Proton spectroscopic imaging: A tool for studying intracerebral tumor models in rat

Water‐suppressed 2D 1 H spectroscopic imaging was used with surface coils to study in vivo the cerebral metabolism changes in rat brain induced by a glial tumor growing in situ . To achieve slice selection without a chemical‐shift artifact, we exploited the depth pulse properties of a spin‐echo sequence. In order to give a spectral response which is independent of the position, the water suppression was achieved by using a spin‐locking excitation and a binomial refocusing pulse. Spectroscopic images were obtained with an in‐plane resolution of 1.1 × 1.1 mm and a slice thickness of roughly 3 mm. The growing of the tumor induced dramatic modifications in the proton spectra, including a nearly complete loss of N ‐acetyl aspartate, an increase of the 1.3‐ppm peak, an increase in choline, and a decrease in creatine. The results demonstrate the potential of spectroscopic imaging in the study of intracranial tumor models in rats. © 1991 Academic Press, Inc.