Irie T, Kajitani M, Itai Y
Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
J Vasc Interv Radiol. 2001 Dec;12(12):1417-21. doi: 10.1016/s1051-0443(07)61701-1.
To estimate the effects of a lead plate, three types of needle holders, tube current, and slice thickness on decreasing the radiation dose to the physician's hand during interventional procedures with computed tomographic (CT) fluoroscopic guidance. The needle holders (I-I devices), which were developed by the authors, maintained the distance between the physician's hand and the CT plane at 7 cm, 10 cm, and 15 cm, respectively.
The dose rate (mSv/tube current/CT fluoroscopy time) was measured in 55 cases, which were divided into six groups. In group A (n = 14), the current was 135 kV, there was a 5-mm slice thickness, and a 7-cm I-I device was used without the lead plate. Group B (n = 11) entailed a 120-kV current, a 5-mm slice thickness, and a 7-cm I-I device without the lead plate. Group C (n = 8) entailed a 120-kV current, 5-mm slice thickness, and 7-cm I-I device with the lead plate. Group D (n = 9) entailed a 120-kV current, 5-mm slice thickness, and 10-cm I-I device with the lead plate. Group E (n = 7) entailed a 120-kV current, 5-mm slice thickness, and 15-cm I-I device with the lead plate. Group F (n = 6) entailed a 120-kV current, 1-mm slice thickness and 10-cm I-I device with the lead plate. To compare the effects of tube voltage, lead plate use, slice collimation, and I-I devices, differences were compared between groups A and B, B and C, D and F, and among groups C, D, and E.
The dose rates of groups A, B, C, D, E, and F were 126.3, 75.2, 17.8, 13.9, 2.8, and 4.1 mSv/mA/sec x 100,000, respectively. There were significant differences in dose rates between groups A and B (t-test, P =.037), B and C (Student t-test, P =.002), D and F (Mann-Whitney test, P =.011), and among groups C, D, and E (Kruskal-Wallis test, P =.016).
The lead plate, the improved I-I devices, use of a 120 kV (vs 135 kV) current, and 1-mm (vs 5 mm) collimation were all useful in decreasing the dose rate.
评估在计算机断层扫描（CT）透视引导下的介入操作过程中，铅板、三种持针器、管电流及层厚对降低术者手部辐射剂量的影响。作者研发的持针器（I-I 装置）可使术者手部与 CT 平面的距离分别保持在 7cm、10cm 和 15cm。
对 55 例患者进行剂量率（mSv/管电流/CT 透视时间）测量，将其分为六组。A 组（n = 14），管电压 135kV，层厚 5mm，使用 7cm 的 I-I 装置且未使用铅板；B 组（n = 11），管电压 120kV，层厚 5mm，使用 7cm 的 I-I 装置且未使用铅板；C 组（n = 8），管电压 120kV，层厚 5mm，使用 7cm 的 I-I 装置且使用铅板；D 组（n = 9），管电压 120kV，层厚 5mm，使用 10cm 的 I-I 装置且使用铅板；E 组（n = 7），管电压 120kV，层厚 5mm，使用 15cm 的 I-I 装置且使用铅板；F 组（n = 6），管电压 120kV，层厚 1mm，使用 10cm 的 I-I 装置且使用铅板。为比较管电压、铅板使用、层厚准直及 I-I 装置的效果，比较了 A 组与 B 组、B 组与 C 组、D 组与 F 组之间的差异，以及 C 组、D 组和 E 组之间的差异。
A、B、C、D、E、F 组的剂量率分别为 126.3、75.2、17.8、13.9、2.8 和 4.1 mSv/mA/sec×100,000。A 组与 B 组之间（t 检验，P = 0.037）、B 组与 C 组之间（Student t 检验，P = 0.002）、D 组与 F 组之间（Mann-Whitney 检验，P = 0.011）以及 C 组、D 组和 E 组之间（Kruskal-Wallis 检验，P = 0.016）的剂量率存在显著差异。
铅板、改良的 I-I 装置、使用 120kV（对比 135kV）管电流以及 1mm（对比 5mm）层厚准直均有助于降低剂量率。
