Browse Technologies

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Hyperpolarization of nuclear spin ensembles has increased NMR sensitivity to a level that is now enabling detection of metabolism in biological tissue on a time-scale of seconds. The present invention is a pulse sequence that efficiently transforms parahydrogen spin order into heteronuclear magnetization. This was achieved via a single streamlined sequence without recursive application, by finding sequential analytic solutions to the density matrix evolution for each of four independent intervals that collectively flank two proton inversions and one heteronuclear excitation. The name hyper-SHIELDED (Singlet to Heteronuclei by Interative Evolution Locks Dramatic Enhancement for Delivery) reflects the sequence's protective effect on PHIP hyperpolarization.

Vanderbilt researchers have developed a new method for using contrast enhanced MRI to non-invasively map and quantify cell size on a voxel-by-voxel basis. Using this approach, it is possible to monitor and detect diseases or treatments that alter the distribution of cell sizes such as cancer, muscular dystrophy, hepatocellular hypertrophy, and hypertrophic cardiomyopathy.

Vanderbilt researchers have developed a novel MRI-based method for fast, robust, and accurate imaging of biological tissue by selecting a specific cell size range (such as tumors) without the need for a contrast agent. One exciting application of this method is imaging brain metastases (BM) that are difficult to differentiate from other brain abnormalities such as radionecrosis when using existing approaches.

Methods of hyperpolarization based on parahydrogen have been expanding recently from the early applications in hydrogenation chemistry to biomedical imaging where they are expected to yield similar information as the competing technology, dynamic nuclear polarization, (DNP). These hyperpolarization experiments have already enabled the measurement of metabolism in vivo at temporal resolutions of seconds. When infused into organisms harboring tumor cells, molecules such as pyruvate and lactate have been shown to be sufficiently long-lived to infiltrate cellular metabolic cycles and be converted at different rates in cancer versus normal tissue. DNP has been used most frequently in these early studies, owing to commercial availability and the flexibility to polarize small molecules such as pyruvate and lactate. Techniques based on chemical addition or exchange of parahydrogen have also shown promise for generating metabolic contrast in vivo at similar levels of signal enhancement and at lower costs.