Delayed contrast enhanced MRI of meniscus with ionic and non-ionic agents

Purpose:

To evaluate the potential difference in post‐contrast T₁ relaxation time of the meniscus (T_1Gd) between osteoarthritic patients (OA) and healthy subjects (HS), and to verify if charge density has any influence on meniscal T_1Gd.

Materials and Methods:

We performed a retrospective analysis of meniscal T₁ relaxation time on data previously acquired for studying articular cartilage with both ionic and non‐ionic contrast media. MR imaging was performed in 10 OA and 8 HS at 120 min following administration of double‐dose ionic Gd‐DTPA^2? on one day and non‐ionic Gd‐DTPA‐BMA on a different day. A three‐dimensional Look‐Locker sequence with echo time of 2 ms was used for data acquisition to allow T₁ mapping of the meniscus.

Results:

Compared with HS, significantly lower meniscal T_1Gd was observed in OA with either ionic Gd‐DTPA^2? (P < 0.01) or non‐ionic Gd‐DTPA‐BMA (P < 0.001) contrast agent. There was a correlation between meniscal T₁(Gd‐DTPA^2?) versus T₁(Gd‐DTPA‐BMA). Meniscal T₁(Gd‐DTPA‐BMA) showed a larger difference and smaller overlap between OA and HS. No significant differences in either pre‐contrast T₁ or post‐contrast T_1Gd were observed between inner and outer zones of the meniscus with either agent.

Conclusion:

Significant differences in meniscal T_1Gd between OA and HS were observed with both ionic and non‐ionic contrast agents, suggesting that charge density is not responsible for the observed differences. J. Magn. Reson. Imaging 2011;33:731–735. © 2011 Wiley‐Liss, Inc.