Effect of age and tumor grade on BOLD functional MR imaging in preoperative assessment of patients with glioma

Purpose: To retrospectively determine if there was a combined effect of advanced age and increased tumor grade on blood oxygen level-dependent (BOLD) functional magnetic resonance (MR) imaging signal intensity (SI) in patients with gliomas. Materials and Methods: The institutional review board approved this HIPAA-compliant study, and the informed consent requirement was waived. Data from 39 patients (27 men, 12 women; age range, 19-78 years) who had histopathologically confirmed gliomas and who underwent surgery after preoperative functional MR imaging were analyzed. Fourteen patients had grade II or grade III gliomas, and 25 patients had grade IV gliomas. A change in BOLD SI was measured in motor cortices of tumor- containing and non-tumor-containing hemispheres. The effect of age and tumor grade, both individually and together, on BOLD functional MR SI was assessed with t tests and regression analysis. Results: In patients with grade IV gliomas, SI change was lower in the tumor-containing hemisphere than in the non-tumorcontaining hemisphere (P = .012). SI change decreased with increased age in the tumor-containing hemisphere in patients with grade II or III gliomas (P = .032) and in the non-tumor-containing hemisphere in patients with grade IV gliomas (P = .026). While advanced age and increased glioma grade reduced SI change, the combined effect of these factors was not additive. In patients with grade IV gliomas, tumor presence reduced SI change, but the level of reduction was uniform across all ages and did not correlate with age (P = .541). Conclusion: In older patients with grade IV gliomas, BOLD SI is equivalent to that measured in younger patients with grade IV gliomas. Advanced age and tumor grade do not have a combined effect for reduction of BOLD SI. Rather, in patients with grade IV gliomas, tumor grade played a dominant role in reduction of SI change, whereas in patients with grade II and III gliomas, reduction of SI change correlated with only advanced age. (C) RSNA, 2008.