Table 2.
Median Metrics for All MRI Parameters at Visits 1, 2, 3, and 4
| MRI Parameter | Visit 1 | Visit 2 | Visit 3 | Visit 4 | P Value | Adjusted P Value |
|---|---|---|---|---|---|---|
| No. | 9 | 9 | 7 | 8 | ||
| ADC, cm2/s | 0.0344 (0.309-0.0373) | 0.0327 (0.0281-0.0386) | 0.0340 (0.310-0.364) | 0.0338 (0.307-0.0357) | … | … |
| LmD, μm | 281 (260-300) | 273 (251-301) | 278 (263-290) | 279 (263-288) | … | … |
| RBC:M | 0.22 (0.15-0.37) | 0.25 (0.18-0.41) | 0.25 (0.19-0.44) | 0.23 (0.19-0.44) | V1-V2, P = .004 V1-V3, P = .047 V1-V4, P = .039 |
V1-V2, P = .023 V1-V3, P = .094 V1, V4, P = .094 |
| RBC:gas | 0.0026 (0.0018-0.0039) | 0.0030 (0.0019-0.0038) | 0.0026 (0.0020-0.0040) | 0.0024 (0.0017-0.0038) | … | … |
| M:gas | 0.0113 (0.0091-0.0125) | 0.0114 (0.0081-0.0179) | 0.0101 (0.0091-0.0113) | 0.0094 (0.0082-0.0104) | V1-V4, P = .031 V2-V4, P = .023 V3-V4, P = .031 |
V1-V4, P = .063 V2-V4, P = .063 V3-V4, P = .063 |
| M T2∗, ms | 2.58 (2.46-2.68) | 2.47 (2.38-2.58) | 2.42 (2.36-2.56) | 2.22 (1.94-2.40) | V1-V2, P = .044 V1-V3, P = .023 V1-V4, P = .008 V2-V4, P = .008 V3-V4, P = .031 |
V1-V2, P = .053 V1-V3, P = .031 V1-V4, P = .023 V2-V4, P = .023 V3-V4, P = .047 |
| RBC T2∗, ms | 2.20 (2.05-2.48) | 2.16 (2.01-2.49) | 2.16 (2.06-2.32) | 2.27 (2.10-2.47) | … | … |
| DCE PBV, mL/100 mL | 37.8 (11.7-53.5) | 47.6 (15.0-60.2) | 45.3 (36.3-58.4) | 53.8 (52.46-60.72) | … | … |
| SD PBV, mL/100 mL | 18.0 (7.5-28.5) | 21.3 (13.0-24.8) | 23.8 (17.9-25.7) | 21.1 (20.8-22.0) | … | … |
| IQR PBV, mL/100 mL | 25.1 (7.8-34.9) | 27.8 (10.5-36.1) | 35.9 (24.2-41.5) | 29.5 (27.0-31.9) | … | … |
| DCE PBF, mL/100 mL/min | 76.9 (19.6-107.2) | 90.2 (30.7-109.5) | 71.1 (60.3-117.7) | 98.3 (93.4-116.2) | … | … |
| SD PBF, mL/100 mL/min | 45.8 (11.5-58.8) | 54.5 (32.0-75.0) | 48.6 (35.6-69.5) | 54.2 (41.0-65.4) | … | … |
| IQR PBF, mL/100 mL/min | 54.0 (14.1-61.3) | 59.2 (25.5-102.9) | 59.0 (43.2-78.7) | 64.8 (54.2-72.4) | … | … |
| Median MTT, s | 6.5 (5.6-8.0) | 7.3 (6.4-8.0) | 7.1 (3.5-9.9) | 6.9 (2.3 – 7.6) | … | … |
| SD MTT, s | 1.3 (0.9-1.6) | 1.2 (0.6-2.6) | 1.3 (0.5-2.2) | 0.7 (0.6-0.9) | … | … |
| IQR MTT, s | 1.3 (1.1-2.0) | 1.6 (0.7-3.1) | 1.3 (0.6-3.5) | 0.7 (0.5-1.1) | … | … |
| VDP, % | 1.6 (0.6-3.9) | 1.3 (0.7-2.6) | 1.2 (0.4-2.1) | 0.8 (0.4-3.7) | V1-V3, P = .016 | V1-V3, P = .094 |
| Normal VP, % | 76.4 (62.5-77.7) | 76.9 (72.3-86.2) | 78.9 (67.4-81.5) | 81.1 (69.0-82.6) | V1-V2, P = .027 V1-V3, P = .031 |
V1-V2, P = .093 V1-V3, P = .093 |
| Low VP, % | 12.5 (10.0-15.4) | 11.9 (8.9-13.1) | 10.9 (9.1-14.8) | 10.6 (10.0-13.7) | … | … |
| Hyper VP, % | 11.7 (9.5-18.3) | 11.0 (4.2-13.3) | 9.7 (7.9-15.8) | 8.4 (6.8-15.2) | … | … |
| Lung ventilation CV, % | 29.0 (27.5-37.1) | 28.8 (22.3-32.2) | 26.9 (25.6-34.1) | 26.1 (25.0 -33.3) | V1-V2, P = .040 V1-V3, P = .016 V1-V4, P = .040 |
V1-V2, P = .078 V1-V3, P = .078 V1-V4, P = .078 |
Data are presented as median (range) of all patients with available data for each visit. If a Skillings-Mack test determined that there was a significant difference between at least two variables, P values are shown for Wilcoxon pairwise tests. P values are shown prior to and following adjustment for multiple testing. ADC = apparent diffusion coefficient; CV = coefficient of variation; DCE = dynamic contrast enhanced; IQR = interquartile range; LmD = mean diffusive length scale; M = membrane; M:gas = membrane to gas fraction; MTT = mean transit time; PBF = pulmonary blood flow; PBV = pulmonary blood volume; RBC:gas = RBC to gas fraction; RBC:M = RBC to membrane fraction; T2∗ = transverse relaxation time; V = visit; VDP = ventilation defect percentage; VP = ventilation percentage.