Electrical impedance tomography: ready for prime time?

Excerpt

Electrical impedance tomography (EIT) continues to fascinate investigators as it is the only noninvasive technique that provides insight into the regional distribution of ventilation. As investigations with computed tomography (CT) have taught us, acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are heterogeneous diseases, and regional differences in compliance are associated with distinct regional differences in opening and closing pressures [1, 2, 3, 4]. While CT images provide important information about alveolar collapse and reversal of atelectasis, the technique is not easily applied to routine management of patients with ALI [5]. The technology underlying EIT was first developed over 30 years ago, and a variety of EIT systems have been used as research devices to investigate gastric emptying, cerebral ischemia, breast cancer, and, relevant to this discussion, lung tissue [6]. Recent investigations have focused on the utility of EIT to detect regional imbalances in ventilation in animals [7, 8, 9] and in patients with ALI [10, 11]. …