XENON CONTRAST CT-CBF MEASUREMENTS IN HIGH-INTENSITY FOCI ON T2-WEIGHTED MR-IMAGES IN CENTRUM SEMIOVALE OF ASYMPTOMATIC INDIVIDUALS

Background and Purpose White matter lesions (WMLs) on T2-weighted MR i mages occurring in the centrum semiovale of normal individuals are a s ubject of great clinical interest. We therefore investigated regional cerebral blood flow (rCBF) of the centrum semiovale among neurological ly normal individuals. Methods One hundred thirty-five neurologically normal subjects were divided into four grades of WML on the basis of t heir MR images. rCBF values in the centrum semiovale were measured by xenon contrast CT methods. Results Advanced age and associated hyperte nsion were significant risk factors for higher grade WMLs. Centrum sem iovale rCBF values on the left side were 24.27+/-2.60 mL.100 g(-1).min (-1) in grade 0, 23.52+/-2.78 in grade I, 19.35+/-2.81 in grade II, 15 .82+/-2.05 in grade III, and 11.31+/-2.56 in grade IV. Differences wer e significant between grades (P<.005 between grade 0 and grades IT, II I, and IV; between grade II and grades III and IV; and between grades III and IV). Patients with hypertension had lower rCBF values than tho se without in grades 0, I, II, and III, with significant difference in grade I (P<.005). Age-matched studies between patients 61 to 70 years old confirmed a significant difference between WML grades. Conclusion s WMLs in centrum semiovale are associated with greater age, hypertens ion, and reduced rCBF values.