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.

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.

Advances in the imaging of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms comprise a heterogeneous group of tumors that differ in their pathogenesis,hormonal syndromes produced,biological behavior and consequently,in their requirement for and/or response to specific chemotherapeutic agents and molecular targeted therapies.Various imaging techniques are available for functional and morphological evaluation of these neoplasms and the selection of investigations performed in each patient should be customized to the clinical question.Also,with the increased availability of cross sectional imaging,these neoplasms are increasingly being detected incidentally in routine radiology practice.This article is a review of the various imaging modalities currently used in the evaluation of neuroendocrine neoplasms,along with a discussion of the role of advanced imaging techniques and a glimpse into the newer imaging horizons,mostly in the research stage.

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。

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。

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。

应用IVIM-DWI研究正常胰腺及急性胰腺炎不同解剖部位

目的应用体素内不相干运动扩散加权成像研究正常胰腺及急性胰腺炎的不同,探讨正常胰腺及急性胰腺炎的胰腺不同解剖部位参数差异及意义。方法29名健康志愿者及33例AP患者行上腹部MRI及IVIM-DWI扫描,测量胰腺头部、颈体部、尾部ADC、f、D、D*值。采用单因素方差、LSD检验和独立样本t检验对比分析正常胰腺及AP胰腺参数差异性。结果正常胰腺不同解剖部位ADC值及f值差异显著,病变为弥漫AP者不同解剖部位各参数差异无统计学意义。AP患者ADC、f、D值均低于正常胰腺,D值高于正常胰腺,差异均有统计学意义(P<0.05)。病变为局限AP患者ADC及f值由高到低排序为NP组>非病变区>病变区,差异有统计学意义(P<0.05)。结论胰腺不同解剖部位ADC、f、D、D*值有作为甄别急性胰腺炎指标的可能,其中f值是间接评估胰腺不同解剖部位微循环灌注情况的主要参数。

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。

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。

DCE-MRI、IVIMDWI、MRS技术在脑胶质瘤术后复发与假性进展鉴别诊断中的应用价值

目的分析动态对比增强磁共振成像(DCEMRI)、体素内不相干运动扩散加权成像(IVIMDWI)、磁共振波谱成像(MRS)技术在脑胶质瘤术后复发与假性进展(PP)鉴别诊断中的应用价值。方法选取本院72例术后同步放化疗脑胶质瘤患者,均于放化疗后3个月接受DCE-MRI、IVIM-DWI与MRS检查,按照二次手术病理学检查或随访结果,将其分为复发组与PP组,比较两组转运常数(Ktrans)、速率常数(Kep)、血管外细胞外间隙容积分数(Ve)、表观扩散系数(ADC)、灌注分数(f)、真性扩散系数(D)与假性扩散系数(D)、胆碱(Cho)/磷酸肌酸(Cr)、Cho/N乙酰天门冬氨酸(NAA),使用受试者工作特征(ROC)曲线分析各指标联合对术后复发与PP的鉴别价值。结果两组Kep、D、D比较无统计学意义(P>0.05);复发组Ktrans、Ve、f、Cho/Cr、Cho/NAA显著高于PP组(P<0.05),ADC显著低于PP组(P<0.05);ROC分析显示,Ktrans、Ve、f、ADC、Cho/Cr、Cho/NAA及联合诊断AUC分别为0.688、0.821、0.835、0.679、0.801、0.785、0.988,其中联合诊断AUC最大,鉴别复发与PP的敏感度95.32%,特异度93.07%。结论DCE-MRI、IVIM-DWI联合MRS对脑胶质瘤术后复发与PP具有较高诊断效能,可为临床更好鉴别肿瘤复发与PP提供可靠指导。

