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Magnetic resonance imaging (MRI) is a very important imaging method for diagnosis and treatment of prostate cancer (PCa) in clinical practice. As functional MRI is growing and maturing, its quantitative parameters are expected to enhance the clinical value of MRI furtherly. Intravoxel incoherent motion diffusion imaging, diffusion tensor imaging, and diffusion kurtosis imaging, which were derived from diffusion weighted imaging, have provided richer and more accurate parameters. The newly-developed magnetic resonance elastography can complement the mechanical characteristics of PCa.
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Humans , Male , Diffusion Magnetic Resonance Imaging , Diffusion Tensor Imaging , Magnetic Resonance Imaging , Motion , Prostatic Neoplasms/diagnostic imagingABSTRACT
Objective To explore the diagnostic value of MR elastography and diffusion?weighted imaging in patients with liver fibrosis in the context of chronic hepatitis B. Methods Twenty?four patients with chronic hepatitis B, whose course of liver disease was more than 6 months and hepatitis B surface antigen was positive, were prospectively enrolled in the First Affiliated Hospital of Soochow University from July to December 2017. All of the patients underwent abdominal transient elastography (TE), routine MRI, magnetic resonance elastography (MRE) and DWI examination, TE and MRI were performed within one week. TE liver stiffness was measured, the MRE liver stiffness and ADC value were measured on MR imagings. All patients were divided into three groups: mild and non fibrosis (F0 to 1), significant fibrosis(F2 to 3) and cirrhosis (F4), according to the recommended standard of FibroTouch. Correlation between TE liver stiffness, MRE liver stiffness and ADC values were identified by using Spearman correlation test. The difference of the MRE liver stiffness and ADC value among the three groups was tested using independent sample t test. The overall predictive ability of MRE and DWI in assessment of liver fibrosis and cirrhosis was analyzed by constructing ROC curve. Results TE and MRI were successfully performed in all subjects, and the image quality was good. The MRE liver stiffness in mild and non fibrosis, significant fibrosis and cirrhosis was (2.32±0.31),(3.43±1.05),(4.77±0.68) kPa with statistically significant difference(F=61.690, P<0.01). The ADC values in three groups were (1.31 ± 0.14)×10-3, (1.23 ± 0.15)×10-3,(1.22±0.12)×10-3mm2/s without significant difference(F=1.074,P=0.360). The TE liver stiffness in three groups was (5.61±1.05),(9.56±0.57),(17.25±3.55)kPa, respectively, there was significant correlation between the MRE liver stiffness and the TE liver stiffness(t=0.858, P<0.01), but no significant correlation between the TE liver stiffness and the ADC value was found (r=-0.326,P=0.120). The area under ROC of MRE liver stiffness in diagnosing liver fibrosis grade (≥F2 and F4) was 0.96 and 1.00 respectively, while the AUC of ADC value was less than 0.70, which were 0.67 and 0.62 respectively. Conclusion MRE is a non?invasive promising tool for assessing liver fibrosis with chronic hepatitis B, while DWI has limited role.
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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 assess segmental liver stiffness (LS) with MRI before and after endovascular intervention in patients with Budd-Chiari syndrome (BCS). MATERIALS AND METHODS: Twenty-three patients (13 males and 10 females; mean age, 42.6 ± 12.6 years; age range, 31–56 years) with BCS as a primary liver disease were recruited for this study. Two consecutive magnetic resonance elastography (MRE) examinations were performed before the endovascular treatment. Fifteen patients who underwent endovascular intervention treatment also had follow-up MRE scans within three days after the procedure. LS was measured in three liver segments: the right posterior, right anterior, and left medial segments. Inter-reader and inter-exam repeatability were analyzed with intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Segmental LS and clinical characteristics before and after the intervention were also compared. RESULTS: Within three days of the endovascular intervention, all three segmental LS values decreased: LS of the right posterior segment = 7.23 ± 0.88 kPa (before) vs. 4.94 ± 0.84 kPa (after), LS of the right anterior segment = 7.30 ± 1.06 kPa (before) vs. 4.77 ± 0.85 kPa (after), and LS of the left medial segment = 7.22 ± 0.87 kPa (before) vs. 4.87 ± 0.72 kPa (after) (all p = 0.001). There was a significant correlation between LS changes and venous pressure gradient changes before and after treatments (r = 0.651, p = 0.009). The clinical manifestations of all 15 patients significantly improved after therapy. The MRE repeatability was excellent, with insignificant variations (inter-reader, ICC = 0.839–0.943: inter-examination, ICC = 0.765–0.869). Bland-Altman analysis confirmed excellent agreement (limits of agreement, 13.4–19.4%). CONCLUSION: Segmental LS measured by MRE is a promising repeatable quantitative biomarker for monitoring the treatment response to minimally invasive endovascular intervention in patients with BCS.
