What Is a Cone Beam CT Scan?

Computerized Tomography (CT) scans, which typically use rotating x-ray machines and digital computers, have been used in medicine for some time. Bones, muscle, blood vessels, and organs can usually be seen on the resulting images. A cone beam CT scan generally provides a high-resolution, three-dimensional view of the anatomy, while using a fraction of the radiation dose that other x-ray imaging systems do. The machine uses a cone-shaped beam, instead of one that fans out, to view anatomy and diagnose injury to organs, cancer, or dental problems.

Introduced in Europe in 1998 and in the United States in 2001, the cone beam CT scan involves a rotating machine that can take up to 600 pictures at a time. The patient usually sits in a chair during the scan, which sometimes takes up to 40 seconds. Settings can vary and sometimes affect the actual time it takes for a full image to be produced. The beam can be shaped into a circular or rectangular shape, or be adjusted to match a particular area in the body.

Computer software reconstructs the data, which are based on three-dimensional units called voxels. Grayscale images are typically produced, and the software programs often also help to adjust the images to match the display capacity of computer monitors. Physicians can choose to view just bone structures, or adjust the setting to see soft tissues, for example. Each image can also be manipulated and viewed from any angle by using the controls on the software.

The benefits of a cone beam CT scan include the fact that the images are generally high-resolution while not being distorted, as in other types of scans such as panoramic images. Fine details can help doctor’s identify abnormalities and their relation to other structures in the body. Musculoskeletal disorders can be visualized, as well as diseases associated with the circulatory system.

Dentists often perform a cone beam CT scan when a patient requires an implant or other oral surgery. They can also see the jaw in detail and assess any disorders that may need to be treated. Impacted teeth, gum problems, and airway obstruction, in the case of sleep apnea, may be analyzed as well. Not only does the scan usually allow for a more accurate diagnosis, but it can also help doctors plan treatments more efficiently. For surgery, a cone beam CT scan typically provides the accuracy needed to help guide surgical instruments to the right locations.