Table 30.

High-Risk Imaging Features of IMH

For Type A IMH	For Type B IMH
Maximum aortic diameter >45–50 mm18,20	Maximum aortic diameter >47–50 mm15,20
Hematoma thickness ≥10 mm4	Hematoma thickness ≥13 mm15
Focal intimal disruption with ulcer-like projection involving ascending aorta or arch18,21	Focal intimal disruption with ulcer-like projection involving the descending thoracic aorta if it develops in acute phase15,16
Pericardial effusion on admission18	Increasing or recurrent pleural effusion19,22
For Both Type A and Type B IMH
Progression to aortic dissection19
Increasing aortic diameter21,22
Increasing hematoma thickness21,22

IMH indicates intramural hematoma.