Basson Derik J, Moodley Halvani
Department of Diagnostic Radiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Department of Radiology, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa.
SA J Radiol. 2022 Mar 24;26(1):2350. doi: 10.4102/sajr.v26i1.2350. eCollection 2022.
Undiagnosed pulmonary embolism carries high mortality and morbidity. Computed tomography pulmonary angiogram (CTPA) is the diagnostic method of choice for accurate diagnosis. Inadequate contrast opacification is the second most common cause of indeterminate CTPAs.
Audit the adequacy of CTPA contrast enhancement and determine whether inadequate enhancement is affected by the size and site of the intravenous cannula, flow rate, contrast volume, contrast leakage and day shift versus after hours services.
Retrospective and prospective audits of the adequacy of contrast enhancement of CTPAs at the Charlotte Maxeke Johannesburg Academic Hospital were conducted using the Royal College of Radiologists guidelines (≤ 11% of studies with < 210 HU). Protocol variables were collected prospectively from questionnaires completed by radiographers performing the CTPAs. Adequate versus inadequate groups were analysed.
A total of 63 (retrospective) and 130 (prospective) patients were included with inadequate contrast enhancement rates of 19% (12/63) and 20.8% (27/130), respectively. The majority of CTPAs were performed during the day 56.2% (73/130) with a 20G cannula 66.2% (86/130) in the forearm 33.8% (44/130) injecting 100 mL - 120 mL contrast 43.1% (56/130) at 3 mL/s 63.1% (82/130). The median flow rate (3 mL/s) and contrast volume (80 mL) were identical in both adequate and inadequate groups, while the remaining variables showed no statistical difference.
The rate of inadequately enhanced CTPAs in this study was high. The protocol variables did not have a significant influence on the rate of inadequate enhancement. Further research, particularly using flow rates > 4 mL/s, is required for protocol optimisation.
未确诊的肺栓塞具有较高的死亡率和发病率。计算机断层扫描肺动脉造影（CTPA）是准确诊断的首选诊断方法。对比剂充盈不足是CTPA结果不确定的第二大常见原因。
评估CTPA对比增强的充分性，并确定增强不足是否受静脉插管的大小和部位、流速、对比剂用量、对比剂渗漏以及日间班次与非工作时间服务的影响。
根据皇家放射科医师学会指南（<210 HU的研究占≤11%），对夏洛特·马克塞克约翰内斯堡学术医院的CTPA对比增强充分性进行回顾性和前瞻性评估。方案变量通过执行CTPA的放射技师填写的问卷前瞻性收集。对充分组和不充分组进行分析。
共纳入63例（回顾性）和130例（前瞻性）患者，对比增强不足率分别为19%（12/63）和20.8%（27/130）。大多数CTPA在白天进行，占56.2%（73/130）；使用20G插管，占66.2%（86/130），在前臂，占33.8%（44/130）；注射100 mL - 120 mL对比剂，占43.1%（56/130）；流速为3 mL/s，占63.1%（82/130）。充分组和不充分组的中位流速（3 mL/s）和对比剂用量（80 mL）相同，而其余变量无统计学差异。
本研究中CTPA增强不足的发生率较高。方案变量对增强不足率没有显著影响。需要进一步研究，特别是使用流速>4 mL/s的情况，以优化方案。
