Ferguson J E, DeAngelis G A, Newberry Y G, Finnerty J J, Agarwal S
Department of Obstetrics and Gynecology, University of Virginia School of Medicine, Charlottesville, USA.
Am J Obstet Gynecol. 1996 Aug;175(2):260-7; discussion 267-9. doi: 10.1016/s0002-9378(96)70133-3.
Our purpose was to determine the maximal fetal exposure to radiation by use of thermoluminescent dosimeters when pelvic measurements were performed by standard or modified digital radiography.
Digital radiography of the pelvis was performed according to a standard technique. Lithium fluoride thermoluminescent dosimeters were positioned on the patient's skin to quantitate the maximal amount of radiation exposure to the fetus. The standard technique often included a portion of fetal vertex. The axial view technique was modified to use an angle of inclination of 17 to 29 degrees relative to the vertical axis.
Digital radiography was well tolerated and interpretable images were consistently obtained. The maximal dose to the fetal vertex by use of the standard digital axial slice was 465 mrad. By modifying the standard digital technique and using an angle of inclination of 17 to 29 degrees it was possible to obtain an axial section without including any portion of the fetal vertex. This reduced the maximal total dose to the fetal vertex to 55 mrad, which is less than the background radiation exposure to the fetus over a 9-month period from natural sources.
Data reported indicate that total fetal radiation exposure is minimal after pelvimetry by digital radiography. Incorporating the modification of the angle for the axial slice, as reported here, resulted in a further significant decrease in fetal radiation exposure.
我们的目的是通过使用热释光剂量计来确定在采用标准或改良数字X线摄影进行骨盆测量时胎儿所接受的最大辐射量。
根据标准技术对骨盆进行数字X线摄影。将氟化锂热释光剂量计放置在患者皮肤上，以量化胎儿所接受的最大辐射量。标准技术通常会包括部分胎儿头部。对轴向视图技术进行了改良，使其相对于垂直轴的倾斜角度为17至29度。
数字X线摄影耐受性良好，始终能获得可解读的图像。使用标准数字轴向切片时胎儿头部所接受的最大剂量为465毫拉德。通过改良标准数字技术并采用17至29度的倾斜角度，可以获得不包括胎儿头部任何部分的轴向截面。这将胎儿头部所接受的最大总剂量降低至55毫拉德，低于胎儿在9个月内从自然来源所接受的背景辐射量。
报告的数据表明，数字X线摄影进行骨盆测量后胎儿所接受的总辐射量极小。采用此处报告的轴向切片角度改良方法，可使胎儿辐射暴露量进一步显著降低。
