Article Figures & Data
Figures
- Fig 1.
Standardized ISODATA image reveals a right hemispheric ischemic lesion. The ischemic lesion is inhomogeneous and contains two different tissue signatures (4 and 5). The MR imaging study was performed 12 hours after symptom onset.
- Fig 2.
Calculation of tissue recovery based on acute phase ISODATA image and outcome-phase T2-weighted image.
A, Acute phase ISODATA image.
B, Acute phase diffusion-weighted image.
C, Outcome (3-month) phase T2-weighted image.
Tables
MR Imaging Parameter (No. of Tissues) Total n = 200 (%) rt-PA Treatment n = 49 (%) No rt-PA Treatment n = 151 (%) P Value* Signature number <3 43 (21.5) 10 (4.5) 33 (17.0) 4 71 (35.5) 21 (10.5) 50 (25.0) 5 57 (28.5) 10 (5) 47 (23.5) ≥6 29 (14.5) 8 (4) 21 (13.82) 0.49 rADC Median 0.78 0.79 0.77 0.91 (2nd, 3rd QL) (0.66, 0.91) (0.68, 0.90) (0.65, 0.92) rT2 Median 18 1.19 1.17 0.20 (2nd, 3rd QL) (1.09, 1.33) (1.10, 1.34) (1.10, 1.25) ADC Median 609.8 μm2/s 620.4 μm2/s 608.3 μm2/s 0.79 (2nd, 3rd QL) (513.8, 694.6) (548.5, 675.4) (497.1, 707.5) T2 Median 85.1 81.0 86.2 0.04 (2nd, 3rd QL) (78.0, 97.6) (76.7, 89.3) (78.1, 98.9) Stroke onset to MR imaging time Median 9.4 7.9 9.8 0.24 (2nd, 3rd QL) (7.8, 11.8) (5.6, 12.0) (8.8, 11.0) Note.—rt-PA indicates recombinant tissue plasminogen activator; rADC, relative apparent diffusion coefficient; rT2, relative T2; QL, quartile; ADC, apparent diffusion coefficient.
* Comparison between rt-PA-treated and non-rt-PA-treated groups using the generalized estimation equations approach considering the correlation among sections and among tissues.
- TABLE 2:
Association of Acute Phase MR Imaging Parameters with Outcome of ≥20% Recovery at 3 Months: Individual Parameter Effect
Variable Odds Ratio (95% CI)* P Value* Odds Ratio (95% CI)† P Value† Tissue signature – – 2.40 (0.98, 5.89) 0.06 rADC 36.41 (4.92, 269.19) <0.01 0.09 (0.002, 4.07) 0.18 rT2 0.06 (0.01, 0.28) <0.01 0.93 (0.05, 18.35) 0.94 ADC 1.005 (1.003, 1.007) <0.01 1.001 (0.99, 1.006) 0.86 T2 0.99 (0.97, 1.011) 0.29 0.97 (0.93, 1.02) 0.24 Stroke onset to MR imaging time 0.97 (0.92, 1.01) 0.13 0.97 (0.92, 1.12) 0.75 rt-PA treatment 1.51 (0.61, 3.75) 0.37 – – Note.—CI indicates confidence interval; –, invalid test; rADC, relative apparent diffusion coefficient; rT2, relative T2, ADC, apparent diffusion coefficient; rt-PA, recombinant tissue plasminogen activator.
* Testing for individual MR image parameter effect or the interaction of MR imaging parameter by rt-PA treatment effect adjusting for acute phase lesion size volume and correlation among sections and among tissues.
† Testing the rt-PA by MR imaging parameter interaction.
