Abstract #3451

Procedure for Normalization of Cerebrovascular Reactivity in Bilateral and Indeterminate Patterns of Hypoperfusion using Dynamic BOLD-CVR

Siddhant Dogra^1,2, Xiuyuan Wang³, James Michael Gee^1,2, Yihui Zhu¹, Koto Ishida⁴, and Seena Dehkharghani^1,2,4

¹Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, New York, USA., New York, NY, United States, ²Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University Grossman School of Medicine, New York, New York, USA., New York, NY, United States, ³Department of Radiology, Weill Cornell Medical College. New York, New York, USA., New York, NY, United States, ⁴Department of Neurology, New York University Grossman School of Medicine, New York, New York, USA, New York, NY, United States

Synopsis

Keywords: fMRI Analysis, fMRI

Motivation: The BOLD response to acetazolamide offers robust estimation of cerebrovascular reactivity (CVR) with dynamic interrogation for maximal (CVR_max) augmentation. The lack of physiologic units limits use to relative CVR reductions versus normal hemispheres, confounding use for bilateral steno-occlusive disease (SOD).

Goal(s): Develop normal voxel search procedure for BOLD-CVR informed by DSC perfusion in SOD.

Approach: DSC in unilateral SOD patients undergoing BOLD-CVR were used to train random forest classifiers and identify voxels with CVR_max within 10% of ground-truth normal hemispheric CVR_max.

Results: Median percent-differences <8% from ground-truth were achieved, indicating robust performance for extension of BOLD-CVR to bilateral SOD.

Impact: We demonstrate the feasibility of a random forest classifier as a normal voxel search algorithm, in order to identify candidate voxels serving as an auto-normalization for CVR studies in settings of bilateral or indeterminate patters of steno-occlusive disease.

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