Comparison of Magnetic Resonance Spectroscopic Imaging and Single Voxel Magnetic Resonance Spectroscopy for Suspected Recurrent Brain Tumour or Radiation Necrosis

YL Chan, H Schlemmer, DKW Yeung, T Wilhelm, P Bachert

Hong Kong J Radiol 2001;4:259-63

Objective: To qualitatively and quantitatively compare spectra obtained on single voxel spectroscopy and magnetic resonance spectroscopic imaging in suspected recurrence of brain tumour or radiation necrosis.

Patients and Methods: Six patients with suspected recurrence of brain tumour or radiation necrosis were studied with single voxel spectroscopy and magnetic resonance spectroscopic imaging using the point-resolved spectroscopy technique, a repetition time of 1500 ms and an echo time of 135 ms.

Results: A high correlation in metabolite ratios obtained from single voxel spectroscopy and magnetic resonance spectroscopic imaging was seen. A tendency to obtain lower Choline/Nacetyl- aspartate ratios on magnetic resonance spectroscopic imaging compared with single voxel spectroscopy was noted.

Conclusion: The threshold established for the differentiation of recurrent tumour from necrosis using single voxel spectroscopy may need to be adjusted when magnetic resonance spectroscopic imaging is performed for the measurement of metabolite ratios.