MRI machines are difficult to access for research and training purposes. The purchase and maintenance of MRI devices is extremely expensive, which is why universities and university hospitals only have a limited number of devices. The existing devices are continuously occupied by patient care and are only available for research and training purposes in very rare exceptional cases. On the other hand, the open-source Tabletop MRI developed by the Otto-von-Guericke University employees and students is inexpensive to purchase and requires no maintenance. This benchtop device allows for the measurement of test-tube-sized samples with the physics of a clinical MRI machine.

The OCRA Tabletop MRI was born from the idea of the Martinos Center in Boston (Harvard Medical School, MIT) [1] and the OCRA (Open-source Console for Real-time Acquisition) [2] project initiated by Thomas Witzel. Through a cooperation, a fully functional mini MRT system was developed at the STIMULATE research campus of the OvGU which combines both projects. The first prototype could be built after a development time of only 2 years thanks to the extensive equipment of our ego.-Incubator FLEXtronic electronics makerspace [3].

The tabletop system is identical in construction to a modern clinical MRT, which is used to examine patients. The core element is a neodymium permanent magnet in a special iron yoke construction, which provides a homogeneous 0.26T magnetic field. The complete RF electronics [4] and gradient coils are located as rack modules magnet yoke. The aluminium housing protects against external interference and enables safe working. RF and gradient electronics are controlled using the OCRA console, based on a Red Pitaya microcontroller and a four 18-bit DACs board, called OCRA1 [5], for generating the analog gradient signals. A 4-channel 600 Watt gradient amplifier [6] is used to amplify the gradient signals. The control is taken over by the OCRA software with an intuitive and customizable graphical user interface based on PyQT and Python. With the OCRA Tabletop MRT, spectroscopy, relaxometry and MR imaging can be performed on test tube-sized samples with a diameter of up to 15 millimeters.

The system creates an open source test environment for commercially available MRI components and enables cost-effective teaching for students on a real, fully digital MRI. In addition, there is the potential to carry out chemical analyzes for various purposes.

Acknowledgements

No acknowledgement found.