Digital Breast Tomosynthesis and Digital Contrast Enhanced Mammography

Abstract

Breast cancer is one of the most common malignancies in the female population. Breast cancer survival is strongly associated with tumor size at detection & the impact of invasive breast cancer increases with the size and extent of invasion at first diagnosis. The general quality of mammography is often questioned. It misses many tumors in dense glandular tissue. Contrast enhanced digital mammography and Digital Breast Tomosynthesis are two techniques that attempt to increase breast lesion conspicuity. Both techniques have been studied independently and in combination. Contrast-enhanced mammography enables visualization of tumors without inference from superimposed structures. It involves injecting the contrast agent intravenously while the patient is imaged with a sequence of digital mammograms that show the flow of the contrast agent over time. It is based on the principle that rapidly growing tumors require increased supply of blood to support their growth. The contrast agent preferentially accumulates in such areas and contrast enhanced mammography offers a method of imaging the distribution of agent in the breast tissue. But it is still a 2D technique. Summary & Conclusion 98 Digital breast tomosynthesis is expected to overcome this limitation by providing slice images of the breast. It has the potential to improve sensitivity in the detection of breast cancer due to reduced overlap of breast tissue, particularly in dense breasts. This may result in earlier breast cancer detection. Digital breast tomosynthesis may also lead to significant improvements in specificity: with the 3D data available, a 3D analysis of the distribution of microcalcifications, or a 3D analysis concerning shape, margins and size of lesions, might be easier. As a result, this could lead to a reduction of the recall rate of patients and fewer biopsies. Finally, digital breast tomosynthesis may eliminate the need for multiple exposures of the same breast. The goal is to combine the advantages of DBT and contrast enhanced mammography. DBT is a “3D mammography” technique while a contrast agent provides physiological information of the findings. Compared with 2D contrast-enhanced digital mammography, the superimposed enhanced breast tissue can be separated by DBT, so the morphology (shape) information of the enhanced lesion can be better characterized. The tumor can also be segmented from the surrounding tissue in order to measure the dynamic curve of the contrast as done in MR.