Biomedical NMR Spectroscopy and Imaging

An application of NMR spectroscopy for biomedical area is most clearly embodied as MRI, a diagnostic imaging tool, where the information obtained by NMR is presented in a visualized image. Signal intensity, more often, T ₁ and T ₂, of H₂O signal in ¹H NMR is utilized for the construction of image in 2-dimensional space, as the so-called slice. To acquire data along the direction of chemical shift, it requires further elaborated time in addition to the mea- surement of MRI data. This is the major reason why the MR spectroscopic imaging is not widely accepted in clin- ical situation. Furthermore, MR images are sometimes obscured with overlapping images generated by separated signals, so-called “chemical shift artifact.” In order to circumvent this bias, it is necessary to employ a technique to enhance the sensitivity of the detection of NMR signal and also to shorten the measurement time by a fast scan technique in MRI. In this section a unique, however, an important area of NMR application, which will lead to the future NMR technology, the so called, molecular imaging (MI) in the near future is discussed.