Objective The aim of this study was to investigate the ability of intravoxel incoherent motion(IVIM) diffusion-weighted magnetic resonance imaging(MRI) to diagnose cervical cancer and to evaluate the response of uteri...Objective The aim of this study was to investigate the ability of intravoxel incoherent motion(IVIM) diffusion-weighted magnetic resonance imaging(MRI) to diagnose cervical cancer and to evaluate the response of uterine cervical cancer to radiochemotherapy(CRT).Methods This prospective study was approved by the institutional review board, and informed consent was obtained from all patients. A total of 23 patients with primary cervical cancer who were undergoing CRT and 16 age-matched healthy subjects were prospectively recruited for IVIM(b = 0–800 s/mm2) and standard pelvic MRI. Bi-exponential analysis was performed to derive f(perfusion fraction), D*(pseudo-diffusion coefficient), and D(true molecular diffusion coefficient) in cervical cancer(n = 23) and the normal cervix(n = 16). The apparent diffusion coefficient(standard ADC) was calculated. The independent-samples t-test and paired-samples t-test were used for comparisons.Results Pre-treatment cervical cancer had the lowest standard ADC(1.15 ± 0.13 × 10-3 mm2/s) and D(0.89 ± 0.10 × 10-3 mm2/s) values, and these were significantly different from the normal cervix and posttreatment cervical cancer(P = 0.00). The f(16.67 ± 5.85%) was lowest in pre-treatment cervical cancer and was significantly different from the normal cervix and post-treatment cervical cancer(p = 0.012 and 0.00, respectively). No difference was observed in D*.Conclusion IVIM is potentially promising for differentiating between the normal cervix and cervical cancer because pre-treated cervical cancer has low perfusion and diffusion IVIM characteristics. Further, the standard ADC, D, and f of cervical cancer showed a tendency to normalize after CRT; thus, IVIM may be useful for monitoring the response to CRT in cervical cancer.展开更多
Intravoxel incoherent motion imaging (IVIM), on the traditional diffusion weighted imaging (DWI) technology, uses the biexponential model and adopts the multi-b-value analysis to obtain the perfusion information of wa...Intravoxel incoherent motion imaging (IVIM), on the traditional diffusion weighted imaging (DWI) technology, uses the biexponential model and adopts the multi-b-value analysis to obtain the perfusion information of water molecule diffusion and microcirculation without the use of contrast agent. It is more and more used in pancreatic diseases, which is of great significance for the diagnosis and identification of pancreatic cancer. This article will review the principles of IVIM imaging and its application in pancreatic diseases, especially in pancreatic cancer diagnosis, the prediction of pathological grade of pancreatic ductal adenocarcinoma, the judgment of lymph node metastasis, and differentiation of pathological classification.展开更多
BACKGROUND Liver fibrosis(LF) is a common pathological feature of all chronic liver diseases.With the accumulation of extracellular matrix in the fibrotic liver, true molecular water diffusion and perfusion-related di...BACKGROUND Liver fibrosis(LF) is a common pathological feature of all chronic liver diseases.With the accumulation of extracellular matrix in the fibrotic liver, true molecular water diffusion and perfusion-related diffusion are restricted. Intravoxel incoherent motion(IVIM) can capture the information on tissue diffusivity and microcapillary perfusion separately and reflect the fibrotic severity with diffusion coefficients.AIM To investigate the diagnostic performance of IVIM in detecting and staging LF with histology as a reference standard.METHODS A comprehensive literature search was conducted to identify studies on the diagnostic accuracy of IVIM for assessment of histologically proven LF. The stages of LF were classified as F0(no fibrosis), F1(portal fibrosis without septa),F2(periportal fibrosis with few septa), F3(septal fibrosis), and F4(cirrhosis)according to histopathological findings. Data were extracted to calculate the pooled sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio, as well as the area under the summary receiver operating characteristic curve(AUC) in each group.RESULTS A total of 12 studies with 923 subjects were included in this meta-analysis with 5 studies(n = 465) for LF ≥ F1, 9 studies(n = 757) for