25-30 August 2019
Henry Ford Building
Europe/Berlin timezone

Rheology and 23Na Multiple Quantum Filtered (MQF) rheo-NMR and MRI of Bile Salt Micelles

27 Aug 2019, 17:15
25m
Lecture Hall D (Henry Ford Building)

Lecture Hall D

Henry Ford Building

Talk MRI developments and applications Instrumentation

Speaker

Dr Galina Pavlovskaya (University of Nottingham)

Description

Bile or gall is a dark green to yellowish brown fluid, produced by the liver of most vertebrates and aids the digestion of lipids in the small intestine. The composition of bile is mostly water (97%) however, it also contains small amount (0.7%) of bile salts, as well as fats and inorganic salt ions. Bile salts are complex molecules that tend to form micellar aggregates in solutions if their and/or salt concentration increases. This process affects rheology of the bile thus making its viscosity shear-dependent during flow in a bile duct. Pathological bile extracted from gallbladder and liver patients is non-Newtonian [1], and is hypothesized that the formation of micellar aggregates in the bile during flow through the duct contributes to this behaviour. This currently is being explored for potential clinical benefits for the use in 23Na whole body MRI. One of the principal components of human bile is taurodeoxycholic (TDC) acid that forms a sodium salt, NaTDC, in the excess of Na+ [2]. We studied temperature and shear effects on the micellar formation in 0.2M NaTDC /0.25M NaCl and in 0.2M NaTDC /0.5M NaCl systems using rheology and 23Na MQF rheo-NMR and MRI. Double quantum filtered magic angle (DQF MA) and triple quantum filtered (TQF) rheo-NMR [3-5] was performed at multiple shear rates and temperatures. The formation of shear-induced phase was clearly demonstrated by 23Na rheo-NMR and it was found that 23Na MQF rheo-NMR methods were able to detect and characterise the formation of the shear–induced phase more efficiently than bulk rheometry methods. 23Na MRI with MQF filters allowed to map zones where shear-induced phase was formed and to characterise molecular alignment in the gap. This demonstrates the potential of 23Na MQF MRI contrast for the in-vivo molecular mechanics for clinical benefits.

Primary authors

Dr Galina Pavlovskaya (University of Nottingham) Ms Alisha Hallwood (University of Nottingham) Mr Samuel Holmes (University of Nottingham) Prof. Thomas Meersmann (Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham) Dr Fioretta Asaro (University of Trieste)

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