Computer-aided diagnosis prior to conventional interpretation of prostate mpMRI: an international multi-reader study
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To evaluate if computer-aided diagnosis (CAD) prior to prostate multi-parametric MRI (mpMRI) can improve sensitivity and agreement between radiologists.
Nine radiologists (three each high, intermediate, low experience) from eight institutions participated. A total of 163 patients with 3-T mpMRI from 4/2012 to 6/2015 were included: 110 cancer patients with prostatectomy after mpMRI, 53 patients with no lesions on mpMRI and negative TRUS-guided biopsy. Readers were blinded to all outcomes and detected lesions per PI-RADSv2 on mpMRI. After 5 weeks, readers re-evaluated patients using CAD to detect lesions. Prostatectomy specimens registered to MRI were ground truth with index lesions defined on pathology. Sensitivity, specificity and agreement were calculated per patient, lesion level and zone—peripheral (PZ) and transition (TZ).
Index lesion sensitivity was 78.2% for mpMRI alone and 86.3% for CAD-assisted mpMRI (p = 0.013). Sensitivity was comparable for TZ lesions (78.7% vs 78.1%; p = 0.929); CAD improved PZ lesion sensitivity (84% vs 94%; p = 0.003). Improved sensitivity came from lesions scored PI-RADS < 3 as index lesion sensitivity was comparable at PI-RADS ≥ 3 (77.6% vs 78.1%; p = 0.859). Per patient specificity was 57.1% for CAD and 70.4% for mpMRI (p = 0.003). CAD improved agreement between all readers (56.9% vs 71.8%; p < 0.001).
CAD-assisted mpMRI improved sensitivity and agreement, but decreased specificity, between radiologists of varying experience.
• Computer-aided diagnosis (CAD) assists clinicians in detecting prostate cancer on MRI.
• CAD assistance improves agreement between radiologists in detecting prostate cancer lesions.
• However, this CAD system induces more false positives, particularly for less-experienced clinicians and in the transition zone.
• CAD assists radiologists in detecting cancer missed on MRI, suggesting a path for improved diagnostic confidence.
KeywordsProstate cancer MRI scans Image interpretation computer assisted Computer-assisted diagnosis
area under the curve
dynamic contrast-enhanced imaging
index of specific agreement
Prostate Imaging Reporting and Data System
The study has received funding by the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research (Grant ZIA BC 010655).
Compliance with ethical standards
The scientific guarantor of this publication is Baris Turkbey, MD.
Conflict of interest
The authors of this manuscript declare relationships with the following companies: Bradford Wood, Philips and InVivo; Ronald Summers, Ping An and iCAD.
Statistics and biometry
One of the authors, Dr. Joanna Shih, has significant statistical expertise.
Institutional review board approval was obtained.
Written informed consent was obtained from all patients in this study.
Study subjects or cohorts overlap
Some study subjects or cohorts have been previously reported in Greer MD, Shih JH, Lay N, et al. Validation of the dominant sequence paradigm and role of dynamic contrast-enhanced imaging in PI-RADS Version 2. Radiology. 2017;285:859–869.
• diagnostic study
• multicentre study
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