Clinical Report: Shortened Biparametric MRI for Prostate Cancer Screening Feasibility

Overview

The ReIMAGINE study evaluated a two-sequence abbreviated biparametric MRI (bpMRI) protocol as a screening tool for prostate cancer (PCa) in men aged 50–75 years. This protocol demonstrated feasibility with reduced scan time (<10 minutes) and a novel binary reporting system to identify screen-positive cases, potentially improving the balance between detecting clinically significant PCa and minimizing false positives.

Background

Prostate cancer remains a leading cause of cancer mortality, with early-stage disease often asymptomatic, complicating diagnosis. While PSA testing reduces mortality, its limited sensitivity and specificity result in over- and underdiagnosis. Multiparametric MRI (mpMRI) is established in diagnosis but is limited by long scan times, cost, and contrast agent use. Biparametric MRI (bpMRI), omitting contrast, offers shorter scan times and comparable diagnostic accuracy, making it a promising screening modality. Abbreviated bpMRI protocols could further enhance feasibility and scalability for population screening.

Data Highlights

The abbreviated bpMRI protocol used two sequences: axial T2-weighted imaging and high b-value diffusion-weighted imaging, with a total acquisition time under 10 minutes. Participants underwent PSA testing and MRI screening; those with PSAd ≥ 0.12 ng/mL2 were considered screen positive regardless of MRI. Screen-positive men were referred for further mpMRI and biopsy as indicated, with follow-up over 2 years to assess outcomes. The study employed a composite reference standard including biopsy, mpMRI, and clinical follow-up data.

Key Findings

• The abbreviated bpMRI protocol was feasible in a population-based screening setting with scan times under 10 minutes and no contrast administration.
• A novel binary MRI reporting system applying a high threshold for screen positivity was successfully implemented.
• PSAd ≥ 0.12 ng/mL2 was used as an independent criterion for screen positivity, enhancing detection sensitivity.
• Screen-positive participants underwent standard-of-care mpMRI and targeted biopsies, with follow-up data collected over 2 years.
• The composite reference standard allowed robust assessment of diagnostic accuracy, integrating biopsy, mpMRI, and clinical outcomes.

Clinical Implications

The abbreviated bpMRI protocol offers a rapid, non-contrast screening tool that may improve the feasibility and scalability of MRI-based prostate cancer screening. Incorporating PSAd thresholds alongside MRI findings can optimize detection of clinically significant disease while minimizing unnecessary interventions. This approach could streamline patient pathways by reducing scan times and resource utilization without compromising diagnostic accuracy.

Conclusion

The ReIMAGINE study supports the potential of a shortened biparametric MRI protocol combined with PSAd assessment as an effective, feasible screening strategy for prostate cancer. Further validation in larger cohorts is warranted to confirm diagnostic performance and clinical utility.

References

1. ReIMAGINE Study Protocol and Outcomes 2019-2021 -- Evaluating Abbreviated bpMRI in PCa Screening