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Guideline Summary
Guideline Title
ACR–ASNR practice guideline for the performance of computed tomography (CT) of the brain.
Bibliographic Source(s)
American College of Radiology (ACR), American Society of Neuroradiology (ASNR). ACR-ASNR practice guideline for the performance of computed tomography (CT) of the brain. [online publication]. Reston (VA): American College of Radiology (ACR); 2010. 6 p.
Guideline Status

This is the current release of the guideline.

Scope

Disease/Condition(s)

Abnormalities of the brain

Note: Refer to the "Indications" section of the "Major Recommendations" field for a detailed list of diseases and conditions.

Guideline Category
Diagnosis
Evaluation
Clinical Specialty
Family Practice
Internal Medicine
Neurological Surgery
Neurology
Pediatrics
Radiology
Intended Users
Advanced Practice Nurses
Allied Health Personnel
Nurses
Physician Assistants
Physicians
Guideline Objective(s)
  • To assist practitioners in providing appropriate radiologic care for patients
  • To describe principles for performing high-quality computed tomography (CT) imaging of the brain in pediatric and adult patients, including advanced applications such as CT perfusion, CT volumetry, CT angiography, and CT venography
Target Population

Adult and pediatric patients undergoing computed tomography (CT) of the brain

Interventions and Practices Considered
  1. Computed tomography of the brain
    • Use of qualified personnel
    • Brain imaging techniques
    • Use of contrast media
    • Advanced applications
  2. Appropriate documentation
  3. Equipment specifications
  4. Minimizing radiation exposure
Major Outcomes Considered

Not stated

Methodology

Methods Used to Collect/Select the Evidence
Searches of Electronic Databases
Description of Methods Used to Collect/Select the Evidence

The Medline literature search is based on keywords provided by the topic author. The two general classes of keywords are those related to the condition (e.g., ankle pain, fever) and those that describe the diagnostic or therapeutic intervention of interest (e.g., mammography, MRI).

The search terms and parameters are manipulated to produce the most relevant, current evidence to address the Practice Guideline or Technical Standard topic being reviewed or developed. Combining the clinical conditions and diagnostic modalities or therapeutic procedures narrows the search to be relevant to the topic. Exploding the term "diagnostic imaging" captures relevant results for diagnostic topics.

The following criteria/limits are used in the searches.

  1. Articles that have abstracts available and are concerned with humans.
  2. Restrict the search to the year prior to the last topic update or in some cases the author of the topic may specify which year range to use in the search. For new topics, the year range is restricted to the last 5 years unless the topic author provides other instructions.
  3. May restrict the search to Adults only or Pediatrics only.
  4. Articles consisting of only summaries or case reports are often excluded from final results.

The search strategy may be revised to improve the output as needed.

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
Expert Consensus
Rating Scheme for the Strength of the Evidence

Not applicable

Methods Used to Analyze the Evidence
Review
Description of the Methods Used to Analyze the Evidence

Not stated

Methods Used to Formulate the Recommendations
Expert Consensus
Description of Methods Used to Formulate the Recommendations

Recommendations are formulated through iterative review by committee, collaborating societies, and membership. Suggested recommendations are reviewed by the committee, and agreement is reached by consensus.

Rating Scheme for the Strength of the Recommendations

Not applicable

Cost Analysis

A formal cost analysis was not performed and published costs analyses were not reviewed.

Method of Guideline Validation
Internal Peer Review
Description of Method of Guideline Validation

Each practice guideline and technical standard, representing a policy statement by the American College of Radiology (ACR), has undergone a thorough consensus process in which it has been subjected to extensive review, requiring the approval of the Commission on Quality and Safety as well as the ACR Board of Chancellors, the ACR Council Steering Committee, and the ACR Council.

Recommendations

Major Recommendations

Computed tomography (CT) is a technology extensively used in neuroradiology that produces cross-sectional displays using ionizing radiation to generate images resulting from X-ray absorption by the specific tissues examined. CT offers a high degree of utility in the examination of the brain. This guideline outlines the principles for performing high-quality CT imaging of the brain in pediatric and adult patients, including advanced applications such as CT perfusion, CT volumetry, CT angiography, and CT venography.

