All exposures were performed using phototiming. In this example, images were obtained of a pelvic phantom at three kV values using a commercial computed radiography (CR) imaging plates. In screen film radiography, the choice of x-ray tube voltage (kV) affected the image contrast this is no longer the case for any digital radiographic system.
Oral Surg Oral Med Oral Pathol Oral Radiol 113:817–826 2012. Position statement of the American Academy of Oral and Maxillofacial Radiology on selection criteria for the use of radiology in dental implantology with emphasis on cone beam computed tomography. Tyndall DA, Price JB, Tetradis S, Ganz SC, Hildebolt C.A cone-beam CT can be a very useful tool in planning your dental treatment and your dentist will only use this tool when the benefits of the examination outweigh any of the minimal risks. However, we always want to be careful with any amount of radiation and will use the principles of ALARA (As Low As Reasonably Achievable) as well as patient selection criteria when deciding what dental images should be taken. The amount of radiation received for a cone-beam CT is minimal in comparison to what we receive being alive on the earth. A typical effective dose from a CT scan of an adult brain is around 2 mSv or 2,000 µSv.) ( Editor’s Note: The dose from head CT scans will vary depending on what one is looking for, e.g., brain, sinuses, jaw. In comparison a medical CT of the head is approximately 860 µSv which equates to approximately 105 days of being alive on the earth. Therefore, the average cone-beam CT is similar to being alive on the earth for a little over two weeks (approximately 16 days). The daily background radiation received from the natural environment is approximately 8.2 µSv per day in the United States (NCRP 2003). We can also compare this to the amount of radiation that one received on the earth every day. 2008), a cone-beam CT is similar to having approximately nine panoramic radiographs depending on the factors stated above. Compared to the effective dose for a panoramic radiograph (conservatively approximately 14 µSv) (Ludlow et al. We can assume that an average radiation dose for a cone-beam CT of the jaws taken for implant purposes is approximately 130 µSv.
*²Ludlow JB Dosimetry of CS9300 Cone Beam CT Unit Study conducted 10 June 2011 on the CS 9300 serial number ZAAN009.ĪEffective dose calculated with International Commission on Radiological Protection 2007 tissue weights.īMedian of published effective dose for digital dental panoramic radiography = 14 µSv.ĬAnnual per Capita = 3.0 mSv (3,000 µSv) per annum or approximately 8.2 µSv per day *¹ Courtesy of Ludlow JB, 50–75 percent increase in dose when HD mode is used.
Number of Days of Annual Per Capita Background Radiation CĬomparison with Somatom Sensation 32-row/64-slice MultiDetector CT Below is a table of various cone-beam CT units and their approximate radiation dosages. The amount of radiation received from a cone-beam CT of the jaws will vary from approximately 18–200 µSv depending on the size of the field of view, resolution of the images, size of the patient, location of the region of interest, as well as the manufacturer settings. It is the recommended examination to determine anatomical relationships as stated by the American Academy of Oral and Maxillofacial Radiology if an implant is going to be placed (Tyndall et al. I will equate the amount of radiation from a cone-beam CT to a panorex because you previously asked and received a response regarding radiation doses from panoramic radiographs.Ī cone-beam CT is a low-dose scan that will allow your dentist to evaluate the anatomy of your jaws in all three planes and can be a useful tool for many dental problems. I also understand that you have had two medical CT scans of your head several years ago as well as a set of full-mouth radiographs last March. I understand that you are concerned about the radiation exposure that you will receive from a cone-beam scan.