Original Article
Copyright ©2013 Baishideng Publishing Group Co.
World J Radiol. Jan 28, 2013; 5(1): 5-16
Published online Jan 28, 2013. doi: 10.4329/wjr.v5.i1.5
Table 1 Magnetic resonance imaging parameters for each sequence used in this study
TR (ms)TE (ms)Flip angle (°)FOV (mm)MatrixResolution (mm)Slice thickness (mm)NoAReceiver bandwidth (Hz/pixel)Scan time (min)Slice orientation
T1-GRE6.62.3812230 × 230448 × 4480.513 × 0.5130.649131006:38Sagittal
T2-TSE tra12 0005790178 × 220624 × 7680.286 × 0.2862110004:37Axial
FLASH2D-T2Star tra5041730176 × 176704 × 7040.25 × 0.25214005:55Axial
FLASH2D-T2Star cor5041730176 × 176704 × 7040.25 × 0.25214005:55Coronal
FLASH2D-T2Star sag5041730176 × 176704 × 7040.25 × 0.25214006:49Sagittal
SWI cor13.3215149 × 199288 × 3840.52 × 0.520.5212013:21Coronal
T1-GRE: T1-weighted gradient-echo; T2-TSE: T2-turbo spin-echo; SWI: Susceptibility-weighted imaging; TR: Time of repetition; TE: Time of echo; FOV: Field of view; NoA: Numbers of averages; tra: Transversal; cor: Coronal; sag: Sagittal.
Table 2 Image quality in terms of artifacts at the level of the zona incerta
SequenceConsensus of two readers
T1-GRE tra5.00 ± 0.00
T1-GRE-cor5.00 ± 0.00
T1-GRE sag5.00 ± 0.00
T2-TSE tra4.78 ± 0.43
FLASH2D-T2Star tra3.94 ± 0.54
FLASH2D-T2Star cor3.94 ± 0.73
FLASH2D-T2Star sag3.94 ± 0.64
SWI tra2.92 ± 0.62
SWI cor2.79 ± 0.43
SWI sag3.00 ± 0.39
SWI-MIP tra2.57 ± 0.51
SWI-MIP cor2.64 ± 0.50
SWI-MIP sag2.57 ± 0.51
Image quality in terms of artifacts at the level of the zona incerta was evaluated for each sequence by consensus of two radiologists using a 6-scale grading system (5: no artifacts; 4: minimal artifacts; 3: moderate artifacts; 2: significant artifacts; 1: massive artifacts; 0: no image/not evaluable). T1-GRE: T1-weighted gradient-echo; T2-TSE: T2-turbo spin-echo; SWI: Susceptibility-weighted imaging; MIP: Minimum intensity projections transversal; tra: Transversal; cor: Coronal; sag: Sagittal.
Table 3 Average signal-to-noise ratios and contrast-to-noise-ratios of the zona incerta at 7.0 T magnetic resonance imaging
SNR
CNR
SequenceNon-adjustedAdjustedNon-adjustedAdjusted
T1-GRE tra46.30 ± 9.481271.09 ± 55.5116.14 ± 2.0135.96 ± 11.79
T1-GRE cor46.33 ± 8.881271.23 ± 55.9816.47 ± 2.1237.87 ± 12.42
T1-GRE sag45.75 ± 9.441267.84 ± 55.2417.05 ± 2.6741.30 ± 15.63
T2-TSE tra17.18 ± 6.51105.03 ± 39.8119.40 ± 4.20121.69 ± 25.68
FLASH2D-T2Star tra40.28 ± 16.321322.23 ± 130.60144.17 ± 12.901353.33 ± 103.191
FLASH2D-T2Star cor53.06 ± 11.091424.48 ± 88.76131.76 ± 8.281254.08 ± 66.241
FLASH2D-T2Star sag57.84 ± 10.311462.75 ± 88.76133.92 ± 11.761271.39 ± 94.051
SWI tra18.94 ± 6.98140.05 ± 51.6210.99 ± 4.9481.26 ± 36.57
SWI cor19.20 ± 8.23141.98 ± 60.8810.40 ± 4.3576.95 ± 32.15
SWI sag18.80 ± 7.52139.05 ± 55.6511.07 ± 4.3081.90 ± 31.85
SWI-MIP tra358.89 ± 152.811331.81 ± 141.281275.70 ± 127.521254.90 ± 117.901
SWI-MIP cor354.00 ± 116.371327.29 ± 107.591275.86 ± 121.591255.05 ± 112.411
SWI-MIP sag312.66 ± 8.441289.07 ± 75.291261.28 ± 121.881241.57 ± 119.151
1To further compare differences of the directly computed signal-to-noise ratios (SNR) and contrast-to-noise-ratios (CNR) values (non-adjusted), the obtained results for each sequence were adjusted to a voxel of 1 mm3 x 1 mm3 x 1 mm3, by applying an associated conversion factor. Sequences with statistically significant superior SNR and CNR values compared to T2-TSE imaging (paired t-test) are denoted. T1-GRE: T1-weighted gradient-echo; T2-TSE: T2-turbo spin-echo; SWI: Susceptibility-weighted imaging; MIP: Minimum intensity projections transversal; tra: Transversal; cor: Coronal; sag: Sagittal.