This is the current release of the guideline.

This guideline updates a previous version: Karis JP, Seidenwurm DJ, Davis PC, Brunberg JA, De La Paz RL, Dormont PD, Hackney DB, Jordan JE, Mukherji SK, Turshi PA, Wippold FJ II, Zimmermann RD, McDermott MW, Sloan MA, Expert Panel on Neurologic Imaging. Epilepsy. [online publication]. Reston (VA): American College of Radiology (ACR); 2006. 8 p.

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

Seizures and epilepsy

To evaluate the appropriateness of initial radiologic examinations for patients with seizures and epilepsy

Patients with seizures and epilepsy

Utility of radiologic examinations in differential diagnosis

Literature Search Procedure

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 American College of Radiology Appropriateness Criteria (ACR AC) 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.

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

Strength of Evidence Key

Category 1 - The conclusions of the study are valid and strongly supported by study design, analysis and results.

Category 2 - The conclusions of the study are likely valid, but study design does not permit certainty.

Category 3 - The conclusions of the study may be valid but the evidence supporting the conclusions is inconclusive or equivocal.

Category 4 - The conclusions of the study may not be valid because the evidence may not be reliable given the study design or analysis.

The topic author drafts or revises the narrative text summarizing the evidence found in the literature. American College of Radiology (ACR) staff draft an evidence table based on the analysis of the selected literature. These tables rate the strength of the evidence for all articles included in the narrative text.

The expert panel reviews the narrative text, evidence table, and the supporting literature for each of the topic-variant combinations and assigns an appropriateness rating for each procedure listed in the table. Each individual panel member forms his/her own opinion based on his/her interpretation of the available evidence.

More information about the evidence table development process can be found in the American College of Radiology (ACR) Appropriateness Criteria® Evidence Table Development document (see "Availability of Companion Documents" field).

Modified Delphi Technique

The appropriateness ratings for each of the procedures included in the Appropriateness Criteria topics are determined using a modified Delphi methodology. A series of surveys are conducted to elicit each panelist's expert interpretation of the evidence, based on the available data, regarding the appropriateness of an imaging or therapeutic procedure for a specific clinical scenario. American College of Radiology (ACR) staff distributes surveys to the panelists along with the evidence table and narrative. Each panelist interprets the available evidence and rates each procedure. The surveys are completed by panelists without consulting other panelists. The ratings are a scale between 1 and 9, which is further divided into three categories: 1, 2, or 3 is defined as "usually not appropriate"; 4, 5, or 6 is defined as "may be appropriate"; and 7, 8, or 9 is defined as "usually appropriate." Each panel member assigns one rating for each procedure per survey round. The surveys are collected and the results are tabulated, de-identified and redistributed after each round. A maximum of three rounds are conducted. The modified Delphi technique enables each panelist to express individual interpretations of the evidence and his or her expert opinion without excessive bias from fellow panelists in a simple, standardized and economical process.

Consensus among the panel members must be achieved to determine the final rating for each procedure. Consensus is defined as eighty percent (80%) agreement within a rating category. The final rating is determined by the median of all the ratings once consensus has been reached. Up to three rating rounds are conducted to achieve consensus.

If consensus is not reached, the panel is convened by conference call. The strengths and weaknesses of each imaging procedure that has not reached consensus are discussed and a final rating is proposed. If the panelists on the call agree, the rating is accepted as the panel's consensus. The document is circulated to all the panelists to make the final determination. If consensus cannot be reached on the call or when the document is circulated, "No consensus" appears in the rating column and the reasons for this decision are added to the comment sections.

Not applicable

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

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

ACR Appropriateness Criteria®

Clinical Condition: Seizures and Epilepsy

Variant 1: Medically refractory epilepsy; surgical candidate and/or surgical planning.

Radiologic Procedure	Rating	Comments	RRL*
MRI head without contrast	8		O
MRI head without and with contrast	8	See statement regarding contrast in text under "Anticipated Exceptions."	O
FDG-PET/CT head	7	May be helpful in preoperative planning.
CT head with contrast	6
MRI functional (fMRI) head without contrast	6	May be helpful in preoperative planning.	O
MEG/MSI	6	May identify IOZ in nonlesional patients (normal MRI), can provide confirmatory localization information, may guide placement of iEEG. May substitute for invasive testing, and may be useful when other tests are discordant.	O
Tc-99m HMPAO SPECT head	5	May provide confirmatory localization information.
CT head without contrast	5
CT head without and with contrast	4
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

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

Variant 2: New onset seizure, unrelated to trauma. EtOH, and/or drug related.

