Short summary

Diagnostic performance of a abbreviated bi-parametric prostate MRI consisting of two sequences (T2w transverse + DWI) was compared to full mpMRI for detection of clinically significant prostate cancer in 542 patients and rendered similar Sens/Spec/NPV/PPV of both protocols
One of four radiologists read T2w axial and DWI first and scored according to PI-RADS v2, then read remaining sequences and scored again.
Interreader agreement assessed in 100 patients read by 3 radiologists.
Standard of Reference: Targeted biopsy if PI-RADS 3-5; urologic followup if PI-RADS 1-2.

Conclusion

A short, 9 minutes 2-sequence protocol offers a cancer detection rate that is equivalent to a conventional full multiparametric contrast-enhanced MR imaging protocol.

Retrospective analysis of 542 prospectively acquired men with suspicion for prostate cancer.
Inclusion criteria:
- PSA ≥ 3 ng/mL
- Previous negative TRUS biopsy

Large, prospectively accrued patient cohort.
Interesting standard of reference (clinical follow-up in MR-negative patients; n=278).
Definition of clinically significant prostate cancer according to clinical data (D'Amico classification)

Scans read by one of four radiologists. No Reader comparison.
Possible Introduction of bias by scoring full mpMRI right after reading short MRI.

The increasing demand for prostate MRI for men with suspicion of prostate cancer may be met with an abbreviated protocol lasting < 10 minutes without the application of contrast media.
If clinically significant prostate cancer is suspected on MRI, additional sequences for characterization or local staging may be added as needed at a later time point.

Different protocols for different questions of referring physicians may be recommended (e.g. detection and biopsy guidance protocol, staging protocol, Mets-protocol, post-treatment protocol, etc.)

It was interesting to see that the group from Aachen validated the findings of our own group regarding accuracy of a 2-sequence protocol which were published just a few months earlier in Radiology: "Detection of Clinically Significant Prostate Cancer: Short Dual-Pulse Sequence versus Standard Multiparametric MR Imaging-A Multireader Study." While Kuhl et al. looked at patients with previously negative TRUS-biopsy, we performed a 2-sequence protocol in biopsy-naive patients. And despite a different standard of reference (Targeted biopsy or clinical follow-up vs Template biopsy), the findings of the two studies were comparable.
In my opinion, an abbreviated MR protocol such as proposed by Kuhl et al. is a valid option to save time and contrast media in certain patients. An option could be to perform DCE only in case the DWI is not adequately acquired due to artifacts, etc.