What is CBCT?
CBCT stands for Cone Beam Computed Tomography. It is a technology used to take three dimensional (3-D) images of your teeth, maxillary sinus, nerve pathways, and bone in the maxillofacial region with a single scan. The CBCT system rotates around the patient in approximately 30 seconds, capturing data using a cone-shaped x-ray beam.
Dental cone beam computed tomography is used when regular two dimensional dental x-rays are not sufficient. With CBCT, clinicians can get highly detailed 3-D views of the facial region with lower radiation exposure than a conventional CT scan. This may help with the diagnosis, treatment planning and evaluation of certain conditions.
How does it Work?
During a cone beam CT examination, the C-arm or gantry rotates around the head in a complete 360-degree rotation while capturing multiple images from different angles that are reconstructed to create a single 3-D image.
The x-ray source and detector are mounted on opposite sides of the revolving C-arm or gantry and rotate in unison. In a single rotation, the detector can generate anywhere between 150 to 200 high resolution two-dimensional (2-D) images, which are then digitally combined to form a 3-D image that can provide your dentist or oral surgeon with valuable information about your oral and craniofacial health.
Difference between CBCT and CT
A CBCT scanner uses a cone beam radiating from an X-ray source in the shape of a cone covering large volume with one single rotation about the patient. The X-ray images are reconstructed by use of algorithms to come up with 3D high resolution images. An example of a CBCT scanner is i-CAT.
On the other hand, a conventional CT scanner uses a fan beam in which transmitted radiation is in the form of a helix/spiral. The images are interpolated into image detectors arranged around the patient in an arc where only single slice images per scan can be produced. In a single breath hold, considerable regions of the body can be imaged. It is also possible to obtain 3D images from conventional CT scans.
What are the advantages of CBCT over CT?
- X-ray beam Limitation
- Image accuracy
- Rapid scan time
- Does reduction
- Reduced image artifact
What are the advantages of 3D over 2D
- No image magnification
- No image distortion
- No superimposition of adjacent structures
- Accurate relation between adjacent structures