Cerebrovascular Diseases-Aneurysm, Vascular Malformation, and Subarachnoid Hemorrhage

Variant: 1 Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.

Procedure	Appropriateness Category	Relative Radiation Level
Arteriography cervicocerebral	Usually Appropriate	☢☢☢
CTA head with IV contrast	Usually Appropriate	☢☢☢
MRA head without IV contrast	May Be Appropriate	O
US duplex Doppler carotid artery	Usually Not Appropriate	O
US duplex Doppler transcranial	Usually Not Appropriate	O
MRA head with IV contrast	Usually Not Appropriate	O
MRA head without and with IV contrast	Usually Not Appropriate	O
MRA neck with IV contrast	Usually Not Appropriate	O
MRA neck without and with IV contrast	Usually Not Appropriate	O
MRA neck without IV contrast	Usually Not Appropriate	O
MRI head perfusion with 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
MRV head with IV contrast	Usually Not Appropriate	O
MRV head without and with IV contrast	Usually Not Appropriate	O
MRV head without IV contrast	Usually Not Appropriate	O
CT head perfusion 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 head without IV contrast	Usually Not Appropriate	☢☢☢
CTA neck with IV contrast	Usually Not Appropriate	☢☢☢
CTV head with IV contrast	Usually Not Appropriate	☢☢☢

Variant: 2 Suspected cerebral vasospasm. Initial imaging.

Procedure	Appropriateness Category	Relative Radiation Level
Arteriography cervicocerebral	Usually Appropriate	☢☢☢
CTA head with IV contrast	Usually Appropriate	☢☢☢
US duplex Doppler transcranial	May Be Appropriate	O
MRI head perfusion with IV contrast	May Be Appropriate	O
MRI head without IV contrast	May Be Appropriate	O
CT head perfusion with IV contrast	May Be Appropriate	☢☢☢
CT head without IV contrast	May Be Appropriate	☢☢☢
US duplex Doppler carotid artery	Usually Not Appropriate	O
MRA head with IV contrast	Usually Not Appropriate	O
MRA head without and with IV contrast	Usually Not Appropriate	O
MRA head without IV contrast	Usually Not Appropriate	O
MRA neck with IV contrast	Usually Not Appropriate	O
MRA neck without and with IV contrast	Usually Not Appropriate	O
MRA neck 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
MRV head with IV contrast	Usually Not Appropriate	O
MRV head without and with IV contrast	Usually Not Appropriate	O
MRV head without IV contrast	Usually Not Appropriate	O
CT head with IV contrast	Usually Not Appropriate	☢☢☢
CT head without and with IV contrast	Usually Not Appropriate	☢☢☢
CTA neck with IV contrast	Usually Not Appropriate	☢☢☢
CTV head with IV contrast	Usually Not Appropriate	☢☢☢

Variant: 3 Known cerebral aneurysm; untreated. Surveillance monitoring.

Procedure	Appropriateness Category	Relative Radiation Level
MRA head without IV contrast	Usually Appropriate	O
CTA head with IV contrast	Usually Appropriate	☢☢☢
Arteriography cervicocerebral	May Be Appropriate	☢☢☢
MRA head with IV contrast	May Be Appropriate (Disagreement)	O
MRA head without and with IV contrast	May Be Appropriate	O
US duplex Doppler carotid artery	Usually Not Appropriate	O
US duplex Doppler transcranial	Usually Not Appropriate	O
MRA neck with IV contrast	Usually Not Appropriate	O
MRA neck without and with IV contrast	Usually Not Appropriate	O
MRA neck without IV contrast	Usually Not Appropriate	O
MRI head perfusion with 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
MRV head with IV contrast	Usually Not Appropriate	O
MRV head without and with IV contrast	Usually Not Appropriate	O
MRV head without IV contrast	Usually Not Appropriate	O
CT head perfusion 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 head without IV contrast	Usually Not Appropriate	☢☢☢
CTA neck with IV contrast	Usually Not Appropriate	☢☢☢
CTV head with IV contrast	Usually Not Appropriate	☢☢☢

Variant: 4 Known cerebral aneurysm; previously treated. Surveillance monitoring.

Procedure	Appropriateness Category	Relative Radiation Level
Arteriography cervicocerebral	Usually Appropriate	☢☢☢
MRA head without and with IV contrast	Usually Appropriate	O
MRA head without IV contrast	Usually Appropriate	O
CTA head with IV contrast	Usually Appropriate	☢☢☢
MRA head with IV contrast	May Be Appropriate (Disagreement)	O
US duplex Doppler carotid artery	Usually Not Appropriate	O
US duplex Doppler transcranial	Usually Not Appropriate	O
MRA neck with IV contrast	Usually Not Appropriate	O
MRA neck without and with IV contrast	Usually Not Appropriate	O
MRA neck without IV contrast	Usually Not Appropriate	O
MRI head perfusion with 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
MRV head with IV contrast	Usually Not Appropriate	O
MRV head without and with IV contrast	Usually Not Appropriate	O
MRV head without IV contrast	Usually Not Appropriate	O
CT head perfusion 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 head without IV contrast	Usually Not Appropriate	☢☢☢
CTA neck with IV contrast	Usually Not Appropriate	☢☢☢
CTV head with IV contrast	Usually Not Appropriate	☢☢☢

Variant: 5 High-risk cerebral aneurysm screening.