Indications

Indications for CT of the brain include, but are not limited to:

  1. Primary Indications
    1. Acute head trauma
    2. Suspected acute intracranial hemorrhage
    3. Vascular occlusive disease or vasculitis (including use of CT angiography and/or venography)
    4. Aneurysm evaluation
    5. Detection or evaluation of calcification
    6. Immediate postoperative evaluation following surgical treatment of tumor, intracranial hemorrhage, or hemorrhagic lesions
    7. Treated or untreated vascular lesions
    8. Suspected shunt malfunctions, or shunt revisions
    9. Mental status change
    10. Increased intracranial pressure
    11. Headache
    12. Acute neurologic deficits
    13. Suspected intracranial infection
    14. Suspected hydrocephalus
    15. Congenital lesions (such as, but not limited to, craniosynostosis, macrocephaly, and microcephaly)
    16. Evaluating psychiatric disorders
    17. Brain herniation
    18. Suspected mass or tumor
  1. Secondary Indications
    1. When magnetic resonance imaging (MRI) is unavailable or contraindicated, or if the supervising physician deems CT to be appropriate
    2. Diplopia
    3. Cranial nerve dysfunction
    4. Seizures
    5. Apnea
    6. Syncope
    7. Ataxia
    8. Suspicion of neurodegenerative disease
    9. Developmental delay
    10. Neuroendocrine dysfunction
    11. Encephalitis
    12. Drug toxicity
    13. Cortical dysplasia, and migration anomalies or other morphologic brain abnormalities

For the pregnant or potentially pregnant patient, see the "ACR Practice Guideline for Imaging Pregnant or Potentially Pregnant Adolescents and Women with Ionizing Radiation" (see the American College of Radiology [ACR] Web site for this practice guideline and additional ones mentioned below.)

Qualification and Responsibilities of Personnel

See the "ACR Practice Guideline for Performing and Interpreting Diagnostic Computed Tomography (CT)."

Specifications of the Examination

The supervising physician must have complete understanding of the indications, risks, and benefits of the examination, as well as alternative imaging procedures. The physician should be familiar with relevant ancillary studies that the patient may have undergone (see the "ACR Practice Guideline for Communication of Diagnostic Imaging Findings"). The physician performing CT interpretation must have a clear understanding and knowledge of the anatomy and pathophysiology relevant to the examination.

The written or electronic request for CT of the brain should provide sufficient information to demonstrate the medical necessity of the examination and allow for its proper performance and interpretation.

Documentation that satisfies medical necessity includes 1) signs and symptoms and/or 2) relevant history (including known diagnoses). Additional information regarding the specific reason for the examination or a provisional diagnosis would be helpful and may at times be needed to allow for the proper performance and interpretation of the examination.

The request for the examination must be originated by a physician or other appropriately licensed health care provider. The accompanying clinical information should be provided by a physician or other appropriately licensed health care provider familiar with the patient's clinical problem or question and consistent with the state's scope of practice requirements. (ACR Resolution 35, adopted in 2006)

  1. General Considerations

    CT protocols for brain imaging should be designed to answer the specific clinical question. The supervising physician should be familiar with the indications for each examination, relevant patient history, potential adverse reactions to contrast media, exposure factors, window and center settings, field of view, collimation, slice intervals, slice spacing (table increment) or pitch, and image reconstruction algorithms. Protocols should be reviewed and updated periodically to optimize the examination.

  1. Brain Imaging

    CT brain imaging may be performed with a sequential single-slice technique, multislice helical (spiral) protocol, or multidetector multislice algorithm. For CT of the brain, contiguous or overlapping axial slices should be acquired with a slice thickness of no greater than 5 mm. In the setting of trauma, images should be obtained and/or reviewed at window settings appropriate for demonstrating brain and bone abnormalities as well as small subdural hematomas and soft tissue lesions (subdural windows). For imaging of the cranial base, an axial slice thickness as thin as possible, but no greater than 3 mm with spiral techniques and 2 mm with multidetector and nonspiral techniques, should be used for 2-dimensional (2D) reformatting or for 3-dimensional (3D) reconstruction.

