Computed tomography airway lumen volumetry in patients with acromegaly: Association with growth hormone levels and lung function.

IntroductionThe segmentation and skeletonisation of images via computed tomography (CT) airway lumen volumetry provide a new perspective regarding the incorporation of this technique in medical practice. Our aim was to quantify morphological changes in the large airways of patients with acromegaly through CT and, secondarily, to correlate these findings with hormone levels and pulmonary function testing (PFT) parameters. MethodsThis was a cross-sectional study in which 28 non-smoker patients with acromegaly and 15 control subjects underwent CT analysis of airway lumen volumetry with subsequent image segmentation and skeletonisation. Moreover, all participants were subjected to PFT. ResultsCompared with the controls, patients with acromegaly presented higher diameters in the trachea, right main bronchus and left main bronchus. The patients with acromegaly also showed a higher tracheal sinuosity index (the deviation of a line from the shortest path, calculated by dividing total length by shortest possible path) than the controls [1.06 (1.02-1.09) vs. 1.03 (1.02-1.04), P=0.04], and tracheal stenosis was observed in 25% of these individuals. The tracheal area was correlated with the levels of growth hormone (r(s)=0.45, P=0.02) and insulin-like growth factor type I (r(s)=0.38, P=0.04). The ratio between the forced expiratory flow and forced inspiratory flow at 50% of the forced vital capacity was correlated with the tracheal area (r(s)=0.36, P=0.02) and tracheal diameters (r(s)=0.58, P<0.0001). ConclusionPatients with acromegaly exhibit tracheobronchomegaly and tracheal sinuosity/stenosis. Moreover, there are associations between the results of CT airway lumen volumetry, hormone levels and functional parameters of large airway obstruction.