American College of Radiology
ACR Appropriateness Criteria®

Seizures and Epilepsy

Variant 1: Medically refractory epilepsy. Surgical candidate or surgical planning.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
MRI head without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
MRI head without and with IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
FDG-PET/CT head Usually appropriate ☢☢☢☢ 10-30 mSv ☢☢☢☢ 3-10 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
CT head with IV contrast May be appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 6 n/a 0 0 0 0 0 0 0 0 0
MEG May be appropriate O 0 mSv 6 n/a 0 0 0 0 0 0 0 0 0
MRI functional (fMRI) head without IV contrast May be appropriate O 0 mSv O 0 mSv [ped] 6 n/a 0 0 0 0 0 0 0 0 0
CT head without IV contrast May be appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 5 n/a 0 0 0 0 0 0 0 0 0
Tc-99m HMPAO SPECT head ictal May be appropriate ☢☢☢☢ 10-30 mSv 5 n/a 0 0 0 0 0 0 0 0 0
CT head without and with IV contrast May be appropriate ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 4 n/a 0 0 0 0 0 0 0 0 0
Variant 2: New-onset seizure. Unrelated to trauma. Alcohol or drug related.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
MRI head without and with IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
CT head without IV contrast Usually appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
MRI head without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
CT head with IV contrast May be appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 6 n/a 0 0 0 0 0 0 0 0 0
CT head without and with IV contrast Usually not appropriate ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 3 n/a 0 0 0 0 0 0 0 0 0
MEG Usually not appropriate O 0 mSv 2 n/a 0 0 0 0 0 0 0 0 0
MRI functional (fMRI) head without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
FDG-PET/CT head Usually not appropriate ☢☢☢☢ 10-30 mSv ☢☢☢☢ 3-10 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
Tc-99m HMPAO SPECT head ictal Usually not appropriate ☢☢☢☢ 10-30 mSv 2 n/a 0 0 0 0 0 0 0 0 0
Variant 3: New-onset seizure. Unrelated to trauma. Age 18–40.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
MRI head without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
CT head without IV contrast Usually appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
MRI head without and with IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
CT head with IV contrast May be appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 6 n/a 0 0 0 0 0 0 0 0 0
FDG-PET/CT head May be appropriate ☢☢☢☢ 10-30 mSv ☢☢☢☢ 3-10 mSv [ped] 4 n/a 0 0 0 0 0 0 0 0 0
Tc-99m HMPAO SPECT head ictal May be appropriate ☢☢☢☢ 10-30 mSv 4 n/a 0 0 0 0 0 0 0 0 0
CT head without and with IV contrast Usually not appropriate ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 3 n/a 0 0 0 0 0 0 0 0 0
MEG Usually not appropriate O 0 mSv 2 n/a 0 0 0 0 0 0 0 0 0
MRI functional (fMRI) head without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
Variant 4: New-onset seizure. Unrelated to trauma. Older than age 40.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
MRI head without and with IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
CT head without IV contrast Usually appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
MRI head without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
CT head with IV contrast May be appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 6 n/a 0 0 0 0 0 0 0 0 0
CT head without and with IV contrast May be appropriate ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 5 n/a 0 0 0 0 0 0 0 0 0
FDG-PET/CT head May be appropriate ☢☢☢☢ 10-30 mSv ☢☢☢☢ 3-10 mSv [ped] 4 n/a 0 0 0 0 0 0 0 0 0
Tc-99m HMPAO SPECT head ictal May be appropriate ☢☢☢☢ 10-30 mSv 4 n/a 0 0 0 0 0 0 0 0 0
MEG Usually not appropriate O 0 mSv 2 n/a 0 0 0 0 0 0 0 0 0
MRI functional (fMRI) head without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
Variant 5: New-onset seizure. Unrelated to trauma. Focal neurological deficit.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
MRI head without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
MRI head without and with IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
CT head with IV contrast Usually appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
CT head without IV contrast Usually appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
CT head without and with IV contrast Usually not appropriate ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 3 n/a 0 0 0 0 0 0 0 0 0
FDG-PET/CT head Usually not appropriate ☢☢☢☢ 10-30 mSv ☢☢☢☢ 3-10 mSv [ped] 3 n/a 0 0 0 0 0 0 0 0 0
Tc-99m HMPAO SPECT head ictal Usually not appropriate ☢☢☢☢ 10-30 mSv 3 n/a 0 0 0 0 0 0 0 0 0
MRI functional (fMRI) head without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
Variant 6: New-onset seizure. Post-traumatic, acute.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
CT head without IV contrast Usually appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 9 n/a 0 0 0 0 0 0 0 0 0
MRI head without and with IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
MRI head without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
CT head with IV contrast May be appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 5 n/a 0 0 0 0 0 0 0 0 0
CT head without and with IV contrast Usually not appropriate ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 3 n/a 0 0 0 0 0 0 0 0 0
MEG Usually not appropriate O 0 mSv 2 n/a 0 0 0 0 0 0 0 0 0
MRI functional (fMRI) head without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
FDG-PET/CT head Usually not appropriate ☢☢☢☢ 10-30 mSv ☢☢☢☢ 3-10 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
Tc-99m HMPAO SPECT head ictal Usually not appropriate ☢☢☢☢ 10-30 mSv 2 n/a 0 0 0 0 0 0 0 0 0
Variant 7: New-onset seizure. Post-traumatic. Subacute or chronic.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
MRI head without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
MRI head without and with IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 8 n/a 0 0 0 0 0 0 0 0 0
CT head without IV contrast Usually appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
CT head with IV contrast May be appropriate ☢☢☢ 1-10 mSv ☢☢☢ 0.3-3 mSv [ped] 6 n/a 0 0 0 0 0 0 0 0 0
FDG-PET/CT head May be appropriate ☢☢☢☢ 10-30 mSv ☢☢☢☢ 3-10 mSv [ped] 5 n/a 0 0 0 0 0 0 0 0 0
MRI functional (fMRI) head without IV contrast May be appropriate O 0 mSv O 0 mSv [ped] 4 n/a 0 0 0 0 0 0 0 0 0
CT head without and with IV contrast Usually not appropriate ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 3 n/a 0 0 0 0 0 0 0 0 0
MEG Usually not appropriate O 0 mSv 2 n/a 0 0 0 0 0 0 0 0 0
Tc-99m HMPAO SPECT head ictal Usually not appropriate ☢☢☢☢ 10-30 mSv 2 n/a 0 0 0 0 0 0 0 0 0
Appendix Key

A more complete discussion of the items presented below can be found by accessing the supporting documents at the designated hyperlinks.

Appropriateness Category:The panel’s recommendation for a procedure based on the assessment of the risks and benefits of performing the procedure for the specified clinical scenario.

SOE: Strength of Evidence. The assessment of the amount and quality of evidence found in the peer reviewed medical literature for an appropriateness recommendation.

  • References: The citation number and PMID for the reference(s) associated with the recommendation.
  • Study Quality: The assessment of the quality of an individual reference based on the number of study quality elements described in the reference.

RRL: Relative Radiation Level. A population based assessment of the amount of radiation a typical patient may be exposed to during the specified procedure.

Rating: The final rating (1-9 scale) for the procedure as determined by the panel during rating rounds.

Median: The median rating (1-9 scale) for the procedure as determined by the panel during rating rounds.

Final tabulations: A histogram showing the number of panel members who rated the procedure as noted in the column heading (ie, 1, 2, 3, etc.).

Additional supporting documents about the AC methodology and processes can be found at www.acr.org/ac.