高级别胶质瘤治疗后的DWI新技术评估进展

高级别胶质瘤(HGG)术后治疗主要采用放疗或联合放化疗,肿瘤复发与治疗反应是影响其术后生存最重要的因素,治疗反应包括假性进展和治疗后坏死。治疗后监测需要及早、有效地鉴别真性进展与治疗反应。DWI是目前最常用于HGG治疗后评估的功能MRI技术。近年来开发的平均及最小ADC值、ADC直方图和功能扩散图等DWI新技术对HGG治疗后评估具有独特作用。     

高级别胶质瘤治疗后预后评估MRI形态学与DWI研究进展

高级别胶质瘤(HGG)发病率高,通常预后较差,但也有部分病人预后较好,总生存期相对较长。预测HGG治疗后预后有助于早期及时调整治疗方案,终止无效治疗,减少不良反应,有利于改善病人预后。近年对MRI形态学的术后残腔液体衰减反转恢复序列信号改变和增强T1WI强化形态,以及扩散加权成像(DWI)的直方图相关参数评估HGG治疗后预后的研究已取得较大进展,就MRI形态学与DWI这两种新技术评估HGG治疗后预后的研究现状予以综述。     

DWI与动脉自旋标记成像在胶质瘤术前诊断中的应用价值

目的 :探讨DWI及动脉自旋标记法(arterial spin labeling,ASL)在胶质瘤术前分级中的应用价值。方法:选取28例经手术病理证实的脑肿瘤患者,其中高级别胶质瘤(high grade glioma,HGG)18例,低级别胶质瘤(low grade glioma,LGG)10例。所有患者均行DWI及ASL扫描,比较不同级别胶质瘤ADC值及脑血流量(CBF)值的差异。结果:HGG肿瘤实质区CBF值大于LGG;HGG肿瘤实质区ADC值小于LGG;且不同级别胶质瘤ADC值与CBF值有显著相关性(r=-0.759,P=0.002)。结论 :DWI及ASL可于术前安全无创地评估脑胶质瘤级别,有助于临床制订治疗方案。     

子宫内膜癌的DWI和DCE-MRI研究进展

扩散加权成像(DWI)和动态增强磁共振成像(DCE-MRI)属功能成像技术,分别通过表观扩散系数(ADC)和时间-信号曲线(TIC)定量或半定量灌注参数评估肿瘤的生物学特性。子宫内膜癌是女性生殖系统最常见的恶性肿瘤,本文就上述MR功能成像技术在子宫内膜癌的检出、诊断、分期和治疗反应的监测等方面的进展作一综述。     

DWI对局部进展期乳腺癌新辅助化疗疗效评价的初步研究

目的:探讨磁共振扩散加权成像(DWI)对局部进展期乳腺癌新辅助化疗疗效评价以及作为预测因子的可行性.方法:根据10例乳腺癌化疗后退缩情况将肿瘤分成缓解和进展两组,比较两组化疗前后ADC值和DWI信号强度的变化,并评价治疗前ADC值与化疗结束肿瘤退缩变化的相关性.结果:无论是治疗前还是治疗后,ADC值和DWI信号强度在缓解组和进展组间差异均无显著性意义(P＞0.05),但缓解组治疗后ADC值升高,而进展组则降低,尤其在b=1000和2000 s/mm2时明显.b=1000 s/mm2时,肿瘤高活性区和低活性区对治疗反应比较显示,肿瘤高活性区ADC值较低,治疗后ADC值升高(1.195±0.230和1.371±0.295);而肿瘤低活性区ADC值较高,治疗后ADC值反而下降(1.632±0.241和1.312±0.297);与病理对照显示,治疗后肿瘤细胞蜕变,并伴有明显的胶元和纤维化形成.治疗前ADC值与治疗后肿瘤退缩呈负相关,当b取1000和2000 s/mm2时相关更明显,前者为r= -0.802,P=0.005,后者的r = -0.745,P=0.013.结论:DWI可以对局部进展期乳腺癌新辅助化疗疗效作评价,并能对治疗疗效作出预测.     

