Role of chest radiography in predicting the extent of airway disease in patients with suspected pulmonary embolism.

An independent evaluation of the chest radiographs and ventilation-perfusion (VP) scintigrams of 119 patients (121 studies) was performed to assess the ability of radiographic findings to indicate the extent of ventilation abnormalities in patients suspected of having pulmonary embolism (PE). VP scans were obtained with krypton-81m in 72 cases and with xenon-133 in 49. All scintigrams showing ventilation abnormalities in greater than 50% of the lung were considered indeterminate for PE, owing to an increased likelihood of false-negative interpretations, as reported in previous studies. Indeterminate VP studies were found in all 21 patients who had radiographic findings of widespread obstructive pulmonary disease (OPD), in 35% with radiographic findings of focal OPD (P less than .001), and in only 18% with no OPD seen radiographically (P less than .001). VP scintigraphy is likely to be indeterminate for PE when widespread OPD is seen by chest radiography and ventilation imaging may not be warranted in these patients.