- TABLE 3:
Effects of Tissue Signature Value, Apparent Diffusion Coefficient Value, and Recombinant Tissue Plasminogen Activator Treatment on Outcome of ≥20% Recovery of Ischemic Lesion at 3 Months: Demonstration of Three-Way Interaction among These Individual Factors Regarding Eventual Recovery in Comparison with the Reference Groups
Recovery # (N) % Odds Ratio (95% CI) Odds Ratio (95% CI) rt-PA Signature rADC (Med) No >4 <0.79 11 (45) 0.24 MLTR group 0.12 (0.03, 0.47)* ≥0.79 14 (23) 0.61 4.27 (1.52, 11.99)* 0.51 (0.11, 2.3) ≤4 <0.79 22 (33) 0.67 6.75 (2.6, 17.51)* 0.81 (0.2, 3.2) ≥0.79 40 (50) 0.80 12.67 (4.4, 36.44)* 1.51 (0.35, 6.45) Yes >4 <0.79 7 (10) 0.70 6.82 (1.84, 25.31)* 0.81 (0.23, 2.86) ≥0.79 6 (8) 0.75 5.5 (0.87, 34.55) 0.66 (0.09, 5.02) ≤4 <0.79 7 (12) 0.58 5.65 (1.56, 20.54)* 0.68 (0.23, 1.97) ≥0.79 14 (19) 0.74 8.37 (2.12, 33.02)* LLTR group ADC (Med) No >4 <609 μm2/s 11 (46) 0.24 MLTR group 0.13 (0.03, 0.52)* ≥609 μm2/s 14 (22) 0.64 4.22 (1.65, 10.79)* 0.57 (0.14, 2.31) ≤4 <609 μm2/s 22 (30) 0.73 9.31 (2.8, 30.99)* 1.26 (0.29, 5.5) ≥609 μm2/s 40 (53) 0.75 9.09 (3.33, 24.83)* 1.23 (0.3, 4.94) Yes >4 <609 μm2/s 7 (9) 0.78 10.18 (1.91, 54.34)* 1.37 (0.28, 6.72) ≥609 μm2/s 6 (9) 0.67 3.73 (0.71, 19.65) 0.5 (0.08, 3.27) ≤4 <609 μm2/s 9 (14) 0.64 6.27 (1.47, 26.74)* 0.84 (0.24, 2.99) ≥609 μm2/s 12 (17) 0.71 7.42 (1.92, 28.64)* LLTR group Note.—rt-PA indicates recombinant tissue plasminogen activator; rADC, relative apparent diffusion coefficient; Med, median; Reference, reference group.
* P < .05 compared with the reference group using the generalized estimation equations approach considering the correlation among sections and among tissues.
- TABLE 4:
Subgroup Analysis for Untreated Patients Only, Indicating the Effects of Tissue Signature Value, Apparent Diffusion Coefficient Value, and Recombinant Tissue Plasminogen Activator Treatment on Tissue Outcome, in Comparison with the Most Likely to Recover and Least Likely to Recover Reference Groups
Recovery # (N) % Odds Ratio (95% CI) Odds Ratio (95% CI) rt-PA Tissue Signature rADC (Med) No ≤3, 4 <0.79 22 (33) 0.67 0.65 (0.32, 1.35) 3.5 (1.24, 9.87)* ≥0.79 40 (50) 0.80 MLTR group 6 (1.84, 19.58)* =5 <0.79 9 (29) 0.31 0.12 (0.05, 0.30)* 0.7 (0.33, 1.49) ≥0.79 11 (18) 0.61 0.42 (0.13, 1.29) 1.95 (0.61, 6.22) ≥6 <0.79 2 (16) 0.13 0.04 (0.01, 0.18)* LLTR group ≥0.79 3 (5) 0.60 0.37 (0.05, 2.90) 1.55 (0.21, 11.46) Signatures rADC (1st QL) No ≤3, 4 <0.66 11 (13) 0.85 2.99 (0.57, 15.73) 70.65 (8.93, 558.74)* ≥0.66 51 (70) 0.73 MLTR group 23.64 (6.62, 84.41)* =5 <0.66 5 (17) 0.29 0.12 (0.04, 0.39)* 2.92 (0.99, 8.6) ≥0.66 15 (30) 0.50 0.35 (0.14, 0.89)* 8.28 (2.28, 30.04)* ≥6 <0.66 1 (10) 0.10 0.04 (0.01, 0.15)* LLTR group ≥0.66 4 (11) 0.36 0.21 (0.05, 0.85)* 4.88 (1.11, 21.47)* Note.—CI indicates confidence interval; rt-PA, recombinant tissue plasminogen activator; rADC, relative apparent diffusion coefficient; Med, median; QL, quartile; Reference, reference group.
* P < .05 compared with the reference group using the generalized estimation equations approach considering the correlation among sections and among tissues.
