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## Complete Summary

#### GUIDELINE TITLE

Cerebrovascular disease.

#### BIBLIOGRAPHIC SOURCE(S)

De La Paz RL, Seidenwurm DJ, Davis PC, Brunberg JA, Dormont PD, Hackney
DB, Jordan JE, Karis JP, Mukherji SK, Turski PA, Wippold FJ Jr,
Zimmermann RD, Sloan MA, Expert Panel on Neurologic Imaging.
Cerebrovascular disease. \[online publication\]. Reston (VA): American
College of Radiology (ACR); 2006. 20 p. \[120 references\]

#### GUIDELINE STATUS

This is the current release of the guideline.

This guideline updates a previous version: Masaryk T, Drayer BP,
Anderson RE, Braffman B, Davis PC, Deck MD, Hasso AN, Johnson BA,
Pomeranz SJ, Seidenwurm D, Tanenbaum L, Masdeu JC. Cerebrovascular
disease. American College of Radiology. ACR Appropriateness Criteria.
Radiology 2000 Jun;215(Suppl):415-35.

The appropriateness criteria are reviewed annually and updated by the
panels as needed, depending on introduction of new and highly
significant scientific evidence.

### COMPLETE SUMMARY CONTENT

 SCOPE\
 METHODOLOGY - including Rating Scheme and Cost Analysis\
 RECOMMENDATIONS\
 EVIDENCE SUPPORTING THE RECOMMENDATIONS\
 BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS\
 QUALIFYING STATEMENTS\
 IMPLEMENTATION OF THE GUIDELINE\
 INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT
CATEGORIES\
 IDENTIFYING INFORMATION AND AVAILABILITY\
 DISCLAIMER

### SCOPE

#### DISEASE/CONDITION(S)

Cerebrovascular disease

#### GUIDELINE CATEGORY

Diagnosis

#### CLINICAL SPECIALTY

Emergency Medicine\
Family Practice\
Internal Medicine\
Neurological Surgery\
Neurology\
Radiology

#### INTENDED USERS

Health Plans\
Hospitals\
Managed Care Organizations\
Physicians\
Utilization Management

#### GUIDELINE OBJECTIVE(S)

To evaluate the appropriateness of initial radiologic examinations for
patients with cerebrovascular disease

#### TARGET POPULATION

Patients with cerebrovascular disease

#### INTERVENTIONS AND PRACTICES CONSIDERED

1.  Ultrasound (US)

    -   Carotid, duplex

    -   Transcranial, Doppler

2.  Magnetic resonance angiography (MRA)

    -   Neck, with or without contrast

    -   Head, with or without contrast

3.  Magnetic resonance imaging (MRI), brain, without and with contrast

4.  Functional magnetic resonance imaging (fMRI), brain, blood-oxygen
    level dependent (BOLD)

5.  MR spectroscopy (MRS), head

6.  Computed tomography angiography (CTA)

    -   Neck

    -   Head, without and with contrast

7.  Computed tomography (CT), head, without and with contrast

8.  Nuclear medicine (NM), single-photon-emission computed tomography
    (SPECT), brain

9.  Position emission tomography (PET), brain

10. Invasive (INV), arteriography, head and neck

#### MAJOR OUTCOMES CONSIDERED

Utility of radiologic examinations in differential diagnosis

### METHODOLOGY

#### METHODS USED TO COLLECT/SELECT EVIDENCE

Searches of Electronic Databases

#### DESCRIPTION OF METHODS USED TO COLLECT/SELECT THE EVIDENCE

The guideline developer performed literature searches of peer-reviewed
medical journals and the major applicable articles were identified and
collected.

#### NUMBER OF SOURCE DOCUMENTS

The total number of source documents identified as the result of the
literature search is not known.

#### METHODS USED TO ASSESS THE QUALITY AND STRENGTH OF THE EVIDENCE

Weighting According to a Rating Scheme (Scheme Not Given)

#### RATING SCHEME FOR THE STRENGTH OF THE EVIDENCE

Not stated

#### METHODS USED TO ANALYZE THE EVIDENCE

Review of Published Meta-Analyses\
Systematic Review with Evidence Tables

#### DESCRIPTION OF THE METHODS USED TO ANALYZE THE EVIDENCE

One or two topic leaders within a panel assume the responsibility of
developing an evidence table for each clinical condition, based on
analysis of the current literature. These tables serve as a basis for
developing a narrative specific to each clinical condition.

