Prostate Cancer Screening Direct Imaging

If your prostate exam or the result of your PSA test indicates the possibility of cancer, your doctor may order diagnostic imaging tests. These are more complex types of prostate exams that allow urologists to “see” the gland, either through ultrasound, radio waves, or x-rays. None of these prostate exams can diagnose cancer 100 percent: a biopsy is necessary to make the final diagnosis.

Trans Rectal Ultrasound (TRUS)

A trans rectal ultrasound uses high frequency sound waves to generate an image of the prostate. A probe is lubricated, and inserted into the rectum. The probe then emits sound waves that are reflected back to the probe by the prostate and other organs. The returned ultrasound waves are used to construct a picture of the gland.

Computed Tomography (CT Scan)

Computed tomography, also known as a CT scan, uses x-rays to generate computerized cross sections of the internal organs. Multiple x-rays are taken during a CT scan, providing the urologist with an overall view of the gland.

Magnetic Resonance Imaging (MRI)

Unlike computed tomography, which uses potentially harmful x-rays, magnetic resonance imaging (MRI) uses magnets and radio waves to generate a 3-dimensional image of internal organs. The resolution of the MRI is so detailed that urologists can tell the difference between cancerous and healthy tissue, even if those changes are very slight.

Proton Magnetic Resonance Spectroscopic Imagery (MRSI)

An MRSI is performed in combination with an MRI. Like magnetic resonance imaging, an MRSI uses magnetic and radio waves. An MRSI, however, can detect differences at the cellular level. A MRSI can detect levels of certain cellular chemicals (metabolites) that will be in low concentrations if prostate cancer is present.

ProstaScint Scan

The ProstaScintTM scan uses injected radioisotopes to locate cancer. The isotopes are injected into the bloodstream, and attach themselves to cancerous cells. Accumulations of the radioisotopes can then be found using a special gamma ray camera. The test is not 100 percent accurate; false positive results have been made.

Radionuclide Bone Scan

Your urologist may suggest a bone scan, to determine whether the cancer has spread to the bones or not. In early-stage prostate cancer, this is usually a precautionary test, performed to rule out possible complications.


National Library of Health. (updated 2001). MRI. Retrieved January 23, 2003 from