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 monitoring chemotherapeutic efficacy in gastric cancer

AIM: To assess intravoxel incoherent motion diffusionweighted imaging(IVIM-DWI) for monitoring early efficacy of chemotherapy in a human gastric cancer mouse model.METHODS: IVIM-DWI was performed with 12 b-values(0-800 s/mm2) in 25 human gastric cancer-bearing nude mice at baseline(day 0), and then they were randomly divided into control and 1-, 3-, 5- and 7-d treatment groups(n = 5 per group). The control group underwent longitudinal MRI scans at days 1, 3, 5 and 7, and the treatment groups underwent subsequent MRI scans after a specified 5-fluorouracil/calciumfolinate treatment. Together with tumor volumes(TV), the apparent diffusion coefficient(ADC) and IVIM parameters [true water molecular diffusion coefficient(D), perfusion fraction(f) and pseudo-related diffusion coefficient(D*)] were measured. The differences in those parameters from baseline to each measurement(ΔTV%, ΔADC%, ΔD%, Δf% and ΔD*%) were calculated. After image acquisition, tumor necrosis, microvessel density(MVD) and cellular apoptosis were evaluated by hematoxylin-eosin(HE), CD31 and terminal-deoxynucleotidyl transferase mediated nick end labeling(TUNEL) staining respectively, to confirm the imaging findings. Mann-Whitney test and Spearman's correlation coefficient analysis were performed.RESULTS: The observed relative volume increase(ΔTV%) in the treatment group were significantly smaller than those in the control group at day 5(ΔTV_(treatment)% = 19.63% ± 3.01% and ΔTVcontrol% = 83.60% ± 14.87%, P = 0.008) and day 7(ΔTV_(treatment)% = 29.07% ± 10.01% and ΔTV_(control)% = 177.06% ± 63.00%, P = 0.008). The difference in ΔTV% between the treatment and the control groups was not significant at days 1 and 3 after a short duration of treatment. Increases in ADC in the treatment group(ΔADC%_(treatment), median, 30.10% ± 18.32%, 36.11% ± 21.82%, 45.22% ± 24.36%) were significantly higher compared with the control group(ΔADC%_(control), median, 4.98% ± 3.39%, 6.26% ± 3.08%, 9.24% ± 6.33%) at days 3, 5 and 7(P = 0.008, P = 0.016, P = 0.008, respectively). Increases in D in the treatment group(ΔD%_(treatment), median 17.12% ± 8.20%, 24.16% ± 16.87%, 38.54% ± 19.36%) were higher than those in the control group(ΔD%_(control), median-0.13% ± 4.23%, 5.89% ± 4.56%, 5.54% ± 4.44%) at days 1, 3, and 5(P = 0.032, P = 0.008, P = 0.016, respectively). Relative changes in f were significantly lower in the treatment group compared with the control group at days 1, 3, 5 and 7 follow-up(median,-34.13% ± 16.61% vs 1.68% ± 3.40%, P = 0.016;-50.64% ± 6.82% vs 3.01% ± 6.50%, P = 0.008;-49.93% ± 6.05% vs 0.97% ± 4.38%, P = 0.008, and-46.22% ± 7.75% vs 8.14% ± 6.75%, P = 0.008, respectively). D* in the treatment group decreased significantly compared to those in the control group at all time points(median,-32.10% ± 12.22% vs 1.85% ± 5.54%, P = 0.008;-44.14% ± 14.83% vs 2.29% ± 10.38%, P = 0.008;-59.06% ± 19.10% vs 3.86% ± 5.10%, P = 0.008 and-47.20% ± 20.48% vs 7.13% ± 9.88%, P = 0.016, respectively). Furthermore, histopathologic findings showed positive correlations with ADC and D and tumor necrosis(r_s = 0.720, P < 0.001; r_s = 0.522, P = 0.007, respectively). The cellular apoptosis of the tumor also showed positive correlations with ADC and D(r_s = 0.626, P = 0.001; r_s = 0.542, P = 0.005, respectively). Perfusionrelated parameters(f and D*) were positively correlated to MVD(r_s = 0.618, P = 0.001; r_s = 0.538, P = 0.006, respectively), and negatively correlated to cellular apoptosis of the tumor(r_s =-0.550, P = 0.004; r_s =-0.692, P < 0.001, respectively).CONCLUSION: IVIM-DWI is potentially useful for predicting the early efficacy of chemotherapy in a human gastric cancer mouse model.

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.

