Table 4.
Additional results of renal multiparametric MRI
AKI | n | NO AKI | n | Healthy volunteers | n | |
---|---|---|---|---|---|---|
Perfusion | ||||||
Global perfusion (ml/100 g/min) | 168 [142–216] | 10 | 202 [174–235] | 9 | 220 [174–242] | 12 |
Regional perfusion ratio (cortex/medulla) | 2.4 [2.2–3.3] | 10 | 2.2 [1.7–3.4] | 7 | ||
Resistance index* | 0.90 [0.82–0.93] | 10 | 0.79 [0.75–0.86] | 8 | ||
Structure and regional water diffusion | ||||||
Total kidney volume (ml) | 356 [331–437] | 10 | 390 [359–447] | 9 | 403 [345–430] | 12 |
T1 cortex (ms)† | 1560 [1524–1638] | 8 | 1522 [1497–1638] | 8 | 1459 [1400–1525] | 12 |
T1 medulla (ms) | 1838 [1732–1872] | 8 | 1792 [1695–1870] | 8 | 1732 [1661–1850] | 12 |
T2 cortex (ms) | 120 [113–134] | 8 | 124 [119–141] | 8 | ||
DWI cortex ADC (× 10–3 mm2/s) | 1.9 [1.9–2.1] | 8 | 2.1 [1.9–2.1] | 8 | ||
DWI medulla ADC (× 10–3 mm2/s) | 1.9 [1.9–2.0] | 8 | 2.1 [1.8–2.1] | 8 | ||
DWI cortex D (× 10–3 mm2/s) | 1.8 [1.7–1.9] | 8 | 1.9 [1.7–2] | 8 | ||
DWI cortex D* (× 10–3 mm2/s) | 26 [23–29] | 8 | 27 [24–28] | 8 | ||
DWI cortex fp | 0.13 [0.11–0.15] | 8 | 0.13 [0.11–0.14] | 8 | ||
DWI medulla D (× 10–3 mm2/s) | 1.8 [1.7–1.9] | 8 | 1.9 [1.7–2] | 8 | ||
DWI medulla D* (× 10–3 mm2/s) | 26 [23–17] | 8 | 27 [26–28] | 8 | ||
DWI medulla FP | 0.14 [0.11–0.17] | 8 | 0.15 [0.12–0.16] | 8 |
Results of renal multiparametric MRI in 19 patients treated in ICU for respiratory failure due to COVID-19 with AKI or NO AKI, and 12 healthy volunteers of similar age. Data presented as median [quartile range]. Significant differences from Mann–Whitney U test between AKI and NO AKI groups are indicated by * if p < 0.05. Significant differences from one way Kruskal–Wallis ANOVA between all groups are indicated by † if p < 0.05 and ††† if p < 0.001. Valid numbers of MRI examinations are specified for each measure and group. Additional results are presented in Fig. 1
T1 longitudinal relaxation time, T2 transverse relaxation time, DWI diffusion weighted imaging, ADC apparent diffusion coefficient, D pure diffusion, D* pseudodiffusion, fp perfusion fraction