LF ≥ F2, 4 studies(n = 413) for LF ≥ F3, and 6 studies(n = 562) for LF = F4. The pooled sensitivity and specificity were estimated to be 0.78(95% confidence interval: 0.73-0.82) and 0.81(0.74-0.86)for LF ≥ F1 detection with IVIM;0.82(0.79-0.86) and 0.80(0.75-0.84) for staging F2 fibrosis;0.85(0.79-0.90) and 0.83(0.77-0.87) for staging F3 fibrosis, and 0.90(0.84-0.94) and 0.75(0.70-0.79) for detecting F4 cirrhosis, respectively. The AUCs for LF≥ F1, F2, F3, F4 detection were 0.862(0.811-0.914), 0.883(0.856-0.909), 0.886(0.865-0.907), and 0.899(0.866-0.932), respectively. Moderate to substantial heterogeneity was observed with inconsistency index(I2) ranging from 0% to 77.9%. No publication bias was detected.CONCLUSION IVIM is a noninvasive tool with good diagnostic performance in detecting and staging LF. Optimized and standardized IVIM protocols are needed to further improve its diagnostic accuracy in clinical practice.展开更多
Diffusion-weighted magnetic resonance imaging(DWMRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer.It has been proven valuable as a functional tool for qualita...Diffusion-weighted magnetic resonance imaging(DWMRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer.It has been proven valuable as a functional tool for qualitative and quantitative analysis of prostate cancer beyond anatomical MRI sequences such as T2-weighted imaging. This review discusses ongoing controversies in DW-MRI acquisition, including the optimal number of b-values to be used for prostate DWI, and summarizes the current literature on the use of advanced DWMRI techniques. These include intravoxel incoherent motion imaging, which better accounts for the nonmono-exponential behavior of the apparent diffusion coefficient as a function of b-value and the influence of perfusion at low b-values. Another technique is diffusion kurtosis imaging(DKI). Metrics from DKI reflect excess kurtosis of tissues, representing its deviation from Gaussian diffusion behavior. Preliminary results suggest that DKI findings may have more value than findings from conventional DW-MRI for the assessment of prostate cancer.展开更多
Background： Diffusion-weighted imaging （DWI） with the intravoxel incoherent motion （IVIM） model has shown promising results for providing both diffusion and perfusion intbrmation in cervical cancer; however, its ...Background： Diffusion-weighted imaging （DWI） with the intravoxel incoherent motion （IVIM） model has shown promising results for providing both diffusion and perfusion intbrmation in cervical cancer; however, its use to predict and monitor the efficacy ofneoadjuvant chemotherapy （NACT） in cervical cancer is relatively rare. The study aimed to evaluate the use of DWl with 1VIM and monoexponential models to predict and monitor the efficacy of NACT in cervical cancer. Methods： Forty-two patients with primary cervical cancer underwent magnetic resonance exams at 3 time points （pre-NACT, 3 weeks after the first NACT cycle, and 3 weeks after the second NACT cycle）. The response to treatment was determined according to the response evaluation criteria in solid tumors 3 weeks after the second NACT treatment, and the subjects were classified as two groups： responders and nonresponders groups. The apparent diffusion coefficient （ADC）, true diffusion coefficient （D）, perfusion-related pseudo-diffusion coefficient （D＊）, and perfusion fraction （f） values were determined. The differences in IVlM-derived variables and ADC between the different groups at the different time points were calculated using an independent samples t-test. Results： The D and ADC values were all significantly higher for the responders than tbr the nonresponders at all 3 time points, but no significant differences were observed in the D＊ and fvalues. An analysis of the receiver operating characteristic （ROC） curves indicated that a D value threshold 〈0.93 × 10 3 mm2/s and an ADC threshold 〈1.11× 10 3 mm2/s could differentiate responders from nonresponders at pre-NACT time point, yielding area under the curve （AUC） of which were 0.771 and 0.806, respectively. The ROC indicated that the AUCs of D and ADC at the 3 weeks after the first NACT cycle and 3 weeks after the second NACT cycle were 0.823, 0.763, and 0.787, 0.794, respectively. The AUC values of D and ADC at these 3 time points were not significantly different （P = 0.641, 0.512, and 0.547, respectively）. Conclusions： D and ADC values may be useful for predicting and monitoring the efficacy of NACT in cervical cancer. An IVIM model may be equal to monoexponential model in predicting and monitoring the efficacy of NACT in cervical cancer.展开更多
