Moulin G, Chagnaud C, Waultier S, Le Brigand B, Espagnan M, Dessi P, Bartoli J M, Châtenet P, Botti G
Department of Radiology, CHU la Timone, Marseille, France.
Neuroradiology. 1996 May;38 Suppl 1:S127-9. doi: 10.1007/BF02278139.
The radiation dose to the lens during CT of the paranasal sinuses was measured in 20 patients. In 10 patients, a "standard" technique with axial and coronal sections was used. In the remaining 10 patients, overlapping axial sections for bidimensional reconstruction were obtained. Radiation dose was measured using thermoluminescent dosimeters. The mean dose was 22 mGy in patients who underwent "standard" CT and 42 mGy in those who underwent CT with overlapping sections. Dose was dependent on the total number of slices and of transorbital axial sections. Coronal sections did not statistically increase the radiation dose to the lenses. Although these doses were significantly below the critical dose for cataracts, CT with overlapping sections gives a considerably higher radiation dose. We recommend the bidimensional reconstruction technique only for selected cases (e.g. preoperative assessment of the roof of the ethmoid sinuses or in patients who can or should not maintain the hyperextended position required for coronal views.
对20例患者进行鼻窦CT检查时测量了晶状体的辐射剂量。其中10例患者采用了包括轴位和冠状位扫描的“标准”技术。其余10例患者则获取了用于二维重建的重叠轴位扫描图像。使用热释光剂量计测量辐射剂量。接受“标准”CT检查的患者平均剂量为22 mGy，而接受重叠扫描CT检查的患者平均剂量为42 mGy。剂量取决于总切片数和经眶轴位切片数。冠状位扫描在统计学上并未增加晶状体的辐射剂量。尽管这些剂量显著低于白内障的临界剂量，但重叠扫描CT的辐射剂量要高得多。我们建议仅在特定情况下（例如筛窦顶部的术前评估或无法或不应保持冠状位视图所需的过伸体位的患者）使用二维重建技术。
