Pitfalls in diagnosis of aortic dissection by angiography: algorithmic approach utilizing CT and MRI.

Dissection of the thoracic aorta is a life-threatening event requiring imaging studies to define the level of the tear and the intimal flap. The "gold standard" has been angiography. This method may fail to demonstrate the dissection, however, due to overlap of the true and false lumens or a very thin flap that is imaged en face rather than tangentially. Computed tomography has a diagnostic accuracy of 95%, but can fail to image the dissection due to technical factors or a thrombosed false lumen. Magnetic resonance imaging requires a hemodynamically stable and cooperative patient. A diagnostic algorithm is proposed for diagnosis of aortic dissection based on renal function and the surgeon's imaging modality preference.