Ultra-short-echo time Sequence for Bi-exponential T1ρ Mapping of Achilles Tendinopathy

Motivation: T1ρ mapping is a promising approach for imaging of Achilles Tendinopathy (AT), but imaging of short T2 components requires UTE-based sequences. Goal(s): Evaluate our 3D magnetization-prepared UTE sequence to discriminate between AT patients from healthy subjects (HS) using bi-exponential (BE) models. Approach: We scanned 6 HS and 4 AT patients with our UTE-T1ρ sequence. We performed mono-exponential (ME) and BE fitting. We used the linear discriminant analysis (LDA) to improve AT detection in the BE model. Wilcoxon rank-sum test was used to measure statistical significance. Results: The composite T1ρ biomarker obtained with LDA in the BE model could discriminate AT patients from HS. Impact: The study demonstrates that the T1ρ mapping obtained from magnetization-prepared 3D-UTE Sequence can potentially detect AT, particularly with BE relaxation models when combined with LDA.