Regional variations of T2* in healthy and pathologic achilles tendon in vivo at 7 Tesla: Preliminary results

The aim of this study was to investigate T in the Achilles tendon (AT), in vivo, using a three‐dimensional ultrashort time echo (3D‐UTE) sequence, to compare field strength differences (3 and 7 T) and to evaluate a regional variation of T in healthy and pathologic tendon. Ten volunteers with no history of pain in the AT and five patients with chronic Achilles tendinopathy were recruited. 3D‐UTE images were measured with the following echo times, at echo time = 0.07, 0.2, 0.33, 0.46, 0.59, 0.74, 1.0, 1.5, 2.0, 4.0, 6.0, and 9.0 ms]. T values in the AT were calculated by fitting the signal decay to biexponential function. Comparing volunteers between 3 and 7 T, short component T was 0.71 ± 0.17 ms and 0.34 ± 0.09 ms (P < 0.05); bulk long component T was 12.85 ± 1.87 ms and 10.28 ± 2.28 ms (P < 0.05). In patients at 7 T, bulk T was 0.53 ± 0.17 ms (P = 0.045, compared to volunteers), T was 11.49 ± 4.28 ms (P = 0.99, compared to volunteers). The results of this study suggest that the regional variability of AT can be quantified by T in in vivo conditions. Advanced quantitative imaging of the human AT using a 3D‐UTE sequence may provide additional information to standard clinical imaging. Finally, as the preliminary patient data suggest, T may be a promising marker for the diagnosis of pathological changes in the AT. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.