高级别胶质瘤假性进展的功能MRI研究

高级别胶质瘤（HGG）治疗后可发生假性进展,但常规MRI对HGG假性进展的诊断价值有限。目前多种功能MRI技术已用于HGG假性进展与真性进展的鉴别诊断,包括扩散成像、¹H-MR波谱成像（MRS）、灌注加权成像（PWI）、酰胺质子转移成像（APT）等,联合这些功能MRI技术及人工智能可进一步改善诊断效能。就这些功能成像及其参数在假性进展方面的研究进展进行综述。     

MR扩散加权成像在肾癌微波消融术后随访中的应用价值

目的探讨磁共振扩散加权成像(DWI)在评价肾癌微波消融(MWA)术后疗效的价值。方法回顾性分析33个肾癌病灶在MWA治疗后1天、1个月、3个月和6个月及以上的DWI信号变化特点和ADC值变化规律。结果术后1天,完全消融区DWI呈低信号,周围伴有高信号的环形反应带;1个月时周围环形反应带变薄,3个月基本消失,消融灶呈混合信号。残留和局部进展组织表现为位于消融区和正常肾组织之间的不规则环状或结节状稍高信号。在b值为800s/mm~2时,术前与术后不同时间、不同组织间的ADC值变化显示:1)肾癌ADC值低于正常肾脏;2)术后完全消融区与术前比较有显著差异,ADC值降低并且呈现逐渐降低的趋势;3)术后各随访时间完全消融区、周围环形反应带、正常肾实质不同组织间的ADC值差异均有统计学意义;4)残留/局部进展组织的ADC值与术前肾癌的ADC值间没有差异。结论DWI能有效区分完全坏死区、活性肿瘤组织和正常肾实质,提供比MR常规扫描更多的诊断信息,在肾癌微波消融疗效评估中发挥重要作用。     

磁共振定量功能成像在评价乳腺癌新辅助化疗中的应用进展

【摘要】新辅助化疗（NACT）已成为局部进展期乳腺癌的标准治疗方案，评估化疗效果对于调整和制定个性化治疗方案至关重要，磁共振功能成像在评估治疗反应方面要优于单纯形态学评价，定量功能成像会提供更多量化的信息。本文总结了目前应用较多的动态对比增强磁共振成像（DCE-MRI）、灌注加权成像（PWI）、扩散加权成像（DWI）及磁共振波谱（MRS）技术的主要进展及优缺点，并探讨了结合纹理分析及人工智能技术的发展方向。     

MR扩散成像在子宫肌瘤HIFU术后早期疗效评价中的价值

目的:探讨磁共振扩散成像在子宫肌瘤高强度聚焦超声治疗后早期疗效评价中的价值。方法:15例患者共21个肌瘤经1次性HIFU刀治疗,术前、术后0.5及24h进行常规磁共振成像及DWI成像,观察肌瘤术前、术后在常规MRI、DWI上信号及ADC值变化特点并进行分析。结果:术后18个肌瘤增强扫描无灌注区,在DWI序列上均有不同程度的信号增高;肌瘤消融区术后0.5h平均ADC值[(1.287±0.213)×10-3 mm2/s]低于术前平均ADC值[(1.442±0.233)×10-3 mm2/s]及残留未消融区平均ADC值[(1.513±0.271)×10-3 mm2/s],术后24h复查,消融靶区平均ADC值[1.369±0.220)×10-3 mm2/s]回升。术前、术后0.5及24h消融区及残留未消融区平均ADC值差异有统计学意义(P<0.05);术后0.5h消融区在DWI上高信号主要分布于外周,中央部信号强度相对较低,呈较有特征性环形高信号改变,而且外周部ADC值低于中央部ADC值。结论:DWI和ADC值是早期评价子宫肌瘤高强度聚焦超声治疗术后疗效的有效手段。     

DWI对晚期肝细胞肝癌患者分子靶向药物治疗的疗效评估

目的 :探讨DWI评估晚期肝细胞肝癌患者分子靶向药物治疗疗效的价值。方法 :选择我院2013年1月至2014年12月收治的行分子靶向药物治疗的晚期肝细胞癌患者12例。依据治疗效果分为A组(有治疗反应组)5例和B组(无治疗反应组)7例。对2组治疗前后病灶最大径和ADC值进行观察,并进行统计学分析。结果:治疗后,A组病灶在MRI T1WI和T2WI信号增大,DWI信号无明显变化;B组病灶的T1WI、T2WI、DWI信号均无明显变化。与B组比较,A组治疗前及治疗后病灶的最大径均偏大(均P0.05)。A组治疗前后ADC值明显变化,而B组ADC值变化不明显(P0.05)。治疗前,A组病灶最大径与ADC值(b=500 s/mm2)呈正相关性(r=0.556,P=0.038);B组病灶最大径与ADC值无明显相关性(P0.05)。结论:DWI可及时、准确评估晚期肝细胞肝癌分子靶向药物治疗的预后。     

IDH突变与高级别胶质瘤治疗后MRI表现及预后的关系

目的:探讨异柠檬酸脱氢酶(IDH)突变表型与高级别胶质瘤(HGG)治疗后MRI表现及患者生存预后的相关性.方法:回顾性分析经手术病理证实的70例HGG患者的临床及术后MRI资料.其中,IDH突变型26例,IDH野生型44例.临床资料主要包括年龄、性别、肿瘤的组织病理学分级和部位.MRI扫描序列包括平扫T1 WI、T2 ...     