Background The diagnosis of liver fibrosis is a difficult task at any time using conventional clinical imaging.Intravoxel incoherent motion （IVIM） can be used to investigate both diffusion and perfusion changes in t...Background The diagnosis of liver fibrosis is a difficult task at any time using conventional clinical imaging.Intravoxel incoherent motion （IVIM） can be used to investigate both diffusion and perfusion changes in tissues.This study was designed to determine the value of IVIM in the diagnosis and staging of liver fibrosis.Methods IVIM examinations were performed on a GE 3.0T MR scanner in 25 patients with liver fibrosis and 25 healthy volunteers as the control group.Patients with liver fibrosis diagnosis were confirmed by pathology and staged on a scale of F0-4.The standard ADC values and the values of a biexponential model （slow ADC （Dslow）,fast ADC （Dfast） and fraction of fast ADC （FF）） were measured in three liver regions per person.The mean standard ADC values,Dslow values,Dfast values and FF values from the study group were compared among the right posterior hepatic lobe,right anterior hepatic lobe and medial segment of the left lobe.Receiver Operating Characteristic （ROC） curves and independent-samples t-tests were used to calculate the mean standard ADC values,Dslow values,Dfast values and FF values from the study group and the control group.Spearman rho correlation analysis was used for the stage of liver fibrosis.The liver fibrosis stages between the groups F0-1 and F2-4,the groups F0-2 and F3-4 were compared.Results Among the liver fibrosis,there was no significant difference in the mean standard ADC values,Dslow values,Dfast values,and FF values obtained from the right posterior hepatic lobe,right anterior hepatic lobe and medial segment of the left lobe.Using ROC analysis,the Area Under the Curve （AUC） values of standard ADC,Dslow,Dfast,FF were all between 0.7 to 0.9.The mean standard ADC values,Dslow values,Dfast values and FF values of the liver in the study group were significantly lower than the values in the control group （P ＜0.05）.As the stage of the fibrosis increased,the values decreased by Spearman rho correlation analysis.The mean values （standard ADC,Dslow,Dfast,and FF） of liver fibrosis stages between the groups F0-1 and F2-4,the groups F0-2 and F3-4 showed significant differences （P＜0.05）.Conclusions IVIM can reflect the conditions of perfusion and diffusion in liver fibrosis and thus distinguish between normal liver and liver fibrosis.The IVIM technique may serve as a valuable tool for detecting and characterizing liver fibrosis,and monitoring its progression in a noninvasive manner.展开更多
目的 比较磁共振小视野体素不相干运动扩散加权成像(reduced field of view,intravoxel incoherent motion,r-fov IVIM)及小视野常规扩散加权成像(reduced field of view,diffusion weighted imaging,r-fov DWI)模型参数预测乳腺侵润性...目的 比较磁共振小视野体素不相干运动扩散加权成像(reduced field of view,intravoxel incoherent motion,r-fov IVIM)及小视野常规扩散加权成像(reduced field of view,diffusion weighted imaging,r-fov DWI)模型参数预测乳腺侵润性导管癌新辅助化疗疗效的价值。方法 前瞻性选取28例单侧乳腺浸润性导管癌患者,收集化疗前、化疗2周期后乳腺r-fov IVIM模型参数真性扩散系数(Dt),假性扩散系数(Dp),灌注分数(f);r-fov DWI参数表观扩散系数(ADC)。根据术后病理结果分为组织学非显著反应组13人,组织学显著反应组15人;采用SPSS 25.0对数据进行处理,比较NAC前和化疗2个周期后两组间的参数值差异。绘制受试者工作特征曲线(receiver operating characteristic,ROO曲线分析以上参数对新辅助化疗疗效的预测价值。结果NAC2周期后ADC值,NAC2周期后与NAC前参数差值ΔADC、ΔDt值,三者的曲线下面积(area under curve,AUC)最大(0.951 VS 0.914、0.914),预测MHR组的效能高;NAC2周期后的Dt值,预测MHR组的效能较好(AUC=0.827)。结论 NAC2周期后,r-fov DWI模型参数ADC值和r-fov IVIM模型参数Dt值越高,且较NAC前升高程度越大,新辅助化疗结束后越容易获得较好的疗效;其中,以NAC2周期后,r-fovDWI模型参数ADC值的预测效能最高,应作为乳腺癌浸润性导管癌临床治疗过程中,新辅助化疗反应评估的主要参考参数。展开更多
基金Supported by grants from the the National Natural Science Foundation of China(No.81371524,81271529)the Hubei Provincial Natural Science Foundation of China(No.2014CFB298)
