AC Portal
Variant: 1   Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
Procedure Appropriateness Category Relative Radiation Level
Radiography skull Usually Not Appropriate ☢
Arteriography cervicocerebral Usually Not Appropriate ☢☢☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRA head and neck with IV contrast Usually Not Appropriate O
MRA head and neck without and with IV contrast Usually Not Appropriate O
MRA head and neck without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
CT head without IV contrast Usually Not Appropriate ☢☢☢
CTA head and neck with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Variant: 2   Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
Procedure Appropriateness Category Relative Radiation Level
CT head without IV contrast Usually Appropriate ☢☢☢
Radiography skull Usually Not Appropriate ☢
Arteriography cervicocerebral Usually Not Appropriate ☢☢☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRA head and neck with IV contrast Usually Not Appropriate O
MRA head and neck without and with IV contrast Usually Not Appropriate O
MRA head and neck without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
CTA head and neck with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Variant: 3   Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
Procedure Appropriateness Category Relative Radiation Level
CT head without IV contrast Usually Appropriate ☢☢☢
Radiography skull Usually Not Appropriate ☢
Arteriography cervicocerebral Usually Not Appropriate ☢☢☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRA head and neck with IV contrast Usually Not Appropriate O
MRA head and neck without and with IV contrast Usually Not Appropriate O
MRA head and neck without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
CTA head and neck with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Variant: 4   Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
Procedure Appropriateness Category Relative Radiation Level
MRI head without IV contrast May Be Appropriate O
CT head without IV contrast May Be Appropriate ☢☢☢
Radiography skull Usually Not Appropriate ☢
Arteriography cervicocerebral Usually Not Appropriate ☢☢☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRA head and neck with IV contrast Usually Not Appropriate O
MRA head and neck without and with IV contrast Usually Not Appropriate O
MRA head and neck without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
CTA head and neck with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Variant: 5   Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
Procedure Appropriateness Category Relative Radiation Level
CT head without IV contrast Usually Appropriate ☢☢☢
MRI head without IV contrast May Be Appropriate O
Radiography skull Usually Not Appropriate ☢
Arteriography cervicocerebral Usually Not Appropriate ☢☢☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRA head and neck with IV contrast Usually Not Appropriate O
MRA head and neck without and with IV contrast Usually Not Appropriate O
MRA head and neck without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
CTA head and neck with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Variant: 6   Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
Procedure Appropriateness Category Relative Radiation Level
CT head without IV contrast Usually Appropriate ☢☢☢
MRI head without IV contrast May Be Appropriate O
Radiography skull Usually Not Appropriate ☢
Arteriography cervicocerebral Usually Not Appropriate ☢☢☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRA head and neck with IV contrast Usually Not Appropriate O
MRA head and neck without and with IV contrast Usually Not Appropriate O
MRA head and neck without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
CTA head and neck with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Variant: 7   Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
Procedure Appropriateness Category Relative Radiation Level
MRI head without IV contrast Usually Appropriate O
CT head without IV contrast Usually Appropriate ☢☢☢
Radiography skull Usually Not Appropriate ☢
Arteriography cervicocerebral Usually Not Appropriate ☢☢☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRA head and neck with IV contrast Usually Not Appropriate O
MRA head and neck without and with IV contrast Usually Not Appropriate O
MRA head and neck without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
CTA head and neck with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Variant: 8   Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
Procedure Appropriateness Category Relative Radiation Level
CTA head and neck with IV contrast Usually Appropriate ☢☢☢
Arteriography cervicocerebral May Be Appropriate ☢☢☢
MRA head and neck with IV contrast May Be Appropriate O
MRA head and neck without and with IV contrast May Be Appropriate (Disagreement) O
MRA head and neck without IV contrast May Be Appropriate (Disagreement) O
CT head without IV contrast May Be Appropriate (Disagreement) ☢☢☢
Radiography skull Usually Not Appropriate ☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Variant: 9   Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
Procedure Appropriateness Category Relative Radiation Level
CTV head with IV contrast Usually Appropriate ☢☢☢
MRI head without IV contrast May Be Appropriate O
MRV head with IV contrast May Be Appropriate (Disagreement) O
MRV head without and with IV contrast May Be Appropriate O
MRV head without IV contrast May Be Appropriate O
CT head without IV contrast May Be Appropriate ☢☢☢
Radiography skull Usually Not Appropriate ☢
Arteriography cervicocerebral Usually Not Appropriate ☢☢☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Variant: 10   Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
Procedure Appropriateness Category Relative Radiation Level
CT maxillofacial without IV contrast Usually Appropriate ☢☢
CT head without IV contrast Usually Appropriate ☢☢☢
CT temporal bone without IV contrast Usually Appropriate ☢☢☢
MRI head without IV contrast May Be Appropriate O
CT head cisternography May Be Appropriate ☢☢☢
DTPA cisternography May Be Appropriate ☢☢☢
Radiography skull Usually Not Appropriate ☢
MR spectroscopy head without IV contrast Usually Not Appropriate O
MRI functional (fMRI) head without IV contrast Usually Not Appropriate O
MRI head with IV contrast Usually Not Appropriate O
MRI head without and with IV contrast Usually Not Appropriate O
MRI head without IV contrast with DTI Usually Not Appropriate O
CT maxillofacial with IV contrast Usually Not Appropriate ☢☢
CT head with IV contrast Usually Not Appropriate ☢☢☢
CT head without and with IV contrast Usually Not Appropriate ☢☢☢
CT maxillofacial without and with IV contrast Usually Not Appropriate ☢☢☢
CT temporal bone with IV contrast Usually Not Appropriate ☢☢☢
CT temporal bone without and with IV contrast Usually Not Appropriate ☢☢☢
FDG-PET/CT brain Usually Not Appropriate ☢☢☢
SPECT or SPECT/CT brain perfusion Usually Not Appropriate ☢☢☢

