A duplex ultrasound is a diagnostic technique that uses painless, high frequency sound waves to visualize structures beneath the skin's surface. The principle is similar to the sonar used on submarines. Sound waves are reflected back when they contact relatively dense structures such as fibrous tissue or blood vessel walls. These reflected sound waves can be converted into pictures of the internal structures being studied.
Experiencing ED can also be a reason to try not penetrative sex. Try planning a sex session with your partner hat isn't focused on your erection at all. Things like kissing, licking, sucking, foreplay and teasing all are super stimulating and don't focus on penetration. Feel free to bring each other to orgasm using these ideas and see if you are able to relax and enjoy the experience. Many men feel like failures when their erections become unreliable. Having a few successful sexual sessions that lead to orgasm without penetration can put the fun back into having sex. Many couples find success using this technique and begin to reengage sexually instead of avoiding being sexual for fear of failure.
Between 10 and 88% of patients diagnosed with cancer experience sexual problems following diagnosis and treatment. The prevalence varies according to the location and type of cancer, and the treatment modalities used. Sexuality may be affected by chemotherapy, alterations in body image due to weight change, hair loss or surgical disfigurement, hormonal changes, and cancer treatments that directly affect the pelvic region.
A common and important cause of ED is vasculogenic. Many men with ED have comorbid conditions such as hyperlipidemia, hypercholesterolemia, tobacco abuse, diabetes mellitus, or coronary artery disease (CAD).  The Princeton III Consensus recommends screening men who present with ED for cardiovascular risk factors; ED may be the earliest presentation of atherosclerosis and vascular disease. 
A study published in May 2014 in The Journal of Sexual Medicine found that some men can reverse erectile dysfunction with healthy lifestyle changes, such as exercise, weight loss, a varied diet, and good sleep. The Australian researchers also showed that even if erectile dysfunction medication is required, it's likely to be more effective if you implement these healthy lifestyle changes.
For best results, men with ED take these pills about an hour or two before having sex. The drugs require normal nerve function to the penis. PDE5 inhibitors improve on normal erectile responses helping blood flow into the penis. Use these drugs as directed. About 7 out of 10 men do well and have better erections. Response rates are lower for Diabetics and cancer patients.