Value of multiple models of diffusion-weighted imaging to predict hepatic lymph node metastases in colorectal liver metastases patients

BACKGROUND About 10%-31% of colorectal liver metastases(CRLM)patients would concomitantly show hepatic lymph node metastases(LNM),which was considered as sign of poor biological behavior and a relative contraindication for liver resection.Up to now,there’s still lack of reliable preoperative methods to assess the status of hepatic lymph nodes in patients with CRLM,except for pathology examination of lymph node after resection.AIM To compare the ability of mono-exponential,bi-exponential,and stretchedexponential diffusion-weighted imaging(DWI)models in distinguishing between benign and malignant hepatic lymph nodes in patients with CRLM who received neoadjuvant chemotherapy prior to surgery.METHODS In this retrospective study,97 CRLM patients with pathologically confirmed hepatic lymph node status underwent magnetic resonance imaging,including DWI with ten b values before and after chemotherapy.Various parameters,such as the apparent diffusion coefficient from the mono-exponential model,and the true diffusion coefficient,the pseudo-diffusion coefficient,and the perfusion fraction derived from the intravoxel incoherent motion model,along with distributed diffusion coefficient(DDC)andαfrom the stretched-exponential model(SEM),were measured.The parameters before and after chemotherapy were compared between positive and negative hepatic lymph node groups.A nomogram was constructed to predict the hepatic lymph node status.The reliability and agreement of the measurements were assessed using the coefficient of variation and intraclass correlation coefficient.RESULTS Multivariate analysis revealed that the pre-treatment DDC value and the short diameter of the largest lymph node after treatment were independent predictors of metastatic hepatic lymph nodes.A nomogram combining these two factors demonstrated excellent performance in distinguishing between benign and malignant lymph nodes in CRLM patients,with an area under the curve of 0.873.Furthermore,parameters from SEM showed substantial repeatability.CONCLUSION The developed nomogram,incorporating the pre-treatment DDC and the short axis of the largest lymph node,can be used to predict the presence of hepatic LNM in CRLM patients undergoing chemotherapy before surgery.This nomogram was proven to be more valuable,exhibiting superior diagnostic performance compared to quantitative parameters derived from multiple b values of DWI.The nomogram can serve as a preoperative assessment tool for determining the status of hepatic lymph nodes and aiding in the decision-making process for surgical treatment in CRLM patients.

Intravoxel incoherent motion diffusion-weighted magnetic resonance imaging for predicting histological grade of hepatocellular carcinoma:Comparison with conventional diffusion-weighted imaging

AIM To compare intravoxel incoherent motion(IVIM)-derived parameters with conventional diffusion-weighted imaging(DWI) parameters in predicting the histological grade of hepatocellular carcinoma(h CC) and to evaluate the correlation between the parameters and the histological grades.METHODS A retrospective study was performed. Sixty-two patients with surgically confirmed h CCs underwent diffusion-weighted magnetic resonance imaging with twelve b values(10-1200 s/mm^2). The apparent diffusion coefficient(ADC), pure diffusion coefficient(D), pseudo-diffusion coefficient(D*), and perfusion fraction(f) were calculated by two radiologists. The IVIM and conventional DWI parameters were compared among the different grades by using analysis of variance(ANOVA) and the Kruskal-Wallis test. Receiver operating characteristic(ROC) analysis was performed to evaluate the diagnostic efficiency of distinguishing between low-grade(grade 1, G1) and high-grade(grades 2 and 3, G2 and G3) hC C. The correlation between the parameters and the histological grades was assessed by using the Spearman correlation test. Bland-Altman analysis was used to evaluate the reproducibility of the two radiologists' measurements.RESULTS The differences in the ADC and D values among the groups with G1, G2, and G3 histological grades of HCCs were statistically significant(P < 0.001). The D* and f values had no significant differences among the different histological grades of h CC(P > 0.05). The ROC analyses demonstrated that the D and ADC values had better diagnostic performance in differentiating the low-grade h CC from the high-grade h CC, with areas under the curve(AUCs) of 0.909 and 0.843, respectively, measured by radiologist 1 and of 0.911 and 0.852, respectively, measured by radiologist 2. The following significant correlations were obtained between the ADC, D, and D~* values and the histological grades: r =-0.619(P < 0.001), r =-0.628(P < 0.001), and r =-0.299(P = 0.018), respectively, as measured by radiologist 1; r =-0.622(P < 0.001), r =-0.633(P < 0.001), and r =-0.303(P = 0.017), respectively, as measured by radiologist 2. The intra-class correlation coefficient(ICC) values between the two observers were 0.996 for ADC, 0.997 for D, 0.996 for D*, and 0.992 for f values, which indicated excellent interobserver agreement in the measurements between the two observers.CONCLUSION The IVIM-derived D and ADC values show better diagnostic performance in differentiating high-grade hC C from low-grade hC C, and there is a moderate to good correlation between the ADC and D values and the histological grades.

