Evaluation of 3‐dimensional stereotactic surface projection rendering of arterial spin labeling data in a clinical cohort.

Background and Purpose: To assess the feasibility of 3‐dimensional stereotactic surface projection (3D‐SSP) as applied to arterial spin labeling (ASL) in a clinical pilot study. Methods: A retrospective sample of 10 consecutive patients who underwent ASL as part of a clinically indicated MR examination was collected during this pilot study. Five additional subjects with normal cerebral perfusion served as a control group. Following voxel‐wise M0‐correction, cerebral blood flow (CBF) quantification, and stereotactic anatomic standardization, voxel‐wise CBF from an individual's ASL dataset was extracted to a set of predefined surface pixels (3D‐SSP). A normal database was created from averaging the extracted CBF datasets of the control group. Patients' datasets were compared individually with the normal database by calculating a Z‐score on a pixel‐by‐pixel basis and were displayed in 3D‐SSP views for visual inspection. Independent, two‐expert reader assessment, using a 3‐point scale, compared standard quantitative CBF images to the 3D‐SSP maps. Results: Patterns and severities of regionally reduced CBF were identified, by both independent readers, in the 3D‐SSP maps. Reader assessment demonstrated preference for 3D‐SSP over traditionally displayed standard quantitative CBF images in three of four evaluated imaging metrics (p =.026,.031, and.013, respectively); 3D‐SSP maps were never found to be inferior to the standard quantitative CBF images. Conclusions: Three‐dimensional SSP maps are feasible in a clinical population and enable quantitative data extraction and localization of perfusion abnormalities by means of stereotactic coordinates in a condensed display. The proposed method is a promising approach for interpreting cerebrovascular pathophysiology. [ABSTRACT FROM AUTHOR]