/picai_labels

Annotations for the PI-CAI Challenge: Public Training and Development Dataset

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Annotations for the PI-CAI Challenge: Public Training and Development Dataset

Imaging Dataset

To download the associated imaging data, visit: https://zenodo.org/record/6517398. Note, the Public Training and Development Dataset of the PI-CAI challenge includes 328 cases from the ProstateX challenge. Thus, we strongly recommend using this dataset exclusively, and not in addition to the ProstateX dataset.

Reference Standard for Annotations

Patient cases used for the training datasets of the PI-CAI challenge were annotated with the same reference standard as used for the ProstateX challenge, i.e. histologically-confirmed (ISUP ≥ 2) positives, and histologically- (ISUP ≤ 1) or MRI- (PI-RADS ≤ 2) confirmed negatives, without follow-up. Note, this means that certain patients (e.g. 11054) can have a prior study that was found to be negative (1001074 in 2018), but a subsequent study that was found to be positive (1001075 in 2020). In this case, each study was annotated with respect to its associated histopathology or radiology findings only. From our institutional findings at RUMC (Venderink et al., 2019), such scenarios typically emerge for less than <1% negative cases.

Annotations and Resources

For all cases, csPCa lesions were delineated and/or csPCa outcomes were recorded, by one of 10 trained investigators or 1 radiology resident, under supervision of one of 3 expert radiologists, at RUMC or UMCG. Lesion delineations were created using ITK-SNAP v3.80.

Out of the 1500 cases shared in the Public Training and Development Dataset, 1075 cases have benign tissue or indolent PCa (i.e. their labels should be empty or full of 0s) and 425 cases have csPCa (i.e. their labels should have lesion blobs of value 2, 3, 4 or 5). Out of these 425 positive cases, only 220 cases carry an annotation derived by a human expert. Remaining 205 positive cases have not been annotated. In other words, only 17% (220/1295) of the annotations provided in picai_labels/csPCa_lesion_delineations/human_expert should have csPCa lesion annotations, while the remaining 83% (1075/1295) of annotations should be empty.

Automated AI-derived delineations of the prostate whole-gland (see algorithm used for this task) and csPCa lesions (Bosma et al., 2022) have also been made available.

Location Description
csPCa_lesion_delineations/
human_expert/original/
Original csPCa annotations, as made by one of the trained investigators or radiology resident. Depending on the annotator/center and their preference, some of these annotations were mapped or created at the spatial resolution of the T2W image, while others have been created at the resolution of the ADC or DWI/HBV images. Either way, for every annotation in this folder, all lesion delineations will always clearly map to observations in DWI/ADC imaging. Available for 1295/1500 (86%) cases.
csPCa_lesion_delineations/
human_expert/resampled/
Original csPCa annotations resampled to the spatial resolution of the associated axial T2-weighted scan. Available for 1295/1500 (86%) cases.
csPCa_lesion_delineations/
AI/Bosma22a
Automated AI-derived delineations of csPCa lesions (Bosma et al., 2022a).
anatomical_delineations/
whole_gland/AI/Bosma22b
Automated AI-derived delineations of the prostate whole-gland (see algorithm used for this task). Note, that AI-derived annotations can be susceptible to errors or faulty segmentations (e.g. whole-gland segmentation for case 11050_1001070).
clinical_information/
marksheet.csv/
Clinical information (patient age, PSA, PSA density, prostate volume) and overview of each study (e.g. anonymized study date, MRI vendor and scanner used for acquisition, GS per lesion {if prostatectomy or biopsies were performed}) in this dataset.

Label Mapping of csPCa Annotations

All expert-derived csPCa annotations carry granular or multi-class labels (ISUP ≤ 1, 2, 3, 4, 5), while all automated AI-derived annotations carry binary labels (ISUP ≤ 1 or ≥ 2).

