1.1 Introduction

3D imaging is a powerful emerging technology in the field of body contouring. Body contouring inherently deals with three-dimensional changes and relationships, and yet preoperative planning and postoperative assessment has historically relied on two-dimensional representations. With the advent of 3D imaging, volumetric analysis can be performed and visualized with an accuracy that 2D photographs are incapable of meeting. This enables surgeons to give patients a better understanding of their likely surgical outcomes and to ensure mutual understanding about surgical goals. It also provides a quantitative means of assessing outcomes and volume-based changes over time in order to further refine technique and optimize surgical outcomes. Newly-developing 3D imaging technologies are advancing the understanding of microvasculature ¹ and allowing surgeons and patients to experiment with various aesthetic outcomes using virtual simulations in real time. ² 3D imaging revolutionizes the way surgeons are able to visualize patient data and holds great potential for both clinical and research applications.

1.2 History of 3D Imaging in Plastic Surgery

The history of 3D imaging begins with stereophotogrammetry, the practice of estimating three-dimensional coordinates on an object’s surface by using photographs of the object taken from different positions. The technique affords a more nuanced understanding of three-dimensional and volumetric relationships than traditional two-dimensional photography. Mannsbach originally suggested applying stereophotogrammetry to the fields of medicine and dentistry in 1922, and in 1939 Zeller first published a contour map of a man’s face using a stereocamera. ³ It was not until 1944, however, that stereophotogrammetry was applied in a clinical setting, with Thalmann using the technique to diagnose orthodontic pathology. ³

Since then many variations upon the technique have developed, most notably computer-assisted systems that greatly improve the speed and depth of analysis. Such advances include optical flow tracking, which incorporates time into three-dimensional analyses to give the user the ability to track soft tissue changes immediately during motion or longitudinally after surgery. One such iteration is 3D speckle tracking, in which white makeup is first applied to the patient’s face or other surfaces of interest. Black makeup is then dotted over the white, creating a speckled appearance that a computer can detect. In a craniofacial case, the patient then makes a series of facial expressions that displace the speckles while the computer tracks and analyzes these changes, producing a report on the patient’s facial expressivity. Newer technologies, such as the Di4D optical flow tracking software (Glasgow, Scotland), are able to track facial motion by digitally creating a mesh over a patient’s face and tracing changes to it over time, thereby obviating the need for makeup application. One of the newest developments in the field of three-dimensional medical imaging is ultrahigh sensitive optical microangiography (UHS-OMAG), with which Doppler monitoring of blood cell movement is able to produce 3D maps of capillary microvasculature in the skin after five seconds of scanning. ¹

What follows will be a review of current clinical applications of three-dimensional imaging technologies like optical flow tracking and UHS-OMAG to the practice of body contouring. Applications to breast and facial surgery will be emphasized as the majority of existent research on 3D imaging technologies comes from these subspecialties. However, many of the principles discussed apply equally to most body contouring procedures.