Radiologic Procedure	Rating	Comments	RRL*
MRI head without and with contrast	8	In the acute or emergency setting, CT may be the imaging study of choice. See statement regarding contrast in text under "Anticipated Exceptions."	O
MRI head without contrast	7	In the acute or emergency setting, CT may be the imaging study of choice.	O
CT head with contrast	6	In the acute or emergency setting, CT may be the imaging study of choice.
CT head without contrast	5	In the acute or emergency setting, CT may be the imaging study of choice.
CT head without and with contrast	3
MRI functional (fMRI) head without contrast	2		O
Tc-99m HMPAO SPECT head	2
FDG-PET/CT head	2
MEG/MSI	2		O
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

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

Variant 3: New onset seizure, unrelated to trauma. Aged 18–40.

Radiologic Procedure	Rating	Comments	RRL*
MRI head without contrast	8	In the acute or emergency setting, CT may be the imaging study of choice.	O
MRI head without and with contrast	7	In the acute or emergency setting, CT may be the imaging study of choice. See statement regarding contrast in text under "Anticipated Exceptions."	O
CT head with contrast	6	In the acute or emergency setting, CT may be the imaging study of choice.
CT head without contrast	5	In the acute or emergency setting, CT may be the imaging study of choice.
Tc-99m HMPAO SPECT head	4
FDG-PET/CT head	4
CT head without and with contrast	3
MRI functional (fMRI) head without contrast	2		O
MEG/MSI	2		O
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

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

Variant 4: New-onset seizure, unrelated to trauma. Older than age 40.

Radiologic Procedure	Rating	Comments	RRL*
MRI head without and with contrast	8	In the acute or emergency setting, CT may be the imaging study of choice. See statement regarding contrast in text under "Anticipated Exceptions."	O
MRI head without contrast	7	In the acute or emergency setting, CT may be the imaging study of choice.	O
CT head with contrast	6	In the acute or emergency setting, CT may be the imaging study of choice.
CT head without contrast	5	In the acute or emergency setting, CT may be the imaging study of choice.
CT head without and with contrast	5
Tc-99m HMPAO SPECT head	4
FDG-PET/CT head	4
MRI functional (fMRI) head without contrast	2		O
MEG/MSI	2		O
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

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

Variant 5: New-onset seizure, unrelated to trauma. Focal neurological deficit.

Radiologic Procedure	Rating	Comments	RRL*
MRI head without and with contrast	8	In the acute or emergency setting, CT may be the imaging study of choice. See statement regarding contrast in text under "Anticipated Exceptions."	O
MRI head without contrast	8	If intravenous contrast is contraindicated. In the acute or emergency setting, CT may be the imaging study of choice.	O
CT head with contrast	7	In the acute or emergency setting, CT may be the imaging study of choice.
CT head without contrast	6	In the acute or emergency setting, CT may be the imaging study of choice.
CT head without and with contrast	3
Tc-99m HMPAO SPECT head	3
FDG-PET/CT head	3
MRI functional (fMRI) head without contrast	2		O
MEG/MSI	2		O
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

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

Variant 6: New-onset seizure. Older than age 18. Post-traumatic, acute.

Radiologic Procedure	Rating	Comments	RRL*
CT head without contrast	9
MRI head without and with contrast	8	See statement regarding contrast in text under "Anticipated Exceptions."	O
MRI head without contrast	7	If intravenous contrast is contraindicated.	O
CT head with contrast	5
CT head without and with contrast	3
Tc-99m HMPAO SPECT head	2
FDG-PET/CT head	2
MRI functional (fMRI) head without contrast	2		O
MEG/MSI	2		O
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

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

Variant 7: New-onset seizure. Older than age 18. Post-traumatic, subacute or chronic.

Radiologic Procedure	Rating	Comments	RRL*
MRI head without contrast	8	If intravenous contrast is contraindicated.	O
MRI head without and with contrast	8	See statement regarding contrast in text under "Anticipated Exceptions."	O
CT head without contrast	7
CT head with contrast	6
FDG-PET/CT head	5
MRI functional (fMRI) head without contrast	4		O
CT head without and with contrast	3
Tc-99m HMPAO SPECT head	2
MEG/MSI	2		O
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

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

Summary of Literature Review

Introduction/Background

A seizure is a finite event of altered cerebral function because of excessive and abnormal electrical discharges of the brain cells. Epilepsy is a chronic condition predisposing a person to recurrent seizures. Epilepsy is common, affecting approximately 2 million people in the United States at any one time with a world-wide age-adjusted incidence of 41-177/100,000 people per year. It has been estimated that about 7%-8% of the population experiences at least one epileptic seizure during their lifetimes. The basic mechanism of epileptic seizures has not been fully elucidated.

