Official Round: Completed

ImageCLEF 2021 Caption - Concept Detection


Note: ImageCLEF Caption 2021 is divided into 2 subtasks (challenges). This is the Concept Detection challenge. For information on the Caption Prediction challenge click here. Both challenges dataset are shared together, so registering for one of these challenges will automatically give you access to the other one.

Note: ImageCLEF 2021 Caption is part of the official ImageCLEF 2021 medical task. Here is a list of other ImageCLEF 2021 medical task challenges:

Note: Do not forget to read the Rules section on this page. Pressing the red Participate button leads you to a page where you have to agree with those rules. You will not be able to submit any results before agreeing with the rules.

Note: Before trying to submit results, read the Submission Instructions section on this page.

Challenge description

Interpreting and summarizing the insights gained from medical images such as radiology output is a time-consuming task that involves highly trained experts and often represents a bottleneck in clinical diagnosis pipelines.

Consequently, there is a considerable need for automatic methods that can approximate this mapping from visual information to condensed textual descriptions. The more image characteristic is known, the more structured are the radiology scans and hence, the more efficient are the radiologists regarding interpretation. We work on the basis of a large-scale collection of figures from open access biomedical journal articles (PubMed Central). All images in the training data are accompanied by UMLS concepts extracted from the original image caption. 

Lessons learned:

In the first and second editions of this task, held at ImageCLEF 2017 and ImageCLEF 2018, participants noted a broad variety of content and situation among training images. In 2019, the training data was reduced solely to radiology images

In ImageCLEF 2020 the focus remained on radiology images, with additional imaging modality information, for pre-processing purposes and multi-modal approaches

The focus in ImageCLEF 2021 lies in using real radiology images annotated by medical doctors. This step aims at increasing the medical context relevance of the UMLS concepts.

To reduce the scope and size of concepts, several concept extraction tools are analyzed prior to caption pre-processing methods.

Concepts with less occurrence will be removed.

As uncertainty regarding additional sources was noted, we will clearly separate systems using exclusively the official training data from those that incorporate additional sources of evidence.

Concept Detection Task

On the basis of the concept vocabulary detected in the first subtask as well as the visual information of their interaction in the image, participating systems are tasked with composing coherent captions for the entirety of an image. In this step, rather than the mere coverage of visual concepts, detecting the interplay of visible elements is crucial for strong performance. Evaluation of this second step is based on metrics such as BLEU that have been designed to be robust to variability in style and wording.


As soon as the data is released it will be available under the "Resources" tab.

  • Development data will be released on 26.02.2021
  • Test data will be released on 29.04.2021

Submission instructions

As soon as the submission is open, you will find a โ€œCreate Submissionโ€ button on this page. 


1. Click on the red 'create submission' button at the top right next to the horizontal menu tabs. If the button is not there please make sure that your EUA was accepted and that you also hit the participate button before.
2. Fill in the required information and select a file to submit. Then hit submit.
3. You will now land on the submissions page and should be able to see the submission status. It will show your score or an error message (if there was a framework error or validation error). The status does not automatically get refreshed, so you have to reload the page to see updates to the status.

Submission format

  • <Figure-ID>|<Concept-ID-1>;<Concept-ID-2>;<Concept-ID-n>
  • The separator between the figure ID and the concepts has to be a pipe character ( | )
  • The separator between the UMLS concepts has to be a semicolon (;)
  • Each figure ID of the test set must be included in the submitted file exactly once (even if there are not concepts)
  • The same concept cannot be specified more than once for a given figure ID
  • The maximum number of concepts per image is 100

Please note that each group is allowed a maximum of 10 runs per subtask.


Note: In order to participate in this challenge you have to sign an End User Agreement (EUA). You will find more information on the 'Resources' tab.

ImageCLEF lab is part of the Conference and Labs of the Evaluation Forum: CLEF 2021. CLEF 2021 consists of independent peer-reviewed workshops on a broad range of challenges in the fields of multilingual and multimodal information access evaluation, and a set of benchmarking activities carried in various labs designed to test different aspects of mono and cross-language Information retrieval systems. More details about the conference can be found here.

Submitting a working note with the full description of the methods used in each run is mandatory. Any run that could not be reproduced thanks to its description in the working notes might be removed from the official publication of the results. Working notes are published within CEUR-WS proceedings, resulting in an assignment of an individual DOI (URN) and an indexing by many bibliography systems including DBLP. According to the CEUR-WS policies, a light review of the working notes will be conducted by ImageCLEF organizing committee to ensure quality. As an illustration, ImageCLEF 2020 working notes (task overviews and participant working notes) can be found within CLEF 2020 CEUR-WS proceedings.


Participants of this challenge will automatically be registered at CLEF 2021. In order to be compliant with the CLEF registration requirements, please edit your profile by providing the following additional information:

  • First name

  • Last name

  • Affiliation

  • Address

  • City

  • Country

  • Regarding the username, please choose a name that represents your team.

This information will not be publicly visible and will be exclusively used to contact you and to send the registration data to CLEF, which is the main organizer of all CLEF labs

Participating as an individual (non-affiliated) researcher

We welcome individual researchers, i.e. not affiliated with any institution, to participate. We kindly ask you to provide us with a motivation letter containing the following information:

  • the presentation of your most relevant research activities related to the task/tasks

  • your motivation for participating in the task/tasks and how you want to exploit the results

  • a list of the most relevant 5 publications (if applicable)

  • the link to your personal webpage

The motivation letter should be directly concatenated to the End User Agreement document or sent as a PDF file to bionescu at imag dot pub dot ro. The request will be analyzed by the ImageCLEF organizing committee. We reserve the right to refuse any applicants whose experience in the field is too narrow, and would therefore most likely prevent them from being able to finish the task/tasks.


Information will be posted after the challenge ends.



ImageCLEF 2021 is an evaluation campaign that is being organized as part of the CLEF initiative labs. The campaign offers several research tasks that welcome participation from teams around the world. The results of the campaign appear in the working notes proceedings, published by CEUR Workshop Proceedings (CEUR-WS.org). Selected contributions among the participants, will be invited for publication in the following year in the Springer Lecture Notes in Computer Science (LNCS) together with the annual lab overviews.


Contact us

Discussion Forum

Alternative channels

We strongly encourage you to use the public channels mentioned above for communications between the participants and the organizers. In extreme cases, if there are any queries or comments that you would like to make using a private communication channel, then you can send us an email at :

  • contact address go here

More information

You can find additional information on the challenge here: https://www.imageclef.org/2021/medical/caption