Identification of Early Changes in Patellar Tendinopathy Using Ultra-high Field Strength MRI

Inclusion Criteria: Common for all groups * Sports active individuals. * Age \[18-45\] years old. * BMI \[18.5-30\] ET - group * Symptom onset within 90 days at inclusion * Clinical signs of patellar tendinopathy. * Activity related pain in the patellar tendon. * Palpation pain in the proximal part of the patellar tendon. * At least one of the following three changes on the ultrasound scanning: * Thickening of the AP diameter on the symptomatic side. * Increased Power Doppler signal on the symptomatic side. * Hypoechogenic area corresponding to the symptomatic area of the tendon. CT - group, * Symptom onset \>90 days ago * Clinical signs of patellar tendinopathy. * Activity related pain in the patellar tendon. * Palpation pain in the proximal part of the patellar tendon. * At least one of the following three changes on the ultrasound scanning: * Thickening of the AP diameter on the symptomatic side. * Increased Power Doppler signal on the symptomatic side. * Hypoechogenic area corresponding to the symptomatic area of the tendon. CTRL - group - Similar activity level as the two patient groups. Exclusion Criteria: Common for all groups * Previous surgery in the knee on the ipsilateral side. * Previous corticosteroid injection in the patellar tendon on the ipsilateral side. * Smoking * Known arthritis * Known diabetes * Known hypercholesterolemia * Previous injections in the ipsilateral tendon. * MRI contraindications * Ferromagnetic objects * Pregna…