The classification of epileptic seizures by the International League Against Epilepsy was last revised in 2010 (see Tables 1 and 2 in the original guideline document for an outline of the International Classification of Epileptic Seizures). The classification is important because etiologic diagnosis, appropriate treatment, and accurate prognostication all depend on the correct identification of seizures and epilepsy. There are two main seizure types (see Table 1 in the original guideline document): generalized and focal. Generalized seizures are further subdivided into tonic-clonic, absence, myoclonic, clonic, tonic, and atonic. The separation of "focal" from "generalized" seizures is a useful construct — even if this separation is not truly distinct. Generalized seizures rapidly affect both hemispheres, and both sides of the body — even when caused by a "focal" lesion. The older classification terms for focal seizures ("simple partial," "complex partial," and "partial") have been supplanted, and these distinctions have been removed. Certain types of seizure disorders are likely to be associated with structural brain lesions, including tumors, infection, infarction, traumatic brain injury, vascular malformations, developmental abnormalities, and seizure-associated brain pathology (see Table 3 in the original guideline document). Hence, knowledge of seizure types helps to determine whether neuroimaging is clinically indicated and what type of study is appropriate.

Computed Tomography/Magnetic Resonance Imaging

While the imaging evaluation of epilepsy was greatly advanced by the clinical introduction of computed tomography (CT) in the early 1970's, because of its superior soft-tissue contrast, multiplanar imaging capability, and lack of beam hardening artifacts, virtually all the substrates of epilepsy are visualized with greater sensitivity and accuracy by magnetic resonance imaging (MRI). As a result, MRI has become the modality of choice for high-resolution structural imaging in epilepsy. Routine evaluation techniques of all clinically available scanner field strengths may be sufficient for determination of mass lesions. However, optimized protocols for scans obtained on high-field (>1.5 T) scanners may be necessary for evaluating focal seizures ("partial complex epilepsy"). These patients require scrutiny of the hippocampus and temporal lobe for atrophy and subtle signal alteration, as well as for detecting certain structural abnormalities such as cortical dysplasias, hamartomas, and other developmental abnormalities. Anatomic imaging identifies a focal abnormality in up to 51% of patients with focal seizures. With the widespread clinical availability of high-performance MRI systems, a comprehensive MRI examination, with functional techniques providing additional information, adding corroborative information, and improving overall accuracy, may in the future be of even greater value in diagnosing epilepsy.

Functional Studies

Although the data provided by MRI are essential in the presurgical evaluation of patients with medically refractory epilepsy, structurally detectable abnormalities are absent in many patients. In these patients, functional studies provide useful information on the location of the seizure focus. Functional imaging techniques, including positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic source imaging (MSI), and functional MRI (fMRI), have contributed to the presurgical evaluation of patients with epilepsy.

Clinical PET with fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG) provides a measure of glucose uptake and thus metabolism. A seizure focus will typically manifest as a focus of hypometabolism on interictal (between episodes of seizure activity) examinations and will be seen as a focus of increased metabolism on ictal (during seizure) examinations. Interictal FDG-PET is sensitive (84%) and specific (86%) by electroencephalogram (EEG) criteria to temporal lobe epilepsy (TLE) and 33% sensitive and 95% specific to extratemporal epilepsy. By comparison, structural imaging using a variety of MR field strengths and techniques yielded a sensitivity and specificity of 55% and a specificity of 78%.

Both bolus MRI and SPECT that uses perfusion agents such as 99mTc-HMPAO or 99mTc-Neurolite, provide an assessment of regional cerebral blood flow rather than brain metabolism. A seizure focus will typically manifest as a focus of hypoperfusion on interictal examinations and will be seen as a focus of increased activity on ictal examinations. The utility of isolated interictal cerebral perfusion assessment in patients without anatomic imaging abnormality is limited. The use of ictal/interictal subtraction imaging with coregistration on MRI and image-guided surgery datasets is proving to be more useful than interictal perfusion imaging alone. Injection of the blood flow agent within 90 seconds of seizure onset does, however, appear to be required to demonstrate the expected localized increase in cerebral perfusion. The use of perfusion techniques in epilepsy is therefore limited because of the technological challenge of injecting EEG-monitored patients within 90 seconds of seizure onset.

fMRI techniques include phosphorus and proton spectroscopy (MRS), perfusion, and blood oxygen level dependent (BOLD) activation. The widespread application of most of these techniques in clinical practice depends on the widespread availability of high-performance MR imagers capable of performing fast echo-planar pulse sequences (EPIs), as well as substantial data post-processing capabilities.

