Can contrast-enhanced ultrasound replace fluoroscopic nephrostogram?

 症状性肾结石是疼痛和发病的重要来源，影响高达12%的美国人，每年产生超过20亿美元的医疗费用。随着发病率的上升，肾结石患者的一个无声的、未被认识到的危险是他们反复暴露于电离辐射。因此，减少患者暴露于电离辐射的策略可能对泌尿系结石患者有短期和长期的益处。在这项研究中，我们建议验证对比增强超声（CEUS）肾图，以取代荧光镜肾图评价顺行肾引流。我们的研究结果将证明，在这种情况下使用CEUS可以显著降低患者的辐射暴露，为引入一种全新的肾脏和输尿管成像方法奠定基础。超声是一种功能强大的便携式成像方式，没有电离辐射的危险，目前在许多诊断环境中使用。静脉注射的微泡造影剂的添加已经将超声的适用性扩展到过去依赖于计算机断层扫描（CT）或荧光透视的新成像应用。CEUS有助于以出色的空间分辨率对内脏器官进行动态实时评估，并且与CT或荧光透视相比，不太可能引起造影剂相关的过敏反应。这项初步研究将是第一个评价CEUS检测输尿管通畅性和顺行肾引流作为荧光镜肾造影替代品的可行性。我们的初步工作表明，在经皮肾结石手术中使用超声可以快速减少患者暴露于电离辐射。此外，我们的造影增强超声肾图的初步经验表明，它是一个可行的替代荧光镜肾图。鉴于这些发现，我们假设对比增强超声肾图将不劣于荧光镜肾图，以评价经皮肾结石手术后肾造瘘管患者的输尿管通畅性。拟议研究的目的是：（1）优化肾造瘘管患者的对比增强超声肾图成像参数，以及（2）进行一项前瞻性试点队列研究，比较对比增强超声肾图与荧光镜肾图，以识别通畅的顺行肾引流。开发对比增强超声肾图作为传统荧光肾图的替代成像方式的意义在于，放置肾造口术管的患者将暴露于大大降低的电离辐射暴露水平。该项目的创新之处在于开发了一种新的对比增强超声应用，这种应用对患者的风险最小，可用于许多环境，并且易于采用。我们相信，在未来，造影剂增强超声与肾造口术注射将是一个常规的组成部分，超声和目前代表了一个变革性的进步，肾脏成像。

 DESCRIPTION (provided by applicant): Symptomatic kidney stones are a significant source of pain and morbidity, affect up to 12% of Americans and generate more than $2 billion in annual healthcare costs. With incidence rates rising, a silent, under-recognized danger for patients with kidney stones is their repetitive exposure to ionizing radiation. Consequently, strategies to reduce patient exposure to ionizing radiation may be of both short and long-term benefit to patients with urinary stone disease. In this study, we propose to validate contrast enhanced ultrasound (CEUS) nephrostogram to replace fluoroscopic nephrostogram for evaluating antegrade renal drainage. Our results will demonstrate that utilizing CEUS in this setting can lead to significantly decreased patient radiation exposure, laying the groundwork to introduce a completely new way of imaging the kidney and ureter. Ultrasound is a powerful, portable imaging modality free of the dangers of ionizing radiation, currently in use across many diagnostic settings. The addition of intravenously injected microbubble contrast agents has extended the applicability of ultrasound to new imaging applications that used to rely on computed tomography (CT) or fluoroscopy. CEUS facilitates dynamic real-time assessment of visceral organs with excellent spatial resolution and is less likely to cause contrast-related allergic reactions compared to CT or fluoroscopy. This pilot study will be the first to evaluate th feasibility of CEUS for detection of ureteral patency and antegrade renal drainage as a replacement to fluoroscopic nephrostogram. Our preliminary work demonstrates that using ultrasound during percutaneous renal stone surgery rapidle reduces patient exposure to ionizing radiation. In addition, our initial experience of contrast enhanced ultrasound nephrostogram demonstrates it to be a viable alternative to fluoroscopic nephrostogram. Given these findings, we hypothesize that contrast enhanced ultrasound nephrostogram will be non-inferior to fluoroscopic nephrostogram to evaluate ureteral patency in patients with nephrostomy tubes after percutaneous renal stone surgery. The aims of the proposed study are: (1) Optimize the parameters for contrast enhanced ultrasound nephrostogram imaging for patients with nephrostomy tubes, and (2) Perform a prospective pilot cohort study comparing contrast enhanced ultrasound nephrostogram to fluoroscopic nephrostogram to identify unobstructed antegrade renal drainage. The significance of developing contrast enhanced ultrasound nephrostogram as an alternative imaging modality to traditional fluoroscopic nephrostogram is that patients with nephrostomy tubes in place will be exposed to drastically reduced levels of ionizing radiation exposure. The innovation of this project is the development of a new application for contrast enhanced ultrasound, one that imparts minimal risk to the patient, can be used in many settings, and can be easily adopted. We believe that in the future, contrast enhanced ultrasound with nephrostomy injection will be a routine component of ultrasound and currently represents a transformative advance in renal imaging.