Assessment of regional lung ventilation by electrical impedance tomography in a patient with unilateral bronchial stenosis and a history of tuberculosis

Abstract

Bronchial stenosis can impair regional lung ventilation by causing abnormal, asymmetric airflow limitation. Electrical impedance tomography (EIT) is an imaging technique that allows the assessment of regional lung ventilation and therefore complements the functional assessment of the lungs. We report the case of a patient with left unilateral bronchial stenosis and a history of tuberculosis, in whom regional lung ventilation was assessed by EIT. The EIT results were compared with those obtained by ventilation/perfusion radionuclide imaging. The patient was using nasal continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea syndrome. Therefore, we studied the effects of postural changes and of the use of nasal CPAP. The EIT revealed heterogeneous distribution of regional lung ventilation, the ventilation being higher in the right lung, and this distribution was influenced by postural changes and CPAP use. The EIT assessment of regional lung ventilation produced results similar to those obtained with the radionuclide imaging technique and had the advantage of providing a dynamic evaluation without radiation exposure.

Helping students to understand physiological aspects of regional distribution of ventilation in humans: a experience from the electrical impedance tomography

“…The EIT equipment utilized was the DIX1800 (Dixtal, Manaus, Brazil). All of the procedures of fitting, adjustment, data collection, and image analysis followed an already validated methodology described elsewhere (4,14,28). Briefly, image acquisition was performed using 32 electrodes arranged around the chest, at the level of the fifth intercostal space.…”

“…After a reflective discussion about these findings from the practical learning activity expressing these differences, our students were able to clearly understand the influence of changing decubitus on regional lung ventilation in normal conditions. Moreover, this knowledge provides a basis for the student to better understand the regional distribution of the ventilation in pathophysiological situations, such as unilateral atelectasis or unilateral bronchial stenosis or obstruction, for example (14).…”

“…With this technique, multiple voltage measurements allow the reconstruction of internal spatial distribution of resistivity, thus yielding anatomic analysis (6,28). More recently, it was shown that EIT is a simple and reliable technique, which may be performed by physicians or physiotherapists, and may assist bedside diagnosis of differences in regional lung ventilation (14). Several advantageous features of EIT, such as noninvasiveness, harmlessness, radiation-free measurement, portability, and excellent time resolution, allow the examination of highly dynamic physiological phenomena and make it very attractive for use in clinical practice, but it has not been fully considered as a teaching tool in the field of physiological aspects of regional distribution of ventilation in humans (9).…”

Lung scintigraphy in differential diagnosis of peripheral lung cancer and community-acquired pneumonia

“…Main cause of challenges consists in similarity of clinical presentation of CAP and other diseases manifesting with development of infiltrative processes in the lungs (malignant neoplasms, infiltrative pulmonary tuberculosis, pulmonary embolism, etc.) [3][4][5][6]. The process for developing a differential diagnosis between CAP and peripheral lung cancer is associated with particular difficulties [3].…”

“…Unfortunately, 60% to 90% of initial patients with lung cancer undergo wrongful treatment for pneumonia, tuberculosis, and some other diseases [4,6]. The causes of late diagnosis of lung cancer generally comprise symptom non-specificity resulting in high likelihood of false negative results of chest X-ray examination [4].…”