Quantitative bi-component T2* analysis of histologically normal Achilles tendons.

INTRODUCTION: the aim of this pilot study was to implement ultrashort echo time (UTE) MRI with bi-component analysis on grossly normal Achilles tendons with histologic correlation.

MATERIALS AND METHODS: six tendon samples which were grossly normal on visual inspection and palpation were harvested. A 2D UTE pulse sequence was implemented on a 3T MR scanner and bi-component and single-component T2* analysis was performed. Tendon samples were histologically processed and evaluated.

RESULTS: mean short T2* fraction was 79.2% (95% confidence interval [CI], 70.1 - 88.3%), mean short T2* was 1.8 ms (95% CI, 1.3 - 2.3 ms), mean long T2* fraction was 20.8% (95% CI, 11.7 - 29.9%), mean long T2* was 9.2 ms (95% CI, 5.1 - 13.3 ms), and mean single-component T2* was 2.5 ms (95% CI, 1.8 - 3.1 ms).

DISCUSSION: 2D UTE MRI with bi-component and single-component T2* analysis was successfully implemented. Inter-individual variation can be demonstrated in grossly and histologically normal Achilles tendons.