Clinical Study Of Functional Magnetic Resonance Imaging On Brain Tumors

Objective To study the value of different functional magnetic resonance imaging techniques including BOLD-fMRI and 1HMRS in evaluating patients with brain tumors, which covers two folds: 1) to investigate the location of functional activation areas of motor and language cortex with BOLD-fMRI in normal and brain tumors, 2) to study the characters of different brain tumors with 1HMRS and the role of 1HMRS on the diagnosis and differentiation of brain tumors. Patients and Methods Forty-two cases (10 normal volunteers, 25 preoperational and 7 postoperational brain tumor patients) and 44 patients with different brain tumors who were confirmed pathologically experienced BOLD-fMRI and 1HMRS, respectively. For the BOLD-fMRI study, the functional imags of brain motor cortex (activated by complex or simple finger movements) and language cortex (activated by Chinese and English) were obtained in 42 subjects. For the 1HMRS study, the single-voxel proton spectroscopy (SVS) was performed and the metabolite, i.e. NAA, Cho, Cr, Lac, Lip, Ala, as well as the ratios of NAA/Cho, NAA/Cr, Cho/Cr were analized in 44 patients. Results All subjects' BOLD-fMRI showed regular singal intensity-time curve within local active areas, and the functional imaging was feasible in all cases. The motor cortex of the normal were mainly in SMC, SMA, PMA and cerebel hemisphere, and more cerebral motor areas could be activated by subdominant hand or complex finger movements. Most of activation areas were in the left hemisphere under language stimulation, which include temporal horizontal gyrus, Wernicke's area, SMA and Broca's area, only left Broca's area could be activated under English stimulation. The functional activation areas could be shrunk and be displaced due to the nearby mass lesions and returned normal after operation. There were no significant differences of Cho/Cr, NAA/Cho and NAA/Cr ratios (P>0.05) among different cerebral anatomical regions. Contrast to contralateral normal brain, NAA were lower and Cho were higher at the tumor regions. There were significant differences of Cho/Cr, NAA/Cho ratios (P<0.005), but no difference of NAA/Cr ratio (P>.05), among different tumor groups and each grade of glioma. Conclusions BOLD-fMRI and 1HMRS improved the diagnostic yield of MRI evaluation in patients with brain tumors. BOLD-fMRI is an effective approach in localizing motor and acoustic language cortex and is valuable for the evaluation of mass lesions before surgery. 1HMRS is useful in the diagnosis and differentiation of brain tumors, histological classification of glioma and therapeutic evaluation.