乳腺癌精准诊疗的重要工具——MRI定量分析技术

乳腺癌严重威胁女性的生命健康和生活质量,MRI是乳腺疾病诊断中重要的工具。随着近年来软硬件技术的提高,越来越多的MRI定量特征被挖掘出来,并较形态判读等非定量特征展现出来更大的优势。本文简要论述了包括常规MRI序列、MRI新技术新方法、MRI影像组学和深度学习等MRI定量分析方法在乳腺病灶良恶性鉴别、新辅助治疗疗效和预后等临床问题中的应用,同时提出了亟待解决的几个问题。乳腺癌的精准诊疗时代对影像学研究提出了更高的要求,希望本文可以启发研究者未来深入挖掘MRI的定量特征和定量分析方法,结合非定量特征,更好地推动MRI在乳腺癌诊疗中的应用,推动临床转化,提升乳腺癌患者的生存时间和生活质量。

HRMRI联合IVIM-DWI对直肠癌壁外血管侵犯的诊断价值分析

目的探究高分辨率磁共振成像(HRMRI)联合体素内不相干运动扩散加权成像(IVIM-DWI)对直肠癌壁外血管侵犯(EMVI)的诊断价值。方法选取2020年5月至2023年5月我院收治的直肠癌患者82例,术前均进行HRMRI联合IVIM-DWI检查,根据术后病理检查结果,观察患者EMVI评分情况,将患者分为EMVI组和非EMVI组,比较两组IVIM-DWI相关参数[快弥散系数(D)和灌注分数(f)]差异,分析HRMRI、IVIM-DWI单独及联合应用对EMVI的诊断价值。结果82例直肠癌患者中,EMVI评分3分、4分的数量分别为19例(23.17%)和13例(15.85%);术后病理结果显示,82例直肠癌患者中有37例(45.12%)出现EMVI,EMVI组患者D、f均高于与非EMVI组患者(P<0.05);HRMRI、IVIM-DWI单独诊断EMVI阳性患者分别为32例(39.02%)、41例(50.00%),联合诊断EMVI阳性患者48例(58.54%);HRMRI、IVIM-DWI单独诊断EMVI的灵敏度分别为67.56%、75.68%,特异度分别为84.44%、71.11%,联合诊断灵敏度为91.89%,特异度为68.88%,Kappa一致性分析结果显示,HRMRI、IVIM-DWI单独、联合诊断EMVI的kappa值分别为0.526、0.463、0.592。结论HRMRI、IVIM-DWI均对直肠癌患者EMVI的诊断具有一定诊断价值,二者联合应用诊断效能更高,值得推广应用。

多模态磁共振技术在脑小血管病中的应用进展

脑小血管病(Cerebral Small Vessel Disease,CSVD)是一种与年龄相关的慢性、进行性小血管疾病,影响小动脉、毛细血管和小静脉,与缺血性卒中和痴呆的高发生率密切相关,并可能导致运动、步态和情绪障碍。磁共振成像(Magnetic Resonance Imaging,MRI)在CSVD的诊断中起关键作用,其典型表现为皮质下小梗死、脑白质高信号、腔隙、脑微出血、血管周围间隙和脑萎缩。由于CSVD的病理机制尚未完全阐明,目前缺乏特异性的治疗方法,因此治疗策略主要集中在管理血管危险因素,以延缓病程进展。随着先进MRI技术的应用,研究已从单纯的影像学特征深入到对CSVD病理学机制的探索。本文综述了多模态磁共振新技术在CSVD中的应用,以提高老年患者的生活质量,减轻社会和家庭负担。