文摘Objective The aim of this study was to investigate the ability of intravoxel incoherent motion(IVIM) diffusion-weighted magnetic resonance imaging(MRI) to diagnose cervical cancer and to evaluate the response of uterine cervical cancer to radiochemotherapy(CRT).Methods This prospective study was approved by the institutional review board, and informed consent was obtained from all patients. A total of 23 patients with primary cervical cancer who were undergoing CRT and 16 age-matched healthy subjects were prospectively recruited for IVIM(b = 0–800 s/mm2) and standard pelvic MRI. Bi-exponential analysis was performed to derive f(perfusion fraction), D*(pseudo-diffusion coefficient), and D(true molecular diffusion coefficient) in cervical cancer(n = 23) and the normal cervix(n = 16). The apparent diffusion coefficient(standard ADC) was calculated. The independent-samples t-test and paired-samples t-test were used for comparisons.Results Pre-treatment cervical cancer had the lowest standard ADC(1.15 ± 0.13 × 10-3 mm2/s) and D(0.89 ± 0.10 × 10-3 mm2/s) values, and these were significantly different from the normal cervix and posttreatment cervical cancer(P = 0.00). The f(16.67 ± 5.85%) was lowest in pre-treatment cervical cancer and was significantly different from the normal cervix and post-treatment cervical cancer(p = 0.012 and 0.00, respectively). No difference was observed in D*.Conclusion IVIM is potentially promising for differentiating between the normal cervix and cervical cancer because pre-treated cervical cancer has low perfusion and diffusion IVIM characteristics. Further, the standard ADC, D, and f of cervical cancer showed a tendency to normalize after CRT; thus, IVIM may be useful for monitoring the response to CRT in cervical cancer.
文摘Intravoxel incoherent motion imaging (IVIM), on the traditional diffusion weighted imaging (DWI) technology, uses the biexponential model and adopts the multi-b-value analysis to obtain the perfusion information of water molecule diffusion and microcirculation without the use of contrast agent. It is more and more used in pancreatic diseases, which is of great significance for the diagnosis and identification of pancreatic cancer. This article will review the principles of IVIM imaging and its application in pancreatic diseases, especially in pancreatic cancer diagnosis, the prediction of pathological grade of pancreatic ductal adenocarcinoma, the judgment of lymph node metastasis, and differentiation of pathological classification.
基金Supported by the National Nature Science Foundation of China,No.81771797 and No.81971571the 1.3.5 Project for Disciplines of Excellence,West China Hospital,Sichuan University,No.ZYJC18008。
文摘BACKGROUND Liver fibrosis(LF) is a common pathological feature of all chronic liver diseases.With the accumulation of extracellular matrix in the fibrotic liver, true molecular water diffusion and perfusion-related diffusion are restricted. Intravoxel incoherent motion(IVIM) can capture the information on tissue diffusivity and microcapillary perfusion separately and reflect the fibrotic severity with diffusion coefficients.AIM To investigate the diagnostic performance of IVIM in detecting and staging LF with histology as a reference standard.METHODS A comprehensive literature search was conducted to identify studies on the diagnostic accuracy of IVIM for assessment of histologically proven LF. The stages of LF were classified as F0(no fibrosis), F1(portal fibrosis without septa),F2(periportal fibrosis with few septa), F3(septal fibrosis), and F4(cirrhosis)according to histopathological findings. Data were extracted to calculate the pooled sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio, as well as the area under the summary receiver operating characteristic curve(AUC) in each group.RESULTS A total of 12 studies with 923 subjects were included in this meta-analysis with 5 studies(n = 465) for LF ≥ F1, 9 studies(n = 757) for LF ≥ F2, 4 studies(n = 413) for LF ≥ F3, and 6 studies(n = 562) for LF = F4. The pooled sensitivity and specificity were estimated to be 0.78(95% confidence interval: 0.73-0.82) and 0.81(0.74-0.86)for LF ≥ F1 detection with IVIM;0.82(0.79-0.86) and 0.80(0.75-0.84) for staging F2 fibrosis;0.85(0.79-0.90) and 0.83(0.77-0.87) for staging F3 fibrosis, and 0.90(0.84-0.94) and 0.75(0.70-0.79) for detecting F4 cirrhosis, respectively. The AUCs for LF≥ F1, F2, F3, F4 detection were 0.862(0.811-0.914), 0.883(0.856-0.909), 0.886(0.865-0.907), and 0.899(0.866-0.932), respectively. Moderate to substantial heterogeneity was observed with inconsistency index(I2) ranging from 0% to 77.9%. No publication bias was detected.CONCLUSION IVIM is a noninvasive tool with good diagnostic performance in detecting and staging LF. Optimized and standardized IVIM protocols are needed to further improve its diagnostic accuracy in clinical practice.
