Conventional VS Cone Beam Computed Tomography
Cone-beam computed tomography (CBCT) is considered a new generation diagnostic imaging technique, while is being used since the early 21st century. While opting for the diagnostic modality, one has several queries and doubts in mind, as:
- What difference is there between cone beam imaging and conventional fan-beam imaging?
- Are there any advantages over conventional CT?
- Are there limitations with CBCT machine use?
- How radiation exposure differs between the two?
- Whether owning a CBCT profitable with long-time practice?
What is a CBCT device?
CBCT is a variation of the conventional CT imaging system, wherein the later one there is the use of a collimated fan-shaped x-ray beam which is directed towards the patient and thereafter to a series of scintillator detectors. The detectors and the source form a ring around the patient with a fixed dimension, making 2D images which are then processed and displayed as a stacked image in 3D format.
While there in dental CBCT machine systems, the x-ray source and the detector panel rotate around the patient, and the x-ray beam is exposed in a cone-shaped fashion. This method captures around 150 to 600 2D sequential images in distinct planes, which are then reconstructed by algorithms to a 3D image display. The 3D images constructed here can be viewed in coronal, sagittal, and axial planes respectively.
Advantages of CBCT over conventional CT
- Lower Radiation to the Patient:
It has been proven in many researches that CBCT dental machine provides a much lower radiation dose as compared to conventional CT scans. Thus, this favors the patient’s health as studies show a lowering radiation dose of about 98% in comparison to normal CT scans.
- Various Fields of Application:
CBCT offers a range of field of view (FOV) to choose from according to the diagnostic need of the patient. These different FOV choices make it easy to diagnose the desired area according to the treatment need as in orthodontics, endodontics, oral and maxillofacial surgeries, otolaryngology, periodontics, prosthodontics, etc. This FOV choice basically enables to opt from the area of interest that is to be exposed by radiation.
- Faster Scan Time:
As compared to conventional CT scans, CBCT requires a lesser scan time because it forms a complete volume image in a single scan rotation while conventional CT scans a single slice image per scan.
The conventional CT machine systems price is much higher as compared to CBCT machine price, thus CBCT is economical, and is scanning cost paid by the patient is also much lower in the case of CBCT scan machines. Thus, is beneficial for the patient as well as to the owner of the diagnostic system.
- Easy To Use:
There is not much technical learning required to operate a dental CBCT system as it is somewhat similar to operate a panoramic imaging system. Along with it, most of the CBCT systems allow the dentist to convert the CBCT image to dental panoramic image too, thus adding an extra benefit.
- Patient Satisfaction:
CBCT makes the patient understand the diagnosis in a better way as a 2D image interpretation is difficult for a patient when compared to a three-dimensional image. Thus CBCT images make the patient more comfortable in accepting the treatment as the patient views a better image to understand the anomaly.
Disadvantages of CBCT over conventional CT
- Contrast Resolution:
The contrast resolution offered by conventional CT is better as compared to a CBCT image as the x-ray beam is divergent in the case of the later one and the built-in flat panel detector related artifacts are also there. If the objective of the imaging is to judge the soft tissue only, then conventional CT imaging must be a better choice comparatively.
These are the distortions in the imaging that are not related to the subject of interest. Streaking and motion artifacts are much common in CBCT imaging as compared to conventional CT imaging.
In the conclusion, it cannot be denied that CBCT is the future of dental imaging with some of its limitations to be kept in mind also. Decisively taking into account the economical fact and the exposure of the patient radiation, CBCT is superior for dental operators as well as also helpful for otolaryngologists.
CBCT imaging is becoming the rage of the day for modern dentistry as the manufacturers are also keeping on updating the systems and the imaging quality of the same. Thus the imaging modality will be better day by day with the time. There is also a wide range of best CBCT machines imaging systems available to opt from the house of different manufacturers, thus one has options to go according to one’s need.