Quantitative synthetic MRI improves peripheral zone prostate cancer detection beyond PI-RADS v2.1

Area of Science:

• Radiology and Medical Imaging
• Oncology
• Prostate Cancer Diagnostics

Background:

• Accurate diagnosis of peripheral zone prostate cancer remains challenging.
• The Prostate Imaging-Reporting and Data System (PI-RADS v2.1) is subjective and often requires contrast agents.
• Synthetic MRI (SyMRI) offers rapid, contrast-free quantitative T1 and T2 relaxation maps.

Purpose of the Study:

• To assess the diagnostic performance of SyMRI compared to PI-RADS v2.1 for peripheral zone prostate cancer.
• To evaluate the utility of quantitative T1, T2, and proton density values from SyMRI.
• To determine if SyMRI can improve upon existing diagnostic standards.

Main Methods:

• Retrospective single-center study of 70 men with suspected prostate cancer.
• Comparison of multi-parametric MRI with SyMRI, followed by histopathological confirmation.
• Independent assignment of PI-RADS v2.1 scores and extraction of quantitative SyMRI values (T1, T2, proton density).

Main Results:

• Malignant lesions showed significantly reduced T1 and T2 values compared to benign lesions (p < 0.01).
• Optimal T1 and T2 thresholds achieved high sensitivity and specificity.
• Combined SyMRI (T1, T2) and PI-RADS analysis yielded the highest diagnostic accuracy (AUC = 0.993), outperforming PI-RADS alone (AUC = 0.663).

Conclusions:

• Quantitative SyMRI provides reproducible, contrast-free biomarkers for enhanced peripheral zone prostate cancer detection.
• Incorporating SyMRI T1 and T2 mapping may improve early diagnosis and reduce reliance on contrast agents.
• Findings are exploratory and require validation in larger, prospective cohorts.