An MRI can examine the knee, and in fact as the best non-invasive test for the knee, an MRI can show a wide range of lesions in the knee in the most detail. Routine tests of the knee include X-rays, CT scans, and MRIs, none of which can show as much detail as an MRI. Among the non-invasive tests of the knee, MRI can clearly detect intra-articular lesions, such as ligament damage, rupture, meniscus damage, joint effusion, and microfractures under the joint, which are difficult to detect with other tests.