Article Figures & Data
Figures
- Fig 1.
A, Intraclass agreement for the 2 readers who evaluated the MTRasym(3.5ppm) of the solid parts of tumors in 42 patients was excellent, with an intraclass correlation coefficient of 0.94 (95% CI, 0.89–0.96). B, Bland-Altman analysis of the difference in MTRasym(3.5ppm) by the 2 readers also showed excellent concordance. C, MTRasym(3.5ppm) values were higher for high-grade gliomas than for low-grade gliomas (P = .0016, Student t test). D, The correlation between MTRasym(3.5ppm) and tumor grade was moderate (Pearson r = 0.506; P = .0006). E, The correlation between the Ki-67 staining index and the APT MTRasym(3.5ppm) was also moderate (Pearson r = 0.502; P = .002).
- Fig 2.
Top row, left to right: Transverse T2-FLAIR MR image (left), postgadolinium T1-weighted MR image, APT image, and the location of MR spectroscopy voxel of a 45-year-old woman with diffuse astrocytoma (grade II). Bottom row, left to right: MRSI indicating peaks for choline (Cho), creatine (Cr) and N-acetylaspartate (NAA); Ki-67 immunohistochemical stain for the same patient. The MTRasym(3.5ppm) value for this patient was 2.83%; the choline peak was slightly increased and the NAA peak slightly decreased; and the Ki-67 labeling index was 5%.
- Fig 3.
Top row, left to right: T2 FSE MR image, postgadolinium T1-weighted MR image, APT image, and the location of MR spectroscopy voxel of a 46-year-old woman with anaplastic oligodendroma (grade III). Bottom row, left to right: MRSI indicating peaks for choline (Cho) and N-acetylaspartate (NAA), and Ki-67 immunohistochemical staining for the same patient. The MTRasym(3.5ppm) value for this patient was 4.39%; the choline peak was obviously increased and the NAA peak obviously decreased; and the Ki-67 labeling index was 30%.
- Fig 4.
The voxel-to-voxel correlational analyses of MTRasym(3.5ppm) with choline (Cho), N-acetylaspartate (NAA), and Cho/NAA ratio in patients with glioma. A, For all patients (regardless of glioma grade), MTRasym(3.5ppm) showed mildly positive correlations with Cho (r = 0.43, P = .009) and the Cho/NAA ratio (r = 0.42, P = .01) and a slightly stronger negative correlation with NAA (r = −0.45, P = .005). B, Subgroup analyses of low-grade gliomas revealed that MTRasym(3.5ppm) correlated with Cho (r = 0.442, P = .031), NAA (r = −0.474, P = .019), and the Cho/NAA ratio (r = 0.448, P = .028). C, Subgroup analyses of high-grade gliomas revealed a similar pattern of correlation, though the absolute values of the correlation coefficients were higher for the high-grade tumors (Cho: r = 0.547, P = .053; NAA: r = −0.644, P = .017; Cho/NAA: r = 0.583, P = .036).
Tables
Characteristics Value or No. of Patients (%) MTRasym(3.5ppm) vs Ki-67 MTRasym(3.5ppm) vs MR Spectroscopy Low-Grade Glioma (n = 28) High-Grade Glioma (n = 14) P Value Low-Grade Glioma (n = 23) High-Grade Glioma (n = 13) P Value Age, ya 44.00 ± 2.81 44.64 ± 3.70 .89 42.96 ± 3.04 43.31 ± 3.73 .94 Sex, no. (%) .82 .97 Male 19 (68) 9 (64) 14 (61) 8 (57) Female 9 (32) 5 (36) 9 (39) 5 (43) Tumor grade, no. (%)b II 28 (100) 0 23 (100) 0 III 0 6 (43) 0 6 (46) IV 0 8 (57) 0 7 (54) - Table 2:
Independent t test and receiver operating characteristic curve analysis of low-/high-grade glioma
MTRasym(3.5ppm) Low-Grade Gliomas (n = 28) High-Grade Gliomas (n = 14) P Value Area Under the Curvea Optimal Threshold (%) Sensitivity (%) Specificity (%) Reader 1 2.65% ± 0.20 3.74% ± 0.17 .001 .813 (.675, .95) 3.11 92.9 71.4 Reader 2 2.63% ± 0.18 3.47% ± 0.16 .004 .770 (.623, .918) 2.85 92.9 71.4 Mean MTRasym(3.5ppm) 2.64% ± 0.18 3.61% ± 0.155 .002 .791 (.650, .931) 2.93 92.9 71.4 Mean Ki-67 labeling index 4.98% ± 1.02 (n = 24) 24.15% ± 5.04 (n = 13) .003 .867 (.702, 1.00) 6.5 84.6 83.3 ↵a Data in parentheses are 95% CIs.
