Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Unit 1352, Houston, TX, 70030-4009, USA.
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, 70030, USA.
J Nucl Cardiol. 2019 Aug;26(4):1161-1165. doi: 10.1007/s12350-018-1186-y. Epub 2018 Jan 17.
Average CT has been shown to be more accurate than conventional helical CT in quantitation of the PET data. The risk of CT irradiation of a cardiac implantable electronic device (CIED) causing an adverse event is low and is generally outweighed by the clinical benefit of a medically indicated examination. However, irradiation of CIED over one breath cycle in cine CT scan for average CT could impose risks on a patient who is pacing dependent. The purpose of this study was to demonstrate that low-dose average CT can be safe for CIED.
A Medtronic CIED of model Protecta VR was submerged in a saline bath for a series of 4-s cine CT scans on a GE CT scanner programmed to deliver a 2-cm-wide radiation at a dose rate of 0.9 to 41.2 mGy/s to the CIED. The number of over-sensings was recorded as the interference of radiation to the CIED.
Dose rates ≥ 1.9 mGy/s caused over-sensing. The higher the dose rate, the more over-sensings there were. The lowest dose rate of 0.9 mGy/s did not cause any over-sensing.
Low-dose average CT at 0.9 mGy/s can be safe for a CIED patient who is pacing dependent.
平均 CT 已被证明比传统螺旋 CT 更能准确量化 PET 数据。心脏植入式电子设备（CIED）受到 CT 辐射而发生不良事件的风险较低，且通常低于医学检查的临床获益。然而，在电影 CT 扫描中，对 CIED 进行一个呼吸周期的平均 CT 照射可能会对依赖起搏的患者造成风险。本研究旨在证明低剂量平均 CT 对 CIED 是安全的。
将 Medtronic 的 CIED Protecta VR 模型浸泡在盐水中，在 GE CT 扫描仪上进行一系列 4 秒电影 CT 扫描，该 CT 扫描仪编程为以 0.9 至 41.2 mGy/s 的剂量率向 CIED 输送 2cm 宽的辐射。记录超感次数作为辐射对 CIED 的干扰。
剂量率≥1.9 mGy/s 会引起超感。剂量率越高，超感次数越多。最低剂量率 0.9 mGy/s 不会引起任何超感。
对于依赖起搏的 CIED 患者，0.9 mGy/s 的低剂量平均 CT 是安全的。
