Radial T2* mapping reveals early meniscal abnormalities in patients with knee osteoarthritis.

OBJECTIVE

We aimed to validate a 2D radial T2* mapping method and its ability to reveal subtle alterations in the menisci of patients with knee osteoarthritis (OA).

METHODS

Of 40 enrolled participants, 20 were diagnosed with OA, and 20 were age- and sex-matched asymptomatic controls. Data from the right knee of each participant were collected using a 1.5-T MRI equipped with a single-channel knee coil. T2* values were acquired using a conventional T2* mapping protocol and a radial T2* mapping method. Mean T2* values in the meniscal white zones, meniscal red zones, and total menisci were calculated. Numerical simulation was performed for validation.

RESULTS

Both simulation and clinical data confirmed that 2D radial T2* mapping provided better discrimination than the conventional method. Compared to controls, the OA group showed significantly greater mean (standard deviation) T2* values in the white zones (9.33 [2.29] ms vs. 6.04 [1.05] ms), red zones (9.18 [2.03] ms vs. 6.81 [1.28] ms), and total menisci (9.26 [2.06] ms vs. 6.34 [1.14] ms). Correlations were found between the Lequesne index and the meniscal T2* values in all three regions (r = 0.528, p = 0.017; r = 0.635, p = 0.003; and r = 0.556, p = 0.011, respectively).

CONCLUSION

These findings indicate that in early OA, radial T2* mapping is an alternative means of assessing meniscal degeneration and can be used to monitor its progression.

KEY POINTS

• Radial T2* mapping outperforms Cartesian T2* mapping. • Radial T2* measurements are useful in assessing meniscal degeneration. • Meniscal T2* values correlate well with disease severity.