Research Summary abstract
British Dental Journal 197, 140 (2004)
Published online: 14 August 2004 | doi:10.1038/sj.bdj.4811529
Research Summary:
Radiation doses of digital cephalometric radiography
E Whaites1
- This article aims to guide readers in taking the correct purchase/use decision of digital radiographic equipment, based on scientific evidence, by achieving a proper balance between diagnostic quality and radiation dose.
- There is a lower radiation dose to the salivary gland when indirect digital rather than direct cephalometric radiography is carried out.
- Their image quality is comparable for both direct and indirect digital cephalometric radiography.
Abstract
Aim The aim of this study was to measure organ doses and calculate the effective dose for indirect and direct digital cephalometric exposures.
Material and methods Indirect digital cephalometric exposures were made of a Rando® phantom head using a Cranex Tome® multipurpose unit with storage phosphor plates from Agfa and the direct digital (Charge Coupled Device, CCD) exposures were made with a Proline Ceph CM® unit. Exposure settings were 70 kV and 4 mAs for indirect digital exposures. Direct digital exposures were made with 70 kV, 10 mA and a total scanning time of 23 s. TLD700® dosemeters were used to measure organ doses, and the effective doses were calculated with (effective dosesal) and without inclusion of the salivary glands. A pilot study was carried out to compare diagnostic image quality of both imaging modalities.
Results Effective doses were 1.7 
Sv for direct digital and 1.6 Sv for indirect digital cephalometric imaging. When salivary glands were included in the calculation, effective dosessal were 3.4 Sv and 2.2 Sv respectively. Organ doses were higher for direct digital imaging, except for the thyroid gland, where the organ doses were comparable. Diagnostic image quality of indirect and direct digital cephalometric images seemed comparable.
Conclusion Effective dose and effective dosesal were higher for direct digital cephalometric exposure compared with indirect digital exposure. Organ doses were higher for direct digital cephalography. From preliminary data, it may be presumed that diagnostic image quality of indirect and direct digital cephalometric images are comparable.
- Senior Lecturer/Honorary Consultant in Dental Radiology, GKT Dental Institute, London
