Abstract 12030: Impact of High-Resolution Epiaortic Ultrasonographic Imaging on Evaluating Aortic Wall Pathology

Abstract

Introduction: Innovative imaging modality for preclinical diagnosis of aortic dissection (AD) has been awaited. Hypothesis: We previously reported that synchrotron radiation-based X-ray phase-contrast tomography (XPCT) imaging revealed densitometrical changes in the tunica media in the aortic wall (TM) of AD. To replicate XPCT findings in clinical practice, we investigated the application of high-resolution ultrasound in intraoperative epi-aortic scan (EAS) imaging. Methods: Twelve patients (normal aorta (5), chronic AD (3), acute type-A AD(4)) were selected. Before beginning cardiopulmonary bypass, the mid-ascending aorta was exposed and an EAS was conducted using EPIQ CVx and an eL18-4 transducer. After aortic repairs, the aortic samples of AD were fixed and applied XPCT, to compare ultrasonographic intensity (UI) of EAS and densitometric changes in XPCT in the same samples. Results: In normal aorta, UI remained unchanged throughout the TM (Figure-1A). In chronic AD, high linear changes in the UI in the middle of the TM was observed in the aorta that had not been dissected (yellow arrow in Figure-1B). In acute AD, high linear changes in the UI were clearly observed in the middle of TM, and aortic dissection was observed as an extension of those liner changes (Figure-1C). A line profile of the UI between the intima and the adventitia showed that the UI remained unchanged in normal aorta, and exhibited a high peak in the middle of the TM in chronic and acute AD (Figure-1A,B,C). These results indicated differences in the UI throughout the TM between normal and pathological aortas. These findings were well consistent with changes in the TM of patients with AD, which were obtained using XPCT (Figure-1D,E). Conclusions: High-resolution ultrasonographic imaging could replace XPCT findings in clinical settings and lead to significant improvements in the presymptomatic diagnosis of various aortic wall pathologies, including aortic dissection.