| Objectives:1) To investigate the value of MR IP/OP imaging (in-and out-phase) in quantifying hepatosteatosis and to study the effect of liver iron overload on the quantification of MR IP/OP 2) To study the value of CT perfusion in quantification of liver fibrosis and to search for sensitive indicators of diagnosing liver fibrosis 3) To study the correlation between hepatosteatosis and liver fibrosis.Materials and Methods:1) establishment of rabbit models of liver fibrosis:Low dose (0.20ml/kg) of carbon tetrachloride with 50% concentration was injected into the peritoneum for inducing liver fibrosis of the rabbits. Total 50 healthy rabbits were randomly grouped into five groups:control group,5; 4 weeks group,10; 8 weeks group, 10; 12 weeks group,10; 16 weeks group,15.2) MR IP/OP Imaging and CT Perfusion were performed in all rabbits at the time of 4 weeks.8 weeks.12 weeks, and 16 weeks after injection of carbon tetrachloride had been starting. The parameters of MR were as follows:TR/TE (180/2.1msec. in-phase; 180/3.2msec. out-phase), slice 5.0mm, spacing 1.0mm, Fov 20.0，Flip angle 80°. The parameters of dual-energe CT perfusion were as follows:Abdomen:120kV,260mAs, TI 0.5 s, cSL 1.2mm; DynMulti4D:100kV, 150mAs, TI 0.57 s, cSL 1.2mm., slice 3 mm.3) Staging of liver fibrosis, hepatosteatosis, and liver iron accumulation was performed histopathologically within 24 hours when MR and CT scan have been done.4) The postprocessing of datas was then done according to the directions of professional software equipped. BF, BV, ALP, PVP, and HPI were obtained from hepatic CT perfusion. Hepatic SIfat was also obtained from MR IP/OP imaging according to the formula:[(Slm-SIout)/SIm]*100, (SIm=Liver SIm/Spleen SIin,SIout=Liver SIou/Spleen SIout).Results:1) 22 rabbits were survived in all 50 rabbits. In control group,4 rabbits were survived. In 4 weeks group,4 rabbits were pathologically diagnosed as stage I of liver fibrosis, and 1 rabbit, stage II. In 8 weeks group.1 rabbit was pathologically diagnosed as stage I, and 2 rabbits, stageⅡ, and 1 rabbit, stageⅢ. In 12 weeks group,3 rabbits were pathologically diagnosed as stageⅡof liver fibrosis, and 1 rabbit, stage III. In 16 weeks group,3 rabbits were pathologically diagnosed as stage I of liver fibrosis. and 1 rabbit, stageⅡ, and 1 rabbit, stageⅢ.2) In quantification of hepatosteatosis with MR IP/OP, close correlation between SIfat and grading of hepatosteatosis was found (r=0.889, p=.0000).Comparison between SIfat of gade I andⅡof hepatosteatosis was significantly different t=4.177. p=.001).Mean value of SIfat in grade I hepatosteatosis was 5.43±3.07, and grade II,11.67±3.57. Significant iron overload can lead to low evaluation of hepatosteatosis with MR IP/OP imaging.3) In quantification of liver fibrosis with CT Perfusion imaging, PVP was found significantly different between FOvsFl and between F1vsF2 (t=8.387, p=.000; t=3.688, p=.003). HPI was also found significantly different between FOvsF1 and between F1vsF2 (t=2.758, p<05; t=23.168, p=.000). BF and BV were found significantly different between F1vsF2 (t=24.912, p=.000:t=4.762. p=.000). ALP was found significantly different between FlvsF2 and between F2vsF3 (t=23.246, p=.000; t=2.362, p<.05). PVP and HPI can differentiate FO from F1 and F1 from F2 liver fibrosis. BF, BV and ALP can differentiate F1 from F2 and F2 from F3 liver fibrosis. PVP was decreasing and ALP, HPI increasing with the progression of liver fibrosis.4) Close correlation between hepatosteatosis and liver fibrosis confirmed histopathologically was also found (r=0.824, p=.000).Conclusions:1) MR IP/OP can quantify hepatosteatosis rapidly and safely, however, significant iron accumulation can lead to its low evaluation.2) CTP was promosing in quantifying liver fibrosis. PVP and HPI were excellent indicators for diagnosing early stage of liver fibrosis. BF, BV and ALP were valuable indicators for diagnosing middle and advanced stages of liver fibrosis.3) Hepatosteatosis can probably promote the progression of liver fibrosis. |
PDF Full Text Request