Last 2 weeks I have configured and played with dmc4che. Its a collection of open source application and utilities for the health care enterprise, PACS and DICOM has been used by hospital in Malaysia from government and pubic sector, 80% of them using PACS/DICOM standard. Its has been developed in Java language to achieve performance and portability, supporting deployment on JDK 1.4 and up.
With integration few components I managed to run it at local server.
In order to complete the test I have downloaded DICOM sample image from http://www.osirix-viewer.com/datasets/
You need to use dmcsnd, example;
./dcmsnd CDRECORD@127.0.0.1:10104 /home/senn/Downloads/GOUDURIX/GOUDURIX/ -L DCMSND:10104
Once you insert the sample image you can start to browse patient ID and so on.
Once you have all these, you can start to play with DICOM and PACS.
To search the PACS we use the DICOM command C-FIND. This command takes as an argument a DICOM object that represent a query. The PACS transforms the object that we send to a query, probably to SQL, runs it and then transform every result record back into a DICOM object and send it back to us in a C-FIND response. The PACS sends one C-FIND response for every result record.
To learn more, I found this very straightforward website to teach DICOM and PACS.