Clinical condition: focal neurologic deficit*

MRI HeadCT Head without ContrastMRA Head and NeckCT Head without and with ContrastCTA Head and NeckMRI Spectroscopy HeadArteriography CervicocerebralFDG-PET Head
Multiple focal neurologic deficits‡‡87§6664#3**2
Single focal neurologic deficit, sudden onset, stable, or incompletely resolving‡‡8††8††75743**2
Single neurologic deficit, sudden onset, progressive‡‡8††8††76743**1
Single focal neurologic deficit, completely resolving‡‡8††8††76733**1
Unexplained acute confusion or altered level of consciousness‡‡8††8††656323
  • Note:—MRI indicates MR imaging; MRA, MR angiography; CTA, CT angiography; FDG-PET, fluorodeoxyglucose–positron-emission tomography.

  • * Appropriateness criteria scale from 1 to 9, 1 = least appropriate, 9 = most appropriate.

  • Consider increased contrast dose for problem solving in selected cases.

  • Include diffusion-weighted imaging.

  • § Acute screening.

  • For suspected vascular abnormality.

  • If MRI is unavailable or contraindicated, consider CT perfusion.

  • # For selected cases.

  • ** For problem solving.

  • †† Both CT and MR may be necessary. CT screens for suspected hemorrhage in the acute setting and MR screens for infarction and masses.

  • ‡‡ Other imaging modalities considered: MRI functional head, received rating of 3; single-photon emission CT head, received rating of 3; X-ray head, received rating of 1.