Tracheobronchomalacia incidentally detected on Tc-99m ventilation/perfusion SPECT.

A Tc-99m Technegas MAA-SPECT was performed on an 81-year-old woman to exclude pulmonary embolism. It showed hypoperfusion and practically absent ventilation of the entire left lung, suggesting a left-sided centrally localized airway obstruction or compression with secondary hypoxic vasoconstriction. Subsequent bronchoscopy and CT scan detected tracheobronchomalacia with significant narrowing of the left bronchus.Tracheobronchomalacia is a rare, benign condition, referring to the deficiency in cartilage of the tracheobronchial tree, caused by a variety of factors.