Low-Dose and Single-Shot X-Ray Phase-Contrast Imaging for Breast
Abstract
Effective screening mechanisms are vital for reducing breast-cancer mortalities, as early detection and the ability to diagnose aggressive cancers in a timely manner would allow for increased treatment options with better patient response. Currently, mammography (or its tomographic versions) is of limited value for many women, as it cannot easily discern between malignant and dense breast tissues at early stages. The root cause is that these tissues absorb x-rays at much the same rate, leading to poor lesion contrast. Newer approaches to x-ray imaging, referred to as phase-contrast methods, have the potential to address this issue of low contrast while offering dramatically higher fine structural visibility, leading to enhanced depiction of tissue boundaries. Phase-contrast imaging does not rely on x-ray absorption, but rather generates lesion contrast by measuring how different tissue types bend x-rays (just as a prism bends visible light). While these phase-sensitive tissue properties would add new information, tissue absorption imagery is also vital as it offers a complementary picture. Any phase-sensitive imaging method also naturally records effects of any x-ray absorption as well -- this cannot be completely avoided in thick tissue. Phase contrast imaging has been investigated for many years now, but with little success for clinical translation. A root cause is the experimental complexity, high radiation dose, and imaging time required to separate the absorption and phase effects from recorded intensity measurements. Dose and imaging time requirements to achieve this in existing phase contrast imaging methods is several-fold higher than clinically acceptable dose and imaging time for conventional mammography. This has stalled any practical utility of phase contrast imaging. However, successful methods to separate tissue absorption and phase imagery will yield complementary images that could help in early-stage detection and discrimination of breast cancer. The objective of this proposal is to develop a laboratory prototype unit based on an innovative approach that we have recently proposed to mitigate all existing hurdles in current phase contrast imaging methods. In order to achieve our goal, we propose to use a cutting-edge spectral x-ray detector that can separate x-ray energy information (like separating colors of light using a prism). This additional information can then be used to achieve a simple one-step and low-dose phase contrast imaging setup that can separate absorption and phase information without any additional measurement steps or movement of imaging components. Our method can be applicable to any x-ray imaging energy range or for thick tissue imaging, enabling a wider scope of utility. Imaging time and dose required will be similar to current mammography or its tomographic counterparts for tomographic imaging of phase contrast. Ability to get tissue properties that causes both x-ray absorption and phase with high fine structure details has the potential to significantly improve sensitivity and specificity in breast cancer detection. Additionally, having multiple images of breast showing varying tissue characteristics can allow potential discrimination based on their aggressiveness.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 31, 2017
- Source ID
- W81XWH1610247
Entities
People
- Mini Das
Organizations
- United States Army
- University of Houston