Silva Claudio, Leal Ema
Department of Radiology, Clinica Alemana de Santiago, School of Medicine, Clinica Alemana - Universidad del Desarrollo, Santiago, Chile.
Indian J Radiol Imaging. 2022 Jan 10;31(4):805-808. doi: 10.1055/s-0041-1741093. eCollection 2021 Oct.
This article provides evidence that detection of venous air microbubbles (VAMB) in chest computed tomography angiography (CTA) can be an indicator for "normalization of deviance" phenomenon in CT. Institutional review board-approved retrospective study, with waiver for informed consent. Contrast-enhanced chest CT performed during 6 months were reviewed for presence of VAMB in venous segments visible in chest CT (subclavian, brachiocephalic vein, superior vena cava) and cardiac chambers. VAMB volumes were quantified through a semiautomatic method (MIAlite plugin for OsiriX), using a region of interest (ROI) covering the bubble. With basal results, protocols for correct injection technique were reinforced, and VAMB were estimated again at 1 and 3 months. Six months later, questionnaires were sent to the CT technologists to inquire about their perception of VAMB. Descriptive measures with central distribution and dispersion were performed; statistical significance was considered at < 0.05. A total of 602 chest CTA were analyzed, 332 were women (55.14%), with a median age of 58 (interquartile range [IQR] 44-72) years. Among those, 16.11% (100 cases) presented VAMB. Most were emergency department patients (51.6%), male (50.3%), with a median age of 54 (IQR 26) years. There was no difference on detection of VAMB regarding sex ( = 0.19), age ( = 0.46), or referral diagnosis ( = 0.35). Mean air bubbles volume was 0.2 mL (range 0.01-3.4 mL). After intervention, the number of exams with VAMB dropped to 3.29 % (3/91) ( < 0.001). On the 6-month query, 50% of the technicians still considered that VMAB is inevitable, and 60% thought that the occurrence is not associated to risk, and therefore, not actionable. VAMB are a frequent finding in chest CTA, and being independent from patient-related variables, it is likely due to technical issues such as intravenous access manipulation during the exam. Reduction after reinforcement of proper performance, and certification of a low concern from CT technicians for any risk associated, provides evidence that there is normalization of deviance in this everyday procedure.
本文提供的证据表明，胸部计算机断层扫描血管造影（CTA）中静脉空气微泡（VAMB）的检测可能是CT中“偏差正常化”现象的一个指标。
机构审查委员会批准的回顾性研究，豁免知情同意。对6个月内进行的对比增强胸部CT进行回顾，以检查胸部CT可见的静脉段（锁骨下静脉、头臂静脉、上腔静脉）和心腔内是否存在VAMB。通过半自动方法（OsiriX的MIAlite插件）对VAMB体积进行量化，使用覆盖气泡的感兴趣区域（ROI）。根据基础结果，强化正确注射技术的方案，并在1个月和3个月时再次评估VAMB。6个月后，向CT技术人员发送问卷，询问他们对VAMB的看法。进行了具有中心分布和离散度的描述性测量；P<0.05时认为具有统计学意义。
共分析了602例胸部CTA，其中332例为女性（55.14%），中位年龄为58岁（四分位间距[IQR]44 - 72岁）。其中，16.11%（100例）出现VAMB。大多数是急诊科患者（51.6%），男性（50.3%），中位年龄为54岁（IQR 26岁）。在VAMB的检测方面，性别（P = 0.19）、年龄（P = 0.46）或转诊诊断（P = 0.35）之间没有差异。平均气泡体积为0.2 mL（范围0.01 - 3.4 mL）。干预后，出现VAMB的检查数量降至3.29%（3/9[1]）（P<0.001）。在6个月的询问中，50%的技术人员仍然认为VMAB是不可避免的，60%的人认为其发生与风险无关，因此无需采取行动。
VAMB在胸部CTA中是一个常见发现，且与患者相关变量无关，这可能是由于检查期间静脉通路操作等技术问题所致。强化正确操作后VAMB减少，以及CT技术人员对任何相关风险的低关注度证明了这一日常程序中存在偏差正常化。
