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DICOM to Flywheel Mapping


Minimum Required DICOM Tags for Functionality

43c1666d (Adding Spell Checker and Link Validator)


The Flywheel Hierarchy closely matches the DICOM Model of the Real World , but with slightly different nomenclature.

  • Patient becomes Subject in Flywheel
  • Study becomes Session in Flywheel
  • Series (roughly) becomes Acquisition in Flywheel


Series to Acquisition mapping is not strictly enforced. Generally raw data from a scanner will map 1:1 (meaning two Series that come in from a scanner will usually be in two different Acquisitions) , but sometimes a derived series with a different SeriesNumber and SeriesInstanceUID will be placed in the same acquisition by the running of a utility gear.

Due to this hierarchy, Flywheel makes a few assumptions about DICOM data contained within the Flywheel hierarchy.

  1. A Flywheel Project will contain unique DICOM series, i.e. there will be no two DICOM series within one Flywheel Project which contain the same value for the tag SeriesInstanceUID
  2. A Flywheel Project will contain entirely unique DICOM Studies (determined by the StudyInstanceUID DICOM tag), irrespective of the organization of the studies within "Subject" containers.; there will be no two Flywheel Sessions within a project which contain DICOM files that have the same value for StudyInstanceUID
  3. A Flywheel Subject will uniquely contain a DICOM Series; there will be no two Flywheel Subjects within a project which contain DICOM files that have the same value for StudyInstanceUID
  4. DICOM files sharing the same SeriesInstanceUID are expected to be zipped in a single zip archive and that zip archive must only contain DICOM files belonging to the same SeriesInstanceUID

Hidden Files

One must take care when uploading zip files that only the DICOM files are in there. On Macs there are often hidden files such as thumbs.db or .__MACOSX folders, which will need to be removed.

If any of these assumptions are violated, the viewer will not behave properly: Either certain files will not be viewable at all, or the dicom hierarchy or study list within the OHIF viewer will not be correct.

Minimum Required DICOM Tags for Functionality


This article lists the minimum DICOM tags Flywheel requires for certain features.

The OHIF Viewer

The OHIF viewer requires the following tags:

Tag VR Name
(0020,000E) UI SeriesInstanceUID
(0020,000D) UI StudyInstanceUID
(0008,0060) CS Modality
(0020,0011) IS SeriesNumber
(0040,0009) SH ScheduledProcedureStepID
(0040,1001) SH RequestedProcedureID
(0008,0020) DA StudyDate
(0008,0030) DM StudyTime
(0020,0010) SH StudyID
(0020,0011) IS SeriesNumber
(0010,0020) LO PatientID

DICOM Classifier Gear

Tag VR Name
(0008,0060) CS Modality
(0008,103E) LO SeriesDescription
(0020,000D) UI StudyInstanceUID
(0020,0010) SH StudyID
(7FE0,0010) OB or OW Pixel Data
(0008,0070) LO Manufacturer

DICOM Connector

The default DICOM tags that the Connector uses to upload data to Flywheel and update key field values are listed below.

It is possible to customize the Connector configuration to use alternative DICOM tags for some of the fields. Mapping the images to the Flywheel hierarchy in the database could be impacted if those values are not available.

Also, some Flywheel field values might not not be populated if DICOM tag values are not available. Learn more about how the DICOM connector uploads images.

Default mappings from DICOM tags to Flywheel fields

Flywheel Hierarchy Field Mappings to DICOM Tags

The following Flywheel fields will be populated by default from the following DICOM tags

Flywheel Field DICOM Tag Name DICOM Tag VR
Group ID Study Comments* (0032,4000)*
Project Label
Subject ID
Session UID Study Instance UID (0020,000D) UI
Session Label Study Description (0008,1030) LO
Acquisition UID Series Instance UID (0020,000E) UI
Acquisition Label Protocol Name (0018,1030) LO

Note It is possible to customize which DICOM field(s) Flywheel should configure to capture Routing String values (Group, Project, and Subject)*

Timestamp field mappings

If these values are not present in the DICOM tags, then the Flywheel timestamp will be blank

Flywheel Field DICOM Tag Name DICOM Tag VR
Timestamp Acquisition Date (0008,0022) DA
Acquisition DateTime (0008,002A) DT
Acquisition Time (0008,0032) TM
If one set of DICOM tag values is not present then we try to use the other
Timestamp Series Date (0008,0021) DA
Series Time (0008,0031) TM