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MRI Prostate

PI-CAI

PI-CAI (Prostate Imaging: Cancer AI) Public Training and Development Dataset

1500 biparametric prostate MRI exams (T2w, high b-value DWI, ADC) of 1476 men from three Dutch centers, with clinically significant prostate cancer labels, lesion delineations and clinical variables, for csPCa detection.

Overview

PI-CAI is a grand challenge on detecting clinically significant prostate cancer (csPCa, ISUP grade group 2 or higher) in prostate MRI, comparing AI systems with radiologists. Its Public Training and Development Dataset was released in 2022 by the Diagnostic Image Analysis Group at Radboud University Medical Center with partners in Groningen and Twente. This entry covers that public part only. The private training data and the hidden validation and testing cohorts are not released.

Composition

The public set holds 1500 MRI studies from 1476 patients, scanned between 2012 and 2021. 425 studies are labelled csPCa and 1075 contain benign tissue or indolent cancer. 328 cases come from the earlier ProstateX challenge, so the two should not be combined. Each study has an axial T2-weighted image, an axial high b-value diffusion image and an ADC map, and some also have sagittal or coronal T2-weighted images. No contrast-enhanced sequences are included. Images are MHA files, distributed as five zip archives named fold0 to fold4.

Acquisition

Exams were acquired at Radboud University Medical Center, University Medical Center Groningen (the clinical table lists this center as PCNN, Prostaat Centrum Noord-Nederland) and Ziekenhuisgroep Twente. The study protocol reports 1.5T and 3T scanners from Siemens and Philips with surface coils: five Siemens and two Philips scanners in the public set.

Annotations

Labels are maintained in the separate picai_labels repository. Positives are histologically confirmed ISUP 2 or higher; negatives are confirmed by histology (ISUP 1 or lower) or by MRI (PI-RADS 2 or lower), without follow-up. Lesions were delineated in ITK-SNAP by trained investigators supervised by expert radiologists. The original expert masks carry the ISUP grade, while the AI-derived and follow-up masks are binary. Expert masks cover 1295 cases; the remaining 205 positives first had only AI-derived masks and later received expert masks from a follow-up study. AI-derived whole-gland masks and a per-study clinical table (age, PSA, PSA density, prostate volume, biopsy type, PI-RADS and Gleason scores per lesion, center) are included.

Known limitations

  • Cases were selected by convenience sampling, so the case mix does not reflect routine care.
  • Some patients have several studies with different outcomes, each labelled on its own.
  • The README on Zenodo and the study protocol differ slightly on median age and lesion counts.
  • The whole-gland masks are automatic and contain known errors.

Cohort

Aggregate numbers from the sources below. Bars are relative to the 1,476 subjects.

Sex

  • Male 1,476 100%

Age

mean 65.6± 7.2 · range 35 to 92

No age bins reported.

Contrast / sequence

studies, values can overlap

  • T2-weighted 1,500 100%
  • Diffusion-weighted 1,500 100%
  • ADC map 1,500 100%

Condition

studies, values can overlap

  • Prostate cancer 653 44%

Country

studies

  • Netherlands 1,500 100%

License and access

Our reading of the license, not legal advice. Before you use the data, read the original license and confirm that your use is allowed. We take no responsibility for how you use a dataset. Full disclaimer

Access
Open download

Download without an account

Access page

Creative Commons Attribution-NonCommercial 4.0 International

Use, share and adapt the data with credit, but only for non-commercial purposes.

Original license text Version read: 4.0 Checked 2026-10-07

What you can do

  • No
  • Conditional
  • Yes
  • Yes

What you can share

  • Conditional
  • Conditional
  • Conditional

What you must do

  • Yes
  • Share alike No
  • No
  • No
  • Manuscript review No
  • Release code No
  • Return results No
  • Delete after use No

Limits

  • No
  • Location limits No

Citation

Saha A, Bosma JS, Twilt JJ, et al. Artificial intelligence and radiologists in prostate cancer detection on MRI (PI-CAI): an international, paired, non-inferiority, confirmatory study. Lancet Oncol 2024; 25: 879-887. https://doi.org/10.1016/S1470-2045(24)00220-1

All numbers

Every number on this page, as stored in stats.csv, with its source.

MeasureBreakdownValueSource
Subjectstotal 1,476zenodo-6624726
Dataset Characteristics
Studiestotal
one case is one MRI study; some patients have more than one study
1,500zenodo-6624726
Dataset Characteristics
Subjectssex=male
all cases are prostate MRI of male patients
1,476saha2022-protocol
p. 9, Item 22a
Studiescontrast=T2w
every case has axial T2w; sagittal and coronal T2w are optional
1,500zenodo-6624726
Imaging Files
Studiescontrast=dwi
axial high b-value (>= 1000 s/mm2) DWI
1,500zenodo-6624726
Imaging Files
Studiescontrast=ADC 1,500zenodo-6624726
Imaging Files
Studiescontrast_set=ADC+dwi+T2w 1,500zenodo-6624726
Imaging Files
Studiescondition=prostate_cancer
studies with case_ISUP >= 1 (any histopathologically confirmed cancer); 425 of them are csPCa (ISUP >= 2) per the Zenodo README
653picai-marksheet
case_ISUP
Studiescountry=NL
three centers in the Netherlands
1,500zenodo-6624726
Dataset Characteristics
Studiesage=30-49
age at the time of each study
31picai-marksheet
patient_age
Studiesage=50-59
age at the time of each study
253picai-marksheet
patient_age
Studiesage=60-69
age at the time of each study
770picai-marksheet
patient_age
Studiesage=70-79
age at the time of each study
421picai-marksheet
patient_age
Studiesage=80+
age at the time of each study
25picai-marksheet
patient_age
Median agetotal
IQR 61-70; the study protocol Table 1 gives 67 (IQR 61-71)
66zenodo-6624726
Dataset Characteristics
Mean agetotal
over 1500 studies
65.6picai-marksheet
patient_age
Age SDtotal
over 1500 studies
7.2picai-marksheet
patient_age
Minimum agetotal
over 1500 studies
35picai-marksheet
patient_age
Maximum agetotal
over 1500 studies
92picai-marksheet
patient_age

Sources

The keys used in the table above.