1 Definition 2 Functional Requirements 3 Syntax 4 Semantics

1 Definition

Medical Imaging Qualifier is a set of data providing additional information on medical imaging data for potential use by a machine.

Medical imaging data represent spatial or spatio‑temporal measurements of anatomical, functional, or molecular properties of biological tissues obtained using imaging modalities such as X‑ray, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Ultrasound, Nuclear Medicine, and Optical Imaging.

The Medical Imaging Qualifier specifies the sub‑types, formats, and attributes of medical imaging data and enables a machine to correctly interpret, process, exchange, or analyze such data independently of the container in which the data are conveyed.

The combination of Medical Imaging Data and Medical Imaging Qualifier is called Medical Imaging Object, specified by AIH-HSP V1.0.

2 Functional Requirements

Medical Imaging Qualifier shall allow the expression of the following elements:

  • Imaging Sub‑Type, identifying the imaging modality and the specific imaging technique used (e.g., Structural MRI, CT Angiography, Doppler Ultrasound).
  • Imaging Format, identifying the data encoding or exchange format used to represent the imaging data (e.g., DICOM Image, NIfTI, JPEG2000) and Sub‑Type / Format Mapping, defining which formats are applicable to which imaging sub‑types.
  • Imaging Attributes, providing additional metadata required for correct interpretation of the imaging data.

Users needing support for additional imaging sub‑types, formats, or attributes shall submit a documented request to the MPAI Secretariat. An appropriate committee will consider the inclusion of such additions.

Users needing additional entries in the Physiological Signal Qualifier or support of new Qualifiers should make a documented request to the MPAI Secretariat. Requests will be considered by the appropriate MPAI committee.

3 Syntax

https://schemas.mpai.community/TFA/V1.5/data/MedicalImagingQualifier.json

4 Semantics

4.1 Imaging Sub‑Types

Imaging Sub‑Types identify the modality and technique used to acquire the imaging data. Examples include, but are not limited to:

  • X‑Ray
    • Projection Radiography
    • Mammography
    • Fluoroscopy
  • Computed Tomography
    • Conventional CT
    • CT Angiography
    • Cone Beam CT
  • Magnetic Resonance Imaging
    • Structural MRI
    • Functional MRI (fMRI)
    • Diffusion MRI (DWI/DTI)
  • Ultrasound
    • B‑Mode Ultrasound
    • Doppler Ultrasound
    • Elastography
  • Nuclear Medicine
    • Positron Emission Tomography (PET)
    • Single‑Photon Emission Computed Tomography (SPECT)
  • Optical Imaging
    • Endoscopy
    • Optical Coherence Tomography (OCT)

4.2 Imaging Formats

Imaging Formats identify the representation or exchange format of the imaging data. Examples include:

  • DICOM Formats
    • DICOM Image
    • DICOM Enhanced Multi‑Frame
    • DICOM Structured Report (SR)
    • DICOM Segmentation
  • Research Imaging Formats
    • NIfTI
    • MINC
    • NRRD
  • Image Exchange Formats
    • TIFF
    • JPEG
    • JPEG2000
    • PNG

4.3 Sub‑Type / Format Mapping

The Medical Imaging Qualifier defines mappings between imaging sub‑types and supported format groups, enabling a machine to determine which formats are valid for a given imaging sub‑type.

For example:

  • Structural MRI may be associated with DICOM Formats and Research Imaging Formats.
  • Optical Coherence Tomography may be associated with Image Exchange Formats.

4.4 Imaging Attributes

Imaging Attributes provide additional contextual information required to correctly interpret the imaging data. Examples include:

  • AnatomicalRegion – anatomical region imaged.
  • Modality – imaging modality used.
  • Laterality – left, right, or bilateral.
  • ContrastAgent – contrast agent used, if any.
  • AcquisitionProtocol – protocol or sequence name.
  • SliceThickness – thickness of image slices.
  • VoxelSpacing – spatial resolution of volumetric data.
  • Orientation – image orientation reference.
  • FrameOfReference – spatial reference frame identifier.
  • ReconstructionMethod – image reconstruction technique.

5 References

 

  • ISO 12052, Digital Imaging and Communications in Medicine (DICOM)

 

 

  • ISO/IEC 19775‑1, Extensible 3D (X3D)

 

 

  • NIfTI‑1 Data Format Specification