Discussion of Lacunar infarction
- Lacunar infarctions are small infarctions lying in deeper noncortical parts of the cerebrum and brainstem.
- Caused by occlusion of penetrating branches that arise from the middle cerebral, posterior cerebral, and basilar arteries and less commonly from the anterior cerebral and vertebral arteries.
- Sites of predilection are the basal ganglia, thalamus, internal and external capsule, ventral pons, and periventricular white matter.
- Lacunar infarctions can be differentiated from Virchow-Robin spaces by signal intensity characteristics.
 Imaging Findings for Lacunar infarction
- An acute lacunar infarction (12 hours up to 7 days) appears as a small high-signal-intensity region on T2-weighted and FLAIR images and as a hypointense area on T1-weighted images.
- High signal intensity is seen on diffusion-weighted images with corresponding low signal intensity on the apparent diffusion coefficient map.
- Enhancement is variable
- A chronic lacunar infarction is better defined and has high signal intensity on T2-weighted images and low signal intensity on T1-weighted images. On FLAIR images, a hyperintense lesion or a lesion with a hypointense center and a hyperintense rim reflecting gliosis is seen.
- Enhancement may last for up to 8 weeks after the acute event
Patient #1: Chronic lacunar infarctions on CT
 See Also
 External Links
 References for Lacunar infarction
- Robert M. Kwee, and Thomas C. Kwee. Virchow-Robin Spaces at MR Imaging. RadioGraphics 2007 27: 1071-1086.