Liver intravoxel incoherent motion diffusion-weighted imaging for the assessment of hepatic steatosis and fibrosis in children

AIM To evaluate the correlation between intravoxel incoherent motion(IVIM) diffusion-weighted imaging(DWI) parameters and the degree of hepatic steatosis and fibrosis in children.METHODS This retrospective study was approved by the institutional review board. The children(≤ 18 years) who underwent liver IVIM DWI with 8 b-values under the suspicion of hepatic steatosis or fibrosis from February 2013 to November 2016 were included. Subjects were divided into normal, fatty liver(FAT), and fibrotic liver(FIB) groups. The slow diffusion coefficient(D), fast diffusion coefficient(D*), perfusion fraction(f), and apparent diffusion coefficient(ADC) were measured. MR proton density fat fraction(PDFF), MR elastography(MRE), and IVIM values were compared.RESULTS A total of 123 children(median age of 12 years old, range: 6-18 years) were included, with 8 in the normal group, 93 in the FAT group, and 22 in the FIB group. The D* values were lower in the FIB group compared with those of the normal(P = 0.015) and FAT(P = 0.003) groups. The f values were lower in the FIB group compared with the FAT group(P = 0.001). In multivariate analyses, PDFF value was positively correlated with f value(β = 3.194, P < 0.001), and MRE value was negatively correlated with D* value(β =-7.031, P = 0.032). The D and ADC values were not influenced by PDFF or MRE value.CONCLUSION In liver IVIM DWI with multiple b-values in children, there was a positive correlation between hepatic fat and blood volume, and a negative correlation between hepatic stiffness and endovascular blood flow velocity, while diffusion-related parameters were not affected.

Intravoxel Incoherent Motion Diffusion Weighted Imaging for the Therapeutic Response of Transarterial Chemoembolization for Hepatocellular Carcinoma

Background: Intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) can not only observe the diffusion of tissue water molecules but also reflect the blood perfusion information of tissue microcirculation. IVIM-DWI has been applied in many clinical areas. However, few studies have addressed the use of IVIM-DWI for the evaluation of transarterial chemoembolization (TACE) response in hepatocellular carcinoma (HCC) patients. Objectives: The purpose of the present study was to explore the role of IVIM-DWI for the therapeutic response of TACE for HCC. Materials and Methods: Twenty patients underwent IVIM-DWI scan on a 3.0T magnetic resonance imaging instrument 1 - 3 days before and 30 to 40 days after TACE. The values of IVIM-DWI parameters, including standard apparent diffusion coefficient (ADC), pure diffusion coefficient (Dslow), pseudo-diffusion coefficient (Dfast) and perfusion fraction (f) were measured. The values of IVIM-DWI parameters before and after TACE were compared using paired t tests. The values between responsive and non-responsive groups were compared using independent-samples t test. P 0.05 indicated statistical significance. Results: After TACE, the ADC and Dslow values in the tumors increased significantly, and the values of Dfast decreased significantly, while the values of f value did not change obviously. The ADC values in responsive group were remarkably higher than those in non-responsive group, the Dfast values in responsive group were significantly lower than those in non-responsive group, but the values of Dslow and f between the two groups were not different significantly. Conclusions: IVIM-DWI parameters can be used as potential markers for the therapeutic response of TACE for HCC.

