Article Figures & Data
Figures
- Fig 1.
Typical output of the SyMRI software: A, Synthetic T2-weighted image of a section of the brain of one of the patients. This synthetic image was generated from the R1, R2, and PD maps in combination with a TE/TR = 100/4500 ms. B, PD map on a scale of 0%–100%, in which 100% corresponds to pure water at 37°C. C, Automatically generated intracranial mask (ICV). D, Automatically generated CSF partial volume map on a scale of 0%–100%. The brain parenchymal volume is calculated as the sum of all ICV minus the sum of all CSF. The brain parenchymal fraction is calculated as BPV/ICV.
- Fig 2.
Brain parenchymal fraction of all subjects at all times. The 4 time points of each individual are connected with a line. The gray line indicates the linear regression slope.
- Fig 3.
Relative difference of intracranial volume (A), brain parenchymal volume (B), and brain parenchymal fraction (C) of all subjects as a function of time after inclusion of the study. D, The relative difference in BPF of all subjects is shown again as a function of time after inclusion is shown, but corrected for PD. This figure is comparable with C, albeit with less variation in the data. The gray lines indicate the linear regression slopes.
- Fig 4.
Observed mean R1 (A), mean R2 (B), and mean proton density (C) of the entire brain (triangles), gray matter (dots), and white matter (squares) as a function of age for all subjects.
Tables
- Table 1:
Patient diagnoses, relapse status, and treatment status at baseline and at follow-up MRI
Clinical and Laboratory Data Baseline 1 Year 2 Years 4 Years Diagnosis (CIS/RRMS/PPMS) 16/19/3 10/25/3 7/28/3 5/30/3 Relapse within last 2 mo before MRI (yes/no) 13/25 3/35 1/37 2/36 Treatmenta (No. of subjects) No DMT 38 17 18 18 Interferon-β 1b 0 16 12 5 Interferon-β 1a 0 1 1 1 Dimethyl fumarate 0 0 0 2 Fingolimod 0 1 1 3 Natalizumab 0 3 6 9 Note:—CIS indicates clinically isolated syndrome; RRMS, relapsing-remitting MS; PPMS, primary-progressive MS; DMT, disease modifying therapy.
↵a In addition, 1 patient received temporary relapse-controlling corticosteroid treatment within 2 months prior to baseline.
- Table 2:
Observed correlation slopes SR1, SR2, and SPD of the relative change in BPF as a function of relative change in R1, R2, and PD of the entire brain and gray and white matter
Brain Gray Matter White Matter SR1 value (%/%) −0.198 −0.133 −0.364 SR1 (95% CI) (%/%) (−0.242 to −0.152) (−0.222 to −0.044) (−0.4376 to −0.290) SR1 P value <.001 .02 <.001 SR2 value (%/%) 0.156 0.303 0.090 SR2 (95% CI) (%/%) (0.039–0.274) (0.228–0.378) (−0.016–0.196) SR2 P value .04 <.001 .2 SPD value (%/%) 0.488 .396 .655 SPD (95% CI) (%/%) (0.382–0.594) (0.146–0.645) (0.535–0.776) SPD P value <.001 .003 <.001 - Table 3:
Observed mean values and slopes of R1, R2, and PD of the entire brain and gray and white matter as a function of subject age
Brain Gray Matter White Matter R1 intercept (s−1) 1.151 0.897 1.495 R1 slope (s−1/y) 0.00054 0.00015 −0.00063 R1 slope (95% CI) (s−1/y) (0.0002–0.0010) (−0.0001–0.0002) (−0.0011–0.0002) R1 slope P value .04 .4 .2 R2 intercept (s−1) 11.44 10.57 12.62 R2 slope (s−1/y) −0.0001 −0.0018 −0.0056 R2 slope (95% CI) (s−1/y) (−0.004–0.002) (−0.004–0.001) (−0.009–0.000) R2 slope P value .5 .3 .05 PD intercept (%) 75.65 82.44 67.44 PD slope (%/y) −0.026 −0.019 0.009 PD slope (95% CI) (%/y) (−0.039–0.013) (−0.025 to −0.013) (−0.003–0.020) PD slope P value <.001 <.001 .2 Note:—y indicates year.
- Table 4:
Observed SDs of the relative changes in BPF at baseline and at 1, 2, and 4 years after inclusiona
Baseline (%) 1 Year (%) 2 Years (%) 4 Years (%) Uncorrected 0.508 0.526 0.454 0.687 Corr. for brain R1 0.362 (28.8%) 0.506 (3.7%) 0.327 (28.1%) 0.599 (12.8%) Corr. for brain PD 0.385 (24.2%) 0.500 (4.9%) 0.303 (33.3%) 0.567 (17.4%) Corr. for GM R2 0.506 (0.4%) 0.465 (11.5%) 0.297 (34.7%) 0.561 (16.2%) Corr. for GM PD 0.481 (5.3%) 0.539 (−2.4%) 0.398 (12.5%) 0.673 (1.9%) Corr. for WM R1 0.343 (32.6%) 0.463 (12.0%) 0.349 (23.2%) 0.568 (17.3%) Corr. for WM PD 0.399 (21.5%) 0.474 (9.8%) 0.326 (28.3%) 0.492 (28.3%) Note:—Corr. indicates corrected.
↵a When BPF is corrected for average R1, R2, or PD values for brain, GM, or WM, the SDs of the observations decrease. The percentage reduction is given in parentheses. Corrections were only included when a high significance was found in Table 2.
