Photoacoustic breast imaging
In view of the impact of breast cancer on society and the shortcoming in the current imaging modalities, there is a continuous search for improved methods for non-invasively imaging the breast and its abnormalities. Several methods and approaches are being intensively investigated for improving sensitivity and/or specificity, as also for improving cost-effectiveness, accessibility, patient burden, personalized care and safety.
One of the integral hallmarks of cancer has been proposed to be angiogenesis, the production of new blood vessels, induced early to support malignant phases in the development of invasive cancers. This process causes locally increased microvascular density with abnormal vessels which are dilated and tortuous. The presence in this enhanced vascularization of hemoglobin (Hb) and its oxygenated variant (HbO2), both with strong and specific optical absorption spectra, is expected to provide cancer with an optical absorption contrast with respect to healthy tissue.
Photoacoustic imaging imaging is attractive for conducting studies in various aspects of breast health due to its ability to visualize angiogenesis-driven optical absorption changes in breast tumors, with submillimeter resolution as deep as 40 mm in breast tissue. In the group we have pioneered work in what we call PAMmography (Photoacoustic Mammography) in collaboration with radiologists at the Medisch Spectrum Twente (MST) in Enschede and Oldenzaal, and at the Ziekenhuisgroep Twente (ZGT) in Hengelo and Almelo.
While handheld implementations have been developed, at the M3I group we are predominantly interested in developing three-dimensional PA computed tomography (CT) embodiments where the breast is pendant in an imaging bowl with a hemispherical (physical or synthesized) array of ultrasound detectors and appropriate light delivery mechanisms. By computed tomography (CT) we mean that images are formed by reconstruction from multiple projections (acquisitions) around the breast.
The following link to several projects in this area:
1. The second generation Photoacoustic Mammoscope (PAM2)
2. The PAMMOTH project (third generation Photoacoustic Mammoscope PAM3)
3. Improving the third generation Photoacoustic Mammoscope (PAM3+)