Achieving gross total resection of brain tumors: intraoperative MR imaging can make a big difference.

are limited by low SNR. However, we anticipate improvement in SNR and vessel contrast enhancement with the development of high-field-strength 3-T MR imaging units. Furthermore, the approval of highrelaxivity blood-pool contrast agents will augment intravascular signal intensity and overall vessel contrast enhancement, particularly with the short TRs that are required for rapid image acquisition. In conclusion, time-resolved contrast-enhanced MRA is emerging as means of imaging intracranial circulation with high spatial and temporal resolutions. Work must still be done to allow the acquisition of full 3D image volumes with subsecond frame rates. However, the acquisition of submillimeter isotropic volumes to depict intracranial circulation with subsecond frame rates are on the horizon.