What others tests may be required?

Your doctor may require some laboratory tests, included serum chemistry, fasting glucose, complete blood count and lipid profile. These tests can reveal evidence of anemia, diabetes, hyperlipidemia or other systemic diseases associated with erectile dysfunction. Serum total testosterone, measured in blood taken in the morning, is tested to evaluate androgenic status. Prolactin is also measured as decreased libido. At the clinician’s discretion, thyroid function tests may also be done to look for thyroid hormone problems. Serum PSA testing is performed as needed if prostate pathology is suspected. Dipstick analysis of urine may reveal glucosuria, an indication of diabetes.
Additional, specialized testing is seldom necessary, because most erectile dysfunction patients can be managed within the ordinary diagnostic setting; however, specific diagnostic testing is required in some circumstances, e.g. in patients with primary erectile dysfunction, to exclude organic disease and in young patients with a history of pelvic or perineal trauma.
Specialized diagnostic testing is carried out in the presence of complex clinical presentations.

McVary KT. Sexual Dysfunction, in Harrison’s Principles of Internal Medicine, D.L. Longo, et al., Editors. 2012, McGraw Hill: New York. p.374-379.
Burnett AL. Evaluation and management of erectile dysfunction, in Campbell-Walsh Urology, L.R. Kavoussi, et al., Editors. 2012, Saunders: Philadelphia. p.721-748.

Combined Intracavernous Injection and Stimulation (CIS) test

The Combined Intracavernous Injection and Stimulation (CIS) test is a first-line evaluation of penile blood flow, involving a direct pharmacological stimulus administered by intracavernous injection of vasodilator drugs into the lateral base of the penis. The injection is associated with genital or audiovisual sexual stimulation.

Medscape.com website, section “Drug and Diseases”, Erectile Dysfunction Workup, Injection of Prostaglandin E1; author: Edward David Kim. Update 2014.
Link

Cavernosography

Dynamic infusion cavernosography is an evaluation of the penile vascular integrity. This technique is usually performed on patients with suspected site-specific venous leakage after a perineal or pelvic trauma or in patients with primary ED, being considered for corrective penile vascular surgery.
After the intracavernous pharmacological injection (CIS), two needles are inserted into the penis to allow simultaneous saline infusion and intracavernous pressure monitoring. Cavernosography is intended to reveal the site of venous leakage.

Burnett AL. Evaluation and management of erectile dysfunction, in Campbell-Walsh Urology, L.R. Kavoussi, et al., Editors. 2012, Saunders: Philadelphia. p.721-748.

Nocturnal Penile Tumescence and Rigidity (NPTR) testing

The penile tumescence device (RigiScan) measures penile rigidity during home nocturnal monitoring. It is placed at the base and near the corona of the penis and connected to a monitor that records a continuous graph depicting the force and duration of erections that occur during sleep. The monitor is strapped to the leg. The Nocturnal Penile Tumescence test is conducted on several nights to obtain an accurate indication of erections that normally occur during the alpha phase of sleep.

Medscape.com website, section “Drug and Diseases”, Practice essentials, Management; author: Edward David Kim. Update 2014.
Link
Burnett Arthur L. (2012) Evaluation and management of erectile dysfunction. In: Kavoussi LR, Parlin AW, Novick AC, Peters CA, editors. Campbell-Walsh Urology. 10th ed. Philadelphia: Saunders; p.721-748.

Doppler evaluation

Doppler evaluation in erectile dysfunction (ED) has a significant role in determining the cause of ED. The advantages of penile Doppler and pharmacologic duplex ultrasonography include objective, minimally invasive evaluation of penile hemodynamics at a relatively low cost. Arteriogenic ED may be secondary to peripheral vascular disease and diabetes, or may be seen in association with coronary artery disease.
Sonographic examination of the penis is performed with the patient in either the supine or lithotomy (frog leg) position with the penis lying on the anterior abdominal wall or supported with towels between the thighs. A sufficient amount of sonographic acoustic gel should be used on the surface of the penis to obtain good-quality images. The examination is performed in transverse and longitudinal planes starting at the level of the glans and moving down to the base of the penis.

Golijanin D, Singer E, Davis R, et al. Doppler evaluation of erectile dysfunction – Part 1. International Journal of Impotence Research 2007;19:37-42.
Golijanin D, Singer E, Davis R, et al. Doppler evaluation of erectile dysfunction – Part 2. International Journal of Impotence Research 2007;19:43-48.