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Female , Humans , Male , Budd-Chiari Syndrome , Elasticity Imaging Techniques , Follow-Up Studies , Liver Diseases , Liver , Magnetic Resonance Imaging , Venous PressureABSTRACT
La fibrosis es un destino donde convergen variados trastornos hepáticos. Al tratarse de un proceso dinámico y reversible, su detección temprana y una intervención terapéutica oportuna, pueden frenar su progresión. La elastografía por resonancia magnética (ERM), es un método no invasivo con notable eficacia para la valoración del grado de fibrosis hepática. La tendencia actual es combinar esa técnica con secuencias de cuantificación de lípidos y hierro, lo cual permite un abordaje multiparamétrico de los trastornos difusos del hígado.
Fibrosis is a common destination where multiple liver disorders converge. Due to its dynamic and reversible process, an early detection and timely therapeutic intervention can interrupt its progression. Magnetic Resonance Elastography (MRE) is a non-invasive method with remarkable efficacy for assessing the degree of liver fibrosis. The current trend is to combine this technique with lipid and iron quantification sequences, which allows a multiparametric approach to diffuse liver disorders.
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Humans , Elasticity Imaging Techniques/methods , Liver Cirrhosis/diagnostic imaging , Magnetic Resonance Spectroscopy , Elasticity Imaging Techniques/trends , Fatty Liver/diagnostic imaging , Liver/diagnostic imagingABSTRACT
Objective To explore the diagnostic value of MRE for differentiating hepatic benign and malignant tumors.Methods 36 patients with liver tumor (a total of 39 lesions,including 20 hepatocellular carcinomas,7 hemangiomas,5 cholangiocellular carcinomas,3 metastases,2 hepatic angiomyolipomas,1 carcinosarcoma,1 castleman’s disease)and 9 healthy volunteers were evaluated with MRE.The elastogram were generated with FUNCTOOL post processing program.The mean value of elasticity of hepatic malignant tumors,hepatic benign tumors,hepatic parenchyma around the malignant tumors,hepatic parenchyma around the benign tumors and the normal liver of healthy volunteers were measured and compared.Results The mean value of elasticity of malignant tumors [(7.39±1.70)kPa]was significantly higher than these of benign tumors [(4.11±0.37)kPa,P 0.05).A cutoff value of 5.08 kPa can accurately differentiate malignant tumors from benign tumors and normal liver parenchyma.Conclusion MRE could be used in diagnosis of hepatic focal tumors,which is helpful for differentiating benign and malignant liver tumors.
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Objective To analyze the advantages and disadvantages of various harmonic magnetic resonance elasticity reconstruction algorithms.Methods Different reconstruction algorithms were categorized according to their mathematical hypotheses.The influence of different assumptions on elasticity reconstruction was investigated with experiments and from mathematical fundamentals.Results The finite element full inversion method had higher precision while more computational time.The algorithms with local homogeneity and incompressibility assumptions were faster while less accurate.The algorithms considering the local change of elastic moduli could effectively reduce boundary artifacts.Conclnsion Different assumptions of algorithms may cause levels of errors between the estimated and real elastic moduli.The selection of elasticity reconstruction algorithms in practical experiment requires a comprehensive tradeoff.
