[Radiological indices of pulmonary hypertension in chronic obstructive pulmonary disease (author's transl)].

This study attempted to correlate mean pulmonary arterial pressure with four radiological indices of pulmonary hypertension in 159 patients with chronic obstructive pulmonary disease. The mean pulmonary arterial pressure at rest (PAPR) and with exercise (PAPE) and four indices measured from the plain chest radiograph were considered. The measurements were: 1) DIP: the distance between the bifurcation of the right and left main pulmonary arteries, 2) DIP/T X 100 where T is a maximal thoracic diameter, 3) R: the diameter of the right descending pulmonary artery, and 4) R/h x 100 where h is T/2. The mean index values +/- SD obtained from three observers were: DIP = 11.4 +/- 1 cm, DIP/T x 100 = 36.1 +/- 3.5 R = 1.9 +/- 4cm, R/h x 100 = 12 +/- 2.7. An analysis of variation demonstrated that the interobserver error was unacceptable for R and R/h x 100 but small for DIP and DIP/T x 100. Increased PAP does not implicate high index values but high values specify abnormal PAP. The results suggest that DIP greater than 13 cm or DIP/T x 100 greater than 42 are diagnostic. A minority presented such values, but in 20 to 30% of these cases this preceded clinical or electrocardiographic manifestations of cor pulmonale.