T1 distribution and bound water fraction of brain tumors

Distribution of T1 values of the brain tumors was analyzed in 13 cases using a 0.1 T MRI system. Mean value, standard deviation and histogram of T1 values of each tumor were calculated from the ROI in the T1 image. Bound water fractions (BWF) were also calculated by the method previously reported. All tumors showed prolonged T1 values and lowered BWFs than normal brain. Though there was no clear correlation between the pathological diagnosis and the mean T1 values, histogram analysis showed some differences according to the pathological diagnosis and the inner structure of the tumor. As the BWF is thought to be independent of the strength of the magnetic field, the BWFs of the normal brain and the brain tumors were calculated from the published data and wery compared with our results. Though the BWFs of the normal brains were presented as relatively similar value, the BWFs of the brain tumors failed to show any constant tendency. (author)