Application Progress of Intravoxel Incoherent Motion Diffusion Weighted Magnetic Resonance Imaging in Pancreatic Cancer

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.

Chemotherapy response evaluation in a mouse model of gastric cancer using intravoxel incoherent motion diffusionweighted MRI and histopathology

AIM To determine the role of intravoxel incoherent motion(IVIM) diffusion-weighted(DW) magnetic resonance imaging(MRI) using a bi-exponential model in chemotherapy response evaluation in a gastric cancer mouse model.METHODS Mice bearing MKN-45 human gastric adenocarcinoma xenografts were divided into four treated groups(TG1, 2, 3 and 4, n = 5 in each group) which received Fluorouracil and Calcium Folinate and a control group(CG, n = 7). DW-MRI scans with 14 b-values(0-1500 s/mm2) were performed before and after treatment on days 3, 7, 14 and 21. Fast diffusion component(presumably pseudo-perfusion) parameters including the fast diffusion coefficient(D*) and fraction volume(f p), slow diffusion coefficient(D) and the conventional apparent diffusion coefficients(ADC) were calculated by fitting the IVIM model to the measured DW signals. The median changes from the baseline to each posttreatment time point for each measurement(ΔADC, ΔD* and Δf p) were calculated. The differences in the median changes between the two groups were compared using the mixed linear regression model by the restricted maximum likelihood method shown as z values. Histopathological analyses including Ki-67, CD31, TUNEL and H&E were conducted in conjunction with the MRI scans. The median percentage changes were compared with the histopathological analyses between the pre-and post-treatment for each measurement.RESULTS Compared with the control group, D* in the treated group decreased significantly(ΔD*treated% =-30%,-34% and-20%, with z =-5.40,-4.18 and-1.95. P = 0.0001, 0.0001 and 0.0244) and f p increased significantly(Δfptreated% = 93%, 113% and 181%, with z = 4.63, 5.52, and 2.12, P = 0.001, 0.0001 and 0.0336) on day 3, 7 and 14, respectively. Increases in ADC in the treated group were higher than those in the control group on days 3 and 14(z = 2.44 and 2.40, P = 0.0147 and P = 0.0164). CONCLUSION Fast diffusion measurements derived from the biexponential IVIM model may be more sensitive imaging biomarkers than ADC to assess chemotherapy response in gastric adenocarcinoma.

Updates in advanced diffusion-weighted magnetic resonance imaging techniques in the evaluation of prostate cancer

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.

Value of intravoxel incoherent motion in detecting and staging liver fibrosis: A meta-analysis

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.

基于扩散加权成像及MRI对四肢软组织肿瘤的诊断价值

目的 探讨基于扩散加权成像及MRI对四肢软组织肿瘤(soft tissue tumors,STTs)的诊断价值。方法 选取本院经病理证实的四肢STTs患者74例,其中良性46例(良性组)、恶性28例(恶性组),均行常规MRI、DWI、IVIM及DKI扫描,分析两组常规MRI检查征象及诸参数差异,包括表观扩散系数(ADC)、真实扩散系数(D)、灌注相关扩散系数(D~*)、灌注分数(f)、平均扩散峰度值(MK)和平均扩散率(MD);运用ROC曲线分析其诊断效能。结果 恶性组肿瘤边界多不清且呈浸润性生长,以团块状为主,瘤周水肿、筋膜尾征多见,50.0%瘤内可见分隔,两组间差异有统计学意义(P<0.05)。恶性组ADC、D和MD值小于良性组,而MK值高于良性组,差异具有统计学意义(P<0.05)。D~*和f值两组差异无统计学意义(P>0.05)。ADC、D、MD、MK值在鉴别四肢STTs良恶性方面均具有一定诊断效能:AUC≥0.688,敏感度≥63.0%,特异度≥67.9%,准确度≥64.9%,其中MD值的诊断效能、特异度最高。ADC+D+MD+MK联合后,AUC为0.887,诊断效能均高于单一参数(Z=1.978~3.101;P<0.05),敏感度为76.1%,特异度为92.9%,准确度78.4%。结论 基于扩散加权成像及MRI对四肢STTs良恶性有较好的判断价值,值得临床推广。

