When a definitive diagnosis is more difficult, imaging and arthroscopic exploration can be used. x-rays usually have no positive findings, and plain CT has no significant effect on the diagnosis of crepitus. MRI: The sequences that can better show the crepitus are gradient-echo T2-weighted images, pressure-lipid T2-weighted images and proton density-weighted images. In case of inadequate joint fluid, arthrography can be used to dilate the knee joint by injection of contrast agent to make the crease image more clear. In MRI, the crease appears as a low-signal band or line shadow located in high-signal joint fluid. The suprapatellar crease is most easily visualized in the sagittal position, often as a band-like low-signal structure, and is located in the upper posterior aspect of the patella. The infrapatellar crease is a linear, low-signal structure that lies anterior to and parallel to the ACL in the sagittal position. The T2-weighted image of the medial patellar crease is clearest in axial and sagittal views, and is more effective when arthrography is performed. Arthroscopy: The clinical signs and symptoms of synovial crease syndrome are not easily distinguishable from other knee pathologies and are often confused. Therefore, the final diagnosis of synovial crepitus syndrome often requires arthroscopy. Most synovial folds are discovered during other arthroscopic procedures. Arthroscopically, a banded, thin, translucent or hypertrophic fibrotic synovial crease may be observed, either attached to the suprapatellar capsule, parallel to the ACL, or sandwiched between the patellofemoral joint, with a wide crease that may wrap over the femoral condyle or even separate the joint cavity into two chambers.