Pockethealth Programming Challenge

This microservice is used for uploading DICOM Files. These files can then be parsed and processed to retrieve the image data and header attributes elements.

Execution

To run the service:

go run main.go

Service will be available on http://localhost:3333

API Endpoints

Upload DICOM File

POST /

Given a DICOM File, store the file in the microservice. This file must be a valid DICOM file. Assigns a file ID to the file and returns it after processing

Sample

Request

curl --request POST --header 'content-data' -F dicom=@test/IM000003 --url http://localhost:3333

Response

HTTP/1.1 200 OK

a2f72f93-fde0-46c6-be57-34ebe99b2a9e

Get DICOM File as PNG

GET /:id/image

Given a File ID, convert the file's pixel data into a PNG and return it. Currently only supports PNG conversion by default.

Sample

Request

curl --request GET --url http://localhost:3333/a2f72f93-fde0-46c6-be57-34ebe99b2a9e/image

Response

HTTP/1.1 200 OK

Get Header Attributes from DICOM File via DICOM Tag

GET /:id/headerAttribute?tag=(0000,0000)

Given a File ID and a Tag, retrieve the header attribute element from that file.

Tag must be formatted (XXXX,YYYY) where XXXX and YYYY are hexadecimal values. See DICOM Tags for more details.

Sample

Request

curl --request GET --url http://localhost:3333/44707cb0-4fe3-41f8-912e-1491d087738d/headerAttribute?tag=(7FE0,0010)

Response

HTTP/1.1 200 OK

{"TagName":"PixelData","Element":"FramesLength=1 FrameSize rows=1053 cols=967"}

Get DICOM File Metadata

GET /:id

Retrieves File Metadata such as the File Location and the User (Currently only User Id 1 is supported).

Debug function for easy data retrieval.

Sample

Request

curl --request GET --url http://localhost:3333/44707cb0-4fe3-41f8-912e-1491d087738d

Response

HTTP/1.1 200 OK

{"Id":"e2cb45d4-db19-458b-9b71-7a09ae4efd79","FileLocation":"persistence/dicom/e2cb45d4-db19-458b-9b71-7a09ae4efd79","UserId":1}

Components

internal/handlers

Contains business logic for handling the incoming requests. Files are divided per handler

internal/model

Contains models shared between handlers

internal/router

Contains the bootstrapping for handlers. Primarily used for passing the DB between handlers

persistence

Contains the Sqlite Metadata database and the filesystem for storing the DICOM files.

test

Contains test DICOM files for manual testing

Manual Test Plan

Upload Dicom File

• [ ] POST with valid DICOM file -> Dicom File uploaded and assigned file ID. Metadata stored in database. File ID returned
• [ ] POST with duplicate DICOM file -> No Duplicate protection. Dicom file uploaded and assigned file ID. Metadata stored in database. File ID returned
• [ ] POST with non DICOM file -> Bad Request. No file or metadata stored
• [ ] GET with valid DICOM file -> Method not Supported

Get Dicom File as PNG

• [ ] GET with valid file ID -> PNG of Dicom file returned
• [ ] GET with invalid file ID -> Not Found
• [ ] POST with valid file ID -> Method not Supported

Get Header Attributes

• [ ] GET with valid file ID and defined tag -> Tag Name and Element returned
• [ ] GET with valid file ID and invalid format tag -> Bad Request
• [ ] GET with valid file ID and non-existent tag -> Bad Request
• [ ] GET with valid file ID and defined tag, but tag does not existing in DICOM file -> Not Found
• [ ] GET with invalid file ID -> Not Found
• [ ] POST with valid file ID and defined tag -> Method not Supported

TODO

• Features
  • Support more image types, toggle-able via query params in the /image endpoint
  • Prevent users from uploading duplicate files by storing Md5 Hashes in Metadata
  • Caching DICOM Files/Caching Images
  • Bulk Upload
  • Bulk Tag Lookup E.g. Allow multiple tag query params
  • Async Pipeline (e.g. Kafka, RabbitMQ) to process header attributes and store in DB for quick lookup
  • Fallback on parsing Dicom file directly if the attribute is not yet stored
  • User Permissions E.g. Tie Uploads to users. Do not allow users to access DICOM files they do not own
  • Authorization on endpoints. E.g. Debug API should be internal users only
• Maintenance
  • Rename service to "Dicom Parser" or just "Dicom". Name is currently just for easy indicator of which coding challenge it is
  • Replace Sqlite Database
  • Proper Logging for errors
  • Better error messages for user on 4XXs
  • Testing
  • Integration Tests
  • E2E Tests