#### METHODS USED TO FORMULATE THE RECOMMENDATIONS

Expert Consensus (Delphi)

#### DESCRIPTION OF METHODS USED TO FORMULATE THE RECOMMENDATIONS

Since data available from existing scientific studies are usually
insufficient for meta-analysis, broad-based consensus techniques are
needed to reach agreement in the formulation of the appropriateness
criteria. The American College of Radiology (ACR) Appropriateness
Criteria panels use a modified Delphi technique to arrive at consensus.
Serial surveys are conducted by distributing questionnaires to
consolidate expert opinions within each panel. These questionnaires are
distributed to the participants along with the evidence table and
narrative as developed by the topic leader(s). Questionnaires are
completed by the participants in their own professional setting without
influence of the other members. Voting is conducted using a scoring
system from 1-9, indicating the least to the most appropriate imaging
examination or therapeutic procedure. The survey results are collected,
tabulated in anonymous fashion, and redistributed after each round. A
maximum of three rounds is conducted and opinions are unified to the
highest degree possible. Eighty percent agreement is considered a
consensus. This modified Delphi technique enables individual, unbiased
expression, is economical, easy to understand, and relatively simple to
conduct.

If consensus cannot be reached by the Delphi technique, the panel is
convened and group consensus techniques are utilized. The strengths and
weaknesses of each test or procedure are discussed and consensus reached
whenever possible. If \"No consensus\" appears in the rating column,
reasons for this decision are added to the comment sections.

#### RATING SCHEME FOR THE STRENGTH OF THE RECOMMENDATIONS

Not applicable

#### COST ANALYSIS

The guideline developers reviewed published cost analyses.

#### METHOD OF GUIDELINE VALIDATION

Internal Peer Review

#### DESCRIPTION OF METHOD OF GUIDELINE VALIDATION

Criteria developed by the Expert Panels are reviewed by the American
College of Radiology (ACR) Committee on Appropriateness Criteria.

### RECOMMENDATIONS

#### MAJOR RECOMMENDATIONS

**ACR Appropriateness Criteria®**

**Clinical Condition: Cerebrovascular Disease**

**Variant 1: Asymptomatic. Structural lesion on physical exam (cervical
bruit) and/or risk factors.**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  US, carotid, duplex  8                   May need to confirm with second
                                           non-invasive study.

  MRA, neck, with or   8                    
  without contrast                         

  CTA, neck            8                    

  MRI, brain, without  5                   Consider perfusion if stenosis
  and with contrast                        found.

  CT, head, without    5                   Consider perfusion if stenosis
  and with contrast                        found.

  US, transcranial,    3                    
  Doppler                                  

  MRI, brain, without  3                    
  contrast                                 

  MRA, head, with or   3                   May be useful if stenosis found.
  without contrast                         

  CT, head, without    3                    
  contrast                                 

  CTA, head, without   3                   May be useful if stenosis found.
  and with contrast                        

  INV, arteriography,  2                    
  neck                                     

  INV, arteriography,  2                    
  head and neck                            

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 2: Carotid territory or vertebrobasilar TIA, initial screening
survey. (In these tables a TIA is the report of an historical transient
ischemic event by the patient or other witness. The acute neurological
deficit in progress must be treated as an acute stroke and can only be
considered a TIA in retrospect if it resolves without intervention.)**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  MRI, brain, with or  8                   Consider perfusion if stenosis
  without contrast                         found. Combined vascular and
                                           cerebral evaluation should be
                                           considered. MR preferred if
                                           treatment not unreasonably
                                           delayed.

  MRA, head and neck,  8                   Combined vascular and cerebral
  with or without                          evaluation should be considered.
  contrast                                 MR preferred if treatment not
                                           unreasonably delayed.

  CT, head, with or    8                   Consider perfusion if stenosis
  without contrast                         found. Primarily to rule out
                                           hemorrhage. Combined vascular and
                                           cerebral evaluation should be
                                           considered. MR preferred if
                                           treatment not unreasonably
                                           delayed.

