A machine prototype for FFC MRI and localized NMR relaxometry

GABRIELA DOMINGUEZ; AGUSTÍN ROMERO; ALEXIS BERTE; GONZALO RODRIGUEZ; ESTEBAN ANOARDO

Mikolajki

Conferencia; 10th Conference on FFC NMR Relaxometry; 2017

Univercity of Warmia and Mazury

We present a fast field-cycling MRI relaxometer developed in our Lab [1]. MRI capabilities ina field-cycling apparatus enables localized relaxometry studies in heterogeneous samples,and the possibility to produce MR images weighted at low magnetic fields (a few mT orlower) in samples showing combined high and low T1 dispersions and short relaxation timesat low-fields (a few milliseconds). The designed instrument is of potential use in smallsanimals, and particularly suitable for the design of relaxation-enhancing contrasts agentsand magnetic localized hyperthermia, within other non-biomedical applications. The systemis based on a FFC magnet with variable geometry of own design [2]. Gradient coils wereoptimized for the restricted available space within the FFC magnet using simplemathematical tools, showing an excellent performance even compared to results obtainedusing established methods [3]. Gradient pulses are amplified using Techron 8607 amplifierswith additional electronic security. Specific probes were designed for a sample volume of35cm3. The magnet is driven using a modified Stelar Spin Master power supply, while the RFand gradient pulses are generated using a SpinCore Radio Processor-G board. Transmitterand receiver functions are operated from a Stelar Spinmaster console. Special digital filterswere implemented to boost-up image quality. A versatile state-of-the-art digital system(DIXITAL) is under development to replace the SpinCore board and the Stelar console, and athe design of a special power supply is in progress. We will show general details of thehardware and some preliminary results.