Kashou Nasser H, Smith Mark A, Roberts Cynthia J
BioMedical Imaging Lab, Wright State University, 3640 Colonel Glenn Hwy, 207 Russ Eng. Center, Dayton, OH, 45435, USA,
Int J Comput Assist Radiol Surg. 2015 Jan;10(1):19-33. doi: 10.1007/s11548-014-1002-3. Epub 2014 Apr 23.
Standard two-dimension (2D) magnetic resonance imaging (MRI) clinical acquisition protocols utilize orthogonal plane images which contain slice gaps (SG). The purpose of this work is to introduce a novel interpolation method for these orthogonal plane MRI 2D datasets. Three goals can be achieved: (1) increasing the resolution based on a priori knowledge of scanning protocol, (2) ameliorating the loss of data as a result of SG and (3) reconstructing a three-dimension (3D) dataset from 2D images.
MRI data was collected using a 3T GE scanner and simulated using Matlab. The procedure for validating the MRI data combination algorithm was performed using a Shepp-Logan and a Gaussian phantom in both 2D and 3D of varying matrix sizes (64-512), as well as on one MRI dataset of a human brain and on an American College of Radiology magnetic resonance accreditation phantom.
The squared error and mean squared error were computed in comparing this scheme to common interpolating functions employed in MR consoles and workstations. The mean structure similarity matrix was computed in 2D as a means of qualitative image assessment. Additionally, MRI scans were used for qualitative assessment of the method. This new scheme was consistently more accurate than upsampling each orientation separately and averaging the upsampled data.
An efficient new interpolation approach to resolve SG was developed. This scheme effectively fills in the missing data points by using orthogonal plane images. To date, there have been few attempts to combine the information of three MRI plane orientations using brain images. This has specific applications for clinical MRI, functional MRI, diffusion-weighted imaging/diffusion tensor imaging and MR angiography where 2D slice acquisition are used. In these cases, the 2D data can be combined using our method in order to obtain 3D volume.
标准二维(2D)磁共振成像(MRI)临床采集协议使用包含切片间隙(SG)的正交平面图像。本研究的目的是为这些正交平面MRI 2D数据集引入一种新颖的插值方法。可实现三个目标:(1)基于扫描协议的先验知识提高分辨率;(2)改善因切片间隙导致的数据丢失;(3)从2D图像重建三维(3D)数据集。
使用3T GE扫描仪收集MRI数据并使用Matlab进行模拟。使用不同矩阵大小(64 - 512)的2D和3D的Shepp - Logan模型和高斯体模,以及一个人脑的MRI数据集和一个美国放射学会磁共振认证体模,对MRI数据组合算法进行验证。
将该方案与MR控制台和工作站中使用的常见插值函数进行比较,计算平方误差和均方误差。在2D中计算平均结构相似性矩阵作为定性图像评估的一种手段。此外,使用MRI扫描对该方法进行定性评估。与分别对每个方向进行上采样并对采样后的数据求平均值相比,这种新方案始终更准确。
开发了一种有效的新插值方法来解决切片间隙问题。该方案通过使用正交平面图像有效地填充了缺失的数据点。迄今为止,很少有人尝试使用脑图像来组合三个MRI平面方向的信息。这在使用2D切片采集的临床MRI、功能MRI、扩散加权成像/扩散张量成像和磁共振血管造影中有特定应用。在这些情况下,可以使用我们的方法组合2D数据以获得3D体积。