Abstract
The purpose of this study was to assess the clinical reliability and to compare routine lung function tests (maximal flows and resistance) and radiological images (computed tomography (CT)-scan and X-ray) in upper airway obstruction. We, therefore, performed these examinations prospectively in 28 female patients (aged 68 +/- 13 yrs) with a goitre and without pulmonary disorders. Lung function measurements consisted of maximum expiratory and inspiratory flow-volume curves and of airway resistance. CT-scans and X-rays were performed during apnoea at functional residual capacity (FRC). Peak expiratory flow was 3.6 +/- 1.3 l.s-1 (i.e. 62 +/- 21% predicted); airway resistance was 0.38 +/- 0.14 kPa (i.e. 149 +/- 58% pred); and specific conductance was 1.0 +/- 0.3 kPa (i.e. 70 +/- 24% pred). Almost all lung function tests were significantly correlated with each other. On CT-scan the tracheal cross-sectional area at the zone of tracheal narrowing could be evaluated in 26 patients and was 58 +/- 17% (CT1/2) of the control area 2 cm above the carina (CT2). On X-ray the sagittal and coronal tracheal diameters at the zone of narrowing could only be measured in 16 subjects and were 60 +/- 17% (X-dia1/2) of the diameter at the control level. CT1/2 and X-dia1/2 were significantly correlated to each other. No correlation was found between the lung function tests and the radiological indices except airway resistance and CT2. Routine lung function and CT-scan do not provide comparable information on the degree of airway obstruction due to a goitre.(ABSTRACT TRUNCATED AT 250 WORDS)