Miscellaneous Findings on Knee MRI

Incidental or miscellaneous findings are frequently found when MRI of the knee is performed for perioperative or other routine indications. An increased awareness of these unexpected findings can help the interpreting physician identify and distinguish these entities to direct appropriate care and follow-up as necessary, and, in some cases, alter surgical decision-making. Vascular or muscular variants are relatively common around the knee and may be symptomatic or pose increased risk at surgery. Bone marrow signal can vary widely depending on age, sex, and even geographic location, and knowledge of the differing appearances on imaging is crucial to distinguish these from pathological findings. Many bone tumors have a predilection for the knee, and may be seen as incidental or unexpected findings, particularly if the lesion is occult radiographically. It is important to recognize the common features of both benign and malignant bone lesions occurring around the knee on radiographs and cross-sectional imaging, to determine their clinical significance, as well as guide further management decisions.