多参数MRI联合临床危险因素术前预测直肠癌淋巴血管间隙侵犯的应用价值

目的探讨多参数MRI联合临床危险因素术前预测直肠癌淋巴血管间隙侵犯(LSVI)的价值。方法回顾性分析池州市人民医院2022年4月至2023年11月经术后病理证实的38例直肠癌患者的临床及影像学资料,所有患者均行常规MRI、合成MRI及IVIM-DWI序列扫描。依据术后病理结果分为LVSI阳性组(n=14)和LVSI阴性组(n=24)。采用单因素和多因素logistic回归分析LVSI阳性组和LVSI阴性组的临床资料,分析LVSI的临床危险因素;比较两组患者合成MRI(T1值、T2值、PD值)及IVIM-DWI参数(D值、D*值、f值),采用受试者工作特征(ROC)曲线评价各定量参数预测模型及联合临床危险因素预测模型的诊断效能。结果合成MRI的T2值及IVIM-DWI的D值、f值在直肠癌LVSI阳性组和阴性组中比较差异具有统计学意义(P<0.05)。术前CEA(OR=10.818,95%CI:1.391~84.124)及临床N分期(OR=11.852,95%CI:1.534~91.552)是直肠癌LVSI的独立危险因素(P<0.05)。单独的T2值、D值、f值及三者联合的曲线下面积(AUC)分别为0.801、0.747、0.766、0.807,联合临床危险因素的预测模型效能最高(AUC=0.845),灵敏度为78.58%,特异度为100%。结论多参数MRI术前可有效预测直肠癌LVSI的状态,结合临床危险因素的联合预测模型可进一步提升预测效能,有助于临床医师制定个性化直肠癌治疗方案。

DCE-MRI和IVIM-DWI评估直肠癌微血管含量的比较研究

目的:探讨动态对比增强磁共振成像(dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI)和体素内不相干运动弥散加权成像(intravoxel incoherent motion diffusion-weighted imaging,IVIM-DWI)在评估直肠癌微血管含量中的差异。方法:研究2019年12月—2022年12月上海中医药大学附属曙光医院经病理学检查诊断为直肠腺癌并行IVIMDWI和DCE-MRI扫描的患者23例。Tofts模型计算DCE-MRI参数为容积分数(volume fraction,V_(e))、容量转移常数(space transport coefficient,K^(trans))和速率常数(rate constant,K_(ep))。IVIM-DWI参数:单纯弥散系数(simple diffusion coefficient,D),灌注相关弥散系数(perfusion related diffusion coefficient,D^(*)),灌注分数(perfusion fraction,f),通过计算双指数模型得到。对与直肠癌微血管含量相关的DCE-MRI和IVIM-DWI定量参数进行分析比较。结果:不同病理学分级的直肠癌K^(trans)和D差异有统计学意义(F=9.159,P=0.002;F=5.106,P=0.016)。在评估直肠癌病理学分级时,K^(trans)优于D。灌注参数K^(trans),K_(ep)和D^(*)与直肠癌微血管含量呈显著正相关(r=0.734,P<0.001;r=0.617,P=0.002;r=0.456,P=0.029)。其中DCE-MRI定量参数评估直肠癌微血管含量优于IVIM-DWI定量参数。结论:与IVIM-DWI相比,DCE-MRI评价直肠癌分化程度和微循状态方面效能更佳。但是考虑到IVIM-DWI不需要注射对比剂,IVIM-DWI仍然可以被推荐用于直肠癌分化程度和微循环状态。

