Abstract
OBJECTIVE: To determine the usefulness of perfusion MR imaging in assessing the histologic grade of cerebral gliomas. MATERIALS AND METHODS: In order to determine relative cerebral blood volume (rCBV), 22 patients with pathologically proven gliomas (9 glioblastomas, 9 anaplastic gliomas and 4 low-grade gliomas) underwent dynamic contrast-enhanced T2*-weighted and conventional T1- and T2-weighted imaging. rCBV maps were obtained by fitting a gamma-variate function to the contrast material concentration versus time curve. rCBV ratios between tumor and normal white matter (maximum rCBV of tumor / rCBV of contralateral white matter) were calculated and compared between glioblastomas, anaplastic gliomas and low-grade gliomas. RESULTS: Mean rCBV ratios were 4.90 degrees +/- 1.01 for glioblastomas, 3.97 degrees +/- 0.56 for anaplastic gliomas and 1.75 degrees +/-1.51 for low-grade gliomas, and were thus significantly different; p <.05 between glioblastomas and anaplastic gliomas, p <.05 between anaplastic gliomas and low-grade gliomas, p <.01 between glioblastomas and low-grade gliomas. The rCBV ratio cutoff value which permitted discrimination between high-grade (glioblastomas and anaplastic gliomas) and low-grade gliomas was 2.60, and the sensitivity and specificity of this value were 100% and 75%, respectively. CONCLUSION: Perfusion MR imaging is a useful and reliable technique for estimating the histologic grade of gliomas.