Procedure	Appropriateness Category	Relative Radiation Level
MRA head without IV contrast	Usually Appropriate	O
CTA head with IV contrast	Usually Appropriate	☢☢☢
US duplex Doppler carotid artery	Usually Not Appropriate	O
US duplex Doppler transcranial	Usually Not Appropriate	O
Arteriography cervicocerebral	Usually Not Appropriate	☢☢☢
MRA head with IV contrast	Usually Not Appropriate	O
MRA head without and with IV contrast	Usually Not Appropriate	O
MRA neck with IV contrast	Usually Not Appropriate	O
MRA neck without and with IV contrast	Usually Not Appropriate	O
MRA neck without IV contrast	Usually Not Appropriate	O
MRI head perfusion with 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
MRV head with IV contrast	Usually Not Appropriate	O
MRV head without and with IV contrast	Usually Not Appropriate	O
MRV head without IV contrast	Usually Not Appropriate	O
CT head perfusion 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 head without IV contrast	Usually Not Appropriate	☢☢☢
CTA neck with IV contrast	Usually Not Appropriate	☢☢☢
CTV head with IV contrast	Usually Not Appropriate	☢☢☢

Variant: 6 Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.

Procedure	Appropriateness Category	Relative Radiation Level
Arteriography cervicocerebral	Usually Appropriate	☢☢☢
MRA head with IV contrast	Usually Appropriate	O
MRA head without and with IV contrast	Usually Appropriate	O
MRA head without IV contrast	Usually Appropriate	O
CTA head with IV contrast	Usually Appropriate	☢☢☢
MRI head without and with IV contrast	May Be Appropriate	O
MRI head without IV contrast	May Be Appropriate	O
US duplex Doppler carotid artery	Usually Not Appropriate	O
US duplex Doppler transcranial	Usually Not Appropriate	O
MRA neck with IV contrast	Usually Not Appropriate	O
MRA neck without and with IV contrast	Usually Not Appropriate	O
MRA neck without IV contrast	Usually Not Appropriate	O
MRI head perfusion with IV contrast	Usually Not Appropriate	O
MRI head with IV contrast	Usually Not Appropriate	O
MRV head with IV contrast	Usually Not Appropriate	O
MRV head without and with IV contrast	Usually Not Appropriate	O
MRV head without IV contrast	Usually Not Appropriate	O
CT head perfusion 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 head without IV contrast	Usually Not Appropriate	☢☢☢
CTA neck with IV contrast	Usually Not Appropriate	☢☢☢
CTV head with IV contrast	Usually Not Appropriate	☢☢☢

Variant: 7 Suspected central nervous system (CNS) vasculitis. Initial imaging.

Procedure	Appropriateness Category	Relative Radiation Level
MRA head without IV contrast	Usually Appropriate	O
MRI head without and with IV contrast	Usually Appropriate	O
MRI head without IV contrast	Usually Appropriate	O
Arteriography cervicocerebral	May Be Appropriate	☢☢☢
CTA head with IV contrast	May Be Appropriate	☢☢☢
US duplex Doppler carotid artery	Usually Not Appropriate	O
US duplex Doppler transcranial	Usually Not Appropriate	O
MRA head with IV contrast	Usually Not Appropriate	O
MRA head without and with IV contrast	Usually Not Appropriate	O
MRA neck with IV contrast	Usually Not Appropriate	O
MRA neck without and with IV contrast	Usually Not Appropriate	O
MRA neck without IV contrast	Usually Not Appropriate	O
MRI head perfusion with IV contrast	Usually Not Appropriate	O
MRI head with IV contrast	Usually Not Appropriate	O
MRV head with IV contrast	Usually Not Appropriate	O
MRV head without and with IV contrast	Usually Not Appropriate	O
MRV head without IV contrast	Usually Not Appropriate	O
CT head perfusion 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 head without IV contrast	Usually Not Appropriate	☢☢☢
CTA neck with IV contrast	Usually Not Appropriate	☢☢☢
CTV head with IV contrast	Usually Not Appropriate	☢☢☢

Panel Members

Summary of Literature Review

Introduction/Background

Special Imaging Considerations

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)

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: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
A. Arteriography Cervicocerebral

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
B. CT Head Perfusion

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
C. CT Head

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
D. CTA Head

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
E. CTA Neck

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
F. CTV Head

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
G. MRA Head

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
H. MRA Neck

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
I. MRI Head Perfusion

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
J. MRI Head

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
K. MRV Head

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
L. US Duplex Doppler Carotid Artery

Variant 1: Known acute subarachnoid hemorrhage (SAH) on CT. Next imaging study.
M. US Duplex Doppler Transcranial

Variant 2: Suspected cerebral vasospasm. Initial imaging.

