Gavala Sophia, Donta Catherine, Tsiklakis Kostas, Boziari Argyro, Kamenopoulou Vasiliki, Stamatakis Harry C
Department of Oral Diagnosis and Oral Radiology, School of Dentistry, University of Athens, 2 Thivon Street Goudi, Athens 115 27, Greece.
Eur J Radiol. 2009 Jul;71(1):42-8. doi: 10.1016/j.ejrad.2008.03.018. Epub 2008 May 2.
(a) To measure the absorbed radiation doses at 16 anatomical sites of a Rando phantom and (b) to calculate the effective doses including and excluding the salivary gland doses in panoramic radiography using a conventional and a digital panoramic device.
Thermoluminescent dosimeters (TLD-100) were placed at 16 sites in a Rando phantom, using a conventional, Planmeca Promax and a digital, Planmeca PM2002CC Proline 2000 (Planmeca Oy, 00880 Helsinki, Finland) panoramic device for panoramic radiography. During conventional radiography the selected exposure settings were 66 kVp, 6 mA and 16s, while during digital radiography two combinations were selected 60 kVp, 4 mA, 18 s and 66 kVp, 8 mA, 18s with and without image processing function. The dosimeters were annealed in a PTW-TLDO Harshaw oven. TLD energy response was studied using RQN beam narrow series at GAEC's Secondary Standard Calibration Laboratory. The reader used was a Harshaw, 4500. Effective dose was estimated according to ICRP(60) report (E(ICRP60)). An additional estimation of the effective dose was accomplished including the doses of the salivary glands (E(SAL)). A Wilcoxon signed ranks test was used for statistical analysis.
The effective dose, according to ICRP report (E(ICRP60)) in conventional panoramic radiography was 17 microSv and E(SAL) was 26 microSv. The respective values in digital panoramic radiography were E(ICRP60)=23 microSv and E(SAL)=38 microSv; while using the lowest possible radiographic settings E(ICRP60) was 8 microSv and E(SAL) was 12 microSv.
The effective dose reduction in digital panoramic radiography can be achieved, if the lowest possible radiographic settings are used.
(a) 测量兰多人体模型16个解剖部位的吸收辐射剂量，(b) 使用传统和数字全景设备计算全景X线摄影中包含和不包含唾液腺剂量的有效剂量。
使用传统的普兰梅卡Promax和数字的普兰梅卡PM2002CC Proline 2000（芬兰普兰梅卡公司，赫尔辛基00880）全景设备进行全景X线摄影时，将热释光剂量计（TLD-100）放置在兰多人体模型的16个部位。传统X线摄影时，选定的曝光参数为66 kVp、6 mA和16秒，而数字X线摄影时，选择了两种参数组合，即60 kVp、4 mA、18秒和66 kVp、8 mA、18秒，有无图像处理功能。剂量计在PTW-TLDO哈肖烘箱中退火。在GAEC二级标准校准实验室使用RQN窄束系列研究TLD能量响应。使用的读数器是哈肖4500。根据国际放射防护委员会（ICRP）第60号报告估计有效剂量（E(ICRP60)）。还完成了包括唾液腺剂量的有效剂量额外估计（E(SAL)）。采用Wilcoxon符号秩检验进行统计分析。
根据ICRP报告，传统全景X线摄影中的有效剂量（E(ICRP60)）为17微希沃特，E(SAL)为26微希沃特。数字全景X线摄影中的相应值为E(ICRP60)=23微希沃特，E(SAL)=38微希沃特；而使用尽可能低的X线摄影参数时，E(ICRP60)为8微希沃特，E(SAL)为12微希沃特。
如果使用尽可能低的X线摄影参数，数字全景X线摄影中的有效剂量可以降低。