  1. Contrast Studies

    Certain indications require administration of intravenous (IV) contrast media or intrathecal contrast (e.g., cisternography) during imaging of the brain. Intravenous contrast enhancement should be performed using appropriate injection protocols and in accordance with the "ACR Practice Guideline for the Use of Intravascular Contrast Media." Cerebrospinal fluid (CSF) contrast administration requires use of nonionic agents approved for intrathecal use and should be performed with regard to applicable guidelines as outlined in the "ACR–ASNR Practice Guideline for the Performance of Myelography and Cisternography."

  1. Advanced Applications

    In addition to directly acquired axial images, reformatted images in coronal, sagittal, or other more complex planes may be constructed from the axial data set to answer specific clinical questions, or the images may be manipulated to allow selective visualization of specific tissues such as in CT perfusion, CT volumetry, CT angiography, or CT venography. Such applications are better performed with helical data sets using very thin slice thickness and overlapping reconstruction rather than routine axial sequential data. See the "ACR–ASNR Practice Guideline for the Performance of Computed Tomography (CT) Perfusion in Neuroradiologic Imaging."

Documentation

Reporting should be in accordance with the "ACR Practice Guideline for Communication of Diagnostic Imaging Findings."

Equipment Specifications

See the original guideline document for information about equipment specifications.

Radiation Safety in Imaging

Radiologists, medical physicists, radiologic technologists, and all supervising physicians have a responsibility to minimize radiation dose to individual patients, to staff, and to society as a whole, while maintaining the necessary diagnostic image quality. This concept is known as "as low as reasonably achievable (ALARA)."

Facilities, in consultation with the medical physicist, should have in place and should adhere to policies and procedures, in accordance with ALARA, to vary examination protocols to take into account patient body habitus, such as height and/or weight, body mass index or lateral width. The dose reduction devices that are available on imaging equipment should be active; if not, manual techniques should be used to moderate the exposure while maintaining the necessary diagnostic image quality. Periodically, radiation exposures should be measured and patient radiation doses estimated by a medical physicist in accordance with the appropriate ACR Technical Standard. (ACR Resolution 17, adopted in 2006 – revised in 2009, Resolution 11)

Clinical Algorithm(s)

None provided

Evidence Supporting the Recommendations

Type of Evidence Supporting the Recommendations

The type of supporting evidence is not specifically stated for each recommendation.

Benefits/Harms of Implementing the Guideline Recommendations

Potential Benefits

Improved performance of computed tomography (CT) of the brain

Potential Harms
  • Computed tomography (CT) is a technology that exposes patients to ionizing radiation.
  • Contrast media is associated with possible adverse reactions.

Qualifying Statements

Qualifying Statements
  • These guidelines are an educational tool designed to assist practitioners in providing appropriate radiologic care for patients. They are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the American College of Radiology cautions against the use of these guidelines in litigation in which the clinical decisions of a practitioner are called into question.
  • The ultimate judgment regarding the propriety of any specific procedure or course of action must be made by the physician or medical physicist in light of all the circumstances presented. Thus, an approach that differs from the guidelines, standing alone, does not necessarily imply that the approach was below the standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the guidelines when, in the reasonable judgment of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources, or advances in knowledge or technology subsequent to publication of the guidelines. However, a practitioner who employs an approach substantially different from these guidelines is advised to document in the patient record information sufficient to explain the approach taken.
  • The practice of medicine involves not only the science, but also the art of dealing with the prevention, diagnosis, alleviation, and treatment of disease. The variety and complexity of human conditions make it impossible to always reach the most appropriate diagnosis or to predict with certainty a particular response to treatment. Therefore, it should be recognized that adherence to these guidelines will not assure an accurate diagnosis or a successful outcome. All that should be expected is that the practitioner will follow a reasonable course of action based on current knowledge, available resources, and the needs of the patient to deliver effective and safe medical care. The sole purpose of these guidelines is to assist practitioners in achieving this objective.

Implementation of the Guideline

Description of Implementation Strategy

Quality Control and Improvement, Safety, Infection Control, and Patient Education

Policies and procedures related to quality, patient education, infection control, and safety should be developed and implemented in accordance with the American College of radiology (ACR) Policy on Quality Control and Improvement, Safety, Infection Control, and Patient Education appearing under the heading Position Statement on QC & Improvement, Safety, Infection Control, and Patient Education on the ACR Web site External Web Site Policy.