  CTA, head and neck   8                   Combined vascular and cerebral
                                           evaluation should be considered.
                                           MR preferred if treatment not
                                           unreasonably delayed.

  US, carotid, duplex  6                    

  US, transcranial,    3                    
  Doppler                                  

  INV, arteriography,  3                    
  neck                                     

  INV, arteriography,  3                    
  head and neck                            

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 3: New focal neurologic defect, fixed or worsening. Less than
3 hours.**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  MRI, brain, with or  8                   Consider perfusion if stenosis
  without contrast                         found. Combined vascular and
                                           cerebral evaluation should be
                                           considered. MR preferred if
                                           treatment not unreasonably
                                           delayed.

  MRA, head and neck,  8                   Combined vascular and cerebral
  with or without                          evaluation should be considered.
  contrast                                 MR preferred if treatment not
                                           unreasonably delayed.

  CT, head, with or    8                   Consider perfusion if stenosis
  without contrast                         found. Combined vascular and
                                           cerebral evaluation should be
                                           considered. MR preferred if
                                           treatment not unreasonably
                                           delayed.

  CTA, head and neck   8                   Combined vascular and cerebral
                                           evaluation should be considered.
                                           MR preferred if treatment not
                                           unreasonably delayed.

  INV, arteriography,  5                   If intra-arterial therapy is
  neck                                     considered.

  INV, arteriography,  5                   If intra-arterial therapy is
  head and neck                            considered.

  US, carotid, duplex  2                    

  US, transcranial,    2                    
  Doppler                                  

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 4: New focal neurologic defect, fixed or worsening. Three to
24 hours.**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  MRI, brain, with or  8                   Diffusion especially valuable.
  without contrast                         Combined vascular and cerebral
                                           evaluation should be considered.
                                           MR preferred if treatment not
                                           unreasonably delayed.

  MRA, head and neck,  8                   Combined vascular and cerebral
  with or without                          evaluation should be considered.
  contrast                                 MR preferred if treatment not
                                           unreasonably delayed.

  CT, head, with or    8                   For perfusion according to
  without contrast                         institutional protocols. Combined
                                           vascular and cerebral evaluation
                                           should be considered. MR preferred
                                           if treatment not unreasonably
                                           delayed.

  CT, head and neck    8                   Combined vascular and cerebral
                                           evaluation should be considered.
                                           MR preferred if treatment not
                                           unreasonably delayed.

  INV, arteriography,  6                   If intra-arterial therapy is
  neck                                     considered.

  INV, arteriography,  6                   If intra-arterial therapy is
  head and neck                            considered.

  US, carotid, duplex  2                    

  US, transcranial,    2                    
  Doppler                                  

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 5: New focal neurologic defect, fixed or worsening. Greater
than 24 hours.**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  MRI, brain, with or  8                   Diffusion especially valuable.
  without contrast                         Combined vascular and cerebral
                                           evaluation should be considered.
                                           MR preferred if treatment not
                                           unreasonably delayed.

  MRA, head and neck,  8                   Combined vascular and cerebral
  with or without                          evaluation should be considered.
  contrast                                 MR preferred if treatment not
                                           unreasonably delayed.

  CT, head, with or    8                   For perfusion according to
  without contrast                         institutional protocols. Combined
                                           vascular and cerebral evaluation
                                           should be considered. MR preferred
                                           if treatment not unreasonably
                                           delayed.

  CT, head and neck    8                   Combined vascular and cerebral
                                           evaluation should be considered.
                                           MR preferred if treatment not
                                           unreasonably delayed.

  INV, arteriography,  6                   If intra-arterial therapy is
  neck                                     considered.

  INV, arteriography,  6                   If intra-arterial therapy is
  head and neck                            considered.

  US, carotid, duplex  2                    

  US, transcranial,    2                    
  Doppler                                  

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 6: Risk for unruptured aneurysm. Positive family history.**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  MRA, head, with and  8                   MR preferred if treatment is not
  without contrast                         unreasonably delayed.

  CTA, head            8                   Noncontrast CT obtained routinely
                                           at the same time. MR preferred if
                                           treatment not unreasonably
                                           delayed.

