Department of Medical Physics & Engineering, Old Medical School, Leeds General Infirmary, Leeds, UK.
Br J Radiol. 2011 Nov;84(1007):1020-6. doi: 10.1259/bjr/53865832.
The purpose of this study was to evaluate and compare organ and effective dose savings that could be achieved using conventional lead aprons and a new, custom-designed shield as out-of-plane shielding devices during chest CT scans.
Thermoluminescent dosimeters were used to measure doses throughout the abdomen and pelvis during CT scans of the chest of a RANDO phantom. Dose measurements were made with no shielding, with lead aprons and with the new shield around the abdomen and pelvis in order to quantify the achievable organ and effective dose reductions.
Average dose savings in the 10 phantom sections ranged from 5% to 78% with the highest point dose saving of 93% being found in the mid-pelvis. When shielding was used, the maximum measured organ dose reduction was a 72% dose saving to the testes. Significant dose savings were found throughout the abdomen and pelvis, which contributed to an effective dose saving of 4% that was achieved over and above the dose savings obtained through conventional optimisation strategies. This could yield significant population dose savings and reductions in collective radiation risk.
In this study significant organ and effective dose reductions have been achieved through the use of abdominal shielding during chest CT examinations and it is therefore recommended that out-of-plane patient shielding devices should be used for all chest CT scans and potentially for every CT scan, irrespective of body part.
本研究旨在评估和比较在胸部 CT 扫描中使用传统铅围裙和新定制屏蔽罩作为非平面屏蔽设备时可实现的器官和有效剂量节省。
使用热释光剂量计在 RANDO 体模的胸部 CT 扫描期间测量腹部和骨盆的剂量。进行了无屏蔽、使用铅围裙和使用新屏蔽罩环绕腹部和骨盆的剂量测量，以量化可实现的器官和有效剂量减少。
在 10 个体模切片中，平均剂量节省率在 5%至 78%之间，最高剂量节省率为 93%，位于中骨盆。使用屏蔽时，对睾丸的最大测量器官剂量减少了 72%。在整个腹部和骨盆中都发现了显著的剂量节省，这促成了超过传统优化策略获得的剂量节省 4%的有效剂量节省。这可能会带来显著的人群剂量节省和集体辐射风险降低。
在这项研究中，通过在胸部 CT 检查中使用腹部屏蔽实现了显著的器官和有效剂量减少，因此建议在所有胸部 CT 扫描中使用非平面患者屏蔽设备，并且可能在每个 CT 扫描中使用，无论身体部位如何。