Hemostasis radiotherapy for gastric cancer: Usefulness of the gastric cancer to spleen apparent diffusion coefficient ratio

The hemostatic effect of radiation therapy on gastric cancer with bleeding is known. However, blood tests and endoscopes are mainly used to determine the therapeutic effect. Additionally, magnetic resonance imaging has been reported to be useful when needed because endoscopes are invasive. In this study, magnetic resonance diffusion-weighted imaging was used to evaluate the hemostatic effect of gastric cancer. The hemostatic effect and apparent diffusion coefficient value were correlated. The apparent diffusion coefficient value was also effective in salvage irradiation during rebleeding. Although the apparent diffusion coefficient value of gastric cancer did not change during rescue irradiation, the degree of hemostatic effect could be evaluated in more detail by using the ratio of the apparent diffusion coefficient values of diffusion-weighted imaging of gastric cancer and the spleen. In the future, it would be desirable to use diffusion-weighted imaging instead of endoscopy to evaluate the gastric cancer to spleen apparent diffusion coefficient ratio in a large number of cases.     

双b值扩散加权成像在脑梗死诊断中的应用

目的:比较双b值DWI对脑梗死体积及ADC值测量的影响,探讨较高b值DWI在脑梗死诊断中的应用价值。方法:回顾性研究30例脑梗死患者,年龄44～84岁,平均67岁,发病时间3～6d,DWI取b值1000和2000s/mm2,分析脑梗死DWI及ADC图,测量兴趣区与对侧正常部位的扩散系数(ADC)并计算相对扩散系数(rADC),测量并计算梗死灶体积。结果:急性和亚急性脑梗死灶均扩散受限,DWI呈高信号、ADC图呈低信号。与b值1000s/mm2相比,b值2000s/mm2DWI示脑灰白质对比度增加,病灶显示更清晰,还能发现新病灶。不同b值下rADC比较没有统计学意义(P=0.884,P>0.05),同侧ADC有统计学意义(P=0.005,P<0.05);对侧ADC有显著统计学意义(P<0.001)。较高b值下梗死体积较低b值增加,且有统计学意义(P=0.04,P<0.05)。结论:DWI是检测脑梗死的重要技术手段,rADC不受b值影响,rADC降低可指导脑梗死诊断;较高b值DWI上脑梗死灶体积测量更准确,有利于观察病灶演变和指导临床治疗。     

扩散加权成像在卵巢肿瘤中的应用

扩散加权成像(DWI)是目前唯一能够检测生物组织内水分子扩散运动的无创方法 ,该种扩散运动可以通过表观扩散系数(ADC)来量化分析。扩散峰度成像(DKI)、体素内不相干运动(IVIM)成像、背景抑制扩散加权全身成像(DWIBS)等DWI新技术用于卵巢肿瘤的评估提高了卵巢肿瘤影像诊断的准确性。综述DWI及其新技术在卵巢肿瘤定性诊断、分期、疗效评估、预后判断中的作用及其潜在缺陷。     

Interest of diffusion-weighted echo-planar MR imaging and apparent diffusion coefficient mapping in gynecological malignancies: a review

Magnetic resonance imaging (MRI) remains the standard modality for the local staging of gynecological malignancies but it has several limitations, particularly for lymph node staging or evaluating peritoneal carcinomatosis. Consequently, there has been a growing interest in functional imaging modalities. Based on molecular diffusion, diffusion-weighted imaging (DWI) is a unique, noninvasive modality that provides excellent tissue contrast and was shown to improve the radiological diagnosis of malignant tumors. Using quantitative apparent diffusion coefficient (ADC) measurement of DWI provides a new tool for better distinguishing malignant tissues from benign tumors. The aim of the present review is to report on the results of DWI for the assessment of patients with gynecological malignancies. An analysis of the literature suggests that DWI studies would improve the diagnosis of cervical and endometrial tumors. It may also improve the assessment of tumor extension in patients with peritoneal carcinomatosis from gynecological malignancies. However, since the signal intensity of some cancers can range from high intensity to low intensity, a degree of uncertainty was demonstrated due to the proximity of the normal uterine myometrium and ovaries. Interestingly, there is also evidence that ADC might improve the follow-up and monitoring of patients who receive anticancer therapies, including chemotherapy or radiation therapy.     