文摘Diffusion-weighted magnetic resonance imaging(DWMRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer.It has been proven valuable as a functional tool for qualitative and quantitative analysis of prostate cancer beyond anatomical MRI sequences such as T2-weighted imaging. This review discusses ongoing controversies in DW-MRI acquisition, including the optimal number of b-values to be used for prostate DWI, and summarizes the current literature on the use of advanced DWMRI techniques. These include intravoxel incoherent motion imaging, which better accounts for the nonmono-exponential behavior of the apparent diffusion coefficient as a function of b-value and the influence of perfusion at low b-values. Another technique is diffusion kurtosis imaging(DKI). Metrics from DKI reflect excess kurtosis of tissues, representing its deviation from Gaussian diffusion behavior. Preliminary results suggest that DKI findings may have more value than findings from conventional DW-MRI for the assessment of prostate cancer.
基金This work was supported by the grants form National Natural Science Foundation of China （No. 81371524 and No. 81271529） and the Hubei Provincial Natural Science Foundation of China （No. 2014CFB298）.
文摘Background： Diffusion-weighted imaging （DWI） with the intravoxel incoherent motion （IVIM） model has shown promising results for providing both diffusion and perfusion intbrmation in cervical cancer; however, its use to predict and monitor the efficacy ofneoadjuvant chemotherapy （NACT） in cervical cancer is relatively rare. The study aimed to evaluate the use of DWl with 1VIM and monoexponential models to predict and monitor the efficacy of NACT in cervical cancer. Methods： Forty-two patients with primary cervical cancer underwent magnetic resonance exams at 3 time points （pre-NACT, 3 weeks after the first NACT cycle, and 3 weeks after the second NACT cycle）. The response to treatment was determined according to the response evaluation criteria in solid tumors 3 weeks after the second NACT treatment, and the subjects were classified as two groups： responders and nonresponders groups. The apparent diffusion coefficient （ADC）, true diffusion coefficient （D）, perfusion-related pseudo-diffusion coefficient （D＊）, and perfusion fraction （f） values were determined. The differences in IVlM-derived variables and ADC between the different groups at the different time points were calculated using an independent samples t-test. Results： The D and ADC values were all significantly higher for the responders than tbr the nonresponders at all 3 time points, but no significant differences were observed in the D＊ and fvalues. An analysis of the receiver operating characteristic （ROC） curves indicated that a D value threshold 〈0.93 × 10 3 mm2/s and an ADC threshold 〈1.11× 10 3 mm2/s could differentiate responders from nonresponders at pre-NACT time point, yielding area under the curve （AUC） of which were 0.771 and 0.806, respectively. The ROC indicated that the AUCs of D and ADC at the 3 weeks after the first NACT cycle and 3 weeks after the second NACT cycle were 0.823, 0.763, and 0.787, 0.794, respectively. The AUC values of D and ADC at these 3 time points were not significantly different （P = 0.641, 0.512, and 0.547, respectively）. Conclusions： D and ADC values may be useful for predicting and monitoring the efficacy of NACT in cervical cancer. An IVIM model may be equal to monoexponential model in predicting and monitoring the efficacy of NACT in cervical cancer.
