Assessment of liver fibrosis in rats by MRI with apparent diffusion coefficient and T1 relaxation time in the rotating frame.
OBJECTIVE
To explore the value of T1 relaxation times in the rotating frame (T1 ρ or T1 rho) for evaluating liver fibrosis stage, compared to apparent diffusion coefficients (ADCs).


METHODS
Liver fibrosis in model rats (n = 50) was produced by carbon tetrachloride (CCl4 ) injection. Five rats died during the experiment. Surviving model rats (n = 45) and controls (n = 15) were subjected to 3.0T MRI and the ADCs (b-values: 0, 800 s/mm(2) ) and T1 ρ values were determined. Liver fibrosis stage (F0-F4) was defined based on METAVIR scoring. Nonparametric statistical methods and receiver operating characteristic (ROC) curve analyses were employed to determine diagnostic accuracy.


RESULTS
Mean ADC and T1 ρ associated negatively (r = -0.732 P < 0.001) and positively (r = 0.863 P < 0.001), respectively, with severity of fibrosis stage. Analysis of ROC curves for fibrosis staging showed that the area under the curve (AUC) for T1 ρ (stage F0 vs. F1-F4 = 0.976, stage F0-F1 vs. F2-F4 = 0.920, stage F0-F2 vs. F3-F4 = 0.938, and stage F0-F3 vs. F4 = 0.931) was larger than that for ADCs (0.917, 0.924, 0.842, and 0.781, respectively).


CONCLUSIONS
ADC and T1 ρ values correlate with liver fibrosis stage. The performance of the T1 ρ parameter was superior to that of the ADC parameter in the differentiation of liver fibrosis stages in a CCl4 rat model.
Department of Medical Image Center, Shenzhen Bao'an Maternal and Child Health Hospital, Shenzhen, Guangdong Province, China.|Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China.
Genwen
G
Hu
Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China.
Xuhui
X
Zhang
Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China.
Wen
W
Liang
Department of Medical Image Center, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong Province, China.
Xing
X
Zhong
Philips Healthcare, Hong Kong, China.
Queenie
Q
Chan
Department of Medical Image Center, Shenzhen Bao'an Maternal and Child Health Hospital, Shenzhen, Guangdong Province, China.
Xiaoying
X
Lin
Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China.
Ting
T
Lin
Department of Pathology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China.
Yufa
Y
Li
Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China.
Xianyue
X
Quan
D000818:Animals; D019540:Area Under Curve; D002251:Carbon Tetrachloride / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry; D038524:Diffusion Magnetic Resonance Imaging; D005355:Fibrosis; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008099:Liver / Q000473:pathology; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D012372:ROC Curve; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results
D003287:Contrast Media; D002251:Carbon Tetrachloride
T1rho; apparent diffusion coefficient; carbon tetrachloride; liver fibrosis; magnetic resonance imaging