Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19102, United States of America.
Department of Radiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America.
Clin Imaging. 2021 Oct;78:94-97. doi: 10.1016/j.clinimag.2021.03.018. Epub 2021 Mar 20.
Acute chest syndrome (ACS), defined by the presence of a chest radiographic opacity in sickle cell disease patients experiencing respiratory symptoms is a leading cause of death in these patients. The etiology is ACS is not well understood however pulmonary microvascular occlusion has been postulated to be a major pathophysiologic driver. Our study aims to assess the value of dual-energy CT (DECT) as a marker of pulmonary microvascular occlusion.
MATERIALS/METHODS: A search tool was used to identify CT angiography studies from 1/1/2017 to 9/15/2019 with any variation of the phrases "Acute chest syndrome" and "Sickle cell". These studies were manually reviewed for the use of DECT technique. An age-matched control group was created. DECT pulmonary blood volume (PBV) maps were reviewed semi-quantitatively for the presence of iodine defects and the number of involved bronchopulmonary segments were scored. Other recorded values included type of parenchymal opacities, diameter of main pulmonary artery (MPA) and presence of right ventricular dilatation. Mean values between cases and controls were compared using a two-sample t-test.
Nine sickle cell DECT cases with PBV maps and nine age-matched controls were evaluated. Bronchopulmonary segments with iodine defects were significantly higher in cases vs controls (mean: 4.7 vs 0.3, p < 0.003). PBV defects were more extensive than parenchymal findings. MPA diameter was higher in cases (2.9 cm) vs control (2.4 cm), P < 0.03.
DECT demonstrates abnormal PBV in sickle cell patients, often the predominant abnormality identified early, and likely reflects the presence of pulmonary microvascular occlusion.
在患有镰状细胞病并出现呼吸症状的患者中，急性胸部综合征（ACS）定义为胸部 X 光片出现不透明影，是此类患者死亡的主要原因。ACS 的病因尚不清楚，但已推测肺微血管闭塞是主要的病理生理驱动因素。本研究旨在评估双能 CT（DECT）作为肺微血管闭塞标志物的价值。
材料/方法：使用搜索工具从 2017 年 1 月 1 日至 2019 年 9 月 15 日，确定了带有任何变体的 CT 血管造影研究，短语为“急性胸部综合征”和“镰状细胞病”。这些研究经过手动审查，以确定是否使用 DECT 技术。创建了一个年龄匹配的对照组。使用半定量方法对 DECT 肺血容量（PBV）图进行分析，以评估碘缺损的存在情况，并对受累支气管-肺段的数量进行评分。记录的其他值包括实质混浊的类型、主肺动脉（MPA）直径和右心室扩张的存在。使用两样本 t 检验比较病例组和对照组之间的平均值。
评估了 9 例镰状细胞病 DECT 病例和 9 例年龄匹配的对照组，发现病例组的碘缺损支气管-肺段明显高于对照组（平均值：4.7 比 0.3，p<0.003）。PBV 缺陷比实质病变更广泛。病例组的 MPA 直径较高（2.9cm），对照组为（2.4cm），P<0.03。
DECT 显示镰状细胞病患者的 PBV 异常，通常是早期发现的主要异常，可能反映了肺微血管闭塞的存在。
