MRI detection of occult venous anomalies in a patient with Williams syndrome: a case report.

Williams syndrome is a multisystem, congenital disorder which is commonly associated with arterial stenoses: supravalvar aortic stenosis and peripheral pulmonary artery stenosis. Venous abnormalities have not been previously reported in children with Williams syndrome. We present a case of a 3-year-old girl with Williams syndrome and diffuse venous ectasia as detected by MRI.