Dr. Stephen Aylward's site has a nice list of this often asked question:

http://www.aylward.org/notes/open-access-medical-image-repositories

I do not know how often he updates that site, however.

Thank you Dr. Yueh Z Lee

I appreciate your fast reply, but I could not find the images

You can try these sites as well:

https://en.wikipedia.org/wiki/List_of_neuroscience_databases

http://www.aycan.de/sample-dicom-images.html

http://www.oasis-brains.org/app/template/Tools.vm;jsessionid=B034F44C713CA37F6FE17D381E0684E1

http://www.pcir.org/researchers/downloads_available.html

http://www.aylward.org/notes/open-access-medical-image-repositories

http://medvis.org/datasets/

Thank you very much. I will check them all.

I found this site:

https://radiopaedia.org/play/7549/entry/112001/case/4756/studies/6767