Department of Radiology, AKH Celle, Celle, Germany.
Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany.
Acta Radiol. 2023 Jun;64(6):2111-2117. doi: 10.1177/02841851231165486. Epub 2023 Apr 12.
Low attenuation volume percentage (LAV%) has been identified as a quantitative imaging biomarker for emphysema with good correlation with spirometry. The influence of intravenous contrast agent on LAV% and its correlation with spirometry is not well known.
To evaluate the influence of intravenous contrast agent on artificial intelligence (AI)-based LAV% in correlation with spirometric Tiffeneau-Pinelli Index (TI).
In a retrospective study, two groups of 47 patients (mean age 68.04 ± 12.64 and 67.89 ± 11.54 years) with either non-enhanced chest computed tomography (CT) or contrast-enhanced CT were compared. Using an AI-based software, LAV% was quantified using a threshold <-950 HU. TI was calculated from spirometry and pathologic airway obstruction was considered with a TI <70. The effect of contrast agent on LAV% and the relationship between TI and LAV% was analyzed. Correlation coefficients between TI and LAV% were compared for both groups.
Patients with non-enhanced CT had a mean LAV% of 9.07 ± 7.53. Of them, 22 patients had a TI <70% and 25 patients a TI ≥70%. Patients with contrast-enhanced CT had a mean LAV% of 6.54 ± 4.62. Of them, 20 patients had a TI <70% and 27 patients had a TI ≥70%. Contrast agent did not show a major effect on LAV% ( = 0.099) and the relationship between TI and LAV% ( = 0.88). In both groups, a significant correlation between TI and LAV% was found (ρ = -0.317 for non-enhanced CT; ρ = -0.514 for contrast-enhanced CT). Difference between correlation coefficients was insignificant.
Our findings suggest that contrast agent does not influence LAV% nor its correlation with TI.
低衰减容积百分比（LAV%）已被确定为一种与肺量计具有良好相关性的定量成像生物标志物。静脉内造影剂对 LAV%的影响及其与肺量计的相关性尚不清楚。
评估静脉内造影剂对基于人工智能（AI）的 LAV%的影响，并与肺量计 Tiffeneau-Pinelli 指数（TI）相关联。
在一项回顾性研究中，比较了两组 47 例患者（平均年龄 68.04 ± 12.64 岁和 67.89 ± 11.54 岁），分别为非增强胸部 CT（CT）或增强 CT。使用基于 AI 的软件，使用阈值 <-950 HU 对 LAV%进行量化。从肺量计计算 TI，并且考虑到气道阻塞病理，TI <70 被认为存在气道阻塞。分析造影剂对 LAV%的影响，以及 TI 和 LAV%之间的关系。比较两组 TI 和 LAV%之间的相关系数。
非增强 CT 的患者 LAV%平均值为 9.07 ± 7.53。其中，22 例患者 TI <70%，25 例患者 TI ≥70%。增强 CT 的患者 LAV%平均值为 6.54 ± 4.62。其中，20 例患者 TI <70%，27 例患者 TI ≥70%。造影剂对 LAV%没有明显影响（=0.099），并且对 TI 和 LAV%之间的关系也没有明显影响（=0.88）。在两组中，均发现 TI 和 LAV%之间存在显著相关性（非增强 CT 为 ρ=-0.317；增强 CT 为 ρ=-0.514）。相关系数之间的差异无统计学意义。
我们的研究结果表明，造影剂不会影响 LAV%及其与 TI 的相关性。
