| 文大光,宋婷妮,张晓咏,等.铅单巾放置位置对自动管电流调制技术CT胸部扫描辐射剂量及性腺辐射剂量影响的体模研究[J].中华放射医学与防护杂志,2026,46(5):471-477.Wen Daguang,Song Tingni,Zhang Xiaoyong,et al.Impact of lead apron placement on radiation dose in automatic tube current modulation CT chest scans and on gonadal radiation dose: A phantom study[J].Chin J Radiol Med Prot,2026,46(5):471-477 |
| 铅单巾放置位置对自动管电流调制技术CT胸部扫描辐射剂量及性腺辐射剂量影响的体模研究 |
| Impact of lead apron placement on radiation dose in automatic tube current modulation CT chest scans and on gonadal radiation dose: A phantom study |
| 投稿时间：2025-08-12 |
| DOI：10.3760/cma.j.cn112271-20250812-00290 |
| 中文关键词: 计算机体层成像 铅单巾 自动管电流调制技术 |
| 英文关键词:Computed Tomography Lead shielding Automatic exposure control (AEC) |
| 基金项目:四川大学华西医院学科卓越发展1·3·5工程项目(ZYGD23024) |
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| 中文摘要: |
| 目的 探究不同铅单巾放置位置对CT胸部扫描中性腺散射剂量、扫描剂量指标及管电流调制的影响,提出防护距离优化方案。方法 使用5种不同探测器宽度的西门子CT机型(16排Scope/19.2 mm、32排Go Up/22.4 mm、64排Flash/38.4 mm、96排Force/57.6 mm、光子计数CT/57.6 mm与19.2 mm)对仿真人体模型进行胸部CT扫描。设置不同铅单巾放置位置,铅单巾上缘距扫描野下缘0、2、4、6 cm及无防护组,记录容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)、RaySafe X2(RX2)空气电离室测量性腺吸收剂量,并分析管电流分布。结果 最佳防护位置与探测器宽度密切相关,探测器宽度在19.2~22.4 mm,防护位置为2 cm时,扫描区域整体辐射剂量指标(CTDIvol、DLP)与无防护差异<2%;探测器宽度为38.4与57.6 mm,需防护位置达到6 cm方可消除差异(ΔCTDIvol≤0.072 mGy,ΔDLP≤2.1 mGy·cm)。所有机型在优化防护距离下,模拟卵巢位置剂量降幅达55.6%~70.3%,且扫描区域整体辐射剂量指标增幅均控制增幅≤2.1%,铅单巾各防护位置均使男性性腺剂量低于仪器检测下限。近距离防护时,扫描野足侧末端层面管电流异常升高(>20%),受影响层数及范围随探测器宽度增大而增加(如Force在防护位置距离扫描区域0 cm时异常范围达75 mm),防护位置远离扫描区域可消除此现象。结论 铅单巾放置位置需根据探测器宽度个体化选择(19.2~22.4 mm探测器:2 cm;38.4与57.6 mm探测器:6 cm),可在确保扫描区域整体辐射剂量指标稳定的前提下,显著降低卵巢散射剂量(>55%),为临床辐射防护优化提供实证依据。 |
| 英文摘要: |
| Objective To investigate the effects of different lead apron placement positions on gonadal scatter dose, scan dose metrics, and interference with tube current modulation during multi-model CT chest scans and to propose an optimized shielding distance protocol. Methods Chest CT scans were performed on an anthropomorphic phantom using five Siemens CT models with varying detector widths: a 16-row Scope (19.2 mm), a 32-row Go Up (22.4 mm), a 64-row Flash (38.4 mm), a 96-row Force (57.6 mm), and a photon-counting CT (57.6 and 19.2 mm). The lead apron was placed with its superior edge at 0, 2, 4, and 6 cm from the inferior edge of the scan field, with an unshielded group serving as control. Recorded parameters included volume computed tomography dose index(CTDIvol), dose length product(DLP), gonadal dose measured with an RaySafe X2(RX2)air ionization chamber, and tube-current distribution. Results The optimal shielding position was closely related to detector width. For detector widths of 19.2-22.4 mm, a 2-cm distance resulted in differences of <2% in CTDIvol and DLP compared with the unshielded group. For detector widths of 38.4 and 57.6 mm, a 6-cm distance was required to eliminate significant differences (ΔCTDIvol ≤ 0.072 mGy, ΔDLP ≤ 2.1 mGy·cm). At these optimized positions, the simulated ovarian dose reduction ranged from 55.6% to 70.3% across all scanners, while the increase in chest dose was ≤2.1%. Male gonadal doses fell below the detection limit of the instrument for all shielding positions. Close-range shielding (0 cm) caused abnormal tube-current increases (>20%) in the most caudal slices of the scan field. The number and extent of affected slices increased with detector width (e.g., up to 75 mm for Force with lead apron at 0 cm), and this effect was eliminated when the shield was placed farther from the scan area. Conclusions The placement of the lead apron should be individualized according to detector width: 2 cm for detectors of 19.2-22.4 mm, and 6 cm for detectors of 38.4 and 57.6 mm. This strategy ensures stable chest dose metrics while significantly reducing ovarian scatter dose (>55%), providing an evidence-based approach for optimizing clinical radiation protection. |
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