  MRI, brain, with or  6                    
  without contrast                         

  MRA, neck, with or   3                    
  without contrast                         

  CT, head, with or    3                   Obtained with CTA.
  without contrast                         

  CTA, neck, with or   2                    
  without contrast                         

  US, carotid, duplex  1                    

  US, transcranial,    1                    
  Doppler                                  

  INV, arteriography,  1                    
  neck                                     

  INV, arteriography,  1                    
  head and neck                            

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 7: Clinically suspected subarachnoid hemorrhage (SAH), not yet
confirmed.**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  CT, head, without    9                    
  contrast                                 

  CT, head, without    5                    
  and with contrast                        

  MRI, brain, with or  4                    
  without contrast                         

  MRA, head, with or   4                    
  without contrast                         

  INV, arteriography,  2                    
  neck                                     

  INV, arteriography,  2                    
  head and neck                            

  MRA, neck, with or   2                    
  without contrast                         

  CTA, head            2                    

  CTA, neck            2                   For treatment planning.

  US, carotid, duplex  1                    

  US, transcranial,    1                    
  Doppler                                  

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 8: Proven SAH by lumbar puncture or imaging.**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  INV, arteriography,  8                   For treatment planning. As part of
  neck                                     cerebral angiography.

  INV, arteriography,  8                    
  head and neck                            

  CT, head, without    8                    
  contrast                                 

  CTA, head            8                    

  MRA, head, with or   7                    
  without contrast                         

  MRI, brain, with or  6                    
  without contrast                         

  MRA, neck, with or   6                   For future treatment planning.
  without contrast                         

  CTA, neck            6                   For future treatment planning.

  US, transcranial,    5                   For vasospasm
  Doppler                                  

  CT, head, without    5                    
  and with contrast                        

  US, carotid, duplex  1                    

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 9: Proven SAH, negative angiogram, follow-up.**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  INV, arteriography,  8                    
  head and neck                            

  MRI, brain, with or  8                   Combined vascular and cerebral
  without contrast                         evaluation should be considered.
                                           MR preferred if treatment not
                                           unreasonably delayed.

  MRA, head, with or   8                   Combined vascular and cerebral
  without contrast                         evaluation should be considered.
                                           MR preferred if treatment not
                                           unreasonably delayed.

  CTA, head            8                   MR preferred if treatment not
                                           unreasonably delayed.

  US, transcranial,    5                   For vasospasm
  Doppler                                  

  INV, arteriography,  5                    
  neck                                     

  MRA, neck, with or   5                    
  without contrast                         

  CT, head, without    5                    
  contrast                                 

  CTA, neck            5                    

  CT, head without and 4                    
  with contrast                            

  US, carotid, duplex  1                    

  fMRI, brain (BOLD)   1                    

  MR, spectroscopy,    1                    
  head (MRS)                               

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 10: Clinically suspected parenchymal hemorrhage (hematoma),
not yet confirmed.**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  CT, head, without    8                    
  contrast                                 

  MRI, brain, with or  7                    
  without contrast                         

  CT, head, without    7                    
  and with contrast                        

  MRA, head, with or   4                    
  without contrast                         

  CTA, head            4                    

  INV, arteriography,  3                    
  head and neck                            

  MRA, neck, with or   3                    
  without contrast                         

  CTA, neck            3                    

  INV, arteriography,  2                    
  neck                                     

  US, carotid, duplex  1                    

  US, transcranial,    1                    
  Doppler                                  

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Variant 11: Proven parenchymal hemorrhage (hematoma)**

  ---------------------------------------------------------------------------
  **Radiologic         **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  MRI, brain, with or  8                   Combined vascular and cerebral
  without contrast                         evaluation should be considered.
                                           MR preferred if treatment is not
                                           unreasonably delayed.

  MRA, head, with or   8                   Combined vascular and cerebral
  without contrast                         evaluation should be considered.
                                           MR preferred if treatment is not
                                           unreasonably delayed.

  CT, head, without    8                   Combined vascular and cerebral
  contrast                                 evaluation should be considered.
                                           MR preferred if treatment is not
                                           unreasonably delayed.

  CTA, head            8                   Combined vascular and cerebral
                                           evaluation should be considered.
                                           MR preferred if treatment is not
                                           unreasonably delayed.

