Table 1:

Clinical condition—Cerebrovascular disease: Ischemia

	MRI, brain, with or without contrast	CT, head, with or without contrast	MRA, head and neck, with or without contrast	CTA, head and neck	Arterio-graphy, neck	Arterio-graphy, head and neck	US, carotid, duplex	US, trans cranial, Doppler
Asymptomatic: positive physical exam (cervical bruit) and/or risk factors.	5^a	5^a ^k	8ⁱ	8^j	2	2	8^h	3
TIA: carotid territory or vertebrobaslar TIA, initial screening survey	8^a ^b ^c	8^a ^b ^c ^d	8^b ^c	8^b ^c	3	3	6	3
Less than 3 hours: new focal neurologic defect, fixed or worsening.	8^a ^b ^c	8^a ^b ^c	8^b ^c	8^b ^c	5^e	5^e	2	2
Three to 24 hours: new focal neurologic defect, fixed or worsening.	8^b ^c ^f	8^b ^c ^g	8^b ^c	8^b ^c	6^e	6^e	2	2
Greater than 24 hours: new focal neurologic defect, fixed or worsening.	8^b ^c ^f	8^b ^c ^g	8^b ^c	8^b ^c	6^e	6^e	2	2

Note: —Appropriateness criteria scale from 1 to 9, 1 = least appropriate, 9 = most appropriate;
a , consider perfusion if stenosis found;
b , combined vascular and cerebral evaluation should be considered;
c , MR preferred if treatment not unreasonably delayed;
d , primarily to rule out hemorrhage;
e , if intra-arterial therapy is considered;
f , diffusion especially valuable;
g , for perfusion according to institutional protocols;
h , may need to confirm with second non-invasive study;
i , MRA of neck only, with or without contrast. MRA head = 3 but recommended if neck stenosis or occlusion found;
j , CTA of neck only. CTA head = 3 but recommended if neck stenosis or occlusion found;
k , CT head without contrast = 3