Molecular Probing and Imaging by Magnetic Resonance Spectroscopy: Possibilities for Imaging Gene Therapy

The aim of this symposium was expressed by Prof. M. Schwaiger and Prof. W. Semmler as follows: “… Gene therapy will demand more sensitive and more specific imaging modalites.” This and the challenging title of the symposium prompted us to reexamine the experience of in vivo magnetic resonance spectroscopy (MRS), particularly in humans. What have MRS and metabolite-specific imaging to offer in this arena? With one exception — the application of 31P MRS to a mouse made transgenic for creatine kinase (Koretsky et al. 1989)1 — we know of no direct attempt to monitor gene therapy with in vivo MRS. Nevertheless, a copious literature supports the view that MRS can successfully identify and assay the major products of gene expression, enzyme activities and metabolite concentrations, in living tissues (Ross and Michaelis 1994).