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Objective:To investigate the efficacy and the clinical value of magnetic resonance elastography(MRE) in diagnosis of hepatic fibrosis with Meta-analysis, and to provide basis for clinical treatment of hepatic fibrosis.Methods:The studies published before February 2, 2017 about MRE and staging of hepatic fibrosis in Chinese or English were retrived in the databases including PubMed, EMBase, Web of Science, Cochrane Library,CNKI, CBMDisc,VIP, Wanfang data, and supplemented by manual retrieval for relevant literatures.The inclusion and exclusion criterions were used to select and extract the literatures.The literatures qualitie were valuated based on QUADAS-2 tool.The sensitivity(SEN), specificity (SPE), diagnostic odds ratio (DOR), positive likelihood ratio (+LR), negative likelihood ratio (-LR) on the groups of F0 vs F1-F4,F0-F1 vs F2-F4,F0-F2 vs F3-F4, F0-F3 vs F4 and heterogeneity were combined and tested with Stata software respectively.HSROC and AUROC were also implemented.Results:A total of 1 332 studies were searched, and 22 were included.21 of them were in English and 1 in Chinese.The results of Meta analysis showed that the SENp, SPEp, +LRp,-LRp, DOR and AUROC in F0 vs F1-F4 group were 88.8%(85.0-91.7),95.9%(91.5-98.0),21.435(10.215-44.979),0.117(0.086-0.159),183.187(72.533-462.650) and 0.96(0.94-0.98) ,respectively;the SENp, SPEp, +LRp,-LRp, DOR and AUROC in F0-F1 vs F2-F4 group were 93.3%(89.2%-35.9%), 94.1%(90.2%-96.5%),15.839(9.344-26.848),0.072(0.044-0.117),221.224(100.980-484.648) and 0.98(0.96-0.99),respectively;the SENp, SPEp, +LRp, -LRp, DOR and AUROC in F0-F2 vs F3-F4 group were 92.9%(88.9%-95.5%),94.6%(91.2%-96.8%),17.348(10.496-28.671),0.075(0.048-0.119),230.434(111.482-476.317)0.98(0.96-0.99), respectively;the SENp, SPEp, +LRp,-LRp, DOR and AUROC in F0-F3 vs F4 group were 97.7%(93.0%-99.3%),93.2%(90.3%-95.2%),14.337(9.910-20.742),0.025(0.008-0.075),580.405(144.871-2325.307) and 0.98(0.96-0.99),respectively.Conclusion:MRE,as a new and noninvasive imaging method, has high diagnostic value in all stages of hepatic fibrosis, which can provide a reliable reference for clinical precise treatment of hepatic fibrosis.
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Objective To compare the diagnostic value of MRE and DWI in staging hepatic fibrosis in pa-tients with CHB. Methods In this retrospective analysis ,we investigated 93 patients with CBH and live fibrosis. Ninety-three patients were grouped according to their pathological grading of fibrosis ,from S0 to S4. Sixteen healthy patients were enrolled as the control group. Spearman correlation analysis was used to analyze the correla-tion between the stiffness and ADC value and their staging fibrosis. ROC analysis was conducted to compare the per-formance of the stiffness and ADC value in staging hepatic fibrosis. Results Both liver stiffness value(r=0.962, P<0.01)and ADC value(r=-0.823,P<0.01)were highly correlated with the stage of liver fibrosis. The area un-der ROC(AUC)for the detection of≥S1≥S2/≥S3/S4 stage fibrosis with the stiffness and ADC value were 0.963/0.868、0.995/0.947、0.998/0.948、0.996/0.889 respectively ,with statistically significant differences (P < 0.05 , resectively). Conclusions MRE and DWI have higher value ,and MRE is more accurate than DWI for staging hepatic fibrosis in patients with CHB.
