Bonney Asha, Wagner Carrie-Anne, Siva Shankar, Callahan Jason, Le Roux Pierre-Yves, Pascoe Diane M, Irving Louis, Hofman Michael S, Steinfort Daniel P
Department of Respiratory Medicine, Royal Melbourne Hospital, Parkville, Victoria, Australia.
Department of Medicine, University of Melbourne, Parkville, Victoria, Australia.
EJNMMI Res. 2020 Jul 28;10(1):86. doi: 10.1186/s13550-020-00672-8.
Emphysema severity is frequently measured on CT via densitometry. Correlation with scintigraphic and spirometric functional measures of ventilation or perfusion varies widely, and no prior study has evaluated correlation between densitometry and lobar ventilation/perfusion in patients with severe emphysema. The aim of this study was to evaluate the utility and findings of gallium-68 (Ga) ventilation/perfusion positron emission tomography-CT (Ga-VQ/PET-CT) in severe emphysema assessment.
Fourteen consecutive patients undergoing evaluation for bronchoscopic lung volume reduction between March 2015 and March 2018 underwent Ga-VQ/PET-CT assessment for lobar functional lung mapping, in addition to CT densitometry. Correlations between CT densitometry and Ga-VQ/PET-CT parameters for individual lobar lung function were sought.
CT densitometry assessment of emphysema correlated only weakly (R = 0.13) with lobar perfusion and was not correlated with ventilation (R = 0.04). Densitometry was moderately (R = 0.67) correlated with V/Q units in upper lobes, though poorly reflected physiological function in lower lobes (R = 0.19). Emphysema severity, as measured by CT densitometry, was moderately correlated with proportion of normal V/Q units and matched V/Q defects in individual lobes.
Assessment of lobar pulmonary function by Ga-VQ/PET-CT provides physiologic information not evident on CT densitometry such as ventilation and perfusion specifics and matched defects. Further research is needed to see if the discordant findings on Ga-VQ/PET-CT provide prognostic information or can be used to modify patient management and improve outcomes.
肺气肿严重程度常通过CT上的密度测定法来衡量。其与通气或灌注的闪烁扫描和肺功能仪功能指标的相关性差异很大，且此前尚无研究评估重度肺气肿患者密度测定与肺叶通气/灌注之间的相关性。本研究的目的是评估镓-68（Ga）通气/灌注正电子发射断层扫描-CT（Ga-VQ/PET-CT）在重度肺气肿评估中的效用和结果。
2015年3月至2018年3月期间，连续14例接受支气管镜肺减容术评估的患者除了进行CT密度测定外，还接受了Ga-VQ/PET-CT评估以进行肺叶功能肺成像。研究了CT密度测定与各肺叶肺功能的Ga-VQ/PET-CT参数之间的相关性。
肺气肿的CT密度测定评估与肺叶灌注仅呈弱相关性（R = 0.13），与通气无相关性（R = 0.04）。密度测定与上叶的V/Q单位呈中度相关性（R = 0.67），但在反映下叶生理功能方面较差（R = 0.19）。通过CT密度测定法测量的肺气肿严重程度与各肺叶正常V/Q单位的比例和匹配的V/Q缺陷呈中度相关。
通过Ga-VQ/PET-CT评估肺叶肺功能可提供CT密度测定中不明显的生理信息，如通气和灌注细节以及匹配的缺陷。需要进一步研究以确定Ga-VQ/PET-CT上不一致的结果是否能提供预后信息或可用于调整患者管理并改善结局。
