In 2006 The International Journal of Impotence Research conducted a study comparing two types of machines that are available to diagnose vascular organic erectile disorder. The comparison of portable ultrasound (MIDUS) and nocturnal RigiScan provided excellent insight into confirming the diagnosis of vascular organic erectile disorder within numerous patients. The use of UltraSound has fallen out of favor, but a number of cases, where a vascular, neurogenic or psychogenic aetiology requires confirmation, the use of these machines is essential to provide diagnosis and treatment.