Lung ventilation scintigraphy in the assessment of obstructive lung diseases.

Educational aims
To describe more recent techniques used to study the regional distribution of ventilation.

To learn the most frequent abnormal patterns of lung ventilation scintigraphy (LVS) in obstructive lung diseases.

To compare the information obtained by this technique with that obtained by traditional lung function tests.

To understand that LVS may provide further information on lung pathophysiology.

Summary
LVS is a well known technique that is used to study the distribution of ventilation in pulmonary diseases. However, its application in current practice has been poorly developed, mainly because of methodological problems. Redistribution of convective ventilation is the leading disorder in patients with chronic obstructive pulmonary disease (COPD) and is the target of most treatments, either by drugs or mechanical ventilation. The current availability of a new delivery inhaler (FAI; Medical Products Research, Legnano, Italy) with fine particles allows: 1) fast aerosol administration; 2) high-quality early images; 3) improved visualisation of pulmonary periphery; and 4) wider physiological distribution of the radioaerosol. Several patterns of distribution of pulmonary ventilation can be described in different airway disorders (asthma and COPD). These abnormalities are often too subtle to be picked up by traditional lung function tests, both in the baseline evaluation and after different interventions. Wider use of this technique may increase the knowledge and the management of obstructive lung diseases.