| 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
The Medical Imaging Qualifier shall allow the expression of the following elements:
2.1 Imaging Sub‑Type
The Qualifier shall identify both:
– Imaging modality (e.g., CT, MRI, Ultrasound)
– Specific acquisition technique (fine-grained sub-type)
The extended specification shall support additional sub‑types including:
– Digital Breast Tomosynthesis
– Fluoroscopy subclasses (Diagnostic, Interventional)
– Dual Energy CT
– Photon-Counting CT
– Scintigraphy
– Hybrid PET/CT and PET/MR explicitly distinguished
2.2 Imaging Format
The Qualifier shall identify the encoding or exchange format used, including:
– DICOM-based formats
– Research formats (e.g., NIfTI)
– Image exchange formats (e.g., JPEG2000)
2.3 Sub‑Type / Format Mapping
The Qualifier shall define explicit mappings between sub‑types and valid format groups, enabling:
– Validation of data compatibility
– Automated processing decisions
– Interoperable data exchange
The mapping shall incorporate newly introduced sub‑types (e.g., PET/MR → DICOM Formats).
2.4 Imaging Attributes
The Qualifier shall include contextual metadata required for interpretation, including:
Core attributes:
– AnatomicalRegion
– Modality
– Laterality
– ContrastAgent
– AcquisitionProtocol
– SliceThickness
– VoxelSpacing
– Orientation
– FrameOfReference
– ReconstructionMethod
Extended attributes:
– ClinicalPurpose
(e.g., Screening, Diagnostic, Interventional, Follow-up)
– AcquisitionContext
(e.g., Portable, Intraoperative, Emergency)
These additions enable workflow-aware and clinically meaningful interpretation.
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 both modality and detailed acquisition technique.
The extended schema includes:
X‑Ray:
– Projection Radiography
– Mammography
– Digital Breast Tomosynthesis
– Fluoroscopy – Diagnostic
– Fluoroscopy – Interventional
– Dental X-Ray
Computed Tomography:
– Conventional CT
– Low-Dose CT
– CT Angiography
– Dual Energy CT
– Photon-Counting CT
– Cone Beam CT
Magnetic Resonance Imaging:
– Structural MRI
– Functional MRI (fMRI)
– Diffusion MRI (DWI/DTI)
– Magnetic Resonance Angiography (MRA)
– Magnetic Resonance Spectroscopy (MRS)
Ultrasound:
– B-Mode Ultrasound
– Doppler Ultrasound
– Color Doppler
– Elastography
– 3D/4D Ultrasound
Nuclear Medicine:
– Scintigraphy
– Single-Photon Emission Computed Tomography (SPECT)
– Positron Emission Tomography (PET)
– PET/CT
– PET/MR
Optical Imaging:
– Endoscopy
– Fundus Photography
– Optical Coherence Tomography (OCT)
– Microscopy
These refinements improve:
– Clinical specificity
– Interoperability
– AI interpretability
4.2 Imaging Formats
Imaging Formats identify representation and exchange encoding.
DICOM Formats:
– DICOM Image
– DICOM Enhanced Multi‑Frame
– DICOM Structured Report (SR)
– DICOM Segmentation
– DICOM Radiotherapy Objects
Research Imaging Formats:
– NIfTI
– Analyze 7.5
– MINC
– NRRD
– HDF5 Imaging Containers
Image Exchange Formats:
– TIFF
– JPEG
– JPEG2000
– PNG
4.3 Sub‑Type / Format Mapping
Mappings define allowable format groups for each sub‑type.
Examples:
– Digital Breast Tomosynthesis → DICOM Formats
– Dual Energy CT → DICOM Formats
– Photon-Counting CT → DICOM Formats
– Functional MRI → Research Imaging Formats
– Diffusion MRI → Research Imaging Formats
– PET/CT → DICOM Formats
– PET/MR → DICOM Formats
– Optical Coherence Tomography (OCT) → Image Exchange Formats
These mappings enable:
– Automated validation
– Processing pipeline selection
– Data interoperability across systems
4.4 Imaging Attributes
Imaging Attributes provide contextual metadata for interpretation.
Core attributes:
– AnatomicalRegion: body region imaged
– Modality: modality identifier
– Laterality: left, right, bilateral
– ContrastAgent: administered agent
– AcquisitionProtocol: sequence or protocol name
– SliceThickness: slice thickness (mm)
– VoxelSpacing: spatial resolution (2D/3D)
– Orientation: spatial orientation
– FrameOfReference: coordinate reference system
– ReconstructionMethod: image reconstruction algorithm
Extended attributes:
ClinicalPurpose:
Specifies the intended clinical use of the imaging:
– Screening
– Diagnostic
– Interventional
– Follow-up
AcquisitionContext:
Describes the operational environment of acquisition:
– Portable
– Intraoperative
– Emergency
