Clinical condition—head trauma

	CT, head, without contrast	MRI, brain, without contrast	X-ray and/or CT, cervical spine^†	CT, head, without and with contrast	MRI, brain, without and with contrast	CTA, head and neck	MRA, head and neck	Angiography, cerebral	X-ray, skull
Minor or mild acute closed head injury (GCS ≥13), without risk factors or neurologic deficit	7^a	4	5	3	2	3^b	3^b	1	1
Minor or mild acute closed head injury, focal neurologic deficit and/or risk factors	9	6^c	6	2	3	5^c ^d	5^c ^d	1	1
Moderate or severe acute closed head injury	9	6	8	2	2	5	5	1	2
Mild or moderate acute closed head injury, child <2 years old	9	7^e	7	2	4^f	4^d	4^d	1	5
Subacute or chronic closed head injury with cognitive and/or neurologic deficit(s)^g	6	8	2^h	2	3	4ⁱ	4ⁱ	1	2
Closed head injury; rule out carotid or vertebral artery dissection^‡	8	8^e	5	6^j	6	8	8^k	6^c	2
Penetrating injury, stable, neurologically intact	9	5^l	8^m	4^j	4^l	7	6^l	5^d	8ⁿ
Skull fracture	9	6^l	6	4	4^l ^o	7^d	4^l	1	5ⁱ

Note:—Appropriateness criteria scale from 1 to 9; 1 indicates least appropriate; 9, most appropriate;
^a , known to be low yield;
^b , rarely indicated with mild trauma;
^c , for problem solving;
^d , if vascular injury suspected;
^e , include diffusion-weighted images;
^f , potentially useful in suspected non-accidental trauma;
^g , PET or SPECT for brain = 4–used for selected cases;
^h , assuming there are no spinal neurologic deficits;
ⁱ , for selected cases;
^j consider perfusion;
^k , add T1 images;
^l , if MRI is safe;
^m , if neck or C-spine is site of injury;
ⁿ , if calvarium is site of injury;
^o , useful if infection is suspected.
† , see the ACR Appropriateness Criteria on Spine Trauma;
‡ , see the ACR Appropriateness Criteria on Cerebrovascular Disease.