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Objective To investigate the value of susceptibility weighted imaging (SWI) with T1ρimaging in staging of hepatic fibrosis(HF) in rabbits. Methods Eighty selected white rabbits from New Zealand were randomly divided into the HF group (n=60) and the control group (n=20). Rabbits in the HF group were injected subcutaneously with 50％CCl4 oil solution to establish HF model,and the normal control rabbits were injected with saline solution subcutaneously.The HF group(n=15) and control group(n=5) were randomly selected at the 4th, 5th, 6th and 10th week after injection, to undergo liver MR scan. The liver signal intensity (SI liver), the muscle signal intensity (SI muscle),liver-to-muscle SI ratios (SIR) and liver T1ρvalues were measured. Scheuer was adopted to stage the rabbits in HF. One-way analysis of variance was used to compare the differences between SIR and T1ρ values in different stages of HF pathological. Spearman correlation was used to analyze the correlation between SIR and T1ρ values in the different stage of HF pathological.The ROC were used to compare the efficacy between SIR and T1ρvalues in the diagnosis of HF pathological stage. Results Among the final qualified 68 rabbits in the study, 17 in F0 phase, 11 in F1 phase, 16 in F2 phase, 11 in F3 phase, and 13 in F4 phase. The SIR were (0.977 ± 0.013), (0.960 ± 0.015), (0.802 ± 0.026), (0.786 ± 0.022), (0.541 ± 0.116); T1ρ values were (22.301 ± 1.849), (24.034 ± 0.867), (25.374 ± 1.309),(25.364±1.945),(30.948±2.925) ms.There were statistically significant in SIR between F0 and F2,F0 and F3, F0 and F4, F1 and F2, F1 and F3, F1 and F4, F2 and F4, F3 and F4 (P<0.01). There were statistically significant in T1ρvalues between F0 and F1,F0 and F2,F0 and F3,F0 and F4,F1 and F2,F1 and F4,F2 and F4, F3 and F4(P<0.05). SIR were negatively correlated with HF staging while T1ρ values were positively. ROC showed that the AUC of the T1ρvalues was slightly larger than SIR in the F4 group(0.992>0.966),and the AUC of the SIR was greater than T1ρvalues in the other groups. Conclusion SWI and T1ρvalues can provide an important objective basis in staging of HF. Both of them have great clinical application prospects but SIR diagnostic efficiency is slightly better than that of T1ρvalues.
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Objective To compare the diagnostic values of magnetic resonance elastography (MRE) and T1ρ imaging in staging hepatic fibrosis (HF) in a rabbit model.Methods The institutional animal care and use committee approved all experiments.Sixty healthy rabbits were divided into HF group (n=44) and control group (n=16).Each eight rabbits in the HF group and 4 rabbits in the control group were randomly selected at the 4th,5th,6th week and the remaining rabbits at the 10th week after subcutaneous injection with 0.1 ml 50％ CCl4 oily solution per kilogram of body respectively,to undergo liver MR scan including axial liver MRE and T1ρ imaging.The values of liver stiffness (LS) and T1ρ were measured.Masson trichrome staining of liver tissue was used.According to the Scheuer scoring system,rabbits were classified into F0 to F4 group based on the percentage of hepatic fibrosis.The difference of LS values and Tip values among stage F0 to F4 were compared by the one-way ANOVA analysis.The correlations between pathological staging and LS,T1ρ values were performed by the Spearman correlation analysis.ROC curve analysis was performed to compare the value of MRE with T1ρ imaging.Results Forty three rabbits were included,there were 10,8,8,8,9 rabbits in F0,F1,F2,F3 and F4 stage,respectively.LS values were (1.051±0.155),(1.335±0.235),(1.401±0.163),(2.001±0.499) and (2.981±0.714) kPa in F0,F1,F2,F3 and F4,respectively,while T1 p values were (23.20±4.02),(24.28±2.93),(25.40± 1.82),(24.69± 1.85) and (31.54±3.39) ms (all P＜0.05).The correlation of LS values with hepatic fibrosis staging measured on MRE was stronger than T19 values (r values were 0.916 and 0.608,all P＜0.01).Area under ROC curve of LS value for differentiating hepatic fibrosis stage were 0.938 to 0.989,while the areas of T1ρ were 0.771 to 0.954.Conclusion MR elastography is an accurate technique for quantitatively staging hepatic fibrosis and superior to T1ρ imaging.
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Objective To evaluate the effect of MRI in reflecting the pathological changes of VX2 carcinoma in rabbits after radiofrequency ablation (RFA) . Methods RFA was performed in the livers of 24 rabbits with planted VX2 carcinoma. The rabbits were divided into 4 groups. After RFA, the rabbits were killed after MR imaging on 0, 1, 2, and 4 weeks, respectively. The correlation between MRI and pathological findings was analyzed. Results In the acute phase, coagulative necrosis of the ablated tumors and inflammatory reaction with hyperemia around were detected at microscopic examination. The ablated tumor showed as hypointensity on T1WI and hyperintensity on T2WI, while rim of high signal intensity on T1WI and low signal intensity on T2WI was found. Gadolinium-enhanced MRI showed a thin high signal rim surrounding the central coagulative necrosis. In the subacute phase, extensive coagulative necrosis and marked infiltration by neutrophils, lymphocytes, macrophages and a peripheral fibrous generation rim were observed microscopically on the ablated tumor. The ablated tumor showed iso-or hyperintensity on T1WI and hypointensity on T2WI, while the periphery of ablated lesions was hypointensity on T1WI and hyperintensity on T2WI. There was prominent rim enhancement along the ablated margin. In the chronic phase, peripheral fibrous rim became obvious, more regular and thicker than at subacute phase as hypointensity on T1WI and T2WI, and unenhancement was observed. Residual or recurrence of tumor was found in 17 rabbits as hypointensity on T1WI and hyperintensity on T2WI, and irregular, thicker rim or nodular enhancing abnormalities. Conclusion MRI can effectively show the histopathological tissue changes of rabbit VX2 carcinoma after ablation and demonstrate the residual or recurrence of tumor.
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0.05).The accuracy of Borrmann type classification in 14 cases of advanced gastric carcinoma undergone gastrectomy was 92.8%.Conclusion The gastric carcinoma detection rate with NHSCT is similar to that with fibro-gastroscopic or double-contrast barium examination.The direct and indirect signs of gastric carcinoma can be found and the Borrmann type classification can be made by NHSCT.However,the non-contrast enhancement scanning is limited for the early gastric carcinoma detection,and can be improved by contrast enhancement scanning.