Abstract Number: Esoc2026a1722 Posterior-to-Anterior Periventricular White Matter Hyperintensity Area Ratio: A Supportive Mri Feature for Differentiating Cerebral Amyloid Angiopathy in Lobar Intracerebral Hemorrhage

Abstract Background and aims Diagnosing cerebral amyloid angiopathy (CAA) with standard imaging remains difficult. Our study explored whether measuring the area of periventricular white matter hyperintensity (PWMH) on standard MRI scans could be used as a supportive feature for CAA in primary lobar intracerebral hemorrhage (ICH). Methods We studied 229 patients (≥50 years) with lobar ICH, classified by Boston v2.0 as CAA (n=123) or CAA-negative (n=106). On FLAIR, the largest anterior and posterior periventricular WMH areas were measured bilaterally; posterior-to-anterior PWMH area ratio (PA-AR) was derived. Results Patients with CAA showed a greater posterior PWMH burden and higher PA-AR (median 1.69 vs. 0.79, p 0.001). The multivariable model incorporating PA-AR and adjusted for covariates had an AUC of 0.804 (65.9% sensitivity, 81.1% specificity). PA-AR was higher in posterior lobar cortical microbleeds (CMBs) than in no CMBs (p=0.001) and mixed-location hemorrhages (MLH) (p=0.004), whereas PA-AR did not differ across cortical superficial siderosis (cSS) distributions (Kruskal–Wallis p=0.099). Conclusions Posterior-dominant periventricular WMH quantified by the PA-AR is independently associated with CAA among lobar ICH and with posterior-predominant lobar CMBs. PA-AR may serve as an assistive MRI feature for distinguishing CAA within the Boston v2.0 framework. Conflict of interest Yingjie Zhang, Sihui Wang, Ju Yi and Shengjun Sun: no conflict of interest requiring disclosure.