将非各向同性体素转换为各向同性体素 [英] Converting non-isotropic to isotropic voxel

问题描述

我正在尝试注册两个大脑图像卷(每个都包括 2D 切片).第一个体积(目标或移动体积)的切片厚度和间距分别为 1.5 和 [1.5 1.5].对于第二个(参考体积)，这些值为 4 和 [0.9375 0.9375].切片的数量也不同.第一卷有 96 个切片，第二卷有 44 个切片.

I am trying to register two brain image volumes (each includes 2D slices). The first volume (target or moving volume) has the slice thickness and spacing of 1.5 and [1.5 1.5] respectively. For the second one (reference volume), these values are 4 and [0.9375 0.9375]. Also the number of slices are different. First volume has 96 slices and second has 44 slices.

我的一个朋友建议使体素各向同性，但我不知道该怎么做.我可以看到第一卷是各向同性的，但不是第二卷.我想知道我该怎么做?

One of my friends, suggested to make the voxels isotropic, but I do not know how to do that. I can see that first volume is isotropic, but not the second one. I am wondering how I should do that?

此外，我将考虑每个卷的两个切片，并对其应用特征提取方法.因此，这两个切片都应该与大脑的同一层(同一场景)相关.考虑到切片数量不同，我该怎么做，如何重新计算第一卷的新切片与第二卷相同?

Also, I will consider two slices of each volume and apply a feature extraction method on it. So, both of these slices should be related to the same layer of the brain (same scene). Considering the different number of slices, what should I do and how should I re-calculate new slices of the first volume to be the same as the second volume?

推荐答案

如果我正确理解您的问题，听起来您想使用具有给定大小的体素的图像堆栈对其进行插值，以便定义新的坐标系其中每个体素是各向同性的(即具有相等的高度宽度和深度，即立方体素).如果是这样可能有帮助:

If I understand your problem correctly, it's sounds like you want to take an image stack with voxels of a given size interpolate it so that you define a new coordinate system in which each voxel is isotropic (i.e. has equal height width and depth, i.e. cubic voxels). If so might the help:

(我以 matlabs 提供的 mri 数据为例)

(I'm using matlabs supplied mri data as an example)

load mri D
D=double(squeeze(D));   % remove singleton dimension, convert to double
szD_a=size(D);          % get size of original image stack
vox_a = [.4, .4, .45];  % define size of voxel in original image stack
vox_b = [.25, .25, .25];% define size of voxel in target image stack
szD_b = ceil((size(D)-1).*vox_a./vox_b)+1; % set size of target image stack

% define coordinates of voxels in original image stack
[Xa,Ya,Za]=meshgrid(...
    [0:szD_a(1)-1]*vox_a(1),...
    [0:szD_a(2)-1].*vox_a(2),...
    [0:szD_a(3)-1].*vox_a(3));

% define coordinates of voxels in original image stack
[Xb,Yb,Zb]=meshgrid(...
    [0:szD_b(1)-1]*vox_b(1),...
    [0:szD_b(2)-1].*vox_b(2),...
    [0:szD_b(3)-1].*vox_b(3));

D_target = interp3(Xa,Ya,Za,D,Xb,Yb,Zb);

figure
for t=0:vox_b(3):max(Zb(:))
    subplot(1,2,1)
    imagesc(D(:,:,floor(t/vox_a(3))+1))
    subplot(1,2,2)
    imagesc(D_target(:,:,floor(t/vox_b(3))+1))
    drawnow
    pause(0.1)
end

这篇关于将非各向同性体素转换为各向同性体素的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！