Korean J Oral Maxillofac Radiol.  2007 Jun;37(2):87-92.

Radiation absorbed doses of cone beam computed tomography

• Lee ET
• Kim GT
• Choi YS
• Hwang EH

Abstract

Purpose: To measure the absorbed doses of cone beam computed tomography (CBCT), which is recently being more frequently used, and to compare them with those of panoramic radiography.
Materials and Methods
To measure the absorbed doses of CBCT (PSR-9000N(TM), Asahi Roentgen Ind. Co., Japan), we placed TLD chips on the skin regions above the parotid and thyroid glands, and on the dorsum of tongue in a dental head phantom. We used two image acquisition modes of the Dental and Panoramic modes of CBCT, which differed in the field of view. Also, panoramic radiographs (Auto IIIN, Asahi Roentgen Ind. Co., Japan) were taken to compare with the absorbed doses of CBCT. Result: In the Dental mode of CBCT, the absorbed doses of the parotid gland, dorsum of tongue, and thyroid gland were 3.53, 3.13, and 0.36 mGy, respectively. In the Panoramic mode of CBCT, they were 9.57, 9.15, and 0.85 mGy, respectively. The panoramic mode showed higher absorbed doses than those of the Dental mode. In the panoramic radiography, the absorbed doses of the parotid gland, dorsum of tongue, and thyroid gland were 1.21, 1.19, and 0.16 mGy, respectively. And they were about 1/3 of the Dental mode and 1/9 of the Panoramic mode of CBCT.
Conclusion
Absorbed doses of CBCT are higher than those of panoramic radiography, and dependent upon the field of view.

Keyword

Tomography, Cone Beam Computed; Radiography, Panoramic; Radiation Dosage

MeSH Terms

Cone-Beam Computed Tomography*
Head
Parotid Gland
Radiation Dosage
Radiography, Panoramic
Skin
Thyroid Gland
Tongue