Table 4:

Comparison of diagnostic criteria and outcomes

	Diffuse Intracranial Dolichoectasia	Vertebrobasilar Dolichoectasia^{^a}
Imaging appearance	Fusiform aneurysmal dilation of an entire vascular segment (ie, supraclinoid ICA, basilar artery, M1 segment of the MCA)	Fusiform: aneurysmal dilation without definable neck involving a portion of an arterial segment with any degree of tortuosity Dolichoectatic: uniform aneurysmal dilation of an artery involving the entire basilar or vertebral or both with any degree of tortuosity Transitional: uniform aneurysmal dilation of an artery with superimposed dilation of a portion of the involved arterial segment
Distribution	≥2 Intracranial vascular beds (ie, vertebrobasilar system, left anterior circulation, or right anterior circulation)	Vertebrobasilar system only
Size criteria	Cavernous ICA: ≥8.5 mm Supraclinoid ICA: ≥8.0 mm MCA: ≥5.0 mm Basilar artery: ≥6.0 mm	Basilar artery diameter of >5.0 mm
Growth rate	10%/year	7%/year^2,10
Ischemic stroke risk	11%/year	3%/year^2,10
Aneurysm rupture risk	6%/year	2%/year^2,10