RESUMO
Objective To investigate whether physiological asymmetry of normal bilateral superficial veins located in dorsolateral aspects of hemispheres is existed on susceptibility-weighted imaging (SWI). Methods There were 45 healthy young volunteers in this study. After exclusion of intracranial lesions by using common brain magnetic resonance imaging examination, they underwent SWI examination. We observed the number, diameter and signal intensity of superficial veins located in dorsolateral aspects of hemispheres according to the images of SWI on transverse sections through the centrum semiovale, trunk of corpus callosum, splenium of corpus callosum, and superior colliculus. Results The frequencies of asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres on transverse sections through the centrum semiovale, trunk of corpus callosum, splenium of corpus callosum, and superior colliculus were 20.0%, 37.8%, 35.6% and 26.7%, respectively. The frequencies of mild asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres on above transverse sections were 17.8%, 31.1%, 31.1% and 24.4% respectively, and the frequencies of prominent asymmetry were 2.2%, 6.7%, 4.4% and 2.2%, respectively. According to chi square test, there was no gender difference in asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres. Conclusion SWI technique was used to show the physiological asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres on different transverse sections. Most of them are mild. Therefore, when cerebrovascular disease occurs, if transverse sections of images by SWI show asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres, the possibility of physiological phenomenon is needed to take into consideration.
