Correlation of regional densitometry patterns, radiological appearances, and pulmonary function tests in chronic bronchitis and emphysema

Abstract

In 20 male patients suffering from chronic bronchitis and emphysema investigated by pulmonary x-ray densitometry, five different types of densitometer trace pattern were observed during the FEV manoeuvre, which appeared to be related to the degree of zonal airway obstruction and the radiological severity of emphysema. We thought some of the features of the traces were caused by displacement of blood from the area of the lung being examined by trapped alveolar air at a pressure exceeding those in the surrounding blood vessels. A close correlation (P<0001) was found between the conventional FEV1 and the pulmonary densitometer score derived from summated regional observations made during the FEV manoeuvre. A similar high degree of correlation was observed between the FEV1 and a score based on regional radiological appearances. Correlations between Pao2 and Paco2 and the densitometer and x-ray scores were of doubtful significance. The findings indicate that critical evaluation of the radiological features of the pulmonary vessels in patients with emphysema is useful in assessing the overall degree of airway obstruction. Regional densitometer pattern analysis is a valuable contributory method of investigating these patients and -the results of a comparison of these two methods suggest that it may be possible to distinguish between larger and smaller airway obstruction.At the present time, methods of investigating regional ventilation include bronchospirometry, bronchial catheterization with mass spectrometry, and isotope scanning and counting techniques.

Potassium studies in chronic obstructive airways disease.

“…The mean value of TBK in the normocapnic group was significantly lower than normal, though that for the hypercapnic group was not. The difference between the mean values of TBK in the two groups (90-2% and (Sutherland et al, 1971). tSignificantly low (p < 0-005).…”

“…Height and weight were measured, and the latter was compared with that predicted for sex, height, and age (Society of Actuaries, Chicago, 1959). A chest radiograph was obtained and examined by a radiologist (GRS) who awarded an "emphysema score" (Sutherland et al, 1971). An arterial blood sample for blood gas estimation was taken on each of two consecutive days from the radial artery with the patient lying rested and breathing room air for 30 minutes.…”