NHLBI Classification for Coronary Artery Dissection
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A Minor radiolucent areas in the lumen without impairment of flow or persistant dye staining after contrast runoff
B Luminmal flap that is radiolucent and that runs parallel to the vessel wall with contrast injection but without impairment of flow or persistant dye staining after contrast runoff
C Contrast appears outside of the vessel lumen as an "extraluminal cap". The staining appears even after contrast clears the lumen
D Spiral radiolucent luminal filling defects. Often persitant staining after contast clears from the vessel.
E New and persistant filling defects in the vessel lumen.
F Lesions that progress to impaired flow or total occlusion.