The goal of this observational study is to understand how diffusion tensor imaging (DTI) relates to other traditional measures and knee function. The main question it aims to answer is: Will regions of known patellar tendon pathology present with smaller DTI scalar parameters, shorter fiber length, and lower fiber density compared to the contralateral tendon and healthy regions in the ipsilateral tendon. Participants will: * undergo MRI and ultrasound imaging * perform knee function test * complete questionnaires