Multi-vendor multi-site T and T quantification of knee cartilage.

Objective: To develop 3D T and T imaging based on the same sequence structure on MR systems from multiple vendors, and to evaluate intra-site repeatability and inter-site inter-vendor reproducibility of T and T measurements of knee cartilage.

Methods: 3D magnetization-prepared angle-modulated partitioned k-space spoiled gradient echo snapshots (3D MAPSS) were implemented on MR systems from Siemens, GE and Philips. Phantom and human subject data were collected at four sites using 3T MR systems from the three vendors with harmonized protocols. Phantom data were collected by means of different positioning of the coil. Volunteers were scanned and rescanned after repositioning. Two traveling volunteers were scanned at all sites. Data were transferred to one site for centralized processing.

Results: Intra-site average coefficient of variations (CVs) ranged from 1.09% to 3.05% for T and 1.78-3.30% for T in phantoms, and 1.60-3.93% for T and 1.44-4.08% for T in volunteers. Inter-site average CVs were 5.23% and 6.45% for MAPSS T and T, respectively in phantoms, and 8.14% and 10.06% for MAPSS T and T, respectively, In volunteers.

Conclusion: This study showed promising results of multi-site, multi-vendor reproducibility of T and T values in knee cartilage. These quantitative measures may be applied in large-scale multi-site, multi-vendor trials with controlled sequence structure and scan parameters and centralized data processing.