3D Digital Camera Accurately Calculates Breast Shape, Volume

NEW ORLEANS—A novel imaging system—consisting of a three-dimensional digital camera mounted on a tripod, an LCD display monitor, and a standard desktop computer (see Figure 1)—may be the harbinger of the future of breast surgery, according to investigators who presented their findings at the 68th Annual Scientific Meeting of the American Society of Plastic and Reconstructive Surgeons (now known as the American Society of Plastic Surgeons).

The 3D digital camera can be used to determine breast shape, dimensions, surface characteristics, and volume, and is not limited to measuring breast volumes less than 425 cc, as are direct measurement devices, said Gregory M. Galdino, MD, resident, Division of Plastic and Reconstructive Surgery, Johns Hopkins Hospital.

“We feel that 3D imaging and photography [Figure 2] will be useful in the postoperative evaluation of breast surgery, evaluation of breast asymmetry, and evaluation of implant volume distribution and implant design,” he said.

The researchers compared breast volumes in 10 patients as measured by the 3D digital camera, the Grossman-Roudner device, and anthropomorphic measurement. The results showed an average relative percentage of error, compared with the standard water displacement method, of 17.3% with the Grossman-Roudner device; 66.7% with the anthropomorphic measurement; 2.2% with a single-plane 3D technique; and 19.1% with the two-plane 3D digital technique.

Thus, Dr. Galdino said, the camera, using the single-plane technique, is able to match standard water displacement to less than 5% error. “One might think that the single-plane method is the best, since it has the lowest percentage of error. However, we feel that the two-plane technique more accurately represents the true volume of the breast,” Dr. Galdino said. “Single-plane techniques, such as water displacement, may exclude the medial or lateral aspect of the breast in large-breasted patients, while including a volume of the chest wall in small-breasted patients.”

The Rainbow 3D camera—developed by Genex Technologies, Inc. (Kensington, Maryland)—uses visible light to capture two-dimensional color and three-dimensional information simultaneously in real time at more than 30 frames per second. Three-dimensional images are transmitted directly from the camera into a desktop computer in under a minute. Genex Technologies also supplies the imaging software. Dr. Galdino emphasized that the light source is eye safe and that it is a photographic technique—not a scanning technique.

To verify the accuracy of the camera, the investigators photographed a 425-cc calibrated cone; the calculated volume of the cone from the photograph was 424 cc. In a further volume calculation, the investigators superimposed two 3D images of a 300-cc cone and a 425-cc cone (representing pre- and post-breast augmentation). The difference in volume as calculated by the 3D images was 128 cc, only 3 cc off the actual difference.

The camera is able to calculate a straight-line distance between two points and distance over a curve accurately to the millimeter. The camera also calculates angles when three points are selected on a 3D photograph.

Dr. Galdino said that upcoming modifications of the camera and software include integrating multiple views into one image, increasing the field of view, adding a high-resolution color overlay onto the megapixel order, and using a laptop to capture and render the images.

Future studies, he said, will include more definitive volume assessment, implant evaluation and distribution, preoperative reconstructive assessment for surgical planning, determination of asymmetry, pre- and postsurgery comparisons, and a 3D breast surgical prediction model, as well as use of the camera for facial analysis.