Automated Breast Ultrasound System: A Pivotal Component to Traditional Mammography

Mammography is an apt randomized controlled trial-proven method for lowering mortality due to breast cancer. The sensitivity of mammography counts on breast density. Finding breast cancer in an early phase provides several challenges. Given breast cancer is a heterogeneous disease, a single screening modality has limitations in imaging all the subtypes at an early stage.

Ultrasound is a diagnostic imaging tool which is more portable as compared to MRI and CT used in a range of areas of healthcare to check blood flow, guide procedures, evaluate pregnancies, assess abnormalities and examine internal organs.

Ultrasound has come up as the most essential adjunct to mammography for diagnosing breast disease. Automated breast ultrasound system is a computer-based system for recording and performing ultrasound of the entire breast using high-frequency sound waves to produce a 3-D volumetric image of the entire breast. The 3-D image aims at allowing radiologists to check the breast from multiple angles that may unveil tumors previously invisible or difficult to find in 2-D mammography.

With a conventional ultrasound, exams can take up to 30 minutes and is highly influenced by the skill of the operators owing to device handheld transducer. Automated breast ultrasound system solves both of these problems by automatically scanning the breast in as little as seven minutes.

With workstation, physicians are facilitated to review ultrasound images from different angles with reconstructions in the axial and coronal planes and three-dimensional.

Owing to the difficulty lingering around two dimensional (2D) image plan, automated three-dimensional (3D) ultrasound has gained prominence. The main goals of automating breast cancer are:

• Produce a high-quality examination, standardized examination which enhances the conspicuity of cancers;
• Decrease the radiologist’s time per case;
• Operator-independence;
• Better lesion size prediction.

Initially, automated breast ultrasound scanners were planned to fittingly examine the breast in its entirety. In a lay man’s language, automated breast ultrasound system (ABUS) scanners are either supine or prone types. The conventional generation prone-type scanners comprises of a large water-filled tank with the transducers mounted at the base. Of late automated breast ultrasound systems with higher frequency probe have emerged with image quality and detectability of breast lesions scanner considerably improved. Having said that, the coverage of the breast owing to the small field of view normally lead to incomplete coverage of lesions.

Presently, the various versions available across the automated breast ultrasound systems market hold the capability of automatically scan the entire breast in a standard manner with optimized settings (imaging presets) for volume acquisition based on the estimated size of the breast—A is smallest size; D+ is largest size—the system applies imaging in the parameters in the course of acquisition based on the estimated size of the breast and automatically send all the images to an ABVS workstation.

Most of the radiologists performing breast use handheld systems to image symptomatic lump and foretell the nature of indeterminate masses discovered through mammography. However, bilateral whole-breast screening using handheld ultrasound is time consuming and has a high number of false positives. Moreover, its practicability has come under the scanner which is attributed to operator dependence, lack of standardized techniques, non-reproducibility, and time taken by the radiologist to perform the exams.

ABUS System having an Edge over Hand Held Ultrasound System

Compared to handheld ultrasound system, automated breast ultrasound system is reproducible and consistent. Moreover, the former is operator dependent, alluding that the ability to detect and accurately document clinically significant findings with respect to HHUS hinges upon the expertise and experience of the person performing the scanning.

Secondly, while anyone can be trained to operate the automated breast ultrasound system equipment for scanning, handheld ultrasound system has to be conducted by a US physician or a technologist with the knowledge of US anatomy and physics.

Thirdly, the acquisition time of automated breast ultrasound system is more consistent, thereby allowing a streamlined workflow. The physician time required by ABUS comprises of the time needed for interpretation, while in the case of HHUS, physician time incorporates of the time needed for conducting the examination which required for interpreting the results.

ABUS system not only leads to higher number of correct diagnosis, but also lowers women’s anxiety pertaining to breast cancer and their own healthcare. Breast tissue density—ratio between glandular tissue or fibrous and fat in the breast—is defined by the appearance of breast tissue on a mammogram.

As dense tissue propels a patient’s cancer risk and makes cancer harder to detect, some states in the U.S. have laws or education programs with respect to breast density.

The palpability of increased sensitivity of ABUS when used concomitantly with mammography substantiated the fact that the technology can be an ideal screening tool for those women within the dense breast population. As many of radiologists are not as acquainted with ultrasound as with other imaging and that scans are volumetric 3-D images, need for standardized training for all radiologists become indispensable.