Clinical Tests For Diagnosing Erectile Dysfunction
Duplex ultrasound
Duplex ultrasound is used to evaluate erectile tissue. It is used to evaluate blood flow, venous leak, signs of atherosclerosis, and scarring of erectile tissue. An erection is induced and the ultrasound is used to see vascular dilation and measure blood pressure in the penis.
Penile nerves function These tests test nerve sensitivity. These tests require the doctor to squeeze the head of the penis, which immediately causes the anus to contract if nerve function is normal. A physician measures the reaction between the squeeze and the contraction. If this test shows latency in reaction then further tests tests are used.
Nocturnal penile tumescence (NPT) This is a simple test of normal erections during sleep. Their absence may indicate a problem with nerve function or blood supply in the penis. There are two methods used to test for nocturnal erection changes: snap gauge and strain gauge. The presence of NPT tends to signify physically functional systems, but the absence of NPT may not be conclusive.
Penile Biothesiometry
This is another test of nerve function in the shaft of the penis. This test uses electromagnetic vibration to evaluate sensitivity. A decreased perception of vibration may indicate nerve damage in the pelvic area, which can lead to impotence.
Dynamic Infusion Cavernosometry
This test involves pumping fluid into the penis and measuring the pressure in the corpus cavernosum during an erection. This test will help establish how severe the venous leak is.Corpus Cavernosometry This is another test of venous leakage that involves infusing saline into the corpus cavernosum. The flow rate needed to maintain an erection indicates the degree of venous leakage. The leaking veins responsible may be visualised by infusing a mixture of saline and x ray contrast medium and performing a cavernosogram.
Digital Subtraction Angiography
In DSA, the images are acquired digitally. In this test a computer uses digital images to isolate and view blood vessels.
Magnetic resonance angiography (MRA)
Magnetic resonance angiography uses magnetic fields and radio waves to provide detailed images of the blood vessels. This is a painless procedure but may involve an agent injected to make veins stand out more vividly.



