evaluations. P values < 0.05 were considered significant.

Results

UTE-Adiab-T_1ρ was significantly higher for the PsA group compared with the asymptomatic group in the enthesis (11.4 ± 2.6 ms vs. 10.4 ± 2.4 ms) and tensile tendon regions (9.8 ± 2.8 ms vs. 7.7 ± 1.7 ms). PsA patients with active Achilles pain showed significantly lower T1ρ in the entheses compared with other patients (10.7 ± 2.6 ms vs. 11.7 ± 2.5 ms). PsA patients treated with Biologics showed significantly lower T_1ρ values in the tendon compared with other patients (9.5 ± 2.5 ms vs. 10.3 ± 3.3 ms). The VAS score of patients showed a significant negative but weak correlation (R = -0.2) with UTE-Adiab-T1ρ of the enthesis. Correlations with SF-12 scores were not significant.

Conclusion

This study highlighted the UTE-Adiab-T_1ρ sequence capability in evaluating tendons and entheses and their potential involvement in PsA disease or response to therapies.