KODAK Dental Systems, Carestream Health Rochester NY, USA/Distributed exclusively in the USA by PracticeWorks, Atlanta, GA, USA Imaging Sciences International, Hatfield, PA, USA/Distributed by KaVo Dental Corp., Biberach, Germany IMTEC Imaging Ardmore, OK, USA/Distributed by GE Healthcare, Piscataway, NJ, USA Imaging Sciences International, Hatfield, PA, USA Imaging Sciences International, Hatfield, PA, USA/Distributed by Gendex, Chicago, IL, USA Sirona Dental Systems, Charlotte, NC, USA Several additional units are in various stages of development, testing, or application for FDA approval.ģD Accuitomo-XYZ Slice View Tomograph/Veraviewpacs 3DĪsahi Roentgen, Kyoto, Japan/Distributed by Belmont, Somerset, NJ, USA Since 2003, a number of other CBCT units have been FDA approved in the United States, including the Kodak 9000 3D, (Carestream/Trophy, Marne-la-Vallée, France), which is currently the highest resolution unit ( Table 1). Corp., Kyoto, Japan) in March 6, the i-CAT (Imaging Sciences International, Hatfield, PA) in October 2, and the CB MercuRay (Hitachi, Medical Corp., Kashiwa-shi, Chiba-ken, Japan) on October 20. FDA approval for three more CBCT units quickly followed in 2003 followed for the 3D Accuitomo, (J. The Food and Drug Administration (FDA) approved the first CBCT unit for dental use in the United States in March 8, 2001-the NewTom DVT 9000 (Quantitative Radiology srl, Verona, Italy). CBCT is a complementary modality for specific applications rather than a replacement for 2D imaging modalities. As CBCT exposure incorporates the entire FOV, only one rotational sequence of the gantry is necessary to acquire enough data for image reconstruction. In this single rotation, CBCT provides precise, essentially immediate and accurate 3D radiographic images. During the exposure sequence hundreds of planar projection images are acquired of the field of view (FOV) in an arc of at least 180°. The X-ray source and detector rotate around a fixed fulcrum within the region of interest (ROI). A divergent pyramidal- or cone-shaped source of ionizing radiation is directed through the middle of the area of interest onto an area X-ray detector on the opposite side of the patient. CBCT is accomplished by using a rotating gantry to which an X-ray source and detector are fixed. In fields of dentistry where 3D imaging is necessary, CBCT is considered by some to be the standard of care. also reported that when those same examiners evaluated the same films at two different times, they only had 19%–80% agreement between the two evaluations. showed that in evaluating healing of periapical lesions using 2D periapical radiographs there was only 47% agreement between six examiners. Success in endodontics is assessed in healing of the periapical bone adjacent to obturated canals. 3D characteristics such as complex dental anatomy and surrounding structures can make interpretation of 2D “shadows” difficult and can contribute to nonhealing of endodontic cases. If any component of the imaging chain process is compromised, the resulting image may demonstrate exposure or geometric errors and be suboptimal. The image produced is a two-dimensional (2D) representation of a three-dimensional (3D) object. Intraoral radiography is based on the transmission, attenuation, and recording of X-rays on an analog film or digital receptor, and requires optimized geometric configuration of the X-ray generator, tooth, and sensor to provide an accurate projection of the tooth.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |