Nobel Prize for MRI, and the minispec role in R&D of Contrast Agents for MRI

For their "discoveries of imaging with magnetic resonance", the Nobel Prize 2003 for Physiology and Medicine was awarded to Profs. Lauterbur and Mansfield. Clearly, Magnetic Resonance Imaging (MRI) has revolutionized the medical field and has turned into one of the most prominent and powerful diagnosis tools today. It was Lauterbur in 1978 who originally proposed the idea of using so-called contrast agents (also called contrast medium) to enhance contrast in the MRI images. Nowadays, pharmaceutical companies offer quite a selection of contrast agents with brands like Magnetvist®, Omniscan_^®, ProHance^®, MultiHance^®, Feridex^®, Resovist^®, Teslascan^®, OptiMARK^® and GastroMARK^®. Contrast agents help to identify pathogenic regions for identification of tumors in organs (spleen, renal, pancreas, liver) or in so-called Magnetic Resonance Angiography (MRA).

Bruker Optics' minispec mq-series of NMR bench-top instruments play a key role in characterizing and validating the properties of contrast agents. The task is to elucidate their influence on the NMR spin-lattice and spin-spin relaxation times (T₁ and T₂ , respectively) of the nuclear spins (predominately proton nuclei from e.g. water molecules) responsible for the MR image. A contrast agent will always increase the relaxation rates, 1/T₁ and 1/T₂, which results in a positive and negative contrast enhancement, respectively. Clinical MRI systems are certainly capable of the measurements, but are not the most efficient instruments for this task. The minispec provides the perfect solution, since it’s able to match the magnetic field strength of Clinical MRI systems (e.g. 0.5 T, 1 T and 1.5 T), at a fraction of the cost and space requirements.

Bruker Optics is the only vendor of 60 MHz and 40 MHz TD-NMR bench-top systems dedicated to contrast agent research. With Bruker’s range of magnet systems available between 6 MHz and 60 MHz and further accessories like sample temperature control systems, full characterization is possible of the contrast agent of interest.