Diagnostics & Images:
Understanding The Best Options For Monitoring

Diagnostic and imaging tools help detect, stage, and monitor prostate cancer. They guide treatment and reduce unnecessary procedures.

PSA Density

PSA density (PSAD) takes into account both the PSA blood test and the size of the
prostate. Because larger prostates naturally produce more PSA, a high PSA number alone
doesn’t always mean cancer. By dividing PSA (ng/mL) by prostate volume (measured
with MRI or ultrasound), doctors get a clearer picture of risk.


Why it matters: A higher PSA density may point toward a need for biopsy, while a
lower PSA density may support staying on active surveillance and avoiding unnecessary
procedures.

Prostate MRI (Multiparametric MRI, or mpMRI)

A prostate MRI takes detailed pictures of the prostate using different imaging sequences. It can show areas that look suspicious for cancer, estimate the size of the prostate, and help guide whether a biopsy is needed or where to target it. An MRI can make monitoring on Active Surveillance safer by spotting changes over time. It does not replace a biopsy, but it can help reduce unnecessary biopsies and give doctors more confidence about what’s happening inside the prostate.

PI-RADS (Prostate Imaging Reporting & Data System)

PI-RADS is a 1–5 scoring system radiologists use to describe how suspicious an area on
prostate MRI looks for clinically significant cancer:

  • PI-RADS 1 – Highly unlikely to be cancer
  • PI-RADS 2 – Unlikely
  • PI-RADS 3 – Uncertain/equivocal
  • PI-RADS 4 – Likely
  • PI-RADS 5 – Highly likely


Why it matters: Doctors use PI-RADS scores to help decide whether a biopsy should
be done, and if so, exactly where to target it.

Micro-Ultrasound

Micro-ultrasound is a newer version of prostate ultrasound that uses a much higher frequency (29 MHz vs. 6–9 MHz for standard TRUS). This allows for sharper, more detailed images.

Why it matters: Early studies suggest it may improve the detection and targeting of suspicious areas compared to traditional ultrasound, but it is not yet widely available.

PSMA PET Scan

PSMA stands for Prostate-Specific Membrane Antigen, a protein found in high amounts on prostate cancer cells. A PSMA PET scan uses a small amount of radioactive tracer that binds to PSMA and highlights even tiny spots of cancer spread.Why it matters: This scan is more sensitive than CT or bone scans and is especially useful for:

  • Staging advanced prostate cancer (seeing if it has spread)
  • Finding recurrence when PSA rises after treatment
  • Guiding treatment choices for advanced disease

Trusted Resources & Further Reading

*Disclaimer: The information on this page is for educational purposes only and is not a substitute for professional medical advice. Always consult a qualified healthcare provider, such as a physician or urologist, about your personal care. Ask questions, seek multiple opinions if needed, and make decisions in partnership with your medical team.*