Magnetic Resonance <scp>T<sub>2</sub></scp>* Is Increased in Patients With Early‐Stage Achilles and Patellar Tendinopathy
Nikolaj M. Malmgaard‐Clausen, Peter Tran, René B. Svensson, Philip Hansen, Janus Damm Nybing, S. Peter Magnusson, Michael Kjær
Abstract
Background T 2 * mapping has proven useful in tendon research and may have the ability to detect subtle changes at an early stage of tendinopathy. Purpose To investigate the difference in T 2 * between patients with early tendinopathy and healthy controls, and to investigate the relationship between T 2 * and clinical outcomes, tendon size, and mechanical properties. Study Type Prospective cross‐sectional. Subjects Sixty‐five patients with early tendinopathy and 25 healthy controls. Field Strength/Sequence Three Tesla, ultrashort time to echo magnetic resonance imaging. Assessment Tendon T 2 * was quantified using a monoexponential fitting algorithm. Clinical symptoms were evaluated using the Victorian Institute of Sports Assessment‐Achilles/Patella (VISA‐A/VISA‐P). In vivo mechanical properties were measured using an ultrasound‐based method that determined force and deformation simultaneously in tendons of patellar tendinopathy patients. Statistical Tests A generalized linear model adjusted for age was applied to investigate the difference between patients and controls. In the two patient groups, linear regressions were applied to investigate the association between T 2 * and tendon size, clinical outcomes, and biomechanical properties. Results There was a significant difference in T 2 * between patients and healthy controls (204.8 [95% CI: 44.5–365.0] μsec, P < 0.05). There was a positive correlation between tendon size and T 2 * for both Achilles ( r = 0.72; P < 0.05) and patellar tendons ( r = 0.53; P < 0.05). There was no significant correlation between VISA‐A and T 2 * ( r = −0.2; P = 0.17) or VISA‐P and T 2 * ( r = −0.5; P = 0.0504). Lastly, there was a negative correlation between modulus and T 2 * ( r = −0.51; P < 0.05). Data Conclusions T 2 * mapping can detect subtle structural changes that translate to altered mechanical properties in early‐phase tendinopathy. However, T 2 * did not correlate with clinical scores in patients with early‐phase Achilles and patellar tendinopathy. Thus, T 2 * mapping may serve as a tool for early detection of structural changes in tendinopathy but does not necessarily describe the clinical severity of disease. Level of Evidence 1 Technical Efficacy Stage 2