A new imaging modality, Photoacoustic (PA) Imaging, was added to the Digital Imaging and Communications in Medicine (DICOM) standard in version 2023c after Supplement 229 Photoacoustic Imaging was approved for final text.
Photoacoustic (PA) Imaging is an imaging modality that enables imaging optical absorption in biological tissues with acoustic resolution. Contrast is generated through absorption by chromophores that range from intrinsic absorbers such as hemoglobin and melanin to extrinsic agents such as indocyanine green (ICG) or diverse types of nano-particles. In principle, excitation at multiple wavelengths allows the modality to discriminate individual chromophores. Prospective applications in the space of clinical imaging range from classification of breast cancer lesions through screening of sentinel lymph nodes to assessment of inflammation. Photoacoustic Imaging is in widespread use in preclinical research labs and is currently being translated to clinical applications in first commercial implementations.
Photoacoustic images represent image output generated by the input of one or more optical excitation wavelengths. Many (but not all) Photoacoustic implementations integrate active pulse/echo ultrasound in a hybrid imaging system to capitalize on well-established contrast for anatomical information. Complementary images such as pulse/echo ultrasound are represented with their own native DICOM definitions.
The ACR Center for Research and Innovation (CRI) conducted two clinical research projects for Seno Medical, an emerging medical imaging company in the PA Imaging space, to provide evidence to the United States Food and Drug Administration (FDA) for the approval of the company’s Imagio® Breast Imaging System. Results from these studies were among the evidence that led to FDA Premarket Approval for use of the system in the United States in January 2021.
Following the clinical research projects, Brian Bialecki, Director of IT Standards and Interoperability at ACR, became the co-chair of the newly formed DICOM WG-34 Photoacoustic, which prepared the DICOM supplement for Photoacoustic (PA) Imaging to be added to the DICOM standard.
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