Accuracy of contrast-enhanced magnetic resonance angiography in chronic thromboembolic disease

Rationale and Objectives. We evaluated the accuracy of contrast-enhanced magnetic resonance (MR) angiography in demonstrating the findings of chronic pulmonary thromboembolism (CPTE) compared with conventional pulmonary angiography. Methods. We examined 18 patients with CPTE proved by conventional pulmonary angiography and 16 healthy control patients. T1-weighted and single-breathhold, two-dimensional multiplanar spoiled gradient-recalled pulmonary images were obtained after injection of gadopentetate dimeglumine. Images were interpreted independently by two radiologists. Results. All patients with CPTE were identified on MR angiography images by both readers. Sensitivity and specificity for MR angiography in diagnosing abnormal segments were 76% and 95% for reader 1 and 68% and 93% for reader 2, respectively. Sensitivity and specificity for MR angiography in depicting abnormal lobes were 83% and 96% for reader 1 and 82% and 93% for reader 2, respectively. Interobserver agreement was high; kappas for abnormal segments and abnormal lobes were .72 and .84, respectively. The T1-weighted spin-echo images demonstrated a mosaic signal intensity pattern in all patients with CPTE. Conclusion. Contrast-enhanced MR angiography accurately depicts abnormal segments and lobes in occlusive vascular disease and clearly distinguishes between patients with CPTE and those with healthy lungs.