This is an excerpt. Read the full article here: https://www.radiologybusiness.com/topics/imaging-informatics/ct-phone-home-rbj-receives-word-ct-front-lines-you-might-not-have-heard
Walk into any dentist’s office today and there’s a good chance you’ll see a cone-beam CT (CBCT) scanner. This technology also has made headway in orthopedic imaging (mostly for the knee, unweighted and weighted sequentially) and angiographic suites, as well as for head and neck scanning and radiation therapy. When it comes to breast imaging, however, the FDA has approved only one CBCT breast scanner, and a small number of systems are installed in the U.S. Most hospitals and radiology practices continue to rely on MRI, ultrasound, tomosynthesis and traditional mammography for breast screening. That’s why the message that John Boone, PhD, professor of radiology and biomedical engineering at UC Davis Health in Sacramento, California, has for the field is disruptive to say the least.
John Boone, PhD, UC-Davis Health
“Cone-beam breast CT is coming to a breast imaging clinic near you soon and will replace mammography five years down the road,” says Boone, who is also chief of medical physics at UC Davis. His lab has spent the past 20 years developing CBCT for breast imaging, and he is founder and shareholder of a company formed to commercialize a breast CT system based on his research. Making clear that commercialization was not his endgame, Boone maintains that “the images are outstanding, the research is compelling, and I firmly believe breast CT imaging should be available to all women today.”
The differences between CBCT and standard CT are vast, and Boone will flesh some of them out at RSNA 2019.
“The benefit of cone-beam CT over traditional mammography and even tomosynthesis is that it is a truly 3D modality that allows you to generate axial, sagittal and coronal images of the breast at high resolution,” he tells RBJ, “and see through the density of the breast by doing thin-section imaging in all planes.”
The CBCT machine—essentially a flat-panel x-ray detector that uses a cone-beam radiating from an x-ray source in the shape of a rectangular cone—allows full-field, 360-degree views of the breast with one rotation of the CBCT hardware around the breast. The acquired image data are reconstructed using algorithms to produce high-resolution 3D pictures for the detection of masses and calcifications by the radiologist. By comparison, a conventional CT device, which produces a narrower swath of images per scan (around 40 mm), would require multiple rotations to cover the necessary field of view for breast imaging. Importantly, conventional transaxial CT also would unnecessarily irradiate the lungs and heart.
As Boone has found, the bottom line could well be that CBCT affords better detection and diagnosis of breast cancer, particularly early-stage. “The three-dimensional attribute of CBCT is very powerful,” he says, allowing that, while MRI also offers that capability, it’s considerably costlier than a breast CT. Make that by a factor of around five if you weigh the purchase price of the two imaging machines, he elaborates. Operational costs of MRI also are much higher and scan times longer, he points out. Claustrophobia and metal implants are additional concerns with breast MRI.
Another advantage of breast CT is the fact it’s simply more comfortable for the patient. The woman lies on the scan table and no physical compression of the breast is required. This benefit was highlighted by Boone’s team back in 2008 and underscored by a study recently published in the European Journal of Radiology showing breast CT to be more tolerable than mammography. In the study, “Comparison of Comfort Between Cone Beam Breast Computed Tomography and Digital Mammography” (Zhaoxiang Ye et al., EJR, Nov. 2019), researchers found CBCT of the breast was favored by women with dense breasts, breast tissue density being a primary predictor of discomfort during mammography.”