Panel Members
Robert Y. Shih, MDa; Judah Burns, MDb; Amna A. Ajam, MD, MBBSc; Joshua S. Broder, MDd; Santanu Chakraborty, MBBS, MSce; A. Tuba Karagulle Kendi, MDf; Mary E. Lacy, MDg; Luke N. Ledbetter, MDh; Ryan K. Lee, i; David S. Liebeskind, MDj; Jeffrey M. Pollock, MDk; J. Adair Prall, MDl; Thomas Ptak, MD, PhD, MPHm; P. B. Raksin, MDn; Matthew D. Shaines, MDo; A. John Tsiouris, MDp; Pallavi S. Utukuri, MDq; Lily L. Wang, MBBS, MPHr; Amanda S. Corey, MDs.
Summary of Literature Review
Introduction/Background
Initial Imaging Definition

Initial imaging is defined as imaging at the beginning of the care episode for the medical condition defined by the variant. More than one procedure can be considered usually appropriate in the initial imaging evaluation when:

  • There are procedures that are equivalent alternatives (i.e., only one procedure will be ordered to provide the clinical information to effectively manage the patient’s care)

OR

  • There are complementary procedures (i.e., more than one procedure is ordered as a set or simultaneously wherein each procedure provides unique clinical information to effectively manage the patient’s care).
Discussion of Procedures by Variant
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
A. Arteriography cervicocerebral
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
B. CT head without IV contrast
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
C. CTA head and neck
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
D. FDG-PET/CT brain
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
E. MR spectroscopy head without IV contrast
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
F. MRI functional (fMRI) head without IV contrast
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
G. SPECT or SPECT/CT brain perfusion
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
H. MRI head
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
I. MRI head with DTI
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
J. Radiography skull
Variant 1: Acute head trauma, mild (GCS 13–15), imaging not indicated by clinical decision rule. Initial imaging.
K. MRA Head and Neck
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
A. Arteriography Cervicocerebral
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
B. CT Head
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
C. CTA Head and Neck
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
D. FDG-PET/CT Brain
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
E. SPECT/CT Brain
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
F. MR Spectroscopy Head
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
G. MRA Head and Neck
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
H. MRI Functional (fMRI) Head
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
I. MRI head 
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
J. MRI Head with DTI
Variant 2: Acute head trauma, mild (GCS 13-15), imaging indicated by clinical decision rule. Initial imaging.
K. Radiography skull
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
A. Arteriography cervicocerebral
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
B. CT head 
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
C. CTA head and neck
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
D. FDG-PET/CT brain
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
E. MR spectroscopy head without IV contrast
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
F. MRA head and neck
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
G. MRI functional (fMRI) head without IV contrast
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
H. MRI head 
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
I. MRI head with DTI
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
J. Radiography skull
Variant 3: Acute head trauma, moderate (GCS 9–12) or severe (GCS 3–8), or penetrating. Initial imaging.
K. SPECT or SPECT/CT brain perfusion
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
A. Arteriography cervicocerebral
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
B. CT head 
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
C. CTA head and neck 
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
D. FDG-PET/CT brain
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
E. MR spectroscopy head 
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
F. MRA head and neck 
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
G. MRI functional (fMRI) head without IV contrast
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
H. MRI head 
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
I. MRI Head with DTI
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
J. Radiography skull
Variant 4: Acute head trauma with unchanged neurologic examination and unremarkable initial imaging. Short-term follow-up imaging.
K. SPECT or SPECT/CT brain perfusion
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
A. Arteriography cervicocerebral
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
B. CT head
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
C. CTA head and neck
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
D. FDG-PET/CT brain
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
E. MR spectroscopy head without IV contrast
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
F. MRA head and neck
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
G. MRI functional (fMRI) head without IV contrast
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
H. MRI head
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
I. MRI Head with DTI
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
J. Radiography skull
Variant 5: Acute head trauma with unchanged neurologic examination and positive finding(s) on initial imaging (eg, subdural hematoma). Short-term follow-up imaging.
K. SPECT or SPECT/CT brain perfusion
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
A. Arteriography cervicocerebral
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
B. CT head
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
C. CTA head and neck
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
D. FDG-PET/CT brain
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
E. MR spectroscopy head without IV contrast
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
F. MRA head and neck
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
G. MRI functional (fMRI) head without IV contrast
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
H. MRI head
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
I. MRI head without IV contrast with DTI
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
J. Radiography skull
Variant 6: Acute head trauma with new or progressive neurologic deficit(s). Short-term follow-up imaging.
K. SPECT or SPECT/CT brain perfusion
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
A. Arteriography cervicocerebral
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
B. CT head
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
C. CTA head and neck
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
D. FDG-PET/CT brain
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
E. MR spectroscopy head
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
F. MRA head and neck
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
G. MRI functional (fMRI) head
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
H. MRI head
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
I. MRI head with DTI
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
J. Radiography skull
Variant 7: Subacute or chronic head trauma with unexplained cognitive or neurologic deficit(s). Initial imaging.
K. SPECT/CT Brain
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
A. Arteriography cervicocerebral
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
B. CT head
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
C. CTA head and neck
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
D. FDG-PET/CT brain
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
E. MR spectroscopy head
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
F. MRA head and neck
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
G. MRI functional (fMRI) head
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
H. MRI head
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
I. MRI head with DTI
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
J. Radiography skull
Variant 8: Head trauma with suspected intracranial arterial injury due to clinical risk factors or positive findings on prior imaging.
K. SPECT/CT Brain
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
A. Arteriography cervicocerebral
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
B. CT head
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
C. CTV head
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
D. FDG-PET/CT brain
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
E. MR spectroscopy head
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
F. MRI functional (fMRI) head
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
G. MRI head
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
H. MRI head with DTI
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
I. MRV head
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
J. Radiography skull
Variant 9: Head trauma with suspected intracranial venous injury due to clinical risk factors or positive findings on prior imaging.
K. SPECT/CT Brain
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
A. CT head cisternography
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
B. CT head
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
C. CT maxillofacial
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
D. CT temporal bone
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
E. DTPA cisternography
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
F. FDG-PET/CT brain
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
G. MR spectroscopy head
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
H. MRI functional (fMRI) head
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
I. MRI head
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
J. MRI head with DTI
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
K. Radiography skull
Variant 10: Head trauma with suspected cerebrospinal fluid (CSF) leak. Initial imaging.
L. SPECT/CT Brain
Summary of Highlights
Supporting Documents

