Department of Radiology, Mayo Clinic Rochester.
Sarcoidosis Vasc Diffuse Lung Dis. 2020;37(4):e2020016. doi: 10.36141/svdld.v37i4.9584. Epub 2020 Dec 16.
A subset of ANCA-associated vasculitis (AAV) patients are known to manifest obstructive airway disease. Using low attenuation areas (LAA) in the lung on HRCT as an imaging marker for obstructive airway disease, we analyze HRCT studies in AAV patients compared to a matched non-AAV group using visual semi-quantitative and automated quantitative analysis for presence and severity of LAA. Furthermore, HRCT and pulmonary function testing are compared to assess agreement between tests for airway obstruction.
100 randomly selected AAV patients with HRCT were compared to 100 best-fit matched control subjects. HRCT cases were visually assessed for LAA, along with additional pulmonary patterns. Automated quantitative software analyzed images for texture features and volume of attenuation values of -950 HU or less (e-950). Evidence of obstructive airway disease established by pulmonary function testing, when available, was compared to HRCT analysis for LAA. Additional clinical information, diagnostic testing and mortality data were also compared.
Both study groups were comprised of 57 females and 43 males with 35 smokers averaging 10.7 pk/yrs, with average age for the AAV and control groups being 59.4 yrs and 61.9 yrs, respectively. Visually, 46 AAV patients demonstrated LAA on HRCT compared to 25 control patients (p=0.0017) with the difference in LAA presence entirely within the non-smoking subgroup (25 to 3, respectively, p=<0.0001). Quantitatively, greater than 5% e-950 demonstrated similar significant differences between AAV (36/100) and controls (19/100) (p=0.0065), predominantly in non-smokers (p=0.006). Obstruction on PFTs was significantly increased in AAV (p=0.002) with moderate agreement of obstructive disease with visual LAA on CT (Kappa 0.509). Of the obstructive disease metrics, visual LAA on CT correlated best with mortality (p=0.0085).
Visual LAA and automated quantitative analysis for e-950 on HRCT demonstrate statistically significant increases in AAV patients compared to age, gender and smoking matched controls, with differences primarily seen in the non-smoking subset. AAV revealed statistically significant greater obstructive pulmonary disease on PFTs .
已知一部分抗中性粒细胞胞浆抗体（ANCA）相关性血管炎（AAV）患者表现出阻塞性气道疾病。我们使用高分辨率 CT（HRCT）上的低衰减区（LAA）作为阻塞性气道疾病的影像学标志物，对 AAV 患者的 HRCT 研究与年龄、性别和吸烟相匹配的对照组进行分析，采用视觉半定量和自动定量分析来评估 LAA 的存在和严重程度。此外，比较 HRCT 和肺功能检查以评估两种检查方法在评估气道阻塞方面的一致性。
比较了 100 例随机选择的 AAV 患者的 HRCT 与 100 例最佳匹配的对照组。对 HRCT 病例进行 LAA 以及其他肺部模式的视觉评估。自动定量软件分析图像的纹理特征和衰减值为-950 HU 或更低（e-950）的体积。当存在时，通过肺功能检查确定阻塞性气道疾病的证据，并与 HRCT 分析 LAA 进行比较。还比较了其他临床信息、诊断检测和死亡率数据。
两组均由 57 名女性和 43 名男性组成，35 名吸烟者平均吸烟 10.7 包/年，AAV 和对照组的平均年龄分别为 59.4 岁和 61.9 岁。在 HRCT 上，46 例 AAV 患者表现出 LAA，而对照组中只有 25 例（p=0.0017），LAA 存在的差异完全在不吸烟亚组中（分别为 25 比 3，p<0.0001）。定量分析显示，AAV（36/100）和对照组（19/100）之间的 e-950 大于 5%存在显著差异（p=0.0065），主要在不吸烟者中（p=0.006）。AAV 的 PFT 上的阻塞明显增加（p=0.002），CT 上的视觉 LAA 与 CT 上的阻塞性疾病具有中度一致性（Kappa 0.509）。在阻塞性疾病指标中，CT 上的视觉 LAA 与死亡率相关性最好（p=0.0085）。
与年龄、性别和吸烟相匹配的对照组相比，HRCT 上的视觉 LAA 和 e-950 的自动定量分析显示 AAV 患者存在统计学上显著增加，差异主要见于不吸烟者。AAV 在 PFT 上显示出统计学上更大的阻塞性肺疾病。
