Feasibility of using T2*mapping to quantitatively evaluate ischemia-reperfusion injury / 中华放射学杂志

ABSTRACT

Objective@#To explore the feasibility of evaluating renal ischemia-reperfusion injury (IRI) at different time by using T2*mapping.@*Methods@#Eighteen New Zealand white rabbits were used to build therenal IRI injury model by blocked the left renal arteries and veins by using noninvasive arterial clip, left renal ischemia-reperfusion was performed by clamping of the left renal pedicle for 60 minutes, followed by reperfusion. All the rabbits underwent MRI examination including axial T2WI and T2*mapping before scanning and 1 h, 12 h, 24 h and 48 h after reperfusion. Every two rabbits were randomly sacrificed at 1 h, 12 h, and 24 h after reperfusion. The rest of the rabbits were sacrificed for pathological examination at 48 h after reperfusion. All specimens were cut into slices and stained with hematoxylin-eosin (HE). The values of T2*, R2* and the pathological scores of cell edema, cell necrosis, interstitial inflammation and tubular castin renal tissues at different time points were measured. Repetitive measurement deviation analysis was performed to compare difference of T2* and R2* at 5 time-points. The relationship between the value of T2* and R2* in renal tissues and the scores of cell edema, cell necrosis, interstitial inflammation and tubular castin renal tissues was analyzed by Spearman correlation analysis.@*Results@#T2* value and R2* value in both inner medulla and outer medulla were statistically significant (P<0.05), while there was no statistically significant in the cortex (P>0.05).Pairwise comparison of T2* and R2* at different time points in the cortex showed statistically significant difference between before and 24 h,before and 48 h, 12 h and 48 h were statistically significant (P<0.05), while the remaining were no statistically significant difference (P>0.05).T2* value of the outer medullar after IRI positively correlated with the scores of cell edema, interstitial inflammation and tubular castin renal tissues (r values were 0.57, 0.38, 0.33; P<0.05). R2* value of the outer medullar after IRI negatively correlated with the scores of cell edema (r value was -0.52, P<0.05).@*Conclusion@#T2* mapping could reflect the dynamic changes in different zones and different time points after renal IRI, especially in the outer medullary band which has good consistency with pathological score.