Figure 5c. Acute intramural hematoma of the aorta in a 45-year-old man with blunt thoracic trauma from a traffic accident. (a) Axial CT image shows a small, linear, hypoattenuating lesion along the left wall of the aortic arch (arrowheads). This lesion represents an acute intramural hematoma. (b) Magnified coronal reformatted image shows the hematoma, which is crescent shaped. The hematoma extends over nearly half of the circumference of the left aortic wall (arrowheads) with minimal eccentric narrowing of the lumen. (c) Magnified sagittal reformatted image of the origin of the left subclavian artery shows cranial extension of the hematoma into the wall of the artery. (d) Transesophageal echocardiogram shows the extent of the hematoma (arrow), which extends into the proximal descending aorta. (Fig 5d courtesy of R. Jenni, MD, University Hospital Zurich, Switzerland.)