Aortic intramural hematoma with pulmonary artery extension mimics pulmonary embolism

A 59-year-old woman presented to emergency department with sudden onset of chest tightness and shortness of breath. Laboratory test revealed elevated D-dimer (1558 ng/mL). The electrocardiogram revealed right axis deviation, S1Q3T3 pattern, and T-wave inversion in leads V1 to V6. Computed tomographic angiography (CTA) was performed with 64-slice computed tomography for suspicious of pulmonary embolism. Contrast-enhanced CTA showed no filling defect in the pulmonary arteries; however, luminal narrowing of the right pulmonary artery was noted. Nonenhanced computed tomographic scan showed smooth eccentric high attenuation change along the wall of main pulmonary artery and right pulmonary artery and also along the ascending and descending aorta. The high attenuation lesions in both of the aorta and pulmonary artery showed no contrast enhancement indicating presence of intramural hematoma (IMH). Based on the image findings, a diagnosis of type A aortic IMH with pulmonary artery extension, instead of chronic pulmonary embolism, was made. Follow-up CTA 3 months later showed much improved of the right pulmonary artery narrowing and nearly complete resolution of the IMH.