Development of Instrumentation for Fluorescence-Guided Surgery

荧光引导手术器械的开发

• 批准号: 7967908
• 负责人: Paul Smith
• 金额: $ 4.52万
• 依托单位: NATIONAL INSTITUTE OF BIOMEDICAL IMAGING AND BIOENGINEERING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7967908
• 关键词: Animal Model; Animals; Biological Preservation; Development; Diagnostic; Dose; Drops; Excision; Feedback; Fluorescence; Fluorescent Probes; Future; Image; Imagery; Label; Lead; Light; Malignant neoplasm of cervix uteri; Malignant neoplasm of ovary; Medical; Modeling; Motion; Mus; Neoplasm Metastasis; Operative Surgical Procedures; Optics; Peritoneal; Property; Real-Time Systems; Resolution; Rhodamine; Rhodamines; Signal Transduction; Specificity; Speed; System; Techniques; Time; Tissues; Work; charge coupled device camera; clinical application; cost; data acquisition; design; fluorescence imaging; fluorophore; improved; in vivo; instrument; instrumentation; interest; nanocrystal; nanoparticle; novel; prototype; research study; success; technique development

The rapid development of molecularly targeted probes for use in vivo has led to growing interest in clinical applications that incorporate information from these probes. In particular, there is a need for techniques to visualize these targeted probes during surgery, particularly to identify tissue either for removal or preservation. When looking at fluorescent probes in tissue, the major difficulty is usually separating the probe fluorescence from the tissue autofluorescence. Because the autofluorescence has different spectral properties than the fluorophore, it can easily be separated using multispectral imaging, in which several full emission spectra can be taken for each pixel. Although the implementation of acousto-optic tunable filters has greatly increased the speed of these techniques, the minimum time required to acquire an image cube is still several seconds with commercially available systems. When imaging using fluorescent probes with lower efficiency or when used at lower doses, the image acquisition time can be as long as several minutes. This data acquisition rate makes the use of multispectral imaging to provide real-time feedback during a surgical procedure impractical. Even when used for diagnostic purposes, the unavoidable motion of the subject during the time required to acquire an image cube can lead to an unacceptable loss of spatial resolution. This project focuses on the development of instrumentation for incorporating fluorescent and multi-spectral imaging into surgical applications, using two major approaches. The first approach is to develop a system for real-time visualization of fluorescent probes to guide surgery. The second approach is to develop a system for diagnostic applications, to provide a white-light stack of images for spatial registration of the multispectral image cube. As an alternative to multispectral imaging, aggressive filtering of both emission and excitation light can help to minimize the effects of tissue autofluorescence. Although the signal level drops as the spectral window is narrowed, this can be overcome by using a sensitive camera, such as a cooled CCD, ICCD, or even an EMCCD. Because a single spectral window is used, substantially faster data acquisition is possible. The immediate application for this instrument was the identification of peritoneal metastases in ovarian cancer, using a GSA-Rhodamine Green probe developed in NCI. The first prototype instrument, used for mock cytoreductive surgery in a murine model of ovarian cancer, had sufficient sensitivity to identify labeled metastases at an image acquisition rate of five frames per second with specificity comparable to that achieved with a multispectral system. An improved prototype, which permitted image acquisition at fifteen frames per second with enhanced sensitivity, was used for cytoreductive surgery on anesthetized animals with similar success to the previous mock surgery. This year, we also continued development on a separate multispectral system to provide a white light image stack for physical registration of the multispectral image cube, using a 92:8 beam splitter and a low-cost monochrome CCD camera in parallel with the multispectral instrumenation. Preliminary experiments on a cervical cancer animal model are underway. The hardware developed for this application could be easily adapted to incorporate a second camera into the instrument for fluorescence guided surgery; this second camera could be used either for a second fluorescence image, in order to provide a simple autofluorescence correction, or for a pseudo-white light image of the surgical field. Finally, some initial proof-of-principle in vivo imaging experiments were performed using upconverters, in this case upconverting nanocrystals that absorb 980 nm light and emit in the visible to near-infrared. These novel compounds could allow single-wavelength imaging with no detectable autofluorescence; the tissue background is so low that a white light image will likely be required to provide anatomical reference. Although considerable work remains in developing these nanoparticles for medical applications, this is a promising avenue for future efforts.

用于体内使用的分子靶向探针的快速发展导致人们对纳入这些探针信息的临床应用的兴趣日益增加。特别是，需要技术在手术过程中可视化这些靶向探针，尤其是鉴定组织以去除或保存。 当查看组织中的荧光探针时，主要的困难通常是将探针荧光与组织自动荧光分开。由于自动荧光的光谱特性与荧光团具有不同的光谱特性，因此可以使用多光谱成像轻松分离它，其中每个像素可以使用几个完整的发射光谱。尽管实现声学可调滤波器的实施大大提高了这些技术的速度，但获取图像立方体所需的最小时间仍然是拥有市售系统的几秒钟。 当使用效率较低或以较低剂量使用时进行荧光探针进行成像时，图像采集时间可能长达几分钟。该数据采集率使使用多光谱成像在不切实际的手术过程中提供实时反馈。 即使用于诊断目的，在获取图像立方体所需的时间内，受试者的不可避免的运动也会导致空间分辨率的不可接受的损失。 该项目的重点是使用两种主要方法将仪器的开发用于将荧光和多光谱成像纳入手术应用中。 第一种方法是开发一种用于实时可视化荧光探针以指导手术的系统。 第二种方法是开发用于诊断应用的系统，以提供白色光堆放图像堆栈，以用于多光谱图像立方体的空间注册。 作为多光谱成像的替代方法，对发射光和激发光的攻击性过滤可以帮助最大程度地减少组织自动荧光的影响。尽管信号电平在光谱窗口的范围内下降，但可以使用敏感的相机（例如冷却的CCD，ICCD甚至EMCCD）来克服这一点。由于使用了单个光谱窗口，因此可以更快地进行数据采集。该仪器的立即应用是使用NCI中开发的GSA-Rhodamine绿色探针鉴定卵巢癌中腹膜转移。 第一种原型仪器在鼠类卵巢癌模型中用于模拟细胞减少手术，具有足够的灵敏度，可以以每秒五帧的图像采集速率鉴定标记的转移酶，其特异性与多光谱系统相当的特异性。 改进的原型允许以每秒15帧的速度获得图像采集，并具有增强的敏感性，用于对麻醉动物的细胞减少手术，其成功与先前的模拟手术相似。 今年，我们还使用92：8束分配器和低成本的单色CCD摄像头与多光谱仪器仪并行开发了单独的多光谱系统，以提供白光图像堆栈，用于多光谱图像立方体的物理注册。 宫颈癌动物模型的初步实验正在进行中。 为该应用程序开发的硬件很容易适应，以将第二个摄像头纳入仪器中，以进行荧光引导手术。该第二台相机可以用于第二个荧光图像，以提供简单的自动荧光校正，也可以用于外科手术场的伪白光图像。 最后，使用上转换器进行了一些初始的原理体内体内成像实验，在这种情况下，将纳米晶体的向上转换，可吸收980 nm的光并在可见的近红外发射。 这些新型化合物可以允许无可检测到的自动荧光的单波长成像。组织背景如此之低，以至于可能需要白光图像来提供解剖参考。尽管在开发这些纳米颗粒的医疗应用方面仍有大量工作，但这是未来努力的有希望的途径。