Image Challenge of the Week!

Here we have a normal flow-volume curve of a properly performed spirometry test:

Normal flow-volume loop
McCarthy, K., & Dweik, R. A., M.D. (2017, August 04). Pulmonary Function Testing . Retrieved September 04, 2017, from http://emedicine.medscape.com/article/303239-overview

Identify the large upper airway obstruction abnormalities shown in the following the flow-volume loops:

variable extrathoracic upper airway obstruction
A
variable intrathoracic upper airway obstruction
B
fixed upper airway obstruction
C

Continue reading Image Challenge of the Week!