Because of its accessibility, the importance of its pathology, and the rapid availability of pathological confirmation, the breast has long served as a kind of test bed for innovations in ultrasonography. Many of these innovations have translated into mainstream applications, while others remain under development or are merely speculative.
AUTOMATED BREAST ULTRASOUND (ABUS)
Whole breast ultrasonography is an example of one technical innovation that is increasingly being adopted in the clinic, partly driven by the increasing use of ultrasound as a screening method for the early detection of breast cancer. In fact, whole breast ultrasound has a long history, dating back to the immersion technique of the Octason that was developed at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Sydney, Australia.1 In this method, an array of single-element transducers (actually 8, hence the name) was mounted in a large water bath. The patient lay prone with one breast immersed, and the transducers were swept through an angle to image the tissue. It incorporated several advances, such as compounding, and allowed pulsed (spectral) Doppler, but it was expensive (owing to the complexity of designing underwater electrical apparatus) and cumbersome. Modern systems use a linear array, and the patient is scanned supine with a membrane covering the breast. The transducer is driven by a motor that sweeps it across part of the breast. The assembly is repositioned to cover the whole breast, and the data is processed into a single set for subsequent display on a workstation. Since this is a 3D data set, the images can be reformatted into nonacquired planes such as the coronal plane. The main advantage of this type of system is that scanning does not require the same skill as conventional breast scanning, so it can be delegated to a less highly trained technician and read subsequently by a radiologist. This advantage makes the workflow similar to that of mammography or MR and is favored in some heath care systems.
It would appear that ABUS has overcome the problem of operator dependency and gives reproducible, standardized imaging.2 However, recent advances in this technology and image quality have increased interest in the role that ABUS may play in the management of breast lesions. One of the first commercially available systems was developed by Siemens Healthcare and termed the Automated Breast Volume Scanner (ABVS) (Figure 44-1).3
Automated Breast Volume Scanner (Siemens). The linear array is held in the articulated arm alongside the conventional scanner.
The feasibility and image quality of ABVS are reasonable and comparable to handheld ultrasound, so it has also been proposed as a suitable screening tool for breast cancer (Figure 44-2).4-6 A recent large-scale Japanese study that randomized a total of 72,998 women to either mammography only or ...