Primary pulmonary hypertension: radiographic and scintigraphic patterns of histologic subtypes

The chest radiograph and perfusion lung scans were evaluated in 39 consecutive patients with primary pulmonary hypertension to see if these noninvasive methods could distinguish among the histologic subtypes. Chest radiographs were categorized as having either normal lung fields or increased bronchovascular markings. Blood flow on lung scans was graded as normal or as having diffuse, nonsegmental, patchy abnormalities. These patterns were then correlated against pathologic specimens obtained from 19 patients, which were graded on vascular changes and microthrombi. Plexogenic arteriopathy was characterized by a normal chest radiograph and normal distribution of tracer on lung scan. Thromboembolism was characterized by a normal chest radiograph but patchy distribution of tracer on lung scan. Pulmonary veno-occlusive disease was characterized by increased bronchovascular markings on chest radiograph as well as patchy distribution of tracer on lung scan. Distinguishing patients on the basis of their histologic characteristics may be important so that vasodilators or anticoagulants can be selected as therapy.