this study was undertaken to determine if routine clinical magnetic resonance imaging sequences using only two different repetition times(TRs)and with only two sequential echo times(TEs) can be used to measure reproducible relative signal intensity and T2 relaxation time for normal brain tissues and cerebrospinal fluid us-ing a 2.9T superconducting system. In 47 patients 6 different anatomic sites were measured. For each anatomic location the mean and standard deviation of these values were determined. On T1-weighted (SE 500msec/30msec) images in globus pallidus and thalamus the standard deviations of relative signal intensity were 6% and 5% respectively. The relative signal intensity of the CSF cortical gray matter and retrobular fat tissue varid more with a standard deviation of 11-14% on T1-weighted images. On t2-weighted (SE 3000msec/30msec and3000msec/80msec) images the relative signal intensity of all anatomic regions varied more than on T1-weighted images. the standard deviation of T2 relaxation times also varied from 10% (fat tissue)to 18% (CSF) These varia-knowing that relative signal intensity and T2 relaxation times calculated from routine imaging sequences are reproducible in only limitted areas these normal ranges can be used to investigate changes occurring in disease states of the limitted regions.