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Objective@#To assess diagnostic performance of multi-parametric MRI including MR elastography (MRE), susceptibility-weighted imaging (SWI) and T1ρ imaging in detecting the early stage of liver fibrosis (LF).@*Methods@#Eighty healthy rabbits were randomly divided into LF group (n=60) and control group (n=20). The LF group (n=12) and control group (n=5) were randomly selected at the end of the 4th, 5th, 6th, 15th week after injection of 50% CCl4 oil solution, respectively. All rabbits underwent 3.0 T MRI scans and histopathological Scheuer staging. Differences between groups were examined using one-way analysis of variance with Dunnett's T3 test. Spearman correlation was used to analyze the correlation between liver stiffness (LS), liver-to-muscle SI ratio (SIR), T1ρ value in different LF stages. ROC curve analysis was used to assess the diagnostic performance.@*Results@#Fifty-five rabbits were included in our study, which covered F0 (n=14), F1 (n=11), F2 (n=10), F3 (n=9) and F4 (n=11). Significant differences of all characteristic values were found among different LF stages (P<0.05).There were significant differences in LS values between F0 and F2, F3, F4, respectively; F1 and F3, F4, respectively; F2 and F4; F3 and F4 (P<0.05). There were significant differences in SIR between F0 and F2, F3, F4, respectively; F1 and F2, F3, F4, respectively; F2 and F4 (P<0.05). T1ρ value showed significant differences between F0, F1, F2, F3 and F4, respectively (P<0.05). LS, SIR, and T1ρ values were correlated with LF stage (r=0.910, -0.808, 0.512, respectively, P<0.01). The area under curve (AUC) for LS value were greater than those for the other two methods (0.953 for≥F1, 0.949 for≥F2, 0.986 for≥F3, 0.979 for F4). The AUCs of the combination of MRE and SWI for detecting≥F1 was 0.965, for≥F2 was 0.983, for≥F3 was 0.991, and for F4 was 0.950. Combining all three MR methods showed the highest diagnostic performance for staging LF with AUCs of 0.969, 0.985, 0.996 and 1.000.@*Conclusion@#MRE is the most prominent MRI method, and combination of MRE and SWI show higher diagnostic performance than the others for staging LF; however, combining all three MR methods exhibits the most excellent diagnostic efficacy.
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Objective To assess diagnostic performance of multi?parametric MRI including MR elastography (MRE), susceptibility?weighted imaging (SWI) and T1ρ imaging in detecting the early stage of liver fibrosis (LF). Methods Eighty healthy rabbits were randomly divided into LF group (n=60) and control group (n=20). The LF group (n=12) and control group (n=5) were randomly selected at the end of the 4th, 5th, 6th, 15th week after injection of 50% CCl4 oil solution, respectively. All rabbits underwent 3.0 T MRI scans and histopathological Scheuer staging. Differences between groups were examined using one?way analysis of variance with Dunnett's T3 test. Spearman correlation was used to analyze the correlation between liver stiffness (LS), liver?to?muscle SI ratio (SIR), T1ρ value in different LF stages. ROC curve analysis was used to assess the diagnostic performance. Results Fifty?five rabbits were included in our study, which covered F0 (n=14), F1 (n=11), F2 (n=10), F3 (n=9) and F4 (n=11). Significant differences of all characteristic values were found among different LF stages (P<0.05).There were significant differences in LS values between F0 and F2, F3, F4, respectively; F1 and F3, F4, respectively; F2 and F4; F3 and F4 (P<0.05). There were significant differences in SIR between F0 and F2, F3, F4, respectively; F1 and F2, F3, F4, respectively; F2 and F4 (P<0.05). T1ρ value showed significant differences between F0, F1, F2, F3 and F4, respectively (P<0.05). LS, SIR, and T1ρ values were correlated with LF stage (r=0.910, -0.808, 0.512, respectively, P<0.01). The area under curve (AUC) for LS value were greater than those for the other two methods (0.953 for≥F1, 0.949 for≥F2, 0.986 for≥F3, 0.979 for F4). The AUCs of the combination of MRE and SWI for detecting≥F1 was 0.965, for≥F2 was 0.983, for≥F3 was 0.991, and for F4 was 0.950. Combining all three MR methods showed the highest diagnostic performance for staging LF with AUCs of 0.969, 0.985, 0.996 and 1.000.Conclusion MRE is the most prominent MRI method, and combination of MRE and SWI show higher diagnostic performance than the others for staging LF; however, combining all three MR methods exhibits the most excellent diagnostic efficacy.
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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 estimate the value of diffusion weighted imaging with background body signal suppression(DWIBS)in tumors of intestinal tract and metastasis.Methods 15 cass with tumors of intestinal tract underwent MRI and DWIBS examinations.Four of them underwent CT scan.Results All primary tumors were showed by conventional MR sequences and DWIBS.DWIBS showed that 4 cases had the invasion of placenta percreta,5 cases had transcoelomic metastasis in abdominal cavity and 5 cases had lymphatic metastasis,while the conventional MR sequences showed the invasion of placenta percreta in 10 cases,the invasion of fat interspace in 8 cases,transcoelomic metastasis in abdominal cavity in 3 cases and lymphatic metastasis in 3 cases.Conclusion DWIBS is better than the conventional MR sequences and CT in detecting the primary tumor of intestinal tract,transcoelomic metastasis in abdominal cavity and lymphatic metastasis.However,the conventional MR sequences and CT is better than DWIBS in detecting the invasion of placenta percreta and fat interspace.
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Objective To evaluate the diagnosis and differentiation of solitary pulmonary nodule (SPN) using dynamic spiral CT scan of thin collimation.Methods The thin collimation no-enhanced CT scan and contrast enhanced scan in 30 seconds,1 minute,1 minutes,2 minutes,5 minutes,10 minutes,and 15 minutes after administration of media 100 ml were performed in 38 cases. Results The mean enhanced CT numbers of lung cancer and inflammatory pseudotumor were much higher than that of tuberculosis(TB) and hamartoma and statistically significant in different time of enhancement;20 HU was the threshold for a positive test,the sensitivity was 100% and the specificity was 96%.In time-attenuation curve analysis,lung cancer reached peak enhancement about 2 minutes,inflammatory pseudotumor in 5 minutes and keep longer enhanced time than that of lung cancer.No marked enhancement in SPN of TB and harmatoma,but ring-shaped enhancement can be seen in some of TB.More valuable imaging signs were found with thin collimation scan and more accurate to measure the CT numbers than traditional scan.Conclusion Dynamic spiral CT scan of thin collimation is a very valuable method for diagnosis and differentiation of SPN.