摘要:
A computer-implemented method for reconstruction of a magnetic resonance image includes acquiring a first incomplete k-space data set comprising a plurality of first k-space lines spaced according to an acceleration factor and one or more calibration lines. A parallel imaging reconstruction technique is applied to the first incomplete k-space data to determine a plurality of second k-space lines not included in the first incomplete k-space data set, thereby yielding a second incomplete k-space data set. Then, the parallel imaging reconstruction technique is applied to the second incomplete k-space data to determine a plurality of third k-space lines not included in the second incomplete k-space data, thereby yielding a complete k-space data set.
摘要:
A reconstructed image is rendered of a patient by a processor from a set of undersampled MRI data by first subtracting two repetitions of the acquired data in k-space to create a third dataset. The processor reconstructs the image by minimizing an objective function under a constraint related to the third dataset, wherein the objective function includes applying a Karhunen-Loeve Transform (KLT) to a temporal dimension of data. The objective function under the constraint is expressed as arg minf{∥φ(f)∥1 subject to ∥Af−y∥2≦ε}. The reconstructed image is an angiogram which may be a 4D angiogram. The angiogram is used to diagnose a vascular disease.
摘要:
A system and method for regression-based segmentation of the mitral valve in 2D+t cardiac magnetic resonance (CMR) slices is disclosed. The 2D+t CMR slices are acquired according to a mitral valve-specific acquisition protocol introduced herein. A set of mitral valve landmarks is detected in each 2D CMR slice and mitral valve contours are estimated in each 2D CMR slice based on the detected landmarks. A full mitral valve model is reconstructed from the mitral valve contours estimated in the 2D CMR slices using a trained regression model. Each 2D CMR slice may be a cine image acquired over a full cardiac cycle. In this case, the segmentation method reconstructs a patient-specific 4D dynamic mitral valve model from the 2D+t CMR image data.
摘要翻译:公开了一种用于2D + t心脏磁共振(CMR)切片二尖瓣回归分割的系统和方法。 根据本文引入的二尖瓣特异性获取方案获取2D + t CMR切片。 在每个2D CMR切片中检测到一组二尖瓣地标,并且基于检测到的界标在每个2D CMR切片中估计二尖瓣轮廓。 使用训练有素的回归模型,从2D CMR切片中估算的二尖瓣轮廓重建完整的二尖瓣模型。 每个2D CMR切片可以是在整个心动周期上获取的电影图像。 在这种情况下,分割方法从2D + t CMR图像数据重建患者特定的4D动态二尖瓣模型。
摘要:
In a method and apparatus for functional imaging an impulse sequence is used in which an examination subject is charged with a readout gradient with sub-pulses of alternating polarity. By means of at least two-dimensional Fourier transformation, an image data matrix having N rows is generated from the raw data thereby acquired. After a stimulation of the subject, a second image data matrix is acquired. The coincidence of opposed signal changes that occur at two pixels disposed from each other by a distance of N/2 rows in the image matrix is checked. Found coincidences are evaluated as functional activity.
摘要:
A computer-implemented method for reconstruction of a magnetic resonance image includes acquiring a first incomplete k-space data set comprising a plurality of first k-space lines spaced according to an acceleration factor and one or more calibration lines. A parallel imaging reconstruction technique is applied to the first incomplete k-space data to determine a plurality of second k-space lines not included in the first incomplete k-space data set, thereby yielding a second incomplete k-space data set. Then, the parallel imaging reconstruction technique is applied to the second incomplete k-space data to determine a plurality of third k-space lines not included in the second incomplete k-space data, thereby yielding a complete k-space data set.
摘要:
A method and system for left ventricle (LV) detection in 2D magnetic resonance imaging (MRI) images is disclosed. In order to detect the LV in a 2D MRI image, a plurality of LV candidates are detected, for example using marginal space learning (MSL) based detection. Candidates for distinctive anatomic landmarks associated with the LV are then detected in the 2D MRI image. In particular, apex candidates and base candidates are detected in the 2D MRI image. One of the LV candidates is selected as a final LV detection result by ranking the LV candidates based on the LV candidates, the apex candidates, and the base candidates using a trained ranking model.
摘要:
In a method as well as a magnetic resonance tomography apparatus for implementation of such a method for improved sensitivity-encoded magnetic resonance imaging using a two-dimensional or three-dimensional acquisition coil array, two-dimensional or three-dimensional undersampling of k-space is undertaken by measurement of a number N of basic partial trajectories τn in k-space that in their entirety form a geometric arrangement of source points, a number M of different operators Cm(Δ km) are determined, with each operator representing an algebraic transformation with which unmeasured target points at an interval Δ km from one of the measured source points are synthesized from a number of measured source points, the operators Cm(Δ km) are applied to at least one subset of the measured source points for at least partial completion of the magnetic resonance data set, and a largely artifact-free image is reconstructed in three-dimensional space on the basis of the measured source points and the synthesized data points.
摘要翻译:在一种方法以及用于实施这种用于使用二维或三维采集线圈阵列改进灵敏度编码的磁共振成像的方法的磁共振断层摄影装置中,k空间的二维或三维欠采样 通过测量k空间中的N个基本部分轨迹τN n N进行,其整体形成源点的几何排列,M个不同算子C m, 确定每个运算符代表一个代数变换(Delta k m)),其中未测量的目标点的间隔距离为Δ k 从测量的源点之一中的一个m SUB>从多个测量的源点合成,运算符C′(Delta< O OYYLE =“SINGLE” m>)被施加到测量的源点的至少一个子集,用于至少部分完成磁共振 ce数据集,并且基于测量的源点和合成数据点在三维空间中重建大量无伪影的图像。
摘要:
In a method for the operation of a magnetic resonance apparatus an anatomical image of a region of an examination subject to be imaged is generated with a prescribable resolution and quality, a functional image of the region to be imaged is generated, the functional image is superimposed on the anatomical image, and at least one area of the region to be imaged wherein the functional image contains unreliable information is identified in the superimposition.
摘要:
A computer-implemented method for learning a tight frame includes acquiring undersampled k-space data over a time period using an interleaved process. An average of the undersampled k-space data is determined and a reference image is generated based on the average of the undersampled k-space data. Next, a tight frame operator is determined based on the reference image. Then, a reconstructed image data is generated from the undersampled k-space data via a sparse reconstruction which utilizes the tight frame operator.
摘要:
A reconstructed image is rendered of a patient by a processor from a set of undersampled MRI data by first subtracting two repetitions of the acquired data in k-space to create a third dataset. The processor reconstructs the image by minimizing an objective function under a constraint related to the third dataset, wherein the objective function includes applying a Karhunen-Loeve Transform (KLT) to a temporal dimension of data. The objective function under the constraint is expressed as arg minf{∥φ(f)∥1 subject to ∥Af−y∥2≦ε}. The reconstructed image is an angiogram which may be a 4D angiogram. The angiogram is used to diagnose a vascular disease.