Figure 1. (A) Computed tomography pulmonary angiogram obtained on the patient’s initial presentation. This axial view on cross-sectional imaging demonstrates patency within the aortic arch without any thrombus visualized. (B) Subsequent computed tomography pulmonary angiogram obtained around day 10 of patient’s hospital course, when D-dimer increased 3-fold from 2350 ng/ mL to 6840 ng/mL and raised suspicion for a new thrombotic event. This axial view on cross-sectional imaging demonstrates formation of new thrombus (arrow) within the aortic arch that was not present on the previous computed tomography pumonary angiogram (Figure 1A). (C) Cross-sectional imaging from a computed tomography pulmonary angiogram obtained on the patient’s initial presentation. Again, demonstrating patency within the aortic arch without any visualized thrombus on sagittal view.