Advantages Disadvantages of Cone Beam Computed Tomography for CBCT scanning
This page covers advantages and disadvantages of Cone Beam Computed Tomography (CBCT). It mentions benefits or advantages of Cone Beam Computed Tomography and drawbacks or disadvantages of Cone Beam Computed Tomography.
Conventional radiography: In this technique, the two dimensional image is formed by superimposition of images
from successive layers of body in the path of X-rays. The problem encountered in this technique is
image of one layer is obscured by superimposition of images above and below layers.
Computed tomography (CT) : Above problem is resolved by CT technique in which images of selected layers are recorded sharpely while images of other layers are recorded unsharpely. Tomography involves synchronized movement of any two of the three subjects viz. x-ray tube, film and patient while the third subject remains stationary. The most common and widely used method is the one in which patient remains stationary while X-ray tube and film (or detector) move in co-ordination.sl
What is Cone Beam Computed Tomography (CBCT) ?
It is a variation on traditional computed tomography. Unlike CT scanner, it uses X-ray tube and detector panel which rotates around the patient capturing data in cone shaped X-ray beam instead of slices as captured by Computed Tomography (CT). Images are reconstructed using algorithms to generate three dimensional images at high resolution.
Let us understand how CBCT works. All the CBCT scanners use x-ray source and detector mounted on rotating gantry. During the rotation of gantry, x-ray source produces divergent cone shaped radiation, while receptor records the residual x-rays after they are attenuated by patient tissues. X-ray source and detector moves through arc of 180 to 360 degrees to produce multiple planar projection images. These images constitute raw primary data. This data are reconstructed by algorithm running in the computer to generate cross sectional images. Sensors such as image sensor (PSP- Photo Stimulable Phosphorus Plates) , CCD sensor and FPD (Flat Panel Detector) are used for X-ray detection.
Benefits or advantages of Cone Beam Computed Tomography
Following are the benefits or advantages of Cone Beam Computed Tomography:
➨It offers rapid scan time.
➨The patient has less radiation exposure compare to CT technique.
➨It delivers three dimensional volume rendering.
➨It provides accurate images with good spatial resolution.
➨The CBCT technique is economical, comfortable and safe to use.
➨It supports interactive display modes and multiplanar reformatting.
➨CBCT imaging provides insight into treatment planning which is unachievable with other methods. This allows clinicians to provide more predictable patient care.
Drawbacks or disadvantages of Cone Beam Computed Tomography
Following are the drawbacks or disadvantages of Cone Beam Computed Tomography:
➨It offers poor contrast resolution. Hence soft tissues can not be viewed.
➨Certain artifacts can not be resolved by CBCT technique and it appears in the image.
➨Noise appears in the image generated by CBCT technique.
➨It is not required to be used where 2D imaging suffices.
Refer difference between CT scanner and CBCT scanner >>.