Ekestubbe A, Thilander A, Gröndahl K, Gröndahl H G
Department of Oral Diagnostic Radiology, University of Göteborg, Sweden.
Dentomaxillofac Radiol. 1993 Feb;22(1):13-7. doi: 10.1259/dmfr.22.1.8508935.
Tomography is often needed prior to implant surgery to evaluate jaw bone dimensions. Computed tomography (CT) is advocated as an alternative. The purpose of this study was to measure the absorbed doses to radiosensitive organ in the head and neck region when CT is used. Measurements were made with extruded LiF thermoluminescent dosemeters within and on an anthropomorphic phantom examined with a Philips Tomoscan LX CT scanner. Axial scanning was performed for the maxilla and both frontal, perpendicular to the alveolus, and axial for the mandible. The highest absorbed doses were at the skin surface, 38 mGy with maxillary scans, and from axial and frontal scans of the mandible 35 mGy and 37 Gy, respectively. The parotid dose was 31 mGy from maxillary scans and in the mandible the submandibular gland dose was 27 mGy with axial scanning and 16 mGy with frontal. The eye lens received its highest dose (5.5 mGy) from frontal scans of the mandible. Although outside the scanning plane the pituitary and the thyroid glands received comparatively high absorbed doses of 0.6-4.0 mGy. All organ doses measured were considerably higher than those reported for conventional tomography.
在种植手术前通常需要进行断层扫描以评估颌骨尺寸。有人主张使用计算机断层扫描（CT）作为替代方法。本研究的目的是测量使用CT时头颈部区域放射敏感器官的吸收剂量。测量是使用挤压型氟化锂热释光剂量计在一个用飞利浦Tomoscan LX CT扫描仪检查的人体模型内部及表面进行的。对上颌骨进行轴向扫描，对下颌骨进行垂直于牙槽嵴的正面扫描和轴向扫描。最高吸收剂量出现在皮肤表面，上颌扫描时为38 mGy，下颌骨的轴向扫描和正面扫描分别为35 mGy和37 Gy。上颌扫描时腮腺剂量为31 mGy，下颌骨中，下颌下腺轴向扫描剂量为27 mGy，正面扫描为16 mGy。晶状体从下颌骨正面扫描中接受的剂量最高（5.5 mGy）。虽然垂体和甲状腺在扫描平面之外，但它们接受的吸收剂量相对较高，为0.6 - 4.0 mGy。所有测量的器官剂量都明显高于传统断层扫描报告的剂量。