Variant 2: Suspected cerebral vasospasm. Initial imaging.
A. Arteriography Cervicocerebral

Variant 2: Suspected cerebral vasospasm. Initial imaging.
B. CT Head Perfusion

Variant 2: Suspected cerebral vasospasm. Initial imaging.
C. CT Head

Variant 2: Suspected cerebral vasospasm. Initial imaging.
D. CTA Head

Variant 2: Suspected cerebral vasospasm. Initial imaging.
E. CTA Neck

Variant 2: Suspected cerebral vasospasm. Initial imaging.
F. CTV Head

Variant 2: Suspected cerebral vasospasm. Initial imaging.
G. MRA Head

Variant 2: Suspected cerebral vasospasm. Initial imaging.
H. MRA Neck

Variant 2: Suspected cerebral vasospasm. Initial imaging.
I. MRI Head Perfusion

Variant 2: Suspected cerebral vasospasm. Initial imaging.
J. MRI Head

Variant 2: Suspected cerebral vasospasm. Initial imaging.
K. MRV Head

Variant 2: Suspected cerebral vasospasm. Initial imaging.
L. US Duplex Doppler Carotid Artery

Variant 2: Suspected cerebral vasospasm. Initial imaging.
M. US Duplex Doppler Transcranial

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
A. Arteriography Cervicocerebral

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
B. CT Head Perfusion

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
C. CT Head

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
D. CTA Head

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
E. CTA Neck

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
F. CTV Head

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
G. MRA Head

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
H. MRA Neck

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
I. MRI Head Perfusion

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
J. MRI Head

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
K. MRV Head

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
L. US Duplex Doppler Carotid Artery

Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring.
M. US Duplex Doppler Transcranial

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
A. Arteriography Cervicocerebral

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
B. CT Head Perfusion

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
C. CT Head

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
D. CTA Head

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
E. CTA Neck

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
F. CTV Head

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
G. MRA Head

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
H. MRA Neck

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
I. MRI Head Perfusion

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
J. MRI Head

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
K. MRV Head

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
L. US Duplex Doppler Carotid Artery

Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring.
M. US Duplex Doppler Transcranial

Variant 5: High-risk cerebral aneurysm screening.

Variant 5: High-risk cerebral aneurysm screening.
A. Arteriography Cervicocerebral

Variant 5: High-risk cerebral aneurysm screening.
B. CT Head Perfusion

Variant 5: High-risk cerebral aneurysm screening.
C. CT Head

Variant 5: High-risk cerebral aneurysm screening.
D. CTA Head

Variant 5: High-risk cerebral aneurysm screening.
E. CTA Neck

Variant 5: High-risk cerebral aneurysm screening.
F. CTV Head

Variant 5: High-risk cerebral aneurysm screening.
G. MRA Head

Variant 5: High-risk cerebral aneurysm screening.
H. MRA Neck

Variant 5: High-risk cerebral aneurysm screening.
I. MRI Head Perfusion

Variant 5: High-risk cerebral aneurysm screening.
J. MRI Head

Variant 5: High-risk cerebral aneurysm screening.
K. MRV Head

Variant 5: High-risk cerebral aneurysm screening.
L. US Duplex Doppler Carotid Artery

Variant 5: High-risk cerebral aneurysm screening.
M. US Duplex Doppler Transcranial

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
A. Arteriography Cervicocerebral

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
B. CT Head Perfusion

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
C. CT Head

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
D. CTA Head

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
E. CTA Neck

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
F. CTV Head

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
G. MRA Head

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
H. MRA Neck

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
I. MRI Head Perfusion

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
J. MRI Head

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
K. MRV Head

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
L. US Duplex Doppler Carotid Artery

Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring.
M. US Duplex Doppler Transcranial

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
A. Arteriography Cervicocerebral

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
B. CT Head Perfusion

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
C. CT Head

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
D. CTA Head

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
E. CTA Neck

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
F. CTV Head

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
G. MRA Head

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
H. MRA Neck

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
I. MRI Head Perfusion

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
J. MRI Head

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
K. MRV Head

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
L. US Duplex Doppler Carotid Artery

Variant 7: Suspected central nervous system (CNS) vasculitis. Initial imaging.
M. US Duplex Doppler Transcranial

Summary of Recommendations

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.