Spherical matrix arrays represent an advantageous tomographic detection geometry for non-invasive deep tissue mapping of vascular networks and oxygenation with volumetric optoacoustic tomography (VOT). Hybridization of VOT with ultrasound (US) imaging remains difficult with this configuration due to the relatively large inter-element pitch of spherical arrays. We suggest a new approach for combining VOT and US contrast-enhanced 3D imaging employing injection of clinically-approved microbubbles. Power Doppler (PD) and US localization imaging were enabled with a sparse US acquisition sequence and model-based inversion based on infimal convolution of total variation (ICTV) regularization. In vitro experiments in tissue-mimicking phantoms and in living mouse brain demonstrate the powerful capabilities of the new dual-mode imaging approach attaining $80~ \mu m$ spatial resolution and a more than 10 dB signal to noise improvement with respect to a classical delay and sum beamformer. Microbubble localization and tracking allowed for flow velocity mapping up to 40 mm/s.

中文翻译：

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使用球形矩阵阵列的双模式体积光声和对比度增强超声成像

球形矩阵阵列代表了一种有利的断层扫描检测几何结构，用于血管网络的非侵入性深层组织映射和体积光声断层扫描 (VOT) 的氧合。由于球形阵列的元件间间距相对较大，因此这种配置很难将 VOT 与超声 (US) 成像混合。我们建议采用一种新的方法来结合 VOT 和美国对比增强 3D 成像，采用临床批准的微泡注射。功率多普勒 (PD) 和 US 定位成像通过稀疏 US 采集序列和基于模型的反演实现，该反演基于总变差 (ICTV) 正则化的小卷积。在模拟组织模型和活体小鼠大脑中的体外实验证明了新的双模式成像方法的强大能力 $80~ \亩 m$相对于经典延迟和总和波束形成器，空间分辨率和超过 10 dB 的信噪比改进。微泡定位和跟踪可实现高达 40 mm/s 的流速映射。