Supplementary Material for: Associations of High Intensities on Magnetization-Prepared Rapid Acquisition with Gradient Echo with Aortic Complicated Lesions in Ischemic Stroke Patients Y.Yamaguchi T.Tanaka Y.Morita S.Yoshimura M.Koga M.Ihara K.Toyoda 2019 <b><i>Background:</i></b> Aortic complicated lesions (ACLs) are key parameters for evaluating aortic embolic sources in embolic stroke, and are usually diagnosed using transesophageal echocardiography (TEE). However, alternative methods for diagnosing ACLs have not been well established. We investigated associations between high-intensity areas on T1-weighted imaging (T1WI) with magnetization-prepared rapid acquisition with gradient echo (MPRAGE) and ACLs on TEE among ischemic stroke patients. <b><i>Methods:</i></b> Participants comprised 135 patients (mean age, 71 years; 35 women) with ischemic stroke or transient ischemic attack who underwent TEE for evaluation of embolic sources and plaque imaging using MPRAGE for evaluation of aortic or carotid plaques. Aortic plaque with signal intensity ≥200% of sternocleidomastoid intensity on MPRAGE was categorized as “high intensity”. ACLs on TEE were defined by focal increases in intima-media thickness (IMT) ≥4.0 mm or the presence of ulcerated or mobile plaques. <b><i>Results:</i></b> Fifty-six patients (42%) showed high-intensity areas on MPRAGE at the aortic arch. Aortic maximum IMT was significantly higher in patients with high intensities than in those without (<i>p</i> < 0.001). Incidences of ACLs (66 vs. 20%, <i>p</i> < 0.001) or ulcerated or mobile plaques (30 vs. 6%, <i>p</i> < 0.001) were significantly higher in patients with high intensities than in patients without. Multivariable logistic regression analysis showed that high intensities on MPRAGE were independently associated with the presence of ACLs (OR 5.72; 95% CI 2.38–13.70) and ulcerated or mobile plaques (OR 4.18; 95% CI 1.29–13.50). <b><i>Conclusions:</i></b> High intensities on T1WI with MPRAGE in the aortic arch were significantly associated with the presence of ACLs. An evaluation of the aortic arch using MPRAGE may be useful for predicting ACLs.