University of Oulu

Christian Gösweiner, Perttu Lantto, Roland Fischer, Carina Sampl, Evrim Umut, Per-Olof Westlund, Danuta Kruk, Markus Bödenler, Stefan Spirk, Andreas Petrovič, and Hermann Scharfetter Phys. Rev. X 8, 021076.

Tuning nuclear quadrupole resonance : a novel approach for the design of frequency-selective MRI contrast agents

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Author: Gösweiner, Christian1; Lantto, Perttu2; Fischer, Roland3;
Organizations: 1Institute of Medical Engineering, Graz University of Technology, 8010 Graz, Austria
2NMR Research Unit, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
3Institute of Inorganic Chemistry, Graz University of Technology, 8010 Graz, Austria
4Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland
5Departement of Chemistry, Umeå University, 901 87 Umeå, Sweden
64Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland
7Institute for Chemistry and Technology of Materials, Graz University of Technology, 8010 Graz, Austria
8Institute of Paper, Pulp and Fibre Technology, Graz University of Technology, 8010 Graz, Austria
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 2 MB)
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Language: English
Published: American Physical Society, 2018
Publish Date: 2018-06-29


The interaction between water protons and suitable quadrupolar nuclei (QN) can lead to quadrupole relaxation enhancement (QRE) of proton spins, provided the resonance condition between both spin transitions is fulfilled. This effect could be utilized as a frequency selective mechanism in novel, responsive T shortening contrast agents (CAs) for magnetic resonance imaging (MRI). In particular, the proposed contrast mechanism depends on the applied external flux density—a property that can be exploited by special field-cycling MRI scanners. For the design of efficient CA molecules, exhibiting narrow and pronounced peaks in the proton T relaxation dispersion, the nuclear quadrupole resonance (NQR) properties, as well as the spin dynamics of the system QN−¹H, have to be well understood and characterized for the compounds in question. In particular, the energy-level structure of the QN is a central determinant for the static flux densities at which the contrast enhancement appears. The energy levels depend both on the QN and the electronic environment, i.e., the chemical bonding structure in the CA molecule. In this work, the NQR properties of a family of promising organometallic compounds containing ²⁰⁹Bi as QN have been characterized. Important factors like temperature, chemical structure, and chemical environment have been considered by NQR spectroscopy and ab initio quantum chemistry calculations. The investigated Bi-aryl compounds turned out to fulfill several crucial requirements: NQR transition frequency range applicable to clinical 1.5- and 3 T MRI systems, low temperature dependency, low toxicity, and tunability in frequency by chemical modification.

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Series: Physical review. X
ISSN: 2160-3308
ISSN-E: 2160-3308
ISSN-L: 2160-3308
Volume: 8
Article number: 021076
DOI: 10.1103/PhysRevX.8.021076
Type of Publication: A1 Journal article – refereed
Field of Science: 114 Physical sciences
116 Chemical sciences
Funding: The authors wish to acknowledge the European Commission in the frame of the H2020 Programs CONQUER (FET-open) under Grant No. 665172, and EURELAX (COST-STSM) under Grant No. 15209-37391 and the Academy of Finland (Project No. 285666) for financial support.
Academy of Finland Grant Number: 285666
Detailed Information: 285666 (Academy of Finland Funding decision)
Copyright information: Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.