FOURIER AND SPLINE BASED RECONSTRUCTIONS IN HELICAL CT

描述(改编自申请者摘要)： 建议的研究是开发、实施和评估准确和高效的 单层和多层螺旋计算中的图像重建方法 体层摄影(CT)。螺旋CT的许多优点，如它的高 体积扫描速度，使其能够取代传统的CT作为测试 在许多临床情况下的选择，并允许开发新的 常规CT无法实现的成像方案。这个 调查人员的初步理论和经验研究强烈表明 建议的重建方法保留了所有固有的 螺旋CT在现有重建方法 在改善诸如混叠响应等物理特性时使用， 纵向分辨率和噪声特性，很少或不附加 计算负担。这些改善具有多项临床意义： (A)提高纵向分辨率可提高诊断的准确性 局灶性病理异常，如肺结节。(B)该机构的能力 以最佳方式降低或控制图像噪声水平的方法可以是 用于改善给定患者辐射的图像质量 或者在保持图像质量不变的同时减少患者的曝光。 减少曝光量还可以减轻过度工作的X射线管的负担。(C) 方法可以产生具有更多各向同性噪声的重建体积和 分辨率属性，这将改善 从这些体积生成的多平面重新格式化的质量。(D)最多 值得注意的是，拟议的方法将允许临床医生权衡 分辨率和噪声的改进，以提高时间分辨率。这将会 尤其有益于CT血管成像，因为它提高了时间分辨率 直接转化为改进的推注跟踪，从而改善图像 对比度。这项建议的具体目的是：(1)发展 基于傅里叶变换的螺旋CT纵向插补方法(2) 基于样条法的螺旋线纵向插补方法研究 CT；(3)开发利用冗余资源的优化方法 扇束信息；(4)新型扇束的开发与评价 重建算法；以及(5)物理特性的评估 和所有建议的方法的临床任务表现； 与现有方法进行比较。

DESCRIPTION (Adapted from Applicant's Abstract): The broad objective of the proposed research is to develop, implement, and evaluate accurate and efficient approaches to image reconstruction in single- and multi-slice helical computed tomography (CT). The numerous advantages of helical CT, such as its high volume-scanning speed, have allowed it to displace conventional CT as the test of choice in many clinical situations and allowed for the development of new imaging protocols that were not even possible with conventional CT. The investigators' preliminary theoretical and empirical studies strongly suggest that the proposed reconstruction approaches preserve all of the inherent advantages of helical CT available when existing reconstruction approaches are used while improving physical characteristics such as aliasing response, longitudinal resolution, and noise properties, with little or no additional computation burden. Such improvements have a number of clinical implications: (a) Improved longitudinal resolution can enhance the diagnostic accuracy of focal pathologic abnormalities such as lung nodules. (b) The ability of the approaches to reduce or control image noise levels in optimal ways can be exploited either for improving image quality for a given patient radiation exposure or for reducing patient exposure while holding image quality constant. Reduced exposure also reduces the burden on overworked x-ray tubes. (c) The approaches can yield reconstructed volumes that have more isotropic noise and resolution properties than can existing approaches, which would improve the quality of multiplanar reformats generated form these volumes. (d) Most significantly, the proposed approaches would allow clinicians to trade off the resolution and noise improvements for improved temporal resolution. This would particularly benefit CT angiography, where improved temporal resolution translates directly into improved bolus tracking and thus improved image contrast. The specific aims of the proposal are: (1) development of a Fourier-based longitudinal interpolation approach for helical CT; (2) development of a spline-based longitudinal interpolation approach for helical CT; (3) development of optimal methods for the exploitation of redundant fan-beam information; (4) development and evaluation of novel fan-beam reconstruction algorithms; and (5) evaluation of the physical characteristics and clinical-task performance of all of the proposed approaches; with comparison to existing approaches.