Ashok Panigrahy MD, Presenter: Nothing to Disclose

Marvin D Nelson MD, Abstract Co-Author: Nothing to Disclose

Mark D Krieger, Abstract Co-Author: Nothing to Disclose

Gordon J McComb, Abstract Co-Author: Nothing to Disclose

Floyd H Gilles, Abstract Co-Author: Nothing to Disclose

Stefan Bluml PhD, Abstract Co-Author: Nothing to Disclose

To determine if short echo time proton MR spectroscopy with absolute quantitation improves the preoperative diagnosis of pediatric brain tumors

Methods: We conducted quantitative single voxel 1H MRS in 42 children with newly diagnosed, untreated brain tumors to measure on an absolute scale markers of tumor metabolism using a 1.5 T magnet. The water signal was used as internal reference and peak intensities were corrected for the amount of tissue within the region of interest. Spectra were acquired with a short echo time (TE = 35ms) to allow detection of not only N-acetyl-aspartate (NAA), creatine (Cr), and choline (Cho), but also fast decaying components of the 1H spectrum such as myo-inositol (mI) and taurine (Tau). The LCModel software was used for objective fully automated processing.

Results:Generally, tumor spectra exhibited features consistent with earlier publications such as elevated Cho/Cr, reduced NAA/Cr, elevated lactate/Cr, and the presence of lipids. Potentially important findings beyond these observation were related to the absolute measurement of taurine, myo-inositol and creatine. Taurine was present and prominent in all primitive neuroectodermal tumors (N=13). Taurine was significantly higher in PNET tumor regions than in other tumors (6.1 ± 2.2 vs. 1.5 ± 1.4, p<0.0001). Choroid plexus papilloma spectra (6 spectra in three patients) were characterized by a strikingly high myo-inositol concentration and low Cr concentrations. Myo-inositol was significantly elevated in choroid plexus papillomas distinguishing these tumors from other tumors (20.7 ± 3.8 vs. 11.4 ± 7.4, p<0.0001). Absolute creatine levels were significantly reduced in pilocytic astrocytoma regions (1.0 ± 0.8 vs. 4.5 ± 1.4, p<0.0001), distinguishing them from astrocytomas and other tumors

Quantitative single voxel proton MRS with a short echo time improves the presurgical diagnosis of pediatric brain tumors , particularly in regards to measuring absolute metabolite concentration of taurine, myo-inositol , and creatine. Supported by grant 4R33CA096032-03 (National Cancer Institute)

Panigrahy, A, Nelson, M, Krieger, M, McComb, G, Gilles, F, Bluml, S, Absolute Quantitative 1H MR Spectroscopy with Short Echo Time Improves Preoperative Diagnosis of Pediatric Brain Tumors.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4415972.html