Relative Signal Intensity Changes of Frontal and Occipital White Matters on T2 Weighted Axial MR Image: Correlation with Age

ABSTRACT

PURPOSE: To assess relative signal intensity changes in frontal and occipital white matter with age, as seenon T2 weighted axial MR images. MATERIALS AND METHODS: Thirty eight normal adults (20-29 years old) and 114children (0-11 years old) were investigated. All had nonspecific neurologic symptoms and their MR images, obtainedusing a 1.5T system (Signa, GE Medical Systems, Milwaukee, U.S.A), appeared to be normal. The signal intensitiesof frontal and occipital white matter were evaluated on T2 weighted axial images at the level of the foramen ofMonro. When the signal intensity of white matter was higher than that of gray matter, grade 0 was assigned ; whenthe opposite situation pertained, this was graded I_III. Grade I indicated that the signal intensity of occipitalwhite matter was lower than that of frontal white matter ; grade II, that the signal intensity of white matter ofboth lobes was similar. When the signal intensity of frontal white matter was lower than that of occipital whitematter, grade III was assigned. We divided the children's age by six months before 2 years of age, and by one yearafter 2 years of age, and then determined grade according to age, age distribution according to grade, and theages at which signal intensities were similar to those of adults. RESULTS: All 38 adults showed a grade IIIpattern ; this grade was apparent as early as 1.5 years of age and by 3 years of age, it was seen in over 50% ofchildren. After 8 years of age, all children were grade III. The age distribution of grade 0 was 0-0.5 years ofage, for grade I this was 0.5-2 years of age, for grade II it was 1-7, and for grade III, it was 1.5-11. CONCLUSION: On T2-weighted MR images, the signal intensity of frontal white matter ultimately shows a lowersignal intensity than that of occipital white matter.