Absorbed and effective doses from cone beam volumetric imaging for implant planning.
OBJECTIVE
Volumetric CT using a cone beam has been developed by several manufacturers for dentomaxillofacial imaging. The purpose of this study was to measure doses for implant planning with cone beam volumetric imaging (CBVI) in comparison with conventional multidetector CT (MDCT).


METHODS
The two CBVI systems used were a 3D Accuitomo (J. Morita), including an image-intensifier type (II) and a flat-panel type (FPD), and a CB MercuRay (Hitachi). The 3D Accuitomo operated at 80 kV, 5 mA and 18 s. The CB MercuRay operated at 120 kV, 15 mA, 9.8 s. The MDCT used was a HiSpeed QX/i (GE), operated at 120 kV, 100 mA and 0.7 s, and its scan length was 77 mm for both jaws. Measurement of the absorbed tissue and organ doses was performed with an Alderson phantom, embedding the radiophotoluminescence glass dosemeter into the organs/tissues. The values obtained were converted into the absorbed dose. The effective dose as defined by the International Commission on Radiological Protection was then calculated.


RESULTS
The absorbed doses of the 3D Accuitomo of the organs in the primary beam ranged from 1-5 mGy, and were several to ten times lower than other doses. The effective dose of the 3D Accuitomo ranged from 18 muSv to 66 muSv, and was an order of magnitude smaller than the others. In conclusion, these results show that the dose in the 3D Accuitomo is lower than the CB MercuRay and much less than MDCT.
Okano
T
T
Department of Radiology, Showa University School of Dentistry, Tokyo, Japan. tokano@senzoku.showa-u.ac.jp
Harata
Y
Y
Sugihara
Y
Y
Sakaino
R
R
Tsuchida
R
R
Iwai
K
K
Seki
K
K
Araki
K
K
D000005:Abdomen / Q000528:radiation effects; D001853:Bone Marrow / Q000528:radiation effects; D001921:Brain / Q000528:radiation effects; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation / Q000379:methods*; D015921:Dental Implants; D006257:Head / Q000528:radiation effects*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007568:Jaw / Q000528:radiation effects; D007908:Lens, Crystalline / Q000528:radiation effects; D008334:Mandible / Q000528:radiation effects; D009333:Neck / Q000528:radiation effects; D010347:Patient Care Planning; D010388:Pelvis / Q000528:radiation effects; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D012469:Salivary Glands / Q000528:radiation effects; D012867:Skin / Q000528:radiation effects; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation; D013909:Thorax / Q000528:radiation effects; D013961:Thyroid Gland / Q000528:radiation effects; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods
D015921:Dental Implants