Longitudinal MR spectroscopic imaging of pediatric diffuse pontine tumors to assess tumor aggression and progression.

Two pediatric patients with diffuse pontine tumors underwent MR spectroscopic imaging pre- and postradiation. Choline/creatine (Cho/Cr) and Cho/N-acetylaspartate (NAA) ratios were elevated before treatment, with no MR imaging contrast enhancement. These ratios were further elevated at 2 posttreatment follow-up studies, despite signs of excellent clinical improvement at initial follow-up. This study suggests that MR spectroscopic imaging is more specific in assessing the aggressiveness of diffuse pontine tumors than conventional MR imaging and can serve as a valuable tool in early prognostication.