The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.

For additional information on the Appropriateness Criteria methodology and other supporting documents, please go to the ACR website at https://www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Appropriateness-Criteria.

Appropriateness Category Names and Definitions

Appropriateness Category Name

Appropriateness Rating

Appropriateness Category Definition

Usually Appropriate

7, 8, or 9

The imaging procedure or treatment is indicated in the specified clinical scenarios at a favorable risk-benefit ratio for patients.

May Be Appropriate

4, 5, or 6

The imaging procedure or treatment may be indicated in the specified clinical scenarios as an alternative to imaging procedures or treatments with a more favorable risk-benefit ratio, or the risk-benefit ratio for patients is equivocal.

May Be Appropriate (Disagreement)

5

The individual ratings are too dispersed from the panel median. The different label provides transparency regarding the panel’s recommendation. “May be appropriate” is the rating category and a rating of 5 is assigned.

Usually Not Appropriate

1, 2, or 3

The imaging procedure or treatment is unlikely to be indicated in the specified clinical scenarios, or the risk-benefit ratio for patients is likely to be unfavorable.
Relative Radiation Level Information

Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, because of both organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared with those specified for adults (see Table below). Additional information regarding radiation dose assessment for imaging examinations can be found in the ACR Appropriateness Criteria® Radiation Dose Assessment Introduction document.

Relative Radiation Level Designations

Relative Radiation Level*

Adult Effective Dose Estimate Range

Pediatric Effective Dose Estimate Range

O

0 mSv

 0 mSv

☢

<0.1 mSv

<0.03 mSv

☢☢

0.1-1 mSv

0.03-0.3 mSv

☢☢☢

1-10 mSv

0.3-3 mSv

☢☢☢☢

10-30 mSv

3-10 mSv

☢☢☢☢☢

30-100 mSv

10-30 mSv

*RRL assignments for some of the examinations cannot be made, because the actual patient doses in these procedures vary as a function of a number of factors (e.g., region of the body exposed to ionizing radiation, the imaging guidance that is used). The RRLs for these examinations are designated as “Varies.”
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Disclaimer

The ACR Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate imaging examinations for diagnosis and treatment of specified medical condition(s). These criteria are intended to guide radiologists, radiation oncologists and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient’s clinical condition should dictate the selection of appropriate imaging procedures or treatments. Only those examinations generally used for evaluation of the patient’s condition are ranked.  Other imaging studies necessary to evaluate other co-existent diseases or other medical consequences of this condition are not considered in this document. The availability of equipment or personnel may influence the selection of appropriate imaging procedures or treatments. Imaging techniques classified as investigational by the FDA have not been considered in developing these criteria; however, study of new equipment and applications should be encouraged. The ultimate decision regarding the appropriateness of any specific radiologic examination or treatment must be made by the referring physician and radiologist in light of all the circumstances presented in an individual examination.