2018 Fiscal Year Annual Research Report
Development of a hybrid tomosynthesis and acoustic imaging modality for early detection of breast cancer
| Project/Area Number |
17H05075
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| Research Institution | Hokkaido University |
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Principal Investigator |
彭 浩 北海道大学, 国際連携研究教育局, 招へい教員 (70790195)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Keywords | Breast cancer / Tomosynthesis / Acoustic imaging / X-ray |
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| Outline of Annual Research Achievements |
Simulation framework developed in first year for modeling X-ray-induced acoustics (XA) in breast imaging was further elaborated. Experiments considering conditions of use as a technique for parallel imaging with mammography/tomosynthesis were conducted. Workflow of Monte Carlo physics simulation of X-ray photon interaction to acoustics wave simulation to image reconstruction was used to model system sensitivity for purposes of diagnostic breast imaging. It becomes clear that the technique of augmenting mammography systems to collect XA images in parallel is feasible within dose levels absorbed by breast glandular tissue under normal screening mammography examinations as they are performed worldwide currently using commercially available multi-channel ultrasound transducer arrays, though several limitations have also been identified. The most concerning is that as acoustic signal is directly proportional to dose absorption and rate, any XA signal would be attenuated relative to decreases in dose rate. Ideally, a pulsed X-ray source (us) would be used, as opposed to the constant source now standard on all mammography systems (ms). This is further problematic in the case of tomosynthesis as the beam remains on for an even longer period of time (s). This effect of signal attenuation was reported in an analytical study at AAPM 2018. The feasibility study summarized here itself has been accepted as an ePoster presentation in the upcoming AAPM 2019. A manuscript detailing system sensitivity of the XA breast imaging designed is also being prepared.
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| Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
In testing phase of hardware, multi-channel signal processing boards purchased in previous fiscal year were identified as too slow in parallel sampling relative to speed of ultrasound waves expected in experiments. In order to collect data at 64X (number of channels in ultrasound transducer also purchased), a new search was conducted and replacement purchases made, which are being characterized currently.
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| Strategy for Future Research Activity |
The focus of this fiscal year's research is to be phantom imaging, as well the translation of the proposed technique to dose verification in proton therapy.
Phantom imaging: we will validate the quantitative results with phantom imaging. The performance will be fully characterized by preparing a set of tissue-mimicking phantoms. These phantoms will have x-ray interaction properties similar to human tissue and include targets containing calcium and iodine/gold of various concentrations and sizes.
Protoacoustic imaging: we will apply the same concept and same hardware/software platform to dose verification in proton therapy.
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Research Products
(2 results)
