Breast tomosynthesis in practice

One of the factors limiting the sensitivity of conventional mammography (analogue and digital) is the obscuring effect of dense breast tissue overlying and underlying a tumor. This problem should be reduced by a tomographic technique. Tomosynthesis implies acquiring multiple projection images over a certain angular range with mathematical reconstruction of slices parallel to the detector plane. This technique is made possible by the recent development of digital detectors with high efficiency, which are capable of acquiring low-dose images with fast read-out and minimal image lag.

Within our group, optimization studies of tomosynthesis have been performed regarding factors such as angular range, number of projection images, data collection mode, and so on.

Tomosynthesis has also been under clinical evaluation in our institution for about 2 years. We have analyzed a series of breast cancer patients selected on the basis of difficult two-dimensional mammograms, and graded the visibility of the malignancies on two-dimensional as well as on three-dimensional mammograms. Furthermore, we have classified the mammograms according to the BIRADS Breast Imaging Reporting and Data System.

The results have shown a significantly better visibility and more accurate BIRADS classification with tomosynthesis. Accordingly, the results suggest that tomosynthesis is a more sensitive technique for the detection of breast cancer than conventional digital mammography. Further studies of the sensitivity and specificity are underway.

We believe that tomosynthesis will play an important role in the detection and diagnosis of breast cancer in the future.