Intravoxel incoherent motion magnetic resonance imaging for diagnosis of cervical cancer and evaluation of response of uterine cervical cancer to radiochemotherapy: A pilot study

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.

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.

Advanced imaging techniques in the therapeutic response of transarterial chemoembolization for hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization(TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusionweighted magnetic resonance imaging(MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusionweighted imaging, blood oxygen level-dependent MRI, positron emission tomography(PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed.

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。

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。

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。

IVIM-DWI对可切除性胃腺癌脉管侵犯的预测价值

目的:探讨体素内不相干运动磁共振成像(IVIM-DWI)术前预测胃腺癌脉管侵犯的价值。方法:2021年1月-2022年5月,前瞻性搜集行根治性胃切除的胃腺癌患者的术前MRI资料,包括IVIM和DWI。根据术后病理结果,将患者分为有、无脉管侵犯组。测量胃癌病灶的厚度、ADC和IVIM-DWI参数(D、D^(*)、f)值,采用student t检验或Mann-Whitney U检验比较两组间连续变量的差异,采用逻辑回归分析筛选脉管侵犯的独立危险因素,采用ROC曲线评估各参数鉴别脉管侵犯状态的效能,采用Delong检验比较各参数预测效能的差异。结果:共纳入73例胃癌手术患者,其中49例有脉管侵犯(67.12%)。有脉管侵犯组的肿瘤处胃壁厚度大于无脉管侵犯组,而ADC、D和f值均低于无脉管侵犯组,差异均有统计学意义(P<0.05);两组间D^(*)值的差异无统计学意义(P>0.05)。ROC曲线分析显示肿瘤处胃壁厚度及ADC、D和f值均能有效预测脉管侵犯状态,AUC分别为0.821、0.686、0.792和0.727(P均<0.05)。肿瘤处胃壁厚度[OR:1.302(1.098~1.543)]和f[OR:686.801(6.126~77004.267)]是预测脉管侵犯的独立危险因素;联合两者进行诊断时,AUC、敏感度和特异度分别为0.897、81.63%和91.67%,其AUC显著高于ADC和f(Delong检验,P均<0.05),但与D和肿瘤处胃壁厚度的差异均无统计学意义(P=0.055、0.052)。结论:IVIM-DWI定量参数及肿瘤处胃壁厚度均能在术前有效预测胃癌脉管侵犯情况,尤其是肿瘤处胃壁厚度和f是胃癌患者脉管侵犯的独立危险因素,两者联合诊断可提高预测效能。

增强MRI联合IVIM-DWI诊断小肝细胞癌价值研究

目的探讨增强磁共振(MRI)联合体素内不相干运动磁共振扩散加权成像(IVIM-DWI)诊断小肝细胞癌(sHCC)的价值。方法2020年5月~2023年5月我院收治的肝脏局灶性病变患者73例,所有患者均接受增强MRI和IVIM-DWI检查,观察病灶增强强化信号特点,分析病灶IVIM-DWI定量参数,即伪扩散系数(D^(*))、真实扩散系数(D)和灌注分数(f)。采用细针穿刺或取术后组织行病理学检查。应用受试者特征工作曲线(ROC)下面积(AUC)评估增强MRI联合IVIM-DWI诊断sHCC的效能。结果经病理学检查,在73例肝脏局灶性病变患者中,诊断sHCC者49例(67.1%)和肝脏异型性增生结节(DN)者24例(32.9%);sHCC病灶T1WI低信号、T2WI高信号、动脉期强化和肝胆期低信号占比分别为61.2%、83.7%、59.2%和89.8%,均显著高于DN病灶的20.8%、33.3%、25.0%和29.2%(P<0.05);sHCC病灶D*和D分别为(50.9±11.6)×10^(-3) mm^(2)/s和(0.8±0.2)×10^(-3) mm^(2)/s,均显著小于DN病灶【分别为(78.4±15.8)×10^(-3) mm^(2)/s和(1.2±0.3)×10^(-3) mm^(2)/s,P<0.05】,而两组f比较,差异无统计学意义【分别为(45.6±8.7)%对(43.9±9.5)%,P>0.5】;ROC分析表明,应用T1WI信号、T2WI信号、动脉期强化、肝胆期信号、D*和D联合诊断sHCC的AUC为0.968,其灵敏度和特异度分别为100.0%和86.0%。结论应用增强MRI和IVIM-DWI联合诊断sHCC的效能较高,可为临床诊疗提供有益的依据,值得进一步深入研究。

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。