搜索结果: 1-15 共查到“知识库 生物医学电子学 CT”相关记录18条 . 查询时间(0.125 秒)
基于序列间先验约束和多视角信息融合的肝脏CT图像分割
CT序列图像 肝脏分割 先验约束 多视角信息融合
2018/5/21
医学电子计算机断层扫描(CT)序列图像中肝脏的准确分割是实现计算机辅助肝手术的重要前提,然而图像中存在的组织病变、边界模糊或缺失、不同组织间的粘连给肝脏分割带来极大挑战。针对这些问题,该文提出一种基于图像序列间先验约束的半自动分割方法,并进一步采取了多视角信息融合的方式实现肝脏的准确分割。该方法的优势在于无需大量数据的收集和复杂的先验训练。在Sliver07公开数据集合的验证结果显示,和领域内主要...
研制用于鼻咽癌放射治疗定位的CT/MRI图像配准辅助装置,并且通过组织勾画差异分析使用该装置后所得配准融合图像在临床中的应用意义。方法 在普通的磁共振头颈线圈中设计特定形状的头枕,保持患者在扫描时与CT定位扫描时相同的体位。采用配对t检验分析CT图像与融合图像中腮腺、下颌骨的勾画差异。结果 患者的头颈部CT、MRI图像的配准精度较未使用该装置的图像具有明显的提高,使用该配准图像得到的融合图像、组织...
基于噪声功率谱的CT图像噪声评价
噪声功率谱 标准差 噪声评价 图像分析
2014/11/17
设计并探讨基于噪声功率谱(NPS)的CT图像噪声评价方法。方法 改变CT图像扫描参数以及重建参数获取图像,采用NPS与传统标准差(SD)两种方法对该图像进行噪声检测,并对比两种检测结果。结果 NPS曲线幅值与层厚和剂量成反比,与重建算法的增强程度成正比。重建算法、层厚和剂量对噪声指数的影响能够在NPS曲线上得到明显的体现。结论 NPS能够从幅值与频率方面反应噪声变化,与SD方法相结合可形成更为完善...
新疆地方性肝包虫CT图像的灰度直方图特征提取与分析
灰度直方图 新疆地方性肝包虫 特征提取 最大类间距
2014/4/4
图像特征提取是图像识别、图像数据挖掘、基于内容的图像检索等工作的基础,是模式识别和分类中的关键问题。本文运用灰度直方图法提取新疆地方性肝包虫CT图像特征,对图像进行尺寸归一、去噪和增强的预处理,并对灰度直方图特征进行统计分析,用最大类间距法获取图像分类的主要特征,同时使用判别分析法对特征的分类能力进行评价。结果表明,灰度直方图法提取的特征在统计分析中存在差异,且提高图像分类的准确率,一定程度上有助...
An Optimized Spline-Based Registration of a 3D CT to a Set of C-Arm Images
3D CT C-Arm Images
2009/9/8
We have developed an algorithm for the rigid-body registration of a CT volume to a set of C-arm images. The algorithm uses a gradient-based iterative minimization of a least-squares measure of dissimi...
An Approximate Cone Beam Reconstruction Algorithm for Gantry-Tilted CT Using Tangential Filtering
Gantry-Tilted CT Tangential Filtering
2009/9/8
FDK algorithm is a well-known 3D (three-dimensional) approximate algorithm for CT (computed tomography) image reconstruction and is also known to suffer from considerable artifacts when the scanning c...
Analysis of Cone-Beam Artifacts in off-Centered Circular CT for Four Reconstruction Methods
Cone-Beam Artifacts CT
2009/9/8
Cone-beam (CB) acquisition is increasingly used for truly three-dimensional X-ray computerized tomography (CT). However, tomographic reconstruction from data collected along a circular trajectory with...
Extending Three-Dimensional Weighted Cone Beam Filtered Backprojection (CB-FBP) Algorithm for Image Reconstruction in Volumetric CT at Low Helical Pitches
CB-FBP Image Reconstruction
2009/9/8
A three-dimensional (3D) weighted helical cone beam filtered backprojection (CB-FBP) algorithm (namely, original 3D weighted helical CB-FBP algorithm) has already been proposed to reconstruct images f...
Improved Image Fusion in PET/CT Using Hybrid Image Reconstruction and Super-Resolution
Improved Image Fusion PET/CT
2009/9/8
Purpose. To provide PET/CT image fusion with an improved PET resolution and better contrast ratios than standard reconstructions. Method. Using a super-resolution algorithm, several PET acquisitions w...
Adaptive Bayesian Iterative Transmission Reconstruction for Attenuation Correction in Myocardial Perfusion Imaging with SPECT/Slow-Rotation Low-Output CT Systems
Myocardial Perfusion Imaging SPECT/Slow-Rotation Low-Output CT Systems
2009/9/7
Objectives. SPECT/slow-rotation low-output CT systems can produce streak artifacts in filtered backprojection (FBP) attenuation maps, impacting attenuation correction (AC) in myocardial perfusion imag...
A Fast CT Reconstruction Scheme for a General Multi-Core PC
A Fast CT Reconstruction Scheme General Multi-Core PC
2009/9/7
Expensive computational cost is a severe limitation in CT reconstruction for clinical applications that need real-time feedback. A primary example is bolus-chasing computed tomography (CT) angiography...
Using the backprojection filtration (BPF) and filtered backprojection (FBP) approaches, respectively, we prove that with cone-beam CT the interior problem can be exactly solved by analytic continuatio...
An Efficient Estimation Method for Reducing the Axial Intensity Drop in Circular Cone-Beam CT
Estimation Method Circular Cone-Beam CT
2009/9/4
Reconstruction algorithms for circular cone-beam (CB) scans have been extensively studied in the literature. Since insufficient data are measured, an exact reconstruction is impossible for such a geom...
Effect of Edge-Preserving Adaptive Image Filter on Low-Contrast Detectability in CT Systems: Application of ROC Analysis
CT Systems ROC Analysis
2009/9/4
Objective. For the multislice CT (MSCT) systems with a larger number of detector rows, it is essential to employ dose-reduction techniques. As reported in previous studies, edge-preserving adaptive im...