Comparison of MR spectroscopy and MR imaging with contrast agent in children with cerebral astrocytomas.

We studied 33 patients with astrocytomas of different grades (68 examinations) by magnetic resonance imaging (MRI) and proton MR spectroscopy ((1)H-MRS). We found that in 80% of the spectra, the presence of signals in the area of 0.8-1.5 ppm, assigned to lipids/lactate in (1)H-MR spectra, correlated with signal enhancement after Gd-DTPA administration. We suggest that visibility of lipid/lactate signals could be due to blood-brain barrier damage, which is characterized by contrast agent enhancement.