SUMMARY:
Prostate MRI image quality plays an important role in the detection of prostate cancer and the accuracy of targeted prostate biopsy. Differences in imaging protocols, clinical team experience, and radiologist interpretation can affect how clearly suspicious tissue is identified and how accurately biopsy needles are guided. The PI-QUAL score provides a standardized way to assess prostate MRI quality, with research linking lower-quality scans to reduced biopsy accuracy. When MRI quality is inadequate, repeat imaging or additional systematic biopsy sampling may be considered to improve diagnostic confidence.
Introduction
Multiparametric MRI (mpMRI) has transformed prostate biopsy from a hit-or-miss systematic procedure guided by transrectal ultrasound (TRUS) into a highly precise targeted biopsy guided by in-bore MRI.
However, some experts still don’t trust the accuracy of a targeted biopsy, especially if guided by mpMRI/TRUS fusion imaging. They prefer adding systematic biopsy sampling to targeted tumor sampling, in case the fusion targeted biopsy missed area(s) of clinically significant prostate cancer.
Such caution is understandable, because fusion imaging may add room for error due to
- Difference in patient positioning between previously captured MRI and real-time TRUS
- Co-registration error (correlating the prostate shape between previous MRI and real-time TRUS)
- Slight patient movement during transrectal ultrasound
In short, the image quality of fusion guidance is not as faithful as that of real-time mpMRI.
How can MRI image quality affect biopsy accuracy?
Since the purpose of a biopsy is to locate and diagnose clinically significant prostate cancer that requires treatment, the quality of imaging must be very high in order to detect or exclude prostate cancer.
Consider the three imaging sequences that are the key parameters of multiparametric MRI:
- T2-weighted imaging must have high spatial resolution to define size and shape of the gland, its three interior zones, neighboring structures, and any suspicious tissue changes within the prostate.
- Diffusion-weighted imaging must be highly attuned to the motion of water molecules in tissues to reveal how dense tumor cells restrict water motion more than normal healthy cells.
- Dynamic contrast-enhanced sequences must allow clear visual inspection of telltale irregular tumor blood flow over a timed period.
If image quality is inferior or compromised in any way, prostate cancer may be visually underestimated (inaccurate PI-RADS score) or even completely missed. Thus, poor image quality may well justify mistrust in biopsy needle accuracy. Simply put, the resulting diagnosis lacks a high degree of confidence.
Why does prostate MRI quality vary between imaging centers?
Unfortunately, mpMRI imaging quality is not always consistent from one imaging center to another. A 2026 paper out of the National Institutes of Health notes that “the diagnostic utility of mpMRI is heavily dependent on image quality, which is often inconsistent across clinical settings.”[i] There are several reasons for variance in MRI imaging quality.
First, the clinical team may not be equally experienced. Second, PI-RADS v2.1 protocols for technical acquisition in each imaging sequence may vary due to lack of familiarity and adherence to them. Finally, radiologists who have less experience may not recognize inferior imaging quality, or interpret correctly what high-quality images are showing.
What is the PI-QUAL score, and what does it measure?
There is a standard to evaluate imaging quality for prostate MRI. It is called the Prostate Imaging Quality (PI-QUAL) score. Created in 2021, it was updated in 2024. The higher the score, the better the quality.
The purpose of PI-QUAL is to standardize mpMRI image quality. It was developed to “assess the diagnostic quality of a scan against a set of objective criteria as per Prostate Imaging-Reporting and Data System [PI-RADS] recommendations, together with criteria obtained from the image.”[ii]
A September, 2026 study published in the European Journal of Radiology found that when PI-QUAL was used to score image quality, the worst accuracy in targeted biopsies was primarily due to poor quality in the T2 weighted parameter[iii], considered the workhorse of mpMRI along with diffusion-weighted imaging.
When might a repeat MRI or additional biopsy sampling be considered?
The authors of the study state that if PI-QUAL scores are low, systematic biopsy needles should be added to targeted biopsy to offset the chance of missing clinically significant prostate cancer. The authors recommend that mpMRI be repeated if the PI-QUAL score is low, in order to optimize identifying clinically significant areas for biopsy.
What does Dr. Dan Sperling say about image quality?
Dr. Dan Sperling, a recognized pioneer and authority in mpMRI of the prostate, affirms the importance of imaging quality. “While there is no doubt that multiparametric MRI has revolutionized prostate cancer detection and diagnosis, patients need to know that the caliber of the scan and the interpretation is not equal from one center to another.
“At the Sperling Prostate Center, we take great pride in our state-of-the-art 3T magnet and highly experienced team when it comes to top level MRI excellence. We are confident in the accuracy of our diagnostic tests, which then assist us in customizing treatment planning for each patient’s case.
“We also offer second opinions for patients who can’t travel to our Center. We encourage second opinions for exactly the reason that MRI scans are not all created equal. We applaud the researchers who work hard to set up standards to help improve consistency in prostate cancer diagnosis.”
For more information, contact the Sperling Prostate Center.
Frequently asked questions (FAQ)
Q: How long does a multiparametric MRI of the prostate take?
A: Typically, a multiparametric MRI of the prostate takes about 45 minutes, including time to place an IV line for the dynamic contrast enhanced parameter.
Q: Does multiparametric MRI involve radiation?
A: No, there is no exposure to radiation as there is in other types of diagnostic scans such as x-rays and CT (computed tomography) scans. The magnetic field is not harmful, and patients are pre-screened to ensure there are no metal implants or objects that could cause problems.
Q: What about anxiety or claustrophobia?
A: If a patient is worried about lying still in the tunnel (bore) of the magnet, medication can be given to calm anxiety and relax. Also, patients are given a means to communicate with the team, and stop the scan immediately should need arise.
Content reviewed by Dr. Dan Sperling, M.D., DABR — updated October, 2026
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
References
[i] Wunsch III DC, Esengur OT, Makwana RD, Harmon SA et al. Impact of MRI quality on the accuracy of targeted prostate biopsy: A prospective PI-QUAL analysis. Eur J Radiol. 2026 Sep 16;205:113254.
[ii] Giganti, F., Kirkham, A., Kasivisvanathan, V. et al. Understanding PI-QUAL for prostate MRI quality: a practical primer for radiologists. Insights Imaging 12, 59 (2021).
[iii] Wunsch III DC et al., ibid.
About Dr. Dan Sperling
Dan Sperling, MD, DABR, is a board certified radiologist who is globally recognized as a leader in multiparametric MRI for the detection and diagnosis of a range of disease conditions. As Medical Director of the Sperling Prostate Center, Sperling Medical Group and Sperling Neurosurgery Associates, he and his team are on the leading edge of significant change in medical practice. He is the co-author of the new patient book Redefining Prostate Cancer, and is a contributing author on over 25 published studies. For more information, contact the Sperling Prostate Center.
