Division of Biological Engineering, Monash University, Victoria, Australia.
J R Soc Interface. 2012 Sep 7;9(74):2213-24. doi: 10.1098/rsif.2012.0116. Epub 2012 Apr 4.
During breathing, lung inflation is a dynamic process involving a balance of mechanical factors, including trans-pulmonary pressure gradients, tissue compliance and airway resistance. Current techniques lack the capacity for dynamic measurement of ventilation in vivo at sufficient spatial and temporal resolution to allow the spatio-temporal patterns of ventilation to be precisely defined. As a result, little is known of the regional dynamics of lung inflation, in either health or disease. Using fast synchrotron-based imaging (up to 60 frames s(-1)), we have combined dynamic computed tomography (CT) with cross-correlation velocimetry to measure regional time constants and expansion within the mammalian lung in vivo. Additionally, our new technique provides estimation of the airflow distribution throughout the bronchial tree during the ventilation cycle. Measurements of lung expansion and airflow in mice and rabbit pups are shown to agree with independent measures. The ability to measure lung function at a regional level will provide invaluable information for studies into normal and pathological lung dynamics, and may provide new pathways for diagnosis of regional lung diseases. Although proof-of-concept data were acquired on a synchrotron, the methodology developed potentially lends itself to clinical CT scanning and therefore offers translational research opportunities.
在呼吸过程中，肺充气是一个涉及机械因素平衡的动态过程，包括跨肺压力梯度、组织顺应性和气道阻力。目前的技术缺乏在足够的时空分辨率下对体内通气进行动态测量的能力，无法精确定义通气的时空模式。因此，对于健康或疾病状态下的肺充气的区域动力学，人们知之甚少。我们使用基于同步加速器的快速成像（高达 60 帧/秒），将动态计算机断层扫描（CT）与互相关速度测量法相结合，以测量哺乳动物肺在体内的区域时变常数和膨胀。此外，我们的新技术还提供了在通气周期中整个支气管树内气流分布的估计。对小鼠和兔仔的肺膨胀和气流的测量结果与独立测量结果一致。在区域水平上测量肺功能的能力将为研究正常和病理肺动力学提供宝贵的信息，并可能为区域性肺病的诊断提供新的途径。虽然在同步加速器上获得了概念验证数据，但所开发的方法有可能适用于临床 CT 扫描，因此为转化研究提供了机会。