IVIM-DWI基于肝段水平对肝纤维化患者测量的可重复性及诊断效能

目的评估肝纤维化患者应用体素内不相干运动扩散加权成像(IVIM-DWI)测量的可重复性,并评估基于肝右叶肝段的IVIM-DWI相关参数对早期及中晚期肝纤维化的诊断效能。方法2020年6月~2022年9月期间招募早期肝纤维化及晚期肝纤维化患者,使用IVIM-DWI序列进行肝脏扫描。两名检查者基于肝右叶各段水平,应用单指数模型、双指数模型和拉伸指数模型测量相关参数数据。对获得的测量数据应用变异系数(CV)进行可重复性检验,剔除可重复性较低(CV>20%)的肝段参数后,用Logistic回归分析最终纳入的IVIM-DWI参数,计算诊断效能并描绘ROC曲线。结果59名早期肝纤维化和38名晚期肝纤维化患者被纳入研究。获得的数据中,D*(CV:29.25%~41.47%)和DDC(CV:22.44%~30.63%)的可重复性较差,而ADC(CV:5.29%~9.76%)、D(9.53%~13.22%)、f(CV:12.83%~16.95%)和α(CV:8.82%~15.52%)的可重复性较好。剔除可重复性较低的参数后,Logistic回归分析建立早期肝纤维化与晚期肝纤维化组的诊断模型并描绘ROC曲线,最终纳入模型的肝段水平参数为SⅦD及SⅧf,最终回归模型的曲线下面积(AUC)为0.857。结论基于肝段的高可重复性,IVIM-DWI对肝纤维化仍能获得较好的诊断效能,其中D、f参数以及肝右叶上段SⅦ、SⅧ在满足可重复性的前提下,可能是较稳定的肝纤维化分级诊断因素。

Assessing the Early Response of Advanced Cervical Cancer to Neoadjuvant Chemotherapy Using Intravoxel Incoherent Motion Diffusion-weighted Magnetic Resonance Imaging： A Pilot Study

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.

IVIM联合DKI成像技术在肝纤维化分级中的应用价值

目的探讨体素内不相干运动成像(IVIM)联合扩散峰度成像(DKI)成像技术在肝纤维化分级中的应用价值。方法选取我院2021年10月至2023年6月期间80例肝纤维化患者(F1期29例、F2期27例、F3-4期24例),纳入观察组,同时期健康体检者50例,纳入对照组,均行肝脏MRI检查,获取IVIM、DKI参数。比较观察组与对照组以及观察组不同肝纤维化分级患者的IVIM、DKI参数,分析各参数与肝纤维化分级之间的相关性,分析肝纤维化分级≥F2期的独立相关因素,构建预测模型,采用受试者工作特征(ROC)曲线分析模型的预测价值。结果观察组IVIM参数ADC、D、D、f值及DKI参数MD值均小于对照组(P<0.05),DKI参数MK、K值均大于对照组(P<0.05);F3-4期患者IVIM参数ADC、D、D、f值及DKI参数MD值均小于F1期、F2期患者(P<0.05),DKI参数MK、K值均大于F1期、F2期患者(P<0.05);Spearman相关性分析显示,肝纤维化分级与ADC、D、D、f、MD值均呈负相关(P<0.05),与MK、K值均呈正相关(P<0.05);Logistic多因素回归分析显示,ADC、D、D、f、MD值均为肝纤维化分级≥F2期的独立相关因素(P<0.05);构建肝纤维化分级≥F2期的预测模型:Y=-4.512-2.819 X1-2.412 X2-1.763 X3-1.338 X4-1.582 X5,ROC曲线显示该模型预测肝纤维化分级≥F2期的ROC曲线下面积为0.926(95%CI=0.881-0.970,P<0.001),最佳截断值对应的敏感度、特异度、约登指数分别为89.20%、87.80%、0.770,拟合优度检验显示χ^(2)=8.205,P=0.084,调整后的R2=0.823。结论IVIM与DKI在肝纤维化分级中具有一定应用价值,结合IVIM与DKI参数所构建的预测模型对于肝纤维化分级≥F2期的患者具有较高的预测精度。