  INV, arteriography,  7                    
  neck                                     

  INV, arteriography,  7                   If suspect AVM
  head and neck                            

  CT, head, without    7                    
  and with contrast                        

  MRA, neck, with or   5                    
  without contrast                         

  CTA, neck            5                    

  US, carotid, duplex  1                    

  US, transcranial,    1                    
  Doppler                                  

  fMRI, brain (BOLD)   1                    

  MR spectroscopy      1                    
  (MRS), head                              

  PET, brain           1                    

  NM, SPECT, brain     1                    

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the tables are listed at the end of the
\"Major Recommendations\" field.

**Summary**

Because of the gravity of stroke\'s sequelae, considerable effort has
been expended to identify risk factors for cardiovascular disease (see
Appendix B in the original guideline document) and strategies for stroke
prevention in high-risk patients. These range from modification of
lifestyle to surgical intervention. Surgery has been shown effective in
altering morbidity of both asymptomatic and symptomatic patients in
randomized, prospective clinical trials in which the intent to treat was
determined partly by imaging. In asymptomatic patients, screening should
be undertaken not only by a sensitive, noninvasive (i.e., low-risk) test
directed at identifying the abnormal cerebrovascular substrate but also
with some consideration for identifying those in risk populations with a
high prevalence of disease (e.g., patients with carotid bruit).

Although the diagnostic accuracy of duplex ultrasound (US), computed
tomography angiography (CTA), and magnetic resonance angiography (MRA),
and time resolved contrast-enhanced MRA (CEMRA) are all high for
internal carotid artery (ICA) stenosis of 70% to 99%, only US appears to
offer cost-effective screening. Alternatively, variability in
performance (efficacy vs. effectiveness) precludes endorsement of its
routine use as the sole examination before endarterectomy, and combined
use with CEMRA is an increasingly common practice. Multislice CTA is
promising but relatively few rigorous studies have been done, and the
technique remains limited by large intravenous contrast injection
volumes, potential contrast toxicity or reaction, radiation dose, and
plaque calcification that may obscure the stenosis. It should be noted
that although surgical outcome studies have been based on catheter
angiography, the possible morbidity of these studies and continuing
improvement in noninvasive exams have made invasive studies less common.
Similarly, a variety of imaging strategies may be undertaken in
symptomatic cases where the initial studies can be directed toward the
brain parenchyma, and a vascular study may be included immediately at
the onset. Elevated ischemic stroke risk in patients with chronic
carotid stenosis or occlusion can also be identified using
single-photon-emission computed tomography (SPECT) and Xenon-CT methods,
which show reduced cerebral vascular reserve (CVR) after acetazolamide
challenge, or by elevated oxygen extraction fraction (OEF) using
^15^O-PET (positron emission tomography). Although there is limited
experience with MR and CT perfusion methods for this purpose, elevated
cerebral blood volume appears to correlate with reduced CVR and
increased stroke risk, and these studies are widely available.

Although stroke is typically acute in onset, occasionally the onset is
less immediate and more gradual or stuttering. Differential diagnostic
considerations in these cases include atypical migraine, multiple
sclerosis, venous occlusive disease, and atypical epilepsy.

Traditionally, if focal neurologic symptoms continue for more than 24
hours, stroke is diagnosed; otherwise, a focal neurologic deficit
lasting less than 24-hours has been defined as a transient ischemic
attack (TIA). However, this time-based definition of TIA may be
inadequate and misleading, potentially leading to inappropriate delays
in diagnosis and treatment. A \"tissue-based\" definition has been
proposed that considers all acute focal neurologic deficits as possible
infarcts and classifies them as acute ischemic cerebrovascular syndromes
(AICS) based on the degree of certainty of tissue ischemic injury,
determined primarily by imaging studies. Because most transient ischemic
neurologic symptoms last for 1 hour or less and 50% or more show tissue
injury on MRI diffusion-weighted imaging (DWI), the TIA Working Group
recently proposed a new definition of TIA as \"*a brief* *episode of
neurologic dysfunction presumptively caused* *by focal brain or retinal
ischemia, typically lasting less* *than one hour, without neuroimaging
evidence of acute* *infarction\".* This change reflects the growing
emphasis on the earliest possible diagnosis and treatment of acute
ischemia and the use of MRI and CT for definitive infarct diagnosis and
exclusion of hemorrhage. In addition, because 15% of all strokes are
heralded by a TIA and the 90 day risk of stroke after a TIA is as high
as 20%, a TIA should trigger an immediate work up for stroke risks and
follow-up imaging studies.