MRS is a set of noninvasive techniques for in vivo chemical analysis of the brain, some of which can be performed on standard-performance clinical MR units. Although MRS has been used extensively for the past 30 years in molecular physics and chemistry, its application to the study of epilepsy is relatively recent. Widely available proton and phosphorus single-voxel techniques have consistently demonstrated metabolite changes in the epileptogenic region of the brain. MRS or chemical shift imaging (CSI) allows simultaneous acquisition of spectra from all brain regions. The pictorial display of MRS information facilitates comparison of the epileptogenic zone with the remainder of the brain and provides localizing information. CSI is not yet widely available in clinical practice. Initial studies suggest that both proton and phosphorus MRS will be useful adjunctive presurgical tests for localizing seizure foci in patients with partial epilepsy, particularly in difficult cases, potentially reducing the need for intracranial-depth electrode EEG recordings and those with extratemporal seizure foci.

Only EEG (using either scalp electrodes or intracranial electrodes [iEEG]) and magnetoencephalography (MEG) directly measure the brain's electrical activity. As such, they could or should be the gold standard for localization. In terms of outcome, being "seizure free" is an appropriate metric. Both EEG and MEG offer significantly higher temporal resolution (ms), as compared with PET, SPECT, and fMRI, which are poor by comparison (sec-min). Recent improvements in MEG technology – with advanced electronics and 100-300 or more channels of whole-head magnetometers – now allow complete brain coverage and overlay of source information on magnetic source images (MSIs). Recent articles in the radiology literature describe both the techniques and the advantages of including MEG in the preoperative evaluation of patients with intractable or medically refractory seizures. The MEG images are often superimposed on high-resolution MRI images. MEG is not a "frontline" tool for evaluation of epilepsy. A literature review supports some utility for MEG in the subset of patients who: a) are surgical candidates for resection, b) do not have a lesion identified on MRI or have multiple potential seizure foci, or c) are candidates for invasive monitoring (iEEG).

MEG is thus complementary to EEG and may provide confirmatory information for the ictal onset zone (IOZ) localization for potential lesions seen on MRI. MEG provides better spatial resolution (2-3 mm) as compared to EEG (7-10 mm). MEG can also guide the placement of iEEG grids; and in certain patients, it may help distinguish among multiple potential seizure foci.

The use and utility of MEG are growing, but are by no means settled. Many of the strong advocates for MEG have become familiar with the technique from their own research and have made their own contributions to this literature. Conversely, one review stated "There is insufficient evidence in the current literature to support the relationship between the use of MEG in surgical planning and seizure-free outcome after epilepsy surgery". It might well be emphasized that MEG has the most value in the hands of experienced users in epilepsy referral centers.

Summary

• This document addresses several subsets of patients with seizures and epilepsy.
• Special circumstances include both acute and subacute to chronic post-traumatic seizures (Variants 6 and 7); seizure associated with neurologic deficit (Variant 5); and, presurgical evaluation (Variant 1).
• Presurgical evaluation and planning deserves special attention. fMRI may be most useful in surgical planning to avoid damage to critical structures.
• Most patients with temporal lobe epilepsy will have an anatomic or structural lesion identified by MRI – most often mesial temporal sclerosis, cortical dysplasia, or neoplasm.
• Many patients with nontemporal lobe epilepsy may not show a convincing structural lesion.
• Some patients may have more than one lesion and/or discordance between electrical findings on EEG and imaging localization. In these types of special circumstances FDG-PET, MEG, and SPECT imaging may help define the most likely ictal onset zone.

Anticipated Exceptions

Nephrogenic systemic fibrosis (NSF) is a disorder with a scleroderma-like presentation and a spectrum of manifestations that can range from limited clinical sequelae to fatality. It appears to be related to both underlying severe renal dysfunction and the administration of gadolinium-based contrast agents. It has occurred primarily in patients on dialysis, rarely in patients with very limited glomerular filtration rate (GFR) (i.e., <30 mL/min/1.73 m²), and almost never in other patients. Although some controversy and lack of clarity remain, there is a consensus that it is advisable to avoid all gadolinium-based contrast agents in dialysis-dependent patients unless the possible benefits clearly outweigh the risk, and to limit the type and amount in patients with estimated GFR rates <30 mL/min/1.73 m². For more information, please see the American College of Radiology (ACR) Manual on Contrast Media (see the "Availability of Companion Documents" field).

