Olden K L, Kavanagh R G, James K, Twomey M, Moloney F, Moore N, Carey K, Murphy K P, Grey T M, Nicholson P, Chopra R, Maher M M, O'Connor O J
Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.
Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Radiology, Cork University Hospital, Cork, Ireland.
Radiography (Lond). 2018 Nov;24(4):334-339. doi: 10.1016/j.radi.2018.04.003. Epub 2018 Apr 26.
Optimization of image quality and patient radiation dose is achieved in part by positioning the patient at the isocenter of the CT gantry. The aim of this study was to establish whether there was increased isocenter misalignment (IM) in CT colonography (CTC) scans by comparing patient position during the prone part of a CTC to patient position during renal stone protocol CT (CT-KUB) and patient position during the supine part of a CTC to patient position during abdominopelvic CT (CT-AP).
Two hundred and twenty two consecutive outpatient adult CTC studies performed between January and December 2016 were retrospectively analyzed. Automated dose-tracking software was used to quantify IM in the x and y planes. Renal stone CT-KUB (n = 100) and standard CT-AP (n = 100) were used as comparison studies.
IM during CTC was significantly greater in the y-axis compared with the x-axis for both prone (p = 0.002) and supine (p < 0.001) scanning. IM was significantly greater during prone CTC compared with CT-KUB (p = 0.008) and during supine CTC compared with CT-AP (p = 0.0001). IM was shown to be slightly greater in studies performed by more experienced radiographers (p = 0.04). IM was not associated with patient age, gender or size (p > 0.05 for all).
Isocenter misalignment is greater during CT colonography compared with CT-KUB or CT-AP. Strategies for improving patient positioning could include radiographer education and automated patient centering solutions.
通过将患者置于CT扫描架的等中心来部分实现图像质量和患者辐射剂量的优化。本研究的目的是通过比较CT结肠成像（CTC）俯卧位扫描时的患者体位与肾结石协议CT（CT-KUB）时的患者体位，以及CTC仰卧位扫描时的患者体位与腹部盆腔CT（CT-AP）时的患者体位，来确定CTC扫描中是否存在更多的等中心偏移（IM）。
回顾性分析了2016年1月至12月期间连续进行的222例门诊成人CTC研究。使用自动剂量跟踪软件在x和y平面上量化IM。将肾结石CT-KUB（n = 100）和标准CT-AP（n = 100）用作对照研究。
对于俯卧位（p = 0.002）和仰卧位（p < 0.001）扫描，CTC期间的IM在y轴上显著大于x轴。与CT-KUB相比，俯卧位CTC期间的IM显著更大（p = 0.008），与CT-AP相比，仰卧位CTC期间的IM显著更大（p = 0.0001）。经验更丰富的放射技师进行的研究中IM略大（p = 0.04）。IM与患者年龄、性别或体型无关（所有p > 0.05）。
与CT-KUB或CT-AP相比，CT结肠成像期间的等中心偏移更大。改善患者体位的策略可包括放射技师培训和自动患者对中解决方案。
