EIT: a non-radiating functional imaging method for cystic fibrosis

描述（由申请人提供）：患有慢性肺部疾病的个体通常具有在没有成像技术的帮助下很难诊断的病症。黄金标准，CT扫描，使病人暴露在电离辐射中，可能对儿童有害。电阻抗断层扫描（EIT）是一种非侵入性、非电离的功能成像技术，其中电极放置在身体表面，并在电极上施加低振幅、低频电流。这导致电极上的电压分布，然后可以测量。从这些电压中，形成一个图像，反映感兴趣区域内的电导率和/或介电常数分布。由于EIT是一种安全、便携的技术，没有破坏性的副作用，因此可以根据需要使用。该项目是开发用于慢性肺病患者成像的EIT系统的长期目标的一部分。本研究的目的是确定电阻抗断层扫描是否可以提供一种方法来获得关于囊性纤维化（CF）患者支气管阻塞的程度和性质的定量和区域信息。特别是，EIT将用于识别CF患者的梗阻（空气捕获）和由肺不张和气道闭塞组成的实变区域，并将这些措施与住院治疗后肺部恶化的改善相关联。第一个具体目标是开发量化支气管阻塞和实变的算法，并确定其敏感性和特异性。该算法将从使用P.I.开发的D-bar重建算法计算的电导率和介电常数的EIT图像中提取信息。数据将在临床指示进行CT扫描的CF患者和健康肺部受试者的肺活量测定中收集，并使用健康受试者的数据和CT VIDA软件计算的数据来确定算法的敏感性和特异性。第二个具体目标是确定这些算法是否可以通过将定量EIT测量的变化与治疗后已知改善的临床测量相关联来证明抗生素治疗对CF合并急性PE患者的有益效果，患者作为自己的对照。计算EIT图像显示的空气捕获和合并从处理前到处理后的区域变化，受试者作为自己的对照。

DESCRIPTION (provided by applicant): Individuals with chronic lung disease often have conditions that are very difficult to diagnose without the aid of imaging technology. The gold standard, CT scanning, exposes the patient to ionizing radiation and may be harmful in children. Electrical impedance tomography (EIT) is a noninvasive, non-ionizing functional imaging technique in which electrodes are placed on the surface of the body, and low amplitude, low frequency current is applied on the electrodes. This results in a voltage distribution on the electrodes which can then be measured. From these voltages, an image is formed that re acts the conductivity and/or permittivity distribution within the region of interest. Since EIT is a saf and portable technology with no damaging side effects, it can be used as needed. This project is part of a long term goal to develop an EIT system for imaging patients with chronic lung disease. The goal of this research is to determine whether electrical impedance tomography can provide a means to obtain quantitative and regional information about the extent and nature of bronchial obstruction in patients with cystic fibrosis (CF). In particular, EIT will be used to identify regions of obstruction (air trapping) and consolidation comprised of atelectasis and airway occlusion in CF patients, and to correlate these measures with improvements seen after hospitalized treatment for a pulmonary exacerbation. The first specific aim is to develop algorithms for quantifying bronchial obstruction and consolidation and to determine their sensitivity and specificity. The algorithms will extract information from EIT images of conductivit and permittivity computed using the D-bar reconstruction algorithm developed by the P.I. Data will be collected during spirometry on CF patients clinically indicated for CT scans and on subjects with healthy lungs, and the sensitivity and specificity of the algorithms will be determined using both the data from the healthy subjects and data calculated from CT VIDA Software. The second specific aim is to determine whether these algorithms can demonstrate the beneficial effects of antibiotic treatment for CF patients with an acute PE by correlating changes in quantitative EIT measures with clinical measures known to improve following therapy, with patients serving as their own controls. Regional changes in air trapping and consolidation from pre to post treatment as indicated by the EIT images will be calculated, with subjects serving as their own control.