IVIM-DWI及多层螺旋CT与肝细胞肝癌微血管侵犯的相关性分析

目的探究体素内不相干运动扩散加权成像(IVIM-DWI)多层螺旋CT(MSCT)与肝细胞肝癌(HCC)微血管侵犯(MVI)的相关性分析。方法选取2019年12月至2022年12月本院收治HCC患者100例临床资料开展回顾性分析。所有患者均经过病理检查、VIM-DWI检查与MSCT检查。100例患者经手术病理确诊为MVI阳性38例,MVI阴性62例。比较两组IVIM-DWI、MSCT定性、定量参数分析的差异,并通过ROC曲线分析IVIM-DWI定量参数、MSCT定量参数及联合数据对HCC存在MVI的诊断价值。结果MVI阳性组边缘毛糙、瘤周低信号、瘤周强化、存在晕征高于MVI阴性组(P<0.05),肿瘤包膜低于MVI阴性组(P<0.05)。两组D、F比较差异无统计学意义(P>0.05),但MVI阳性组ADC、D低于MVI阴性组(P<0.05)。MVI阳性组动脉期CT值低于MVI阴性组(P<0.05),延迟期CT值、门静脉期CT值、肿瘤大小高于MVI阴性组(P<0.05)。ROC曲线分析显示,ADC、D、D、f、延迟期CT值、门静脉期CT值、动脉期CT值、肿瘤大小诊断HCC存在MVI的AUC分别为0.775、0.856、0.609、0.565、0.708、0.728、0.643、0.705。MSCT参数、IVIM-DWI参数、联合数据诊断HCC存在MVI的AUC分别为0.809、0.832、0.920,均具有较好准确性。结论IVIM-DWI、MSCT定性、定量参数均与HCC患者MVI相关,而IVIMDWI、MSCT诊断MVI均具有一定价值,且联合诊断准确性更高。

磁共振增强T1 mapping和IVIM-DWI技术评估乙型肝炎肝硬化患者肝脏储备功能价值研究

目的分析应用磁共振(MR)体素内不相干运动扩散加权成像(IVIM-DWI)和钆塞酸二钠增强T1 mapping参数评估乙型肝炎肝硬化患者肝脏储备功能的价值。方法2020年3月~2022年3月我院诊治的乙型肝炎肝硬化患者60例,接受吲哚菁绿15 min滞留率检测和MR增强扫描,测量增强前20 min和增强后20 min T1弛豫时间,计算肝细胞增强分数,并应用Mltalytics 1.0.1软件自动测算表观扩散系数(ADC)和真性水分子扩散系数(D)。应用受试者工作特征(ROC)曲线分析参数评估肝储备的效能。结果在60例肝硬化患者中,吲哚菁绿15 min滞留率<10%者30例(A组),≥10%但<30%者16例(B组),≥30%者14例(C组);C组增强前T1弛豫时间和增强后T1弛豫时间分别为(700.5±71.2)ms和(324.1±99.6)ms,显著长于A组【分别为(612.2±28.3)ms和(148.3±51.9)ms,P<0.05】或B组【分别为(682.5±73.1)ms和(256.2±88.1)ms,P<0.05】,而ADC、D和肝细胞增强分数分别为(0.5±0.1)×10^(3)、(0.5±0.1)×10^(3)和(50.2±11.6)%,均显著低于A组【分别为(1.2±0.1)×10^(3)、(1.0±0.4)×10^(3)和(80.8±10.9)%,P<0.05】或B组【分别为(0.8±0.2)×10^(3)、(0.7±0.2)×10^(3)和(59.4±19.7)%,P<0.05】;ROC曲线分析显示,增强前和增强后20 min T1弛豫时间、ADC、D和肝细胞增强分数评估乙型肝炎肝硬化患者肝脏储备功能均具有较高的价值(灵敏度均在70.0%以上,特异度均在76.7%以上)。结论应用MR IVIM-DWI和T1 mapping参数评估乙型肝炎肝硬化患者肝脏储备功能具有很大的临床价值,可为临床决策提供影像学依据。

