Accuracy of MR angiography compared with radionuclide scanning in identifying the cause of pulmonary arterial hypertension.

Abstract

MR imaging has proven accurate in identifying patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, we know of no attempt to distinguish patients with CTEPH from patients with other causes of pulmonary arterial hypertension (PAH). Primary pulmonary hypertension (PPH) is the disease most frequently confused with CTEPH. We examined patients with CTEPH or PPH and control subjects to identify MR imaging features that might distinguish CTEPH from PPH, to compare the accuracy of MR angiography (MRA) with that of radionuclide scanning, and to determine the cardiac and pulmonary vascular measurements in these groups.T1-weighted and two-dimensional multiplanar spoiled gradient-recalled scans were obtained in 30 patients with CTEPH who had undergone conventional pulmonary angiography, 10 patients with PPH, and 13 control subjects with no known vascular disease. Ventilation-perfusion scans were available in all patients with CTEPH and in six of the 10 patients with PPH. The MR scans were asse...