3T 1H-MR Spectroscopy in Grading of Cerebral Gliomas: Comparison of Short and Intermediate Echo Time Sequences
J.-h. Kima,
K.-H. Changb,c,
D.G. Nab,
I.C. Songb,c,
B.J. Kwonb,
M.H. Hanb,c and
K. Kimc
a Department of Radiology, Seoul Municipal Boramae Hospital, Seoul, Korea
b Department of Radiology, Seoul National University Hospital, Seoul, Korea
c Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
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Fig 1. Box plots of the ratios of the metabolites at both TE sequences in the patients with cerebral gliomas. The horizontal thick line is the median, the upper and lower ends of the boxes are the 3rd and 1st quartiles, and the vertical lines show the full range of values in the data. The extremes and outliers were omitted.
A, Cho/Cr at short TE; B, Cho/NAA at short TE; C, LL/Cr at short TE; D, mIns/Cr at short TE; E, Cho/Cr at intermediate TE; F, Cho/NAA at intermediate TE; G, LL/Cr at intermediate TE; H, mIns/Cr at intermediate TE.
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Fig 2. A 35-year-old man with low-grade (grade II) astrocytoma.
A, Axial T2-weighted image reveals diffuse infiltrating glioma involving left basal ganglia and frontotemporal area with a square voxel (6.2 cm3).
B, 1H-MR spectrum obtained at short TE (2000/35) shows increased Cho/Cr ratio (1.9:1), increased Cho/NAA ratio (2.3:1) and increased lipid-lactate (LL)/Cr ratio (1.6:1).
C, 1H-MR spectrum obtained at intermediate TE (1500/144) shows more increased Cho/Cr ratio (2.4:1), more increased Cho/NAA ratio (4.9:1) and hardly discernible peak of lipid-lactate between 0.9 and 1.3 ppm (LL/Cr ratio: 0.3:1). The baseline of the spectrum is noisier than B.
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Fig 3. A 38-year-old man with anaplastic (grade III) oligodendroglioma.
A, Axial FLAIR image reveals a infiltrating tumor in the right parietal lobe with a square voxel (4.2 cm3).
B, 1H-MR spectrum obtained at short TE (2000/35) shows increased Cho/Cr ratio (2.4:1), increased Cho/NAA ratio (4.1:1), and increased lipid-lactate (LL)/Cr ratio (2.1:1).
C, 1H-MR spectrum obtained at intermediate TE (1500/144) shows more increased Cho/Cr ratio (2.9:1), more increased Cho/NAA ratio (5.7:1), and much smaller peaks of lipid-lactate at 1.3 ppm (LL/Cr: 0.8:1). The baseline of the spectrum is noisier than B.
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Fig 4. A 61-year-old man with glioblastoma (grade IV).
A, Axial FLAIR image reveals a large necrotic tumor in the right frontal lobe with a rectangular voxel (8.0 cm3).
B, 1H-MR spectrum obtained at short TE (2000/35) shows increased Cho/Cr ratio (1.5:1), increased Cho/NAA ratio (1.2:1), and markedly increased LL/Cr ratio (3.8:1) at 1.3 ppm.
C, 1H-MR spectrum obtained at intermediate TE (1500/144) shows more increased Cho/Cr ratio of (2.2:1), more increased Cho/NAA ratio (2.1:1), and a smaller inverted lactate peak with smaller lipid peaks at 1.2–1.4 and 0.9 ppm (LL/Cr: 0.9:1). The baseline of the spectrum is noisier than B.
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Fig 5. Graph shows 4 ROC curves of Cho/Cr and LL/Cr ratios at both TEs for differentiation of high-grade glioma from low-grade glioma. Az value (area under the ROC curve) is the highest in LL/Cr ratio at short TE and lowest in Cho/Cr ratio at intermediate TE. But there are no significant differences among all the Az values.
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