Assessment on T1 mapping values using gadoxetic acid-enhanced MRI examination in comparison with organic anion transporters and multi-drug resistance proteins values on the hepatocytes on colorectal liver metastases / 中华放射学杂志

ABSTRACT

Objective To evaluate the relationship between the T1 relaxation times using gadoxetic acid-enhanced MRI with the organic anion transporter (OATP) and multi-drug resistance protein (MRP) values on colorectal liver metastasis and around normal liver parenchyma.Methods The perspective study included in fifteen patients with liver metastasis from colorectal cancer,who were confirmed colorectal cancer by colonoscopy,liver metastasis by CT scanning and would be underwent liver metastasis surgery.The lesion on the 15 patients was all single.The patients were performed plain scanning,diffusion weighted imaging and dynamic enhancement MRI examination using gadoxetic acid.Besides,for T1 mapping,a dual flip angle three-dimensional gradient echo sequence was performed before and at 20 minutes after gadoxetic acid administration.The reduction rate of T1 relaxation time (ΔT) (before and after gadoxetic-acid administration) of colorectal liver metastasis and around normal liver parenchyma was calculated.The specimens of hepatic metastases and around normal liver parenchyma were obtained during the colorectal liver metastasis operation.After that,they were analyzed by Western-blot and the values on OATP1,OATP8 and MRP2,MRP3 were recorded.The values on OATP1,OATP8 and MRP2,MRP3 and ΔT on hepatic metastases and around normal liver parenchyma were compared with t analysis.The correlation between the sum of the values (hepatic metastases adding around normal liver parenchyma) on OATPI,OATPS,MRP2,MRP3 with T1 relaxation times were calculated by Spearman.Results The scanning images on colorectal liver metastasis using gadoxetic acid MRI examination were as followsrelatively low signal intensity on T1WI; relatively higher signal intensity on T2WI; showing surrounding moderate enhancement on arterial phase and low signal intensity on portal venous phase,delay phase and hepatobililary phase.The values on OATP1,OATP8,MRP2,MRP3 and AT on the hepatic metastases were(0.21±0.09),(0.34±0.21),(0.41±0.22),(0.26±0.14)ng/ml and (33±9)％,respectively.The values on OATP1,OATP8,MRP2,MRP3 and ΔT around normal liver parenchyma were (0.46±0.24),(0.67±0.35),(0.22±0.13),(0.13±0.06) ng/ml and(68±9)％ (t values were 36.37,58.89,24.56,22.52 and 57.16;P＜0.05).The values on patients on OATP1,OATP8,MRP2 and MRP3 [(0.67±0.31),(1.00±0.37),(0.63±0.23),(0.40±0.13)ng/ml,respectively] showed relationship with the values on patients on ΔT(51±9)％ (r values were 0.491,0.432,-0.414 and-0.371;P values were 0.006,0.017,0.023 and 0.040).Conclusion The sum of the values (the hepatic metastases adding around normal liver parenchyma) on OATP1,OATP8,MRP2 and MRP3 showed correlation with the sum of values on the ΔT using gadoxetie acid-enhanced MRI examination,which explained relationship with the quantity of gadoxetic acid absorbed by hepatocyte and the T1 relaxation time on molecular level.