多参数磁共振成像鉴别低高危前列腺癌的应用价值

目的 探讨体素内不相干运动扩散加权成像(IVIM-DWI)和扩散峰度成像(DKI)参数在不同Gleason评分前列腺癌(PCa)间的差异,并评估其鉴别低高危PCa的应用价值。方法 回顾2018年1至12月浙江中医药大学附属第一医院经病理检查证实为PCa的49例患者资料,其中低危PCa患者(Gleason评分≤3+4)13例,高危PCa患者(Gleason评分≥4+3)36例。所有患者均行常规前列腺MRI、IVIM-DWI和DKI序列扫描。勾画PCa感兴趣区(PCa-ROI)并测量其表观扩散系数(ADC值)、IVIM主要参数[真性扩散系数(D值)、伪扩散系数(D^(*)值)、灌注分数(f值)]和DKI主要参数[平均扩散系数(MD值)、平均峰度(MK值)]。比较低危组与高危组间各参数的差异,并绘制ROC曲线分析各参数鉴别低高危PCa的效能。结果 低危组的ADC值、D值、D^(*)值、f值、MD值和MK值分别为0.654±0.125、0.355±0.142、18.700(4.290,48.300)、0.421±0.143、1.914±0.506、0.791±0.206;高危组的ADC值、D值、D^(*)值、f值、MD值和MK值分别为0.550±0.118、0.382±0.115、11.600(5.363,29.950)、0.332±0.137、1.496±0.502、0.946±0.196。其中ADC值、MD值和MK值比较差异均有统计学意义(均P<0.05),而D值、D^(*)值、f值比较差异均无统计学意义(均P>0.05)。ADC值、MD值和MK值鉴别低高危PCa时,AUC分别为0.732、0.739和0.750,灵敏度分别为0.692、0.769和0.639,特异度分别为0.750、0.728和0.846。结论 传统ADC值对鉴别低高危PCa已具有一定应用价值,而部分DKI参数具有相同效果,且可能会在其他方面为其提供补充。

体素内不相干运动扩散加权成像在子宫内膜癌中的研究进展

子宫内膜癌(endometrial carcinoma,EC)是我国常见的妇科恶性肿瘤之一。早期病变可以通过手术得到有效治疗,一般不需要辅助治疗,但高危和晚期疾病的治疗比较复杂,治疗方案的制定一般与患者的术前病理诊断、组织学类型以及年龄、有无生育要求等有关。分子分型的提出使我们对异质性有了更深入的了解,在提示预后、评估复发风险、指导治疗以及遗传筛查上都有重要意义。体素内不相干运动(intravoxel incoherent motion,IVIM)采用多b值成像,其衍生参数可以从不同角度全面地反映肿瘤的微观情况,进而同时获得肿瘤内部扩散运动和微循环灌注信息。在这篇综述中,我们概述了体素内不相干运动的原理及其对子宫内膜癌的组织学分型和分子分型、肿瘤分级及浸润深度、术前风险分层以及鉴别诊断等的应用价值,为子宫内膜癌患者的精确诊断和个体化治疗提供数据支持。

