OrthancPi : Mini DICOM PACS Server

Introduction

Orthanc is a belgian, open-source, lightweight, standalone, simple, fast and cross-platform DICOM PACS server for healthcare and medical research. OrthancPi is the porting of the Orthanc code to the Raspberry Pi platform.

Orthanc is developed and maintained by Sébastien Jodogne, a Medical Imaging Engineer at the Medical Physics Department from the University Hospital of Liège (CHU) in Belgium. He holds a PhD degree in Computer Science from the University of Liège in Belgium.

Sébastien Jodogne is also the Chief Innovation Officer of OSIMIS, a spin-off from the CHU Liège, founded in September 2015. OSIMIS provides support to a series of health care and industry organisations, helping them implement Orthanc in order to achieve interoperability.

Hardware

Raspberry Pi's (RPI's) are credit-card–sized single-board computers. They use an SDcard to store the software and the data. OrthancPi runs on the Raspberry models B Pi 1, Pi 2 and Pi 3 with different WiFi adapters. The model Pi 3 is recommended for performance reasons (10 x the speed of model 1) and because a dual-band WiFi chip (Broadcom BCM43438) is integrated on the board. The same chip supports Bluetooth 4.0 to allow the wireless connection of a keyboard and mouse.

The following USB WiFi adapters have been tested for the other RaspberryPi models :

Raspberry Pi 1 model B in a transparent box with a TP-Link TL-WN725N WiFi USB stick

Software

To set up your Raspberry Pi, download a disk-image file from the RadioLogic website :

unzip it to a folder of your choice and copy the unzipped file orthancpi-1.4.18-<driver>-1.0.0.img to an SD card. The recommended procedure is to use the Win32DiskImager program on a Windows 7 (or later) computer.

Win32DiskImager

Writing the Raspberry Pi software to an SDcard

The archives contain also README, LICENCES and CHANGELOG files for your information.

Installation

Insert the SDcard in the Raspberry Pi, plug a WiFi stick to tan USB port (if you are not using the Pi 3 model) and connect a 5V - 2A powersupply to the micro USB power port. Thats all.

Raspberry Pi 2 model B in a black case with a Racksoy WiFi USB stick (external antenna)

If you scan now the available WiFi networks in your neighbourhood with a laptop, notebook, tablet or mobile phone, you should see a new network with the SSID (Service Set IDentifier) RadioLogic. The following figure shows the list of WiFi networks on an iPad.

iPad screenshot of the WiFi panel listing available networks

Connect to the RadioLogic network with the security key 123456789.

iPad screenshot of the WiFi panel showing the connection to the RadioLogic Wifi network

By clicking on the " i " icon you can check the IP adresses in the WiFi panel. Your DHCP attributed IP address will be in the range 192.168.123.3 to 192.168.123.99.

iPad screenshot of the WiFi panel showing the IP adresses provided by the RadioLogic Wifi network

Operation

Open now your web browser and enter the URL http://192.168.123.1:8042 to view the OrthancPi Explorer homepage. The next figure shows the result in an iPad Safari browser. The list of patient studies is empty.

iPad screenshot of the empty OrthancPi Explorer window

Click on the upload button to save your first DICOM files in Orthanc Explorer. Go to the official Orthanc website to look at step 2 of the beginners guide to Orthanc if you don't know how to do.

iPad screenshot of the OrthancPi upload window

After uploading the DICOM files related to some patient studies, the patient names will be displayed in the patient window.

iPad screenshot of the OrthancPi Explorer window listing the uploaded patient DICOM studies

Click on a patient name to view the details of the associated DICOM studies.

iPad screenshot of the OrthancPi Explorer window listing the details of the selected DICOM studies

To power off the Orthanc Pi, it is recommended to properly shut down the Raspberry Pi before simply un-plugging the power supply. If the power adapter is not well filtered, it can cause inductive spikes that could corrupt the SDcard, but never can kill the Raspberry Pi. Even if most Raspberry Pi users report that they never experienced SDcard corruption by un-plugging the power supply when the system is running, this is not good behavior. A simple solution is to use an secure shell (SSH client) to send the remote command sudo shutdown -h now to the OrthancPi to close all processes. There are numerous SSH clients integrated in the operating system (Mac OS X) or available as standalone applications, for example Putty for Windows and Linux or WebSSH Essential for iOS.

The SSH host IP is 192.168.123.1, the port number is 22, the userID is pi and the SSH password is orthancpi. The following figure shows an iPad screenshot showing the shutdown dialog in the WebSSH client app.

iPad screenshot of the WebSSH client

If you don't want to do this extra step, at least remove the micro USB cable from the Raspberry Pi before switching off the power supply to avoid the inductive spikes.

Features

OrthancPi is set up as follows :

Configuration

If you want to change the configuration of OrthancPi, you can use the secure shell presented above. A more comfortable way is to use a graphical user interface (GUI) by accessing the Raspberry Pi desktop with a VNC client on a remote laptop, notebook, tablet or mobile phone to manage the headless OrthancPi.

The following VNC clients have been tested :

Another method is to connect a keyboard and a mouse to the USB ports (or via Bluetooth in the case of Raspberry Pi 3 model B) and a monitor to the HDMI port of your Raspberry Pi. In all cases you should see the following Raspberry Pi desktop.

Screenshot of the Raspberry Pi desktop with open submenus

To change the Raspberry Pi configuration, got to the menu Preferences - Raspberry Pi Configuration

Screenshot of the Raspberry Pi configuration panel

If you use an SDcard with a size greater than 8GB, you must expand the filesystem to free the additional space

To change the Orthanc configuration, select the configuration.json file in the folder /../.. with the File editor and open it with the Text Editor (menu Accessories -> Text Editor). The default configuration file is available at the Orthanc website.

Screenshot of the Raspberry Pi Text Editor to modify the Orthanc server configuration.json file

Do your modifications, save the file and reboot OrthancPi (menu Shutdown -> Reboot). If you need additional information about the configuration parameters, go to the official Orthanc website and look at step 3 of the beginners guide to Orthanc.

By the way you can also power-off OrthancPi with the Shutdown menu in the Raspberry Pi desktop (menu Shutdown -> Reboot).

Timekeeping

The Raspberry Pi doesn't have a real-time clock and the date is set to January 1, 1970 (Unix time) at each start of OrthancPi. This is not a problem because there are no critical timestamps used in the application. If you want to use the correct date and time, you can set it inside the terminal (SSH or VNC) with the command sudo date -s "Day Month Date hh:mm:ss UTC Year". A simpler way is to connect OrthancPi with an Ethernet cable to an Internet router during a short time to synchronize it automatically with an NTP server.

Development

If you want to know more about the development and the technical details of OrthancPi, you are welcome to visit the following webpages :

Licences

OrthancPi is ruled by the following licences :

Raspberry Pi is a trademark of the Raspberry Pi Foundation.