Breast ImagingE1187. Multifaceted Diagnostic Role of Tomosynthesis
Chen X, Lee S, Mahoney M. University of Cincinnati Medical Center, Cincinnati, OH
Address correspondence to X. Chen (email@example.com)
Background Information: Digital breast tomosynthesis (DBT) is a new technology that acquires a series of low-dose images of the compressed breast from different angles while the radiography tube moves along an overhead arc. The projection image dataset is then used to reconstruct 1-mm thin-section images in standard mammographic views. Displaying the breast tissue in 1-mm-thick slices results in decreased tissue overlap, improved lesion visibility, better delineation of lesion margins, and more accurate characterization of lesion architecture.
Educational Goals/Teaching Points: DBT increases the sensitivity and specificity of screening mammography, evidenced by increased cancer detection rates and reduced recall rates. Multiple studies have also described the benefits of DBT in the diagnostic setting. This exhibit illustrates the diagnostic efficacy of DBT in various case scenarios.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques: There are many advantages of DBT in the diagnostic setting. DBT offers improved sensitivity, specificity and diagnostic accuracy of noncalcified lesions over conventional supplemental mammographic views, across both fatty and dense breast tissue. There is subjective reader preference for DBT over conventional mammograms in lesion conspicuity and feature analysis due to improved diagnostic confidence and decreased number of BI-RADS 3 category designations as well as improved diagnostic workflow efficiency and decreased radiation exposure by elimination or decrease in additional imaging. There is potential to replace conventional supplemental mammography at diagnostic workup and obviate diagnostic ultrasound in selective cases. The diagnostic efficacy of DBT is evidenced in various case scenarios by its recognition of summation artifact leading to dismissal of false lesions, confirmation of true asymmetry or focal asymmetry, with potential upgrade to mass, and detection of architectural distortion when occult on conventional mammography. DBT has better characterization of masses (shape, margins and density) and can triangulate and localize one-view-only lesions to facilitate targeted ultrasound evaluation. DBT also performs localization of lesions in skin or microcalcifications in blood vessels to confirm benignity and can streamline evaluation of multiple lesions with whole breast tomosynthesis. Detection of encapsulated fat in lymph node or hamartoma, thus obviating the need for ultrasound or biopsy, and detection of lesions occult on conventional mammogram in symptomatic patients and identification of important incidental findings is all possible with DBT. Additional advantages of DBT include breast cancer staging (determining tumor size and detecting multifocal, multicentric, or contralateral disease) and guidance for biopsy or needle localized excision of lesions only visible on tomosynthesis.
Conclusion: Radiologists should be familiar with the advantages of DBT over conventional supplemental mammography in the diagnostic workup of breast lesions, as it leads to improved diagnostic accuracy, better workflow efficiency, and decreased patient anxiety, cost, and radiation exposure.