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Relaxation properties of a dual‐labeled probe for MRI and neutron capture therapy
Author(s) -
Tatham Alicia T.,
Nakamura H.,
Wiener E.C.,
Yamamoto Y.
Publication year - 1999
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/(sici)1522-2594(199907)42:1<32::aid-mrm6>3.0.co;2-5
Subject(s) - gadolinium , neutron capture , relaxation (psychology) , boron , rotational correlation time , chemistry , carborane , nuclear magnetic resonance , albumin , dispersion (optics) , proton , neutron , analytical chemistry (journal) , radiochemistry , chromatography , molecule , medicine , stereochemistry , organic chemistry , nuclear physics , biochemistry , physics , optics
Pharmaceutical agents labeled with both boron and gadolinium have potential applications in both boron neutron capture therapy (NCT) and magnetic resonance imaging. Pre‐ and post‐injection T 1 maps provide a method for the indirect measurement of the gadolinium and boron concentrations that can then be used in NCT treatment planning. This requires an understanding of the relaxation properties of the agent. In this paper we present an analysis of the relaxation properties of a dual boron and gadolinium agent, Gd (III)‐diethylenetriaminepentaacetate‐carborane [Gd (III)‐DTPA‐carborane], in vitro in the presence and absence of serum albumin. The nuclear magnetic relaxation dispersion profile of solutions containing albumin obtained with a field cycling relaxometer exhibit a peak in the frequency range from 8 to 50 MHz. This indicates a long rotational correlation time relative to the solution without serum albumin. Results from other experiments indicate that this peak results from the binding of Gd (III)‐DTPA‐carborane derivative to serum albumin. Temperature studies indicate that the water proton relaxation efficiency of bound agent is limited by the water residence time as the relaxivity increases from 19 ± 1 to 32.6 ± 0.8 (sec · mM) ‐1 when the temperature is increased from 5 to 35°C. Magn Reson Med 42:32–36, 1999. © 1999 Wiley‐Liss, Inc.