Diffusion weighted imaging: Technique and applications

Diffusion weighted imaging (DWI) is a method of signal contrast generation based on the differences in Brownian motion. DWI is a method to evaluate the molecular function and micro-architecture of the human body. DWI signal contrast can be quantified by apparent diffusion coefficient maps and it acts as a tool for treatment response evaluation and assessment of disease progression. Ability to detect and quantify the anisotropy of diffusion leads to a new paradigm called diffusion tensor imaging (DTI). DTI is a tool for assessment of the organs with highly organised fibre structure. DWI forms an integral part of modern state-of-art magnetic resonance imaging and is indispensable in neuroimaging and oncology. DWI is a field that has been undergoing rapid technical evolution and its applications are increasing every day. This review article provides insights in to the evolution of DWI as a new imaging paradigm and provides a summary of current role of DWI in various disease processes.     

3.0TDCE-MRI及DTI在胶质瘤分级中的价值

目的：探讨动态增强磁共振成像(DCE-MRI)及扩散张量成像(DTI)在胶质瘤分级中的价值。方法31例胶质瘤患者行3.0T DCE-MRI 及 DTI 检查,测量定量参数包括：容量转移常数(Ktrans )、血管外细胞外间隙容积比(Ve )、速率常数(Kep )、对比剂浓度下峰面积(iAUC)及相对各向异性分数(rFA)。低级别、高级别胶质瘤组间 DCE-MRI、rFA 参数与微血管密度(MVD)、微血管结构(MVS)相关性评估采用 Spearman 相关性检验。结果胶质瘤分级与 MVD 计数和 MVS 改变呈正相关。14例低级别胶质瘤的 Ktrans 值、Kep 值、Ve 值、iAUC 值及 rFA 值分别为(0.02±0.01)min-1、1.82(0.18~8.54)min-1、0.05±0.03、2.47±1.66和0.55±0.22;17例高级别胶质瘤参数值分别为(0.11±0.02)min-1、1.31(0.12~7.58)min-1、0.28±0.10、10.84±6.46和0.28±0.08。各参数值组间除 Kep 外,其他参数差异均有统计学意义(P <0.05)。Ktrans 、Ve 、iAUC 值与 MVD 计数及 MVS 呈正相关(P <0.05),rFA 值与MVD 计数及 MVS 呈负相关(P <0.01)。结论DCE-MRI、DTI 定量参数对胶质瘤分级以及肿瘤新生血管增生、血管微结构改变都有重要的评估价值。     

Hepatic ADC value correlates with cirrhotic severity of patients with biliary atresia

Introduction

At least 40% of survivors of biliary atresia have progressive cirrhosis even after undergoing Kasai operation. The values of hepatic apparent diffusion coefficient and apparent-diffusion-coefficient-related indices were applied to biliary atresia patients and correlated with cirrhotic severity scores of model for end-stage liver disease or pediatric end-stage liver disease model, Child-Turcotte, and Child-Pugh systems.

Materials and methods

Thirty-three biliary atresia patents (mean = 1140, 61–4314 days of age) received magnetic resonance image examinations due to complications of biliary atresia from April 2008 to August 2009. Two non-breath-hold diffusion weighted imaging sequences were performed with motion-probing gradients in three directions with two b values: 0/100 and 0/500 s/mm²; 1000 ms/61.1 ms, time to repeat/time to echo; number of excitation, 1.0; 8 mm section thickness; 40 cm × 40 cm field of view; 128 × 256 matrix in all biliary atresia patients and 18 control subjects. We used the Spearman rank correlation test to analyze the relationship among the scores of model for end-stage liver disease or pediatric end-stage liver disease model, Child-Turcotte and Child-Pugh scores and right hepatic apparent diffusion coefficients, apparent diffusion coefficient using b factor of 500-albumin product and alanine transaminase/apparent diffusion coefficient with b factor of 500 ratio.

Results

The right hepatic apparent diffusion coefficient using b factor of 100, apparent diffusion coefficient with b factor of 500 and product of apparent diffusion coefficient with b factor of 500-albumin level were significantly negatively correlated (p ≤ 0.0125) with model for end-stage liver disease or pediatric end-stage liver disease model, Child-Turcotte, and Child-Pugh scores of biliary atresia patients. The ratio of alanine transaminase level/right hepatic apparent diffusion coefficient with b factor of 500 was also significantly (p ≤ 0.0251), moderately correlated with Child-Turcotte and Child-Pugh scores (rho = 0.5256 and 0.7518, respectively).

Conclusion

Right hepatic apparent diffusion coefficient with b factor of 500 and alanine transaminase/right hepatic apparent diffusion coefficient with b factor of 500 can be useful for long-term follow-up of cirrhotic severity in biliary atresia patients.