With the introduction of CT scanning by Hounsfield in the early 1970\'s
came the ability to acutely assess the brain, subarachnoid, and
ventricular spaces noninvasively. Similarly, on the basis of the x-ray
attenuation of blood and edema relative to cerebrospinal fluid (CSF) and
brain parenchyma, CT is effective in detecting acute hemorrhage into
brain parenchyma, the subarachnoid, subdural, or intraventricular
spaces, and in distinguishing acute hemorrhage from ischemia/infarction.
Because of its ready availability and high sensitivity to the presence
or absence of acute blood, noncontrast CT historically has been the
preferred modality for initial imaging of suspected stroke, but it has
lacked a similar sensitivity to acute ischemia and infarction.

Alternatively, DWI MRI has been shown to be exquisitely sensitive to
acute infarction within minutes of the precipitating ictus, although
tissue with small apparent diffusion coefficient (ADC) reductions (e.g.,
20% below normal) may represent reversible ischemia that does not
progress to completed infarct. Additional information obtainable through
the combined use of dynamic cerebral blood volume techniques
(perfusion-weighted imaging, PWI) as well as vascular imaging (MRA)
makes MRI an appealing tool for diagnosis and treatment monitoring of
acute cerebrovascular disease. However, enthusiasm for MRI in the
setting of acute stroke has often been stifled by the variable and
confounding appearance of hemorrhage on MRI. The recognition and
characterization of the MRI findings in intracranial hemorrhage are
understandable if one considers: 1) the location, specifically
subarachnoid vs. intraparenchymal; 2) the oxidative state of hemoglobin
and the subsequent breakdown products; 3) the type of imaging pulse
sequence used (T1 vs. T2, spin-echo vs. gradient-echo, conventional
spin-echo vs. Rapid Acquisition Relaxation Enhanced \[RARE\] sequences);
and 4) the field strength of the machine used to acquire the images.

Recent experience using T2\* (gradient echo) imaging to detect low
signal parenchymal hemorrhage and fluid-attenuated inversion recovery
(FLAIR) scans to detect high signal subarachnoid blood have helped to
renew interest in MRI as a first-line modality in patients with acute,
focal neurologic deficits. Although the presence of small hemorrhages on
gradient-echo MRI may better predict hemorrhagic complications of
recombinant tissue plasminogen activator (rtPA) therapy, there is
insufficiently widespread clinical experience to recommend MRI over CT
for routine exclusion of intracranial hemorrhage. It is also important
to reemphasize the issue of availability of MRI in the context of the
therapeutic window and potential contraindications e: patients with
pacemakers, cerebral aneurysm clips, ocular foreign bodies, or cochlear
implants, and those suffering from claustrophobia, or morbid obesity
(\>320 pounds).

As mentioned previously, CT is highly sensitive to the presence or
absence of acute blood and has been the mainstay in emergent evaluation
of acute cerebrovascular disease. Documented acute subarachnoid or
parenchymal hemorrhage are conditions associated with high morbidity and
mortality. In the case of aneurysmal subarachnoid hemorrhage (SAH), this
is partly due to the relatively high rate of early rebleeding. In
patients presenting with SAH, early surgery or coiling is offered as a
strategy to circumvent this problem, which in turn requires early
cerebral angiography. Intra-arterial angiography\'s sensitivity to
cerebral aneurysms is estimated to be greater than 90%; in the setting
of acute SAH this figure decreases to slightly greater than 80%.
Initially negative studies may require additional angiography at a
future time.