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Objective To compare the diagnostic value of MRE and DWI in staging hepatic fibrosis in pa-tients with CHB. Methods In this retrospective analysis ,we investigated 93 patients with CBH and live fibrosis. Ninety-three patients were grouped according to their pathological grading of fibrosis ,from S0 to S4. Sixteen healthy patients were enrolled as the control group. Spearman correlation analysis was used to analyze the correla-tion between the stiffness and ADC value and their staging fibrosis. ROC analysis was conducted to compare the per-formance of the stiffness and ADC value in staging hepatic fibrosis. Results Both liver stiffness value(r=0.962, P<0.01)and ADC value(r=-0.823,P<0.01)were highly correlated with the stage of liver fibrosis. The area un-der ROC(AUC)for the detection of≥S1≥S2/≥S3/S4 stage fibrosis with the stiffness and ADC value were 0.963/0.868、0.995/0.947、0.998/0.948、0.996/0.889 respectively ,with statistically significant differences (P < 0.05 , resectively). Conclusions MRE and DWI have higher value ,and MRE is more accurate than DWI for staging hepatic fibrosis in patients with CHB.
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OBJECTIVE: To cross-validate liver stiffness (LS) measured on shear wave elastography (SWE) and on magnetic resonance elastography (MRE) in the same individuals. MATERIALS AND METHODS: We included 94 liver transplantation (LT) recipients and 114 liver donors who underwent either MRE or SWE before surgery or biopsy. We determined the technical success rates and the incidence of unreliable LS measurements (LSM) of SWE and MRE. Among the 69 patients who underwent both MRE and SWE, the median and coefficient of variation (CV) of the LSM from each examination were compared and correlated. Areas under the receiver operating characteristic curve in both examinations were calculated in order to exclude the presence of hepatic fibrosis (HF). RESULTS: The technical success rates of MRE and SWE were 96.4% and 92.2%, respectively (p = 0.17), and all of the technical failures occurred in LT recipients. SWE showed 13.1% unreliable LSM, whereas MRE showed no such case (p < 0.05). There was moderate correlation in the LSM in both examinations (r = 0.67). SWE showed a significantly larger median LSM and CV than MRE. Both examinations showed similar diagnostic performance for excluding HF (Az; 0.989, 1.000, respectively). CONCLUSION: MRE and SWE show moderate correlation in their LSMs, although SWE shows higher incidence of unreliable LSMs in cirrhotic liver.
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Adolescent , Adult , Female , Humans , Male , Middle Aged , Elasticity Imaging Techniques/methods , Linear Models , Liver Cirrhosis/diagnosis , Liver Transplantation , Living Donors , Magnetic Resonance Imaging , ROC Curve , Sensitivity and SpecificityABSTRACT
Objective: To study magnetic resonance elastography (MRE) technique. Methods: An external force actuator was developed, the imaging pulse sequence of MRE was designed,and tissue simulating phantoms were constructed. The actuator controlled by the pulse sepuence produced shear waves at low frequency on the surface of the phantoms. A modified gradient echo sequence was developed with motion sensitizing gradient (MSG)imposed along X,Y or Z direction.Cyclic displacement within the medium induced by shear waves caused a measurable phase shift in the received MR signal.From the measured phase shift,the displacement at each voxel could be calculated,and the propatating shear waves within the medium were directly imaged. By adjusting the phase offsets,the dynamic propagation of shear waves in a wave cycle was obtained.The phase images were processed to aquire quantitative elasticity image using local frequency estimation(LFE)method. The experiments were implemented with 1.0% and 1.5% tissue simulating agarose gel. Shear waves at frequency of 150 Hz,200 Hz,250 Hz,and 300 Hz were applied. Results: The phase images of MRE directly imaged the propagating shear waves within the phantoms.The wavelength of shear waves varied with the change of exciting frequency and stiffness of the phantoms. The wavelength of shear waves was exactly proportional to the frequency and stiffness of the phantom. The contrast of elasticity in agarose gel with two concentrations was clearly demonstrated on elasticity images.Conclusion: The phase images of MRE can directly visualize the propagation of shear waves in the medium. The elasticity image of MRE can quantitatively image the elastic modulus of the medium