Annotations.

Last updated January, 2025

Annotations are available in MIDRC, both based on expert human annotators and “Helper AI”.

Note that the availability of third party annotations does not automatically imply their endorsement by MIDRC.

Illustration of how large language models can be used to automate exam labeling

This diagram illustrates the process by which large language models (LLMs) can be used to to automate the labeling process at the exam, series and image level.  A helper AI algorithm can extract, correct and normalize the values in the DICOM header to a common vocabulary that is both machine and human consumable and returned in a JSON payload.  Simultaneously, the clinical report can be evaluated by another pre-trained LLM that is prompted to extract the relevant features and return them in a structured format (e.g. A table as shown) mapped to a standard format such as SNOMED or ICD-10.  Human experts can then do spot-checks or audits of the automated process. 

Annotations are often a required element in the performance of supervised learning and can serve as ground-truth for validation and testing.  Annotations may consist of labels created by a human expert, metadata extracted from a linked record (e.g EMR) or values derived from an algorithm, that is, from “Helper AI”. The term "Helper AI" is often used to reference methods in which AI tools are used to automate portions of the data curation process.  This includes algorithms that analyze the data in the DICOM header and even evaluate the pixel data to check and correct errors, and normalize the information to a common vocabulary.  Many of the text fields the DICOM header contains errors or use a non-standard vocabulary that varies by site and even by device within an organization.  Helper AI methods can be used to map exam and series descriptions to a catalog of standardized naming conventions such as the RadLex Playbook or the LOINC catalog.  Helper AI can also verify and correct other parameters such as image orientation, modality, pulse sequence descriptors, body part(s) included on the image, protocol and even the presence of contrast material.  Normalizing these values automatically and at scale makes it easier for a researcher to select cohorts of exams from multiple sources without pre-existing knowledge of the different naming conventions that were used. 

Annotations in MIDRC: 

  • Are applicable at various levels of granularity, from the entire imaging exam to individual pixels in an image.  

  • Can take various forms such as a free text, a measurement or a region (e.g. bounding box).  

  • Can provide a reference standard to supplement the images themselves and can be used to train an AI model and subsequently test performance of trained models.  

  • May be produced internal to MIDRC or submitted from external sources along with contributed imaging data or subsequently as part of an external project.

  • May originate from MIDRC research activities or the Grand Challenge Workgroup (GCWG).  

Since most of the MIDRC data is publicly available, in some instances annotations may be temporarily withheld (for the purpose of a Challenge).  All publicly available annotations will be linked to the public training imaging data made available in Gen3 whenever possible. 

Below is a list of public annotation sets that are available on the Gen3 data portal linked to the images and downloadable for your use.  Some of the annotations are viewable directly on the OHIF viewer but in some instances the format is not supported because they utilize a non-standard format.

MIDRC annotations.


Third party annotations.


How to find/view segmentation annotations.

Find and view DICOM annotations that are viewable in MIDRC's integrated OHIF viewer:

  1. Go to the data explorer at data.midrc.org/explorer

  2. Select the "Imaging Studies" main tab

  3. Select the "Annotations" filters tab

  4. Under the filter "Datafile Annotation Name" select an annotation type you’re interested in such as: midrc_bpr_landmarks, midrc_bpr_regions, midrc_lung_measures, midrc_lung_segs etc.

  5. Click the "Browse in DICOM Viewer" button in the explorer table to view a particular study.

  6. When the OHIF viewer tab opens, scroll down to the bottom of the list of imaging series, and double-click on one of the series labeled "SEG". 

  7. A message will ask "Do you want to open this Segmentation?", and click "Yes".


Questions? Check out our answers to frequently asked questions!

How to acknowledge 1) MIDRC funded research and 2) use of data downloaded from the MIDRC Data Commons