PurposeWe address the misconception that the typical physician dose is higher for CT fluoroscopy (CTF) procedures compared to C‐Arm procedures.MethodsWe compare physician scatter doses using two methods: a literature review of reported doses and a model based on a modified form of the dose area product (DAP). We define this modified form of DAP, “cumulative absorbed DAP,” as the product of the area of the x‐ray beam striking the patient, the dose rate per unit area, and the exposure time.ResultsThe patient entrance dose rate for C‐Arm fluoroscopy (0.2 mGy/s) was found to be 15 times lower than for CT fluoroscopy (3 mGy/s). A typical beam entrance area for C‐Arm fluoroscopy reported in the literature was found to be 10.6 × 10.6 cm (112 cm2), whereas for CTF was 0.75 × 32 cm (24 cm2). The absorbed DAP rate for C‐Arm fluoroscopy (22 mGy*cm2/s) was found to be 3.3 times lower than for CTF (72 mGy*cm2/s). The mean fluoroscopy time for C‐Arm procedures (710 s) was found to be 21 times higher than for CT fluoroscopy procedures (23 s). The cumulative absorbed DAP for C‐Arm procedures was found to be 9.4 times higher when compared to CT procedures (1.59 mGy*m2 vs. 0.17 mGy*m2).ConclusionsThe higher fluoroscopy time in C‐Arm procedures leads to a much lower cumulative DAP (i.e., physician scatter dose) in CTF procedures. This result can inform interventional physicians deciding on whether to perform inter‐procedural imaging inside the room as opposed to retreating from the room.

中文翻译：

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技术说明：C 型臂和 CT 透视手术中医生剂量的比较

目的我们纠正了这样的误解：与 C 臂手术相比，CT 透视 (CTF) 手术的典型医生剂量较高。方法我们使用两种方法比较医生分散剂量：报告剂量的文献综述和基于改进形式的模型剂量面积乘积 (DAP)。我们将 DAP 的这种修改形式定义为“累积吸收 DAP”，作为照射患者的 X 射线束面积、单位面积剂量率和曝光时间的乘积。结果 C- 的患者入口剂量率手臂透视 (0.2 mGy/s) 比 CT 透视 (3 mGy/s) 低 15 倍。文献中报道的 C 臂透视的典型光束入口面积为 10.6 × 10.6 cm (112 cm2），而 CTF 为 0.75 × 32 厘米（24 厘米2）。 C 臂透视吸收的 DAP 率（22 mGy*cm2/s) 比 CTF (72 mGy*cm2/秒）。 C 臂手术的平均透视时间（710 秒）比 CT 透视手术（23 秒）长 21 倍。发现 C 臂手术的累积吸收 DAP 比 CT 手术高 9.4 倍（1.59 mGy*m）2对比 0.17 mGy*m2). 结论 C 臂手术中较长的透视时间导致 CTF 手术中的累积 DAP（即医生散射剂量）低得多。这一结果可以帮助介入医生决定是否在房间内进行手术间成像，而不是退出房间。