Label Expert-Derived Annotations AI-Derived Annotations
0 ISUP ≤ 1 ISUP ≤ 1
1 N/A ISUP ≥ 2
2 ISUP 2 N/A
3 ISUP 3 N/A
4 ISUP 4 N/A
5 ISUP 5 N/A

List of Clinical Information Descriptors

Descriptor Meaning
patient_id Anonymized patient ID.
study_id Anonymized study ID. Multiple study IDs can be assigned to the same patient ID.
mri_date Anonymized date at the time of the MRI study.
patient_age Patient age at the time of the MRI study.
psa Prostate-specific antigen level (PSA) (unit: ng/mL), as stated in the radiology report associated with the MRI study. If this value is missing, then it was not reported for the given study.
prostate_volume Prostate volume (unit: mL), as stated in the radiology report associated with the MRI study. In clinical practice, this value is typically approximated using the conventional prolate ellipsoid model. If this value is missing, then it was not reported for the given study.
psad Prostate-specific antigen density (PSAd) (unit: ng/mL²), as stated in the radiology report associated with the MRI study. Note, this value may not neccessarily be the same as the PSA divided by the prostate volume, due to approximations and rounding errors during clinical reporting. If this value is missing, then it was not reported for the given study.
histopath_type Procedure used to sample lesion tissue specimen for microscopic or histopathologic analysis. Its value can be SysBx for systematic biopsies, MRBx for MR-guided biopsies, SysBx+MRBx for systematic and MR-guided biopsies, or RP for radical prostatectomy. If its value is missing, then no tissue sampling procedure was performed; indicating a negative MRI study.
lesion_GS Gleason score (GS) assigned to each lesion after histopathologic analysis, where scores for different lesions are separated by , (commas). If its value is missing, then no tissue sampling procedure was performed; indicating a negative MRI study. If its value is N/A only for specific lesion(s), then those lesion(s) (as observed in radiology) were not biopsied or graded in histopathology (typically the case for PI-RADS 1-2 lesions).

Dataset Characteristics

Characteristic Frequency
Number of sites 11
Number of MRI scanners 5 S, 2 P
Number of patients 1476
Number of cases 1500
— Benign or indolent PCa 1075
— csPCa (ISUP ≥ 2) 425
Median age (years) 66 (IQR: 61–70)
Median PSA (ng/mL) 8.5 (IQR: 6–13)
Median prostate volume (mL) 57 (IQR: 40–80)
Number of positive MRI lesions 1087
— PI-RADS 3 246 (23%)
— PI-RADS 4 438 (40%)
— PI-RADS 5 403 (37%)
Number of ISUP-based lesions 776
— ISUP 1 311 (40%)
— ISUP 2 260 (34%)
— ISUP 3 109 (14%)
— ISUP 4 41 (5%)
— ISUP 5 55 (7%)

Open-Source Contributions

We encourage open-source contributions! For instance, you can contribute expert-derived delineations of the prostate whole-gland and zonal anatomy at the spatial resolution of axial T2-weighted images. If you're interested, feel free to propose PRs for inclusion to this repo. Pending quality control, substantial contributions will be merged in and credited accordingly.

Reference

If you are using this dataset or some part of it, please cite the following article:

A. Saha, J. J. Twilt, J. S. Bosma, B. van Ginneken, D. Yakar, M. Elschot, J. Veltman, J. J. Fütterer, M. de Rooij, H. Huisman, "Artificial Intelligence and Radiologists at Prostate Cancer Detection in MRI: The PI-CAI Challenge (Study Protocol)", DOI: 10.5281/zenodo.6667655

BibTeX:

@ARTICLE{PICAI_BIAS,
    author = {Anindo Saha, Jasper J. Twilt, Joeran S. Bosma, Bram van Ginneken, Derya Yakar, Mattijs Elschot, Jeroen Veltman, Jurgen Fütterer, Maarten de Rooij, Henkjan Huisman},
    title  = {{Artificial Intelligence and Radiologists at Prostate Cancer Detection in MRI: The PI-CAI Challenge (Study Protocol)}}, 
    year   = {2022},
    doi    = {10.5281/zenodo.6667655}
}

License

CC BY-NC 4.0

Managed By

Diagnostic Image Analysis Group, Radboud University Medical Center, Nijmegen, The Netherlands

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