Detection of transgene expression using hyperpolarized 13C urea and diffusion-weighted magnetic resonance spectroscopy.
Patrick PS., Kettunen MI., Tee S-S., Rodrigues TB., Serrao E., Timm KN., McGuire S., Brindle KM.
PURPOSE: To assess the potential of a gene reporter system, based on a urea transporter (UTB) and hyperpolarized [(13) C]urea. METHODS: Mice were implanted subcutaneously with either unmodified control cells or otherwise identical cells expressing UTB. After injection of hyperpolarized [(13) C]urea, a spin echo sequence was used to measure urea concentration, T1 , and diffusion in control and UTB-expressing tissue. RESULTS: The apparent diffusion coefficient of hyperpolarized urea was 21% lower in tissue expressing UTB, in comparison with control tissue (P