Cerebrovascular reactivity mapping in patients with low grade gliomas undergoing presurgical sensorimotor mapping with BOLD fMRI.

PURPOSE

(i) to validate blood oxygenation level dependent (BOLD) breathhold cerebrovascular reactivity (BH CVR) mapping as an effective technique for potential detection of neurovascular uncoupling (NVU) in a cohort of patients with perirolandic low grade gliomas undergoing presurgical functional MRI (fMRI) for sensorimotor mapping, and (ii) to determine whether NVU potential, as assessed by BH CVR mapping, is prevalent in this tumor group.

MATERIALS AND METHODS

We retrospectively evaluated 12 patients, with histological diagnosis of grade II glioma, who performed multiple motor tasks and a BH task. Sensorimotor activation maps and BH CVR maps were compared in two automatically defined regions of interest (ROIs), ipsilateral to the lesion (i.e., ipsilesional) and contralateral to the lesion (i.e., contralesional).

RESULTS

Motor task mean T-value was significantly higher in the contralesional ROIs (6.00 ± 1.74 versus 4.34 ± 1.68; P = 0.00004) as well as the BH mean T-value (4.74 ± 2.30 versus 4.09 ± 2.50; P = 0.009). The number of active voxels was significantly higher in the contralesional ROIs (Z = 2.99; P = 0.03). Actual NVU prevalence was 75%.

CONCLUSION

Presurgical sensorimotor fMRI mapping can be affected by NVU-related false negative activation in low grade gliomas (76% of analyzed tasks).