Division of Respiratory Medicine, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
Department of Radiology, St. Marianna University School of Medicine, Kawasaki, Japan.
Respiration. 2021;100(2):109-115. doi: 10.1159/000511437. Epub 2021 Jan 21.
Relapsing polychondritis (RP) is a rare systemic disease of unknown origin, with cartilaginous involvement in multiple organs. Airway involvement is the most important prognostic factor in RP.
Spirometric measurements and minimum tracheal cross-sectional area (mtCSA) have been reported as useful to assess the degree of airway stenosis. Because the length and severity of tracheal involvement in RP can vary, mtCSA might not provide enough information to assess tracheal abnormalities. We introduced tracheal volume (TrV) as a new method to evaluate correlations between chest computed tomography (CT) measurements and pulmonary function tests, including impulse oscillometry (IOS).
We analyzed chest CT images, spirometry, and IOS collected at our institution from April 2004 to March 2019. We calculated correlations between chest CT measurements using software (TrV, TrV/tracheal length [TrV/TL], and mtCSA) and pulmonary function parameters.
Twenty-five of 73 clinically diagnosed patients with RP were included. Spirometric findings showed moderate airway obstruction. Peak flow (PEF) was strongly correlated with mtCSA, TrV, and TrV/TL (ρ = 0.74, p < 0.001). FEV1 was significantly correlated with mtCSA (ρ = 0.56, p = 0.004), TrV (ρ = 0.52, p = 0.007), and TrV/TL (ρ = 0.53, p = 0.006). Whereas respiratory resistance at 5 Hz (R5) and 20 Hz (R20) and resonant frequencies (RFs) were significantly correlated with TrV (ρ = -0.46, p = 0.021; ρ = -0.46, p = 0.046; and ρ = -0.42, p = 0.037, respectively), IOS parameters and mtCSA were not.
In patients with RP, TrV and mtCSA were strongly correlated with spirometric measurements. Respiratory resistances assessed by IOS correlated only with TrV. This suggests TrV assessment reflects pulmonary function in patients with RP more appropriately than mtCSA.
复发性多软骨炎（RP）是一种病因不明的罕见全身性疾病，多器官软骨受累。气道受累是 RP 的最重要预后因素。
已有研究报告称，肺量计测量和最小气管横截面积（mtCSA）可用于评估气道狭窄程度。由于 RP 中气管受累的长度和严重程度可能有所不同，mtCSA 可能无法提供足够的信息来评估气管异常。我们引入气管容积（TrV）作为一种新方法，以评估胸部计算机断层扫描（CT）测量值与肺功能测试（包括脉冲震荡法（IOS））之间的相关性。
我们分析了 2004 年 4 月至 2019 年 3 月在我院采集的胸部 CT 图像、肺量计和 IOS。我们使用软件计算了胸部 CT 测量值（TrV、TrV/气管长度[TrV/TL]和 mtCSA）与肺功能参数之间的相关性。
25 例经临床诊断的 RP 患者纳入研究。肺量计检查结果显示中度气道阻塞。最高呼气流速（PEF）与 mtCSA、TrV 和 TrV/TL 呈强相关性（ρ=0.74，p<0.001）。FEV1 与 mtCSA（ρ=0.56，p=0.004）、TrV（ρ=0.52，p=0.007）和 TrV/TL（ρ=0.53，p=0.006）呈显著相关性。而 5Hz（R5）和 20Hz（R20）呼吸阻力和共振频率（RFs）与 TrV 呈显著相关性（ρ=-0.46，p=0.021；ρ=-0.46，p=0.046；ρ=-0.42，p=0.037），而 IOS 参数和 mtCSA 与它们无相关性。
在 RP 患者中，TrV 和 mtCSA 与肺量计测量值呈强相关性。IOS 评估的呼吸阻力仅与 TrV 相关。这表明，与 mtCSA 相比，TrV 评估更能反映 RP 患者的肺功能。
