Department of Electrical and Computer Engineering, The University of Iowa, Iowa City, Iowa, USA.
University of Iowa Technology Institute, The University of Iowa, Iowa City, Iowa, USA.
Lasers Surg Med. 2022 Sep;54(7):994-1001. doi: 10.1002/lsm.23560. Epub 2022 Jun 2.
We previously developed a real-time fluorescence imaging topography scanning (RFITS) system for intraoperative multimodal imaging, image-guided surgery, and dynamic surgical navigation. The RFITS can capture intraoperative fluorescence, color reflectance, and surface topography concurrently and offers accurate registration of multimodal images. The RFITS prototype is a promising system for multimodal image guidance and intuitive 3D visualization. In the current study, we investigated the capability of the RFITS system in intraoperative fluorescence vascular angiography for real-time assessment of tissue perfusion.
STUDY DESIGN/MATERIALS AND METHODS: We conducted ex vivo imaging of fluorescence perfusion in a soft casting life-sized human brain phantom. Indocyanine green (ICG) solutions diluted in dimethyl sulfoxide (DMSO) and human serum were injected into the brain phantom through the vessel simulating tube (2 ± 0.2 mm inner diameter) by an adjustable flow peristaltic pump. To demonstrate the translational potential of the system, an ICG/DMSO solution was perfused into blood vessels of freshly harvested porcine ears (n = 9, inner diameter from 0.56 to 1.27 mm). We subsequently performed in vivo imaging of fluorescence-perfused vascular structures in rodent models (n = 10). 5 mg/ml ICG solutions prepared in sterile water were injected via the lateral tail vein. All targets were imaged by the RFITS prototype at a working distance of 350-400 mm.
3D visualization of 10 µg/ml ICG-labeled continuous moving serum in the brain phantom was obtained at an average signal-to-background ratio (SBR) of 1.74 ± 0.03. The system was able to detect intravenously diffused fluorescence in porcine tissues with an average SBR of 2.23 ± 0.22. The RFITS prototype provided real-time monitoring of tissue perfusion in rats after intravenous (IV) administration of ICG. The maximum fluorescence intensity (average SBR = 1.94 ± 0.16, p < 0.001) was observed at T of ~30 seconds after the ICG signal was first detected (average SBR = 1.19 ± 0.13, p < 0.01).
We have conducted preclinical studies to demonstrate the feasibility of applying the RFITS system in real-time fluorescence angiography and tissue perfusion assessment. Our system provides fluorescence/color composite images for intuitive visualization of tissue perfusion with 3D perception. The findings pave the way for future clinical translation.
我们之前开发了一种实时荧光成像地形扫描（RFITS）系统，用于术中多模态成像、图像引导手术和动态手术导航。RFITS 可以同时捕获术中荧光、颜色反射和表面地形，并提供多模态图像的精确配准。RFITS 原型是一种用于多模态图像引导和直观 3D 可视化的有前途的系统。在本研究中，我们研究了 RFITS 系统在术中荧光血管造影中实时评估组织灌注的能力。
研究设计/材料和方法：我们对软铸人生大脑模型中的荧光灌注进行了离体成像。通过可调节流量蠕动泵将吲哚菁绿（ICG）溶液稀释在二甲基亚砜（DMSO）和人血清中注入血管模拟管（内径 2 ± 0.2 毫米）。为了证明系统的转化潜力，将 ICG/DMSO 溶液灌注到新鲜收获的猪耳血管中（n = 9，内径 0.56 至 1.27 毫米）。随后，我们在啮齿动物模型中进行了荧光灌注血管结构的体内成像（n = 10）。通过侧尾静脉注射 5mg/ml ICG 溶液。所有目标均由 RFITS 原型在 350-400mm 的工作距离处进行成像。
在大脑模型中以平均信号背景比（SBR）1.74 ± 0.03 获得了 10µg/ml ICG 标记连续移动血清的 3D 可视化。该系统能够检测到猪组织中静脉扩散的荧光，平均 SBR 为 2.23 ± 0.22。RFITS 原型在大鼠静脉（IV）注射 ICG 后提供了组织灌注的实时监测。在首次检测到 ICG 信号后约 30 秒（平均 SBR = 1.94 ± 0.16，p < 0.001）时观察到最大荧光强度（平均 SBR = 1.19 ± 0.13，p < 0.01）。
我们进行了临床前研究，以证明应用 RFITS 系统进行实时荧光血管造影和组织灌注评估的可行性。我们的系统提供荧光/彩色复合图像，用于具有 3D 感知的组织灌注直观可视化。这些发现为未来的临床转化铺平了道路。
