IC‐P‐154: SLEEP DISORDERED BREATHING AND BRAIN BETA‐AMYLOID BOTH PREDICT TIME‐TO‐PROGRESSION FROM NORMAL COGNITION TO MILD COGNITIVE IMPAIRMENT WITH BRAIN BETA‐AMYLOID MODIFYING THE PROGRESSION RISK

and maximally for protocol-3 at 17446687 mm. The linearregression between protocol-2-3 showed the strongest relationship (p< 0.001; r 1⁄4 0.92), while the relationship between “penumbra” volumes for Protocol-1-2 (p1⁄4 0.003; r1⁄4 0.68) and Protocol-1-3 (p 1⁄4 0.013; r 1⁄4 0.56) were less robust. In addition, protocol-3 appeared optimal for co-registration of diffusion tensor and arterial spin labeling imaging for the detection of pre-WMH pathologic changes within the “penumbra“. Conclusions: Reliable volumetric quantification methodologies are essential for the determination of longitudinal WMH change over a one-year period, amenable to use in future clinical trials of small vessel ischemic disease. Future work, validating our optimal WMH “penumbra” quantification protocol amenable to multi-site studies is underway currently.