An external marker was attached to the surface of the swelling (round dot). The leg could not be stretched in this newborn.
A sharply demarcated, mildly T1 hypo-intense and T2 mild hyperintense, thin-walled nodular lesion is seen on the lateral side of the knee joint. It contains internal septations and also some hypo-intense nodular components suggestive of phleboliths, although they are not visible on the plain film.
With fat suppression the lesion is markedly hyperintense compared to the surrounding tissue, the septations and phleboliths are well demonstrated.
T1 post-gadolinium demonstrates mild and rather inhomogeneously enhancement.