Recent clinical practice has shifted toward use of noncontrast CT for
SAH detection, followed immediately by CTA for aneurysm detection.
Comparisons between CTA and catheter angiography in SAH patients,
beginning with single-slice methods and more recently with multislice
methods, have shown overall aneurysm detection sensitivities of 85% to
95%, lower for smaller aneurysms, to approximately 50% for those less
than 2 mm in diameter. Treatment of intracranial aneurysms following SAH
is increasingly based on CTA alone. Late appearances of new neurological
changes suggestive of post-SAH vasospasm, ischemia, or hydrocephalus are
increasingly investigated with transcranial Doppler (TCD) and CT imaging
with CTA and CT perfusion (CTP), while catheter angiography and SPECT
are being used less frequently than in the past.

Because of the cumulative long-term risk of morbidity and mortality from
subarachnoid hemorrhage, especially with larger aneurysms (\>25 mm in
diameter) and the relatively low risk of clipping or coiling unruptured
intracranial aneurysms, there may be a clinical role for prophylactic
screening. Intra-arterial angiography carries the risk of thromboembolic
complication and is relatively expensive; MRI and CTA provide less
expensive, noninvasive alternative, although their sensitivity to
lesions less than 5 mm in diameter is suspect. To date, individuals with
a history of aneurysm or SAH in a first-degree relative have been
considered candidates for screening. Nevertheless, significant gaps in
knowledge of the natural history (and thus risk of rupture) of
intracranial aneurysms remain. Hence, while screening with MRA or CTA
may be appropriate in patients with a positive family history, its
impact on patient outcome is questionable.

Parenchymal brain hemorrhage may be associated with underlying vascular
malformations such as arteriovenous malformation (AVM), pial
arteriovenous fistulae, and cavernous malformations in younger patients
as well as dural fistulae in older individuals. Diagnosis, assessment of
risk for future hemorrhage, and effective treatment planning are all
predicated on determination of size of the underlying lesion, location
within the brain parenchyma, pattern of venous drainage, and presence of
intranidal aneurysm. Acutely, this information is most frequently
obtained by intra-arterial angiography, which in more complicated cases
may be supplemented by MRI. Although time-resolved elliptic centric
bolus contrast CEMRA techniques with multicoil sensitivity encoding
currently have temporal resolution in the 1-2 second range, they do not
yet rival catheter digital subtraction angiography (DSA) arteriography
for separation of arterial and venous phases of high-flow AVMs, but may
be useful for follow-up of partially embolized lesions. Baseline and
follow-up MRI may be particularly appropriate in partially embolized
cases or in patients undergoing stereotactic radiosurgery as a
noninvasive, low risk means of identifying ischemic complications and
assessing response to therapy.

**Assumptions**

All patient scenarios should be addressed as though the patients had
been referred for imaging following a history and physical examination
including neurological, vascular, and ophthalmoscopic exams.

**Abbreviations**

-   AVM, arteriovenous malformation

-   BOLD, blood oxygen level dependent

-   CT, computed tomography

-   CTA, computed tomography angiography

-   fMRI, functional magnetic resonance imaging

-   INV, invasive

-   MR, magnetic resonance

-   MRA, magnetic resonance angiography

-   MRI, magnetic resonance imaging

-   MRS, magnetic resonance spectroscopy

-   NM, nuclear medicine

-   PET, positron emission tomography

-   SAH, subarachnoid hemorrhage

-   SPECT, single photon-emission computed tomography

-   TIA, transient ischaemic attack

-   US, ultrasound

#### CLINICAL ALGORITHM(S)

Algorithms were not developed from criteria guidelines.

### EVIDENCE SUPPORTING THE RECOMMENDATIONS

#### TYPE OF EVIDENCE SUPPORTING THE RECOMMENDATIONS

The recommendations are based on analysis of the current literature and
expert panel consensus.

### BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS

#### POTENTIAL BENEFITS

Selection of appropriate radiologic imaging procedures for evaluation of
patients with acute cerebrovascular disease

#### POTENTIAL HARMS

Risks associated with thrombolytic therapy

### QUALIFYING STATEMENTS

#### QUALIFYING STATEMENTS

An American College of Radiology (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 exams 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
U.S. Food and Drug Administration (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.

### IMPLEMENTATION OF THE GUIDELINE

#### DESCRIPTION OF IMPLEMENTATION STRATEGY

An implementation strategy was not provided.