文摘Background The diagnosis of liver fibrosis is a difficult task at any time using conventional clinical imaging.Intravoxel incoherent motion （IVIM） can be used to investigate both diffusion and perfusion changes in tissues.This study was designed to determine the value of IVIM in the diagnosis and staging of liver fibrosis.Methods IVIM examinations were performed on a GE 3.0T MR scanner in 25 patients with liver fibrosis and 25 healthy volunteers as the control group.Patients with liver fibrosis diagnosis were confirmed by pathology and staged on a scale of F0-4.The standard ADC values and the values of a biexponential model （slow ADC （Dslow）,fast ADC （Dfast） and fraction of fast ADC （FF）） were measured in three liver regions per person.The mean standard ADC values,Dslow values,Dfast values and FF values from the study group were compared among the right posterior hepatic lobe,right anterior hepatic lobe and medial segment of the left lobe.Receiver Operating Characteristic （ROC） curves and independent-samples t-tests were used to calculate the mean standard ADC values,Dslow values,Dfast values and FF values from the study group and the control group.Spearman rho correlation analysis was used for the stage of liver fibrosis.The liver fibrosis stages between the groups F0-1 and F2-4,the groups F0-2 and F3-4 were compared.Results Among the liver fibrosis,there was no significant difference in the mean standard ADC values,Dslow values,Dfast values,and FF values obtained from the right posterior hepatic lobe,right anterior hepatic lobe and medial segment of the left lobe.Using ROC analysis,the Area Under the Curve （AUC） values of standard ADC,Dslow,Dfast,FF were all between 0.7 to 0.9.The mean standard ADC values,Dslow values,Dfast values and FF values of the liver in the study group were significantly lower than the values in the control group （P ＜0.05）.As the stage of the fibrosis increased,the values decreased by Spearman rho correlation analysis.The mean values （standard ADC,Dslow,Dfast,and FF） of liver fibrosis stages between the groups F0-1 and F2-4,the groups F0-2 and F3-4 showed significant differences （P＜0.05）.Conclusions IVIM can reflect the conditions of perfusion and diffusion in liver fibrosis and thus distinguish between normal liver and liver fibrosis.The IVIM technique may serve as a valuable tool for detecting and characterizing liver fibrosis,and monitoring its progression in a noninvasive manner.
文摘目的 比较磁共振小视野体素不相干运动扩散加权成像(reduced field of view,intravoxel incoherent motion,r-fov IVIM)及小视野常规扩散加权成像(reduced field of view,diffusion weighted imaging,r-fov DWI)模型参数预测乳腺侵润性导管癌新辅助化疗疗效的价值。方法 前瞻性选取28例单侧乳腺浸润性导管癌患者,收集化疗前、化疗2周期后乳腺r-fov IVIM模型参数真性扩散系数(Dt),假性扩散系数(Dp),灌注分数(f);r-fov DWI参数表观扩散系数(ADC)。根据术后病理结果分为组织学非显著反应组13人,组织学显著反应组15人;采用SPSS 25.0对数据进行处理,比较NAC前和化疗2个周期后两组间的参数值差异。绘制受试者工作特征曲线(receiver operating characteristic,ROO曲线分析以上参数对新辅助化疗疗效的预测价值。结果NAC2周期后ADC值,NAC2周期后与NAC前参数差值ΔADC、ΔDt值,三者的曲线下面积(area under curve,AUC)最大(0.951 VS 0.914、0.914),预测MHR组的效能高;NAC2周期后的Dt值,预测MHR组的效能较好(AUC=0.827)。结论 NAC2周期后,r-fov DWI模型参数ADC值和r-fov IVIM模型参数Dt值越高,且较NAC前升高程度越大,新辅助化疗结束后越容易获得较好的疗效;其中,以NAC2周期后,r-fovDWI模型参数ADC值的预测效能最高,应作为乳腺癌浸润性导管癌临床治疗过程中,新辅助化疗反应评估的主要参考参数。
