Table 1.

Diagnostic criteria for intracranial artery dissection.

Diagnostic Criteria
Definite case
Satisfying any of Diagnostic Criteria I, II, or III below
I. Either intimal flap or double lumen visible on cerebral angiogram
II. Either intimal flap or double lumen visible on MRI or MRA (tomogram image). Handled identically if the transverse image on 3D-CTA and ultrasound examination is sufficiently delineated and a clear intimal flap and double lumen are visible.
III. If any of Findings IV, V, or VI are observed and a clear change is seen in the findings over time with repeated imaging examinations. Limited to cases in which a cause other than dissection can be ruled out
Suspected case
Satisfying any of Diagnostic Criteria IV, V, or VI below
IV. Nonspecific findings suggesting arterial dissection (pearl sign, tapered occlusion) are visible on cerebral angiogram other than the findings in I above
V. Findings are visible on MRA angiogram that appear to correspond to the pearl and string sign, string sign, or tapered occlusion on cerebral angiogram
VI. Intense signal suggesting intramural hematoma visible on MRI T1-weighted image

Referenced by the Strategies against Stroke Study for Young Adults in Japan criteria [27]. Abbreviations: MRI, magnetic resonance imaging; MRA, magnetic resonance angiography; CTA, computed tomography angiography.