Biomedical Imaging Resource, Mayo Clinic, Rochester, MN, USA.
Int J Comput Assist Radiol Surg. 2012 Jan;7(1):13-25. doi: 10.1007/s11548-011-0621-1. Epub 2011 Jun 14.
Medical imaging and its application in interventional guidance has revolutionized the development of minimally invasive surgical procedures leading to reduced patient trauma, fewer risks, and shorter recovery times. However, a frequently posed question with regard to an image guidance system is "how accurate is it?" On one hand, the accuracy challenge can be posed in terms of the tolerable clinical error associated with the procedure; on the other hand, accuracy is bound by the limitations of the system's components, including modeling, patient registration, and surgical instrument tracking, all of which ultimately impact the overall targeting capabilities of the system.
While these processes are not unique to any interventional specialty, this paper discusses them in the context of two different cardiac image guidance platforms: a model-enhanced ultrasound platform for intracardiac interventions and a prototype system for advanced visualization in image-guided cardiac ablation therapy.
Pre-operative modeling techniques involving manual, semi-automatic and registration-based segmentation are discussed. The performance and limitations of clinically feasible approaches for patient registration evaluated both in the laboratory and in the operating room are presented. Our experience with two different magnetic tracking systems for instrument and ultrasound transducer localization is reported. Ultimately, the overall accuracy of the systems is discussed based on both in vitro and preliminary in vivo experience.
While clinical accuracy is specific to a particular patient and procedure and vastly dependent on the surgeon's experience, the system's engineering limitations are critical to determine whether the clinical requirements can be met.
医学成像及其在介入指导中的应用彻底改变了微创手术的发展，使患者创伤更小、风险更低、恢复时间更短。然而，对于图像引导系统，人们经常会提出一个问题，“它的准确性如何？”一方面，可以根据与该程序相关的可容忍临床误差来提出准确性挑战；另一方面，准确性受到系统组件的限制，包括建模、患者注册和手术器械跟踪，所有这些最终都会影响系统的整体目标能力。
虽然这些过程并非介入性专业独有的，但本文将在两种不同的心脏图像引导平台的背景下讨论这些过程：用于心脏内介入的模型增强超声平台和用于图像引导心脏消融治疗的高级可视化原型系统。
讨论了涉及手动、半自动和基于注册的分割的术前建模技术。介绍了在实验室和手术室中评估的用于患者注册的临床可行方法的性能和局限性。报告了我们在两种不同的用于器械和超声换能器定位的磁跟踪系统方面的经验。最终，根据体外和初步体内经验讨论了系统的整体准确性。
虽然临床准确性特定于特定的患者和程序，并且极大地依赖于外科医生的经验，但系统的工程限制对于确定是否可以满足临床要求至关重要。
