Common patterns on flow-volume loops

The flow-volume loops are plotted against absolute lung volume to show the influence of changes in lung volume. For both loops in each panel, the leftward intersection with the horizontal axis is at total lung capacity (TLC, maximal inhalation) and the rightward intersection is at residual volume (RV, maximal exhalation).
(A) Patient with airflow limitation (solid lines) compared to predicted (dashed lines).
(B) Patient with mixed disease with reduced airflow and reduced lung volumes. It is important to note that if one only measures airflow, this mixed picture would have been missed.
(C) The flow-volume loop observed in a patient with restrictive disease where the increased recoil causes increased airflow.
(D) Consistent truncation of the inspiratory phase of the loop, characteristic of a variable extrathoracic obstruction, eg, tracheal collapse as might be due to intubation trauma.
(E) Another extrathoracic process of a more transient nature characteristic of vocal cord dysfunction.
(F) Consistent truncation of both inspiration and expiration, characteristic of a fixed obstruction, eg, tracheal stenosis.