INTRAMURAL HEMORRHAGE OF THE THORACIC AOR TA - IMAGING FEATURES AND DIFFERENTIAL-DIAGNOSIS

Purpose: Aortic wall thickening due to intramural hemorrhage may be th e only sign of aortic dissection. The aim of this study was to evaluat e the incidence, imaging features and differential diagnoses of intram ural hemorrhage (IMH) of the thoracic aorta. Methods: 98 patients with clinically suspected aortic dissection were investigated via Spiral-C T and MRT. Diagnosis of IMH based on the presence of smooth crescentic or concentric wall thickening over a longer segment of the thoracic a orta without flow visualization and without compression or distortion of the aortic lumen. Results: 69 patients had classic aortic dissectio ns and 7 patients were diagnosed to have IMH of the thoracic aorta. On e patient with IMH of the ascending aorta died of aortic rupture and s ubsequent pericardial tamponade 12 hours after onset of symptoms. In o ne patient with IMH of the descending aorta on initial examination, th ere was a progression of overt aortic dissection at follow-up after th ree weeks. In two patients with IMH of the descending aorta, wall thic kening decreased in size at follow-up (10-15 weeks), whereas in one pa tient it remained unchanged. Conclusion: IMH of the aorta should be co nsidered a precursor of aortic dissection. At follow-up IMH may decrea se in size, rupture or progress to overt aortic dissection.