体素内不相干运动联合表观扩散系数对前列腺癌诊断价值的研究

目的 探讨体素内不相干运动(intravoxel incoherent motion, IVIM)定量参数联合表观扩散系数(apparent diffusion coefficient, ADC)对前列腺癌(prostatecancer,PCa)的诊断价值。材料与方法 收集本院行前列腺多参数磁共振成像(multiparametric MRI, mpMRI)检查患者74例,其中PCa 41例(外周带PCa 28例,移行带PCa 13例),良性前列腺增生(benign prostatic hyperplasia, BPH)33例。采用双指数模型拟合算法获得真实扩散系数(true diffusion coefficient, D)、伪扩散系数(pseudo-diffusion coefficient, D^(*))、灌注分数(perfusion fraction, f)、ADC值等定量参数。比较PCa与前列腺T2WI低信号、高信号增生结节的D值、D^(*)值、f值、ADC值差异。采用受试者工作特征(receiver operating characteristic, ROC)曲线及曲线下面积(area under the curve, AUC)评价IVIM定量参数联合ADC对PCa的诊断效能。分析IVIM各定量参数、ADC与Gleason评分的相关性。结果 PCa的ADC值、D值及f值低于T2WI低信号、高信号增生结节,差异有统计学意义(P<0.05)。D值在鉴别PCa与前列腺T2WI低信号增生结节中的AUC最大,特异度最高,差异具有统计学意义(P<0.05)。联合ADC值、D值、f值在鉴别PCa与T2WI低信号增生结节中的AUC、敏感度显著提高(分别为0.948、90.24%)。ADC值在鉴别PCa与T2WI高信号增生结节中的AUC、敏感度、特异度均非常高(分别为0.997、97.65%、100.00%)。ADC值、IVIM各定量参数与Gleason评分无显著相关性(P=0.068、0.455、0.822、0.297)。结论 IVIM定量参数联合ADC可显著提高对PCa与BPH的鉴别诊断效能。

多模态磁共振技术对乳腺癌腋窝淋巴结转移的预测价值

目的探讨动态增强MRI(DCE-MRI)联合体素内不相干运动(IVIM)及扩散峰度成像(DKI)技术预测乳腺癌腋窝淋巴结转移的价值。方法选取本院经病理证实的165例乳腺癌患者,77例有腋窝淋巴结转移(axillary lymph node,ALN),88例无腋窝淋巴结转移,术前乳腺病灶均行DCE-MRI及IVIM、DKI检查。分析临床资料、常规MRI征象和两组间的容量转移常数(K^(trans)),血管外细胞外间隙容积比(Ve),速率常数(Kep)及真实扩散系数(D),灌注相关扩散系数(D*),灌注分数(f)和平均扩散峰度值(MK)、平均扩散率(MD)。采用两独立样本t检验及Mann-Whitney U检验比较DCE-MRI和IVIM、DKI诸参数的差异,绘制ROC比较其诊断效能。结果ALN转移组边缘多较无转移组模糊(P=0.032);ALN转移组瘤内强化多不均匀,环形强化占比较大(P=0.012)。ALN转移组患者D、MD值低于无ALN转移组(P<0.01),且呈低度负相关(r=-0.441,r=-0.259);ALN转移组K^(trans)、Kep、D*及MK值高于无ALN转移组(P<0.01),其中K^(trans)值与ALN转移呈中度正相关(r=0.621),Kep、D*及MK值与ALN转移呈低度正相关(r=0.337;r=0.255,r=0.398)。DCE-MRI模型的K^(trans)值的诊断效能最高,ROC曲线下面积(AUC)为0.859,诊断效能高于其他定量参数(Z=2.275~4.028,P<0.05)。DCE-MRI模型为K^(trans)+Kep,AUC为0.868;IVIM模型为D+D*,AUC为0.781;DKI模型为MD+MK,AUC为0.730,其中DCE-MRI模型(AUC=0.868)的诊断效能高于IVIM(AUC=0.781)及DKI(AUC=0.730)模型,AUC差异有统计学意义(Z=2.001,P=0.046;Z=3.156,P=0.002)。而将DCE-MRI、IVIM、DKI模型联合,AUC为0.913,诊断效能均高于单一模型(Z=2.483~4.838,P<0.05),敏感度为90.9%,特异度为81.8%,准确率86.1%,亦高于单一模型。结论DCE-MRI和IVIM、DKI模型可用于预测乳腺癌腋窝淋巴结转移,其中DCE-MRI模型及其K^(trans)值诊断效能较高,且将DCE-MRI联合IVIM、DKI模型在乳腺癌腋窝淋巴结性质的鉴别能力优于单一模型。