Bicomponent ultrashort echo time analysis for assessment of patients with patellar tendinopathy

Purpose To compare bicomponent ultrashort echo time (UTE) parameters of patellar tendon between healthy volunteers and patients with patellar tendinopathy. Materials and Methods This study was performed with Institutional Review Board approval and with all subjects signing informed consent. A UTE‐ mapping sequence was performed at 3.0T on the knees of 10 healthy volunteers and in 11 patients with patellar tendinopathy. The UTE‐ relaxation times of the fast relaxing macromolecular bound water component ( ) and the slow relaxing bulk water component ( ) and the fraction of the fast relaxing macromolecular bound water component (F F ) of patellar tendon were measured in all subjects. Wilcoxon rank‐sum tests were used to compare UTE‐ parameters between healthy volunteers and patients with patellar tendinopathy. Results Mean , , and F F of the patellar tendon was 1.5 msec, 23.1 msec, and 79.5%, respectively, for healthy volunteers and 1.9 msec, 22.3 msec, and 75.5%, respectively, for patients with patellar tendinopathy. There were statistically significant differences between groups of subjects for ( P = 0.01) and F F ( P = 0.007) but not ( P = 0.10) of the patellar tendon. Conclusion Patients with patellar tendinopathy had significantly higher and significantly lower F F of patellar tendon than healthy volunteers, which suggests that bicomponent UTE‐ parameters can detect changes in the composition and microstructure of degenerative tendon. Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1441–1447.