For specific issues regarding computed tomography (CT) quality control, see the "ACR Practice Guideline for Performing and Interpreting Diagnostic Computed Tomography (CT)" (see the ACR Web site External Web Site Policy).

Equipment monitoring should be in accordance with the ACR Technical Standard for Diagnostic Medical Physics Performance Monitoring of Computed Tomography (CT) Equipment (see the ACR Web site External Web Site Policy).

Institute of Medicine (IOM) National Healthcare Quality Report Categories

IOM Care Need
Getting Better
Living with Illness
IOM Domain
Effectiveness
Patient-centeredness

Identifying Information and Availability

Bibliographic Source(s)
American College of Radiology (ACR), American Society of Neuroradiology (ASNR). ACR-ASNR practice guideline for the performance of computed tomography (CT) of the brain. [online publication]. Reston (VA): American College of Radiology (ACR); 2010. 6 p.
Adaptation

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

Date Released
2004 (revised 2010)
Guideline Developer(s)
American College of Radiology - Medical Specialty Society
American Society of Neuroradiology - Professional Association
Source(s) of Funding

American College of Radiology

Guideline Committee

Guidelines and Standards Committee of the Commission on Neuroradiology in collaboration with the Subcommittee on Standards and Guidelines of the American Society of Neuroradiology (ASNR)

Composition of Group That Authored the Guideline

Principal Drafter: John E. Jordan, MD

American College of Radiology (ACR) Guidelines and Standards Committee: Suresh K. Mukherji, MD, FACR (Chair); Jacqueline A. Bello, MD, FACR; Mark H. Depper, MD; Carol A. Dolinskas, MD, FACR; Sachin Gujar, MD; John E. Jordan, MD; Stephen A. Kieffer, MD, FACR; Edward J. O'Brien, Jr., MD, FACR; Jeffrey R. Petrella, MD; John L. Ulmer, MD; R. Nick Bryan, MD, PhD, FACR (Chair, Commission)

American Society of Neuroradiology (ASNR) Guidelines Committee: Suresh K. Mukherji, MD, FACR (Chair); John D. Barr, MD; Jacqueline A. Bello, MD, FACR; Carol A. Dolinskas, MD, FACR; Kavita K. Erickson, MD; Scott H. Faro, MD; Blaise V. Jones, MD; John E. Jordan, MD; Edward E. Kassel, MD, FACR; Stephen A. Kieffer, MD, FACR; Eric J. Russell, MD, FACR; Jeffrey A. Stone, MD; Robert W. Tarr, MD; Patrick A. Turski, MD, FACR

Comments Reconciliation Committee: Michael M. Raskin, MD, MPH, JD, MBA, FACR (Chair); Kimberly E. Applegate, MD, MS, FACR; Howard B. Fleishon, MD, MMM, FACR; John E. Jordan, MD; Alan D. Kaye, MD, FACR; Paul A. Larson, MD, FACR; Lawrence A. Liebscher, MD, FACR; Carolyn C. Meltzer, MD, FACR; Suresh K. Mukherji, MD, FACR; Christopher J. Roth, MD; Michael I. Rothman, MD; Lawrence N. Tanenbaum, MD, FACR

Financial Disclosures/Conflicts of Interest

Not stated

Guideline Status

This is the current release of the guideline.

Guideline Availability

Electronic copies: Available in Portable Document Format (PDF) from the American College of Radiology (ACR) Web site External Web Site Policy.

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 are available:

  • The process of developing ACR practice guidelines and technical standards. Reston (VA): American College of Radiology. Electronic copies: Available from the American College of Radiology (ACR) Web site External Web Site Policy.
  • Purpose and intended use. Reston (VA): American College of Radiology. Electronic copies: Available from the ACR Web site External Web Site Policy.
Patient Resources

None available

NGC Status

This NGC summary was completed by ECRI Institute on October 13, 2011.

Copyright Statement

Copyright © by the American College of Radiology, 1891 Preston White Dr., Reston, VA 20191-4397, 703-648-8900. All rights reserved. No reproduction of this material in any format, electronic or otherwise, is permitted except with prior written consent from the American College of Radiology.

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