Clinical Application Of Multivoxel ~1H-MR Spectroscopy In Analyzing The Peritumoral Area Of Intracranial Tumors

PurposeTo study the multivoxel proton magnetic resonance spectroscopy(~1H-MRS) fingdings in peritumoral areas of intracranial tumors and to investigate the value of multivoxel ~1H-MRS in evaluating of peritumoral area of intracranial tumors.Method and Materials1.Research objectThirty-eight patients of intracranial tumor were recruited in this study with 15 gliomas,9 metastases(primary tumor:6 lung cancer,1 renal cancer,2 breast cancer) and 14 meningeomas.All patients were not receiving chemotherapy or radiotherapy, and there is no injury or surgery before examination.2.Instrument and methodAll examinations were performed on Philips 1.5T MR scanner with circularly polarized head coils.All patients underwent MR conventional imaging using spin echo sequence(T1WI:TR=128ms,TE=2.3ms;T2WI:TR= 3000ms,TE=80ms). Multivoxel proton MRS was performed orderly using Point-resolved spectroscopy(PRESS) sequence with TE of 135ms,TR of 1500ms,slice thickness of 10mm,phase encode of 20cm×20cm,FOV of 22～32cm and NEX of 1.Pre-scan completed shimming and water depression automatically,then we selected ROI according to the feature of the focal.Spectra of three voxels were taken from parenchyma of the tumors,peritumoral region and corresponding contra lateral normal appearing white matter,and these regions were evaluated in every patient.The areas of skeleton,brain ventricle,blood vessel,necrosis,bleeding area,gas and calcification were excluded from the voxels.Imaging time was about 320s.Post-processing was completed automatically with spectral analysis software.3.Statistics analysisMetabolite change of parenchyma,peritumoral region and contra lateral normal appearing white matte in the spectrum was measured.We applied one-way analysis of variance(ANOVA) to doing inter-class comparisons,and intra-class comparisons were used two-sample t-test.ResultIn multivoxel ~1H-MRS from the parenchyma of the meningeomas,gliomas and metastases,the ratios of NAA/Cr,Cho/Cr and NAA/Cho all changed significantly by comparing with that of normal control brain tissues(P<0.01).The ratios of NAA/Cr, Cho/Cr and NAA/Cho were changed significantly in the parenchyma among gliomas and meningeomas(P<0.01,P<0.01,P<0.05);the same variation was observed among meningeomas and metastases;but there was no significant difference among gliomas and metastases(P>0.05).The ratios of NAA/Cr,Cho/Cr and NAA/Cho were changed significantly in peritumoral region among gliomas and normal control brain tissues(P<0.05,P<0.01, P<0.01);but there was no significant difference in meningeoma and metastases(P>0.05).The ratios of NAA/Cr,Cho/Cr and NAA/Cho were changed significantly in peritumoral region among gliomas and meningeoma(P<0.01,P<0.05, P<0.01).The ratios of NAA/Cr,Cho/Cr and NAA/Cho were changed significantly in peritumoral region between gliomas and metastases(P<0.01,P<0.05,P<0.01),but there was no significant difference among meningeomas and metastases(P>0.05).ConclusionEvaluation of peritumoral region of intracranial tumors with multivoxel ~1H-MRS combining and routine MRI may be useful in the diagnosis,differentiation and deciding the border of intracranial tumors.