#### IMPLEMENTATION TOOLS

Personal Digital Assistant (PDA) Downloads

For information about
[availability](#identifying-information-and-availability), see the
\"Availability of Companion Documents\" and \"Patient Resources\" fields
below.

### INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT CATEGORIES

#### IOM CARE NEED

Getting Better\
Living with Illness

#### IOM DOMAIN

Effectiveness

### IDENTIFYING INFORMATION AND AVAILABILITY

#### BIBLIOGRAPHIC SOURCE(S)

De La Paz RL, Seidenwurm DJ, Davis PC, Brunberg JA, Dormont PD, Hackney
DB, Jordan JE, Karis JP, Mukherji SK, Turski PA, Wippold FJ Jr,
Zimmermann RD, Sloan MA, Expert Panel on Neurologic Imaging.
Cerebrovascular disease. \[online publication\]. Reston (VA): American
College of Radiology (ACR); 2006. 20 p. \[120 references\]

#### ADAPTATION

Not applicable: The guideline was not adapted from another source.

#### DATE RELEASED

1996 (revised 2006)

#### GUIDELINE DEVELOPER(S)

American College of Radiology - Medical Specialty Society

#### SOURCE(S) OF FUNDING

The American College of Radiology (ACR) provided the funding and the
resources for these ACR Appropriateness Criteria®.

#### GUIDELINE COMMITTEE

Committee on Appropriateness Criteria, Expert Panel on Neurologic
Imaging

#### COMPOSITION OF GROUP THAT AUTHORED THE GUIDELINE

*Panel Members*: Robert L. De La Paz, MD; David J. Seidenwurm, MD;
Patricia C. Davis, MD; James A. Brunberg, MD; Pr. Didier Dormont; David
B. Hackney, MD; John E. Jordan, MD; John P. Karis, MD; Suresh Kumar
Mukherji, MD; Patrick A. Turski, MD; Franz J. Wippold II, MD; Robert D.
Zimmerman, MD; Michael A. Sloan, MD, MS

#### FINANCIAL DISCLOSURES/CONFLICTS OF INTEREST

Not stated

#### GUIDELINE STATUS

This is the current release of the guideline.

This guideline updates a previous version: Masaryk T, Drayer BP,
Anderson RE, Braffman B, Davis PC, Deck MD, Hasso AN, Johnson BA,
Pomeranz SJ, Seidenwurm D, Tanenbaum L, Masdeu JC. Cerebrovascular
disease. American College of Radiology. ACR Appropriateness Criteria.
Radiology 2000 Jun;215(Suppl):415-35.

The appropriateness criteria are reviewed annually and updated by the
panels as needed, depending on introduction of new and highly
significant scientific evidence.

#### GUIDELINE AVAILABILITY

Electronic copies: Available in Portable Document Format (PDF) from the
[American College of Radiology (ACR) Web
site](http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonNeurologicImaging/CerebrovascularDiseaseDoc2.aspx).

ACR Appropriateness Criteria® *Anytime*, *Anywhere*™ (PDA application).
Available from the [ACR Web
site](http://www.acr.org/SecondaryMainMenuCategories/ACRStore/FeaturedCategories/QualityandSafety/ac_pda.aspx).

Print copies: Available from the American College of Radiology, 1891
Preston White Drive, Reston, VA 20191. Telephone: (703) 648-8900.

#### AVAILABILITY OF COMPANION DOCUMENTS

The following is available:

-   ACR Appropriateness Criteria®. Background and development. Reston
    (VA): American College of Radiology; 2 p. Electronic copies:
    Available in Portable Document Format (PDF) from the [American
    College of Radiology (ACR) Web
    site](http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/background_dev.aspx).

#### PATIENT RESOURCES

None available

#### NGC STATUS

This summary was completed by ECRI on July 31, 2001. The information was
verified by the guideline developer as of August 24, 2001. This NGC
summary was updated by ECRI Institute on April 26, 2007.

#### COPYRIGHT STATEMENT

Instructions for downloading, use, and reproduction of the American
College of Radiology (ACR) Appropriateness Criteria® may be found on the
[ACR Web
site.](http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/ACRAppropriatenessCriteriaTermsandConditionsDoc1.aspx)

### DISCLAIMER

#### NGC DISCLAIMER

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Date Modified: 11/3/2008