Abbreviations

• CT, computed tomography
• EtOH, ethyl alcohol
• FDG-PET, fluorine-18-2-fluoro-2-deoxy-D-glucose-positron emission tomography
• fMRI, functional magnetic resonance imaging
• HMPAO, hexamethylpropyleneamine oxime
• iEEG, intracranial electroencephalography
• IOZ, intracranial onset zone
• MEG, magnetoencephalography
• MRI, magnetic resonance imaging
• MSI, magnetic source imaging
• SPECT, single-photon emission computed tomography
• Tc, technetium

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".

Algorithms were not developed from criteria guidelines.

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

Selection of appropriate radiologic imaging procedures for evaluation of patients with seizures and epilepsy

Relative Radiation Level (RRL)

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 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, both because of 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 to those specified for adults. Additional information regarding radiation dose assessment for imaging examinations can be found in the American College of Radiology (ACR) Appropriateness Criteria® Radiation Dose Assessment Introduction document (see "Availability of Companion Documents" field).

Gadolinium-based Contrast Agents

Nephrogenic systemic fibrosis (NSF) is a disorder with a scleroderma-like presentation and a spectrum of manifestations that can range from limited clinical sequelae to fatality. It appears to be related to both underlying severe renal dysfunction and the administration of gadolinium-based contrast agents. It has occurred primarily in patients on dialysis, rarely in patients with very limited glomerular filtration rate (GFR) (i.e., <30 mL/min/1.73 m²), and almost never in other patients. Although some controversy and lack of clarity remain, there is a consensus that it is advisable to avoid all gadolinium-based contrast agents in dialysis-dependent patients unless the possible benefits clearly outweigh the risk, and to limit the type and amount in patients with estimated GFR rates <30 mL/min/1.73 m². For more information, please see the American College of Radiology (ACR) Manual on Contrast Media (see the "Availability of Companion Documents" field).

The 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 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 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.

An implementation strategy was not provided.

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

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

Committee on Appropriateness Criteria, Expert Panel on Neurologic Imaging

Panel Members: James G. Smirniotopoulos, MD; Franz J. Wippold II, MD; Rebecca S. Cornelius, MD; Edgardo J. Angtuaco, MD; Daniel F. Broderick, MD; Douglas C. Brown, MD; Jeffrey L. Creasy, MD; Patricia C. Davis, MD; Charles F. Garvin, MD; Kathryn Holloway, MD; Charles T. McConnell Jr, MD; Laszlo L. Mechtler, MD; Joshua M. Rosenow, MD; David J. Seidenwurm, MD; Konstantin Slavin, MD; Paul J. Tobben, MD; Alan D. Waxman, MD

Not stated

This is the current release of the guideline.

This guideline updates a previous version: Karis JP, Seidenwurm DJ, Davis PC, Brunberg JA, De La Paz RL, Dormont PD, Hackney DB, Jordan JE, Mukherji SK, Turshi PA, Wippold FJ II, Zimmermann RD, McDermott MW, Sloan MA, Expert Panel on Neurologic Imaging. Epilepsy. [online publication]. Reston (VA): American College of Radiology (ACR); 2006. 8 p.

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

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

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

The following are available:

• ACR Appropriateness Criteria®. Overview. 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.
• ACR Appropriateness Criteria®. Literature search process. Reston (VA): American College of Radiology; 1 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.
• ACR Appropriateness Criteria®. Evidence table development. Reston (VA): American College of Radiology; 4 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.
• ACR Appropriateness Criteria®. Radiation dose assessment introduction. Reston (VA): American College of Radiology; 2 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.
• ACR Appropriateness Criteria® Manual on contrast media. Reston (VA): American College of Radiology; 90 p. Electronic copies: Available in PDF from the ACR Web site.

None available

This summary was completed by ECRI on July 31, 2001. The information was verified by the guideline developer as of August 24, 2001. This summary was updated by ECRI Institute on April 26, 2007 and July 8, 2011.

Instructions for downloading, use, and reproduction of the American College of Radiology (ACR) Appropriateness Criteria® may be found on the ACR Web site .