ABSTRACT
Nowadays three-dimensional (3D) ultrasound (US) is increasingly being utilized in clinical interventions for pre-procedural planning and diagnoses, intra-procedural surgical guidance, and post-procedural quality assessment. 3D freehand US refers to the technique that acquires 3D US volume, without restriction on the probe movement, from a series of tracked 2D US images. The advantages of freehand US include the ability to acquire volumetric data with a large spatial extent, thus providing a complete view of the anatomy and improved image fidelity due to the ability to acquire images of the same anatomy from multiple vantage points. This chapter describes the technical detail and some of the clinical applications of freehand 3D US and discusses its strengths, weaknesses, and future direction.
