ABSTRACT
Advances in three-dimensional (3D) ultrasound imaging have progressed over the past two decades with the development of two-dimensional (2D) array-based systems by commercial companies, mechanical 3D ultrasound scanning devices for specific applications, and machine learning algorithms that are used to provide tools to enhance clinical applications. In this chapter, we review the development and testing of various mechanical methods used to generate 3D ultrasound images. We review two approaches for manipulating one-dimensional arrays to scan the anatomy and generate 3D ultrasound images: (1) motorized external fixtures that house conventional ultrasound transducers and ( 2) motorized scanning methods internal to the handheld fixture. The external fixture approaches have been used to generate a linear sweeping motion to image the carotid arteries, tilting motion for applications such as imaging of neonatal brains, rotational motion for intra-cavity applications such as prostate and gynecologic brachytherapy, and hybrid motion combining tilting and linear sweeping motions to generate large 3D ultrasound images for application such as focal liver tumor ablation. Some of these approaches have been developed by researchers and licensed to commercial companies who have integrated them into commercial products. The internal-fixture 3D scanners are available commercially and typically used for obstetrical and abdominal imaging.
