Wide variation in definition, detection, and description of lacunar lesions on imaging.

BACKGROUND AND PURPOSE Variation in the definition of lacunar lesions on imaging and difficulties in their detection may be hampering lacunar stroke research. We assessed literature definitions of imaging lacunar lesions and the definitions and detection of lacunar lesions among small-vessel disease researchers. METHODS We assessed definitions of imaging lacunar lesion in 50 randomly selected articles from 3 stroke-related journals and an online survey of small-vessel disease researchers. In the literature review, we assessed clinical/imaging definitions of lacunar stroke. In the survey, we assessed lacunar lesion detection, effects of lesion appearance, background white matter lesions, and provision of relevant data. RESULTS Among 50 articles, imaging definitions were varied and often limited; size was stated in 21 of 43 (49%) studies of acute and in 9 of 20 (45%) studies of old lesions and site in 18 (42%) and 4 (20%), respectively. Clinical definitions also varied, and images were read mostly by nonradiologists. Among 56 survey respondents, multiple descriptions were used for recent and old, symptomatic and asymptomatic, lesions on imaging. Most agreed on definitions for site (98%) and "old lacunar infarct" (61%) size. Cavitated (vs noncavitated) lesions were usually identified as lacunar lesions; with increasing white matter lesions, however, noncavitated lesions were very unlikely to be identified, even with prior imaging available (7.8%). CONCLUSIONS Imaging definitions of lacunar lesions vary widely, in part due to variation in lesion detection and classification. A consensus for imaging definitions of small-vessel disease features would be helpful.