Medical Imaging Learning (1)
1. Section
Coronal plane: before and after separation
Sagittal plane: separates left and right
Transverse plane / Axial plane: separate upper and lower
2. Direction
Left ( L eft ) Right ( R ight ) Front ( A interior ) Back ( P osterior ) Upper ( Su superior) Lower ( Inferior )
These six directions are based on the patient itself, the right side of the patient is the right side, and the left side in medical images
3. Coordinate system
There are three coordinate systems, world coordinate system, anatomical coordinate system and image coordinate system
3.1 World coordinate system
The world coordinate system is a Cartesian coordinate system, represented by x, y, and z
3.2 Anatomical coordinate system
Like the world coordinate system, it is represented by x, y, and z . The anatomical coordinate system uses the six coordinates : A direction is used as the positive and negative axis of the coordinate axis, we need to specify the direction of the positive axis
This is divided into anatomical coordinate systems and divided into several types:
Right-handed coordinate system:
include:
LPS(Left, Posterior, Superior): MHD图像(meta image), ITK工具包, ITK-Snap软件(该软件中写的是RAI)使用
Ps:有时候不一定用连续字母来表示正方向，有时候也表示出发(from)的方向(也就是负方向), 此时上面的LPS会被写成RAI, 对应的到达(to)方向才是LPS.
RAS(Right, Anterior, Superior): Nifti图像和3D Slicer软件使用
左手坐标系：例如LAS
3.3图像坐标系
图像坐标系统中不仅包含了体素值(三维中的像素一般称为体素 voxel), 还包含采样原点(origin), 采样间距(spacing)等信息.
原点：图像的第一个体素在解剖坐标系中的坐标,
间距:沿着每个轴相邻体素之间的距离
4.坐标变换
