In vivo regional cerebral blood volume: quantitative assessment with 3D T1-weighted pre- and postcontrast MR imaging.

PURPOSE: To assess the use of pre-and postcontrast three-dimensional (3D) T1-weighted images to obtain quantitative regional cerebral blood volume (rCBV) maps and to delineate the vascular system of the brain. MATERIALS AND METHODS: Sagittal 3D pre-and postcontrast T1-weighted images were acquired in 10 patients and two volunteers. The images were processed with a knowledge-based segmentation algorithm to obtain independent blood volume maps of gray matter (GM), white matter (WM), and blood vessels and to quantitate rCBV in various cortical and deep cortical structures. Localized maximum intensity projection (MIP)-rCBV images were used to reveal the brain's venous system and vascularity in and around any lesions present. RESULTS: Group-averaged (n = 8) rCBV maps from both GM (4.80% +/- 0.37) and WM (2.02% +/- 0.14) yielded a ratio of GM-to-WM rCBV of 2.38 +/- 0.20. The ratio of rCBV between cortical and deep cortical GM was 1.15. rCBV maps showed better vascular contrast than did the postcontrast images in delineation of blood vessels and in the lesions present in two patients. A localized MIP-rCBV image had more than five times higher vascular contrast-to-noise ratio than that of the postcontrast MIP image. CONCLUSION: rCBV maps can be obtained in a standard clinical setting and can be used to reveal information on local blood volume.