体素内不相干运动弥散加权成像在儿童腹部良恶性肿瘤诊断中的应用价值

目的分析体素内不相干运动弥散加权成像(IVIM-DWI)在儿童腹部良恶性肿瘤诊断中的应用价值。方法选取2020年1月~2022年12月我院收治的110例腹部肿瘤患儿为研究对象,其中良性肿瘤42例,恶性肿瘤68例,所有患儿均接受腹部MRI平扫、多弥散敏感系数(b)值IVIM-DWI扫描,分析腹部良恶性肿瘤的IVIM-DWI参数,并对参数敏感度、诊断界值、特异度等进行分析。结果42例良性肿瘤患者中良性成熟畸胎瘤20例,肝血管瘤10例,节细胞神经瘤8例,肝脏局灶性结节增生4例。68例恶性肿瘤患者中神经母细胞瘤30例,肝母细胞瘤14例,肾母细胞瘤10例,淋巴瘤8例,未成熟畸胎瘤、横纹肌肉瘤、肾透明细胞肉瘤各2例;良性肿瘤与恶性肿瘤患儿f值比较,差异无统计学意义(P>0.05),良性组患儿表观弥散系数(ADC)、真实弥散系数(D)值高于恶性组(P<0.05),灌注相关弥散系数(D*)值低于恶性组(P<0.05);受试者工作特征(ROC)曲线分析结果显示,ADC值诊断良恶性肿瘤的ROC曲线下面积(AUC)、特异度和准确率明显高于D、D*值。结论在儿童腹部实体肿瘤良恶性鉴别的IVIM-DWI参数中,ADC值的AUC、特异度和准确率较高,可以作为小儿腹部实体肿瘤良恶性鉴别的重要参考依据。

IVIM-DWI参数联合DCE-MRI参数对肝癌患者经肝动脉化疗栓塞治疗后复发的预测价值

目的探讨体素内不相关运动扩散加权成像(IVIM-DWI)参数联合磁共振动态对比增强(DCE-MRI)参数对肝癌患者经肝动脉化疗栓塞(TACE)治疗后复发的预测价值。方法160例经TACE治疗有效的肝癌患者根据复发情况分为复发组和未复发组,比较两组的IVIM-DWI参数(D、D^(*)、ADC)、DCE-MRI参数(K_(trans)、K_(ep)、V_(e)),分析相关参数对肝癌患者TACE治疗后复发的预测价值。结果复发组的D低于未复发组,D^(*)、K_(trans)、K_(ep)均高于未复发组(P<0.05);两组的ADC、V_(e)比较,差异无统计学意义(P>0.05)。ROC曲线显示,D^(*)、D、K_(trans)、K_(ep)联合对肝癌患者TACE治疗后复发具有良好的预测价值(AUC=0.814)。结论IVIM-DWI参数联合DCE-MRI参数可有效预测肝癌患者TACE治疗后的复发情况。

IVIM-DWI与DCE-MRI在良性前列腺增生和前列腺癌鉴别诊断中的应用

目的观察体素内不相干运动磁共振加权成像(IVIM-DWI)与动态增强磁共振成像(DCE-MRI)对良性前列腺增生和前列腺癌的鉴别诊断意义。方法回顾性分析经病理分析确诊为良性前列腺增生和前列腺癌115例患者的临床资料,良性前列腺增生患者纳入良性组(80例),前列腺癌患者纳入恶性组(35例),所有患者均接受IVIM-DWI、DCE-MRI检查。比较2组患者IVIM-DWI[表观扩散系数(ADC)、真实扩散系数(D)、灌注分数(f)]、DCE-MRI[转运常数(K^(trans))、速率常数(K_(ep))、血管外细胞间隙体积百分数(V_(e))]定量参数差异,并使用受试者操作特征(ROC)曲线分析二者鉴别诊断效能,使用Pearson相关系数分析二者与Gleason评分的相关性。结果恶性组ADC、D、f、V_(e)低于良性组,K^(trans)、K_(ep)均高于良性组,差异有统计学意义(P<0.05);ADC、D、f、K^(trans)、K_(ep)、V_(e)对良性前列腺增生和前列腺癌鉴别诊断的曲线下面积(AUC)分别为0.951、0.831、0.725、0.708、0.849、0.787;恶性组不同Gleason评分患者ADC、D比较,差异有统计学意义(P<0.05),f、K^(trans)、K_(ep)、V_(e)比较,差异无统计学意义(P>0.05);ADC、D与Gleason评分负相关(P<0.05),f、V_(e)、K^(trans)、K_(ep)与Gleason评分无相关性(P>0.05)。结论IVIM-DWI与DCE-MRI均可有效鉴别良性前列腺增生和前列腺癌,其中IVIM-DWI的定量参数ADC、D可作为病情评估参考指标。