Conventional CT scanners make use of a fan-beam. Transmitted radiation takes the form of a helix or spiral. The data are then interpolated or re-binned by the scanner into a set of slices making up a volume. Large anatomical regions of the body can be imaged during a single breath hold, reducing the possibility of artifacts caused by patient movement. Images are then reconstructed using algorithms to produce 3-dimensional images at high resolution. Cone Beam Computed Tomography (CBCT) or Dental Volume Tomography (DVT) scanners (such as the i-CAT) utilise a cone beam, which radiates from the x-ray source in a cone shape, encompassing a large volume with a single rotation about the patient.
Design of machine
Conventional CT makes use of a lie-down machine with a large gantry. When patients lie down, the soft tissues tend to collapse. This is of particular importance to orthodontists when predicting the tissue changes likely to result from specific tooth movements. Because the i-CAT is a sitting-up machine, it offers more accurate information for dental practitioners. The radiation dose from a conventional CT also does not justify taking a CT scan of, for example, a child in order to make soft tissue measurements.
The radiation exposure to a patient from a conventional CT is approximately 100-300 microsieverts (µSv) for the maxilla and 200-500 µSv for the mandible. The radiation exposure (for both mandible and maxilla) from the i-CAT is between 34-102 microsieverts (µSv) depending on the time and resolution of the scan.
Type of exposureRadiation Dose Conventional CT Maxilla – 250µSv Mandible – 480µSv Cone Beam CT Double jaw – 30-100µSv
Conventional CT require the patient's head to be manually tilted to create images suitable for the dentist's needs (e.g. parallel to the occlusal plane, the hard palate, or the lower border of the mandible). When positioning to the lower border of the mandible, the patient's jaw is tilted quite far upward with strain to the neck, which patients find uncomfortable. Patient positioning is the same for all patients in the i-CAT. The patient's lower jaw is positioned in the chin cup and the forehead stabilised using Velcro straps if necessary. The scan is taken and the images can be re-positioned if necessary using the software.
i-Cat is an amazing CT scanner specially designed for dental use (Cone Beam Technology). It is non-invasive, comfortable, safe, quick, precise (accuracy, up to 0.1 mm) with amazing results guaranteed! The i-CAT Cone Beam 3-D Dental Imaging System provides high-definition, three-dimensional, digital imaging at reduced cost, and exposes the patient to less radiation than traditional CT scans.
Why use i-CAT?
The i-CAT opens your eyes to a third dimension. It’s easy to understand and allows you to see critical anatomy that has previously not been available with traditional scans. All sorts of extra vital information can now be seen: cysts, polyps, size of ridges for block harvest bifurcated mandibular canal etc. This further enhances the patient’s experience as he is safe in the knowledge that he is getting the best available technology. Every day we scan new patients and each one is amazed at the amount of information that a CT scan can produce. Patients are truly impressed by the technology: the 3d and their skin imaging, and the speed and comfort that it offers.
When to use i-CAT?
Dental Implants: CT reduces costs, saves chair time and delivers better results. With a typical scan time of only 20 seconds or less, the patient is exposed to significantly less radiation than traditional CT scans of the oral and maxillofacial region.Orthodontic: Improve orthodontic diagnosis and treatment by providing the multiple projection perspective necessary to accurately assess tooth relationships and further support the objective interpretation of anatomy. Impaction: i-Cat delivers precise 3D views of impacted molars within the alveolar bone, location relative to adjacent teeth, and proximity to vital structures, such as the nerve canal, sinus walls, and cortical borders.
i-Cat detects and evaluates problems before they become serious by accurately measuring bone and jaw deformities, assessing bone lesions and changes of the jaw, and detecting other pathologies, such as cysts, tumours, and disease.
3D images allow the specialist to view critical structures for complete TMJ analysis and diagnosis clearly showing the condyles and surrounding structures, of bone morphology, joint space, and function all critical to TMJ dysfunction treatment and care. A ten-second, high-speed scan captures TMJ open jaw views.
Air Way assessment:
3D data enhances airway assessment and can result in reconsideration of the treatment plan if the patient has a typical airway, versus a restricted airway, which may be susceptible to collapse