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NAT suspected or (+) high-risk factors (neuro signs, mental status Δ, basilar skull fx) CT head w/o contrast preferred1,2 [9] If clinical status discordant w/ (-) CT findings, mod to severe trauma, or suspected NAT,3 consider MRI head4,5 [7] If concern for associated vascular injury:6 - MRA w/o contrast [4,3] preferred; CTA7 w/ contrast may be used for problem solving [4,1]
- If CTA or MRA results uncertain/high clinical suspicion, proceed to conventional angiography8,9
Footnotes 1 Noncontrast CT advantages: wide availability, speed, and ability to detect significant hemorrhage/herniation/hydrocephalus/fx. Small hemorrhages may be missed, but sensitivity can be improved w/ multiplanar reformations.
2 Decision to image w/ CT should consider the increased risks of ionizing radiation in children.
3 Skull radiographs are still often performed as part of skeletal survey in suspected NAT. Skull x-ray and head CT are complementary (fractures in plane of transaxial CT image may not be apparent).
4 MRI advantages: more sensitive vs CT for small parenchymal lesions/ischemia/shear injury; helpful in pts whose clinical status is discordant w/ (-) CT findings, in mod/severe injury, and if NAT suspected.
5 Role of MRI in suspected NAT: detection of microhemorrhages/axonal shear injury, small subdural collections, prior/repeated trauma (can be occult on CT); MRI may help define/record full extent of injury.
6 Suspect vascular injury if evidence of arterial stroke by exam/imaging or fx extending through skull-base vascular channels.
7 CTA provides high spatial resolution/rapid assessment but exposes pt to ionizing radiation, particularly when performed in addition to a necessary, noncontrast head CT.
8 Subtle injuries may be occult on either CTA or MRA, thus conventional angiography remains the definitive dx test for vascular injury.
9 Angiography reserved for cases w/ uncertain diagnoses/high clinical suspicion due to its invasive nature/radiation/limited availability/need for sedation.
No NAT suspected and (-) high-risk factors No imaging studies typically indicated10 - If clinical assessment11 (difficult at this age) is uncertain/indeterminate, CT head w/o contrast12,13 [3] may be considered but low-yield
Footnotes 10 Estimated overall risk of clinically significant brain injury from minor trauma in pts <2 yo is <1%; if mental status changes, 4%; if clinically suspected fracture, 3.6%. Calvarial fx is more common in infants (fx threshold ≈10% of a child/adult), but head x-ray is not indicated if CT w/ reformations is performed.
11 In a study of >10,000 pts <2 yo, the following set of criteria had a 100% NPP and 100% sensitivity for TBI: normal mental status + no nonfrontal scalp hematoma/LOC/severe injury mech/palpable skull fx + acting normally according to parents. However, some uncertainty remains regarding which clinical findings may constitute mental status Δ in very young children.
12 Decision to image w/ CT should consider the increased risks of ionizing radiation in children.
13 Axonal injury is more common in pts <2 yo and is frequently occult by CT. Therefore, MRI may have a greater role in eval of the unmyelinated brain of these pts.
No imaging studies typically indicated14,15,16 Footnotes 14 Overall incidence of clinically important TBI is ≈0.05% to 0.9% in pts w/o any indications of intracranial abnormality by hx/exam.
15 CT head w/o contrast has a low yield [3]. Decision to image w/ CT should consider the increased risks of ionizing radiation in children.
16 The following set of criteria has a 99.9% NPP and 96.8% sensitivity for clinically important injury: normal mental status + none of the following: LOC/vomiting/severe injury mechanism/signs of basilar skull fx/severe HA. There are contradictory reports concerning probability of traumatic head injury in children w/ HA, vomiting, LOC, and severe mechanisms of injury (<1% risk of significant TBI in 1 study, higher in others).
CT head w/o contrast preferred17,18 [9] If clinical status discordant w/ (-) CT findings, mod to severe trauma, or suspected NAT,19 consider MRI head20,21 [7] If concern for associated vascular injury:22 - MRA w/o contrast [4,3] preferred; CTA23 w/ contrast may be used for problem solving [4,1]
- If CTA or MRA results uncertain/high clinical suspicion, proceed to conventional angiography24,25
Footnotes 17 Noncontrast CT advantages: wide availability, speed, and ability to detect significant hemorrhage/herniation/hydrocephalus/fx. Small hemorrhages may be missed, but sensitivity can be improved w/ multiplanar reformations.
18 Decision to image w/ CT should consider the increased risks of ionizing radiation in children.
19 Skull radiographs are still often performed as part of skeletal survey in suspected NAT. Skull x-ray and head CT are complementary (fractures in plane of transaxial CT image may not be apparent).
20 MRI advantages: more sensitive vs CT for small parenchymal lesions/ischemia/shear injury; helpful in pts whose clinical status is discordant w/ (-) CT findings, in mod/severe injury, and if NAT suspected.
21 Role of MRI in suspected NAT: detection of microhemorrhages/axonal shear injury, small subdural collections, prior/repeated trauma (can be occult on CT); MRI may help define/record full extent of injury.
22 Suspect vascular injury if evidence of arterial stroke by exam/imaging or fx extending through skull-base vascular channels.
23 CTA provides high spatial resolution/rapid assessment but exposes pt to ionizing radiation, particularly when performed in addition to a necessary, noncontrast head CT.
24 Subtle injuries may be occult on either CTA or MRA, thus conventional angiography remains the definitive dx test for vascular injury.
25 Angiography reserved for cases w/ uncertain diagnoses/high clinical suspicion due to its invasive nature/radiation/limited availability/need for sedation.
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With cognitive and/or neuro signs If pt had imaging at prior ER visit, criteria for repeat imaging: - Significant Δ in neuro status26
- (+) Findings on prior CT
- Mod or severe head injury regardless of prior imaging
MRI27 head w/o contrast28 preferred [8] - If MRI unavailable/delayed, obtain CT29 head w/o contrast [7]
If concern for associated vascular injury:30 - MRA w/o contrast [3] preferred; CTA31 w/ contrast may be used for problem solving [4,1]
- If CTA or MRA results uncertain/high clinical suspicion, proceed to conventional angiography32,33
Footnotes 26 However, absence of neurologic changes does not preclude possibility of secondary or progressive injury.
27 MRI advantages: useful for eval of persistent/unexplained/new neuro deficits in subacute setting; greater sensitivity for blood products (from small brainstem/infratentorial hemorrhages or subacute extraaxial hemorrhage) which become less dense on CT over time; superior detection of nonhemorrhagic contusions/ischemia.
28 Contrast-enhanced sequences not indicated unless concern for infxn (eg, penetrating injury or fx involving sinuses).
29 Decision to image w/ CT should consider the increased risks of ionizing radiation in children.
30 Suspect vascular injury if evidence of arterial stroke by exam/imaging or fx extending through skull-base vascular channels.
31 CTA provides high spatial resolution/rapid assessment but exposes pt to ionizing radiation, particularly when performed in addition to a necessary, noncontrast head CT.
32 Subtle injuries may be occult on either CTA or MRA, thus conventional angiography remains the definitive dx test for vascular injury.
33 Angiography reserved for cases w/ uncertain dx/high clinical suspicion due to its invasive nature/radiation/limited availability/need for sedation.
No cognitive or neuro signs [Not addressed in this guideline | Epocrates note]
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