diff --git a/cg/ct.md b/cg/ct.md
index 6284fe8..70c4bee 100644
--- a/cg/ct.md
+++ b/cg/ct.md
@@ -1,8 +1,27 @@
 # CT
 
-[vtk-js doc](https://kitware.github.io/vtk-js/docs/)
+- [vtk-js doc](https://kitware.github.io/vtk-js/docs/)
 
 ## CornerstoneJS
 
 ### 概念
 
+#### ImageId
+就是一个url, url scheme决定某个ImageLoader插件真实的加载图像，Cornerstone3D委托注册的ImageLoader去加载，这样Cornerstone3D就可以同时显示多张图像，来自不同服务上的各种协议
+
+![image id](../images/cg/ct/image-id-format.png)
+
+
+## DICOM
+
+WADO:Web Access to DICOM Objects
+
+- [DICOM PS3.1 2023b - Introduction and Overview](https://dicom.nema.org/medical/dicom/current/output/html/part01.html)
+- [dcm4che DICOM Toolkit & Library](https://github.com/dcm4che/dcm4che)
+- [一个开源的系统](https://github.com/weiyangtang/dcm4cheSystem)
+- [dicom标准中文版](https://github.com/weiyangtang/dcm4cheSystem/releases/tag/dicom%E6%A0%87%E5%87%86%E4%B8%AD%E6%96%87%E7%89%88)
+
+- [DCMTK is a collection of libraries and applications implementing large parts the DICOM standard](https://dcmtk.org/dcmtk.php.en)
+- [DCMTK github](https://github.com/DCMTK/dcmtk)
+
+- [WADO Server 测试网站](https://www.dicomserver.co.uk//WADO/)
\ No newline at end of file
diff --git a/images/cg/ct/image-id-format.png b/images/cg/ct/image-id-format.png
new file mode 100644
index 0000000..b82c2b2
Binary files /dev/null and b/images/cg/ct/image-id-format.png differ
diff --git a/index/standard.md b/index/standard.md
index 75fe701..46cfa66 100644
--- a/index/standard.md
+++ b/index/standard.md
@@ -23,6 +23,7 @@
 ## Images
 
 - [图像格式](../others/images.md)
+- [The DICOM Standard Current Edition](https://www.dicomstandard.org/current)
 
 ### OHIF