磁共振弥散加权成像在肿瘤鉴别诊断中的应用

磁共振弥散加权成像（DWI）依靠不同组织间水分子弥散的差异性，提供一种与以往T1加权像、T2加权像不同的、新的成像对比。其在超早期脑缺血定位、定位诊断中的作用已被肯定，并已逐渐应用于其他系统疾病的诊断和鉴别诊断，其利用已引起人们广泛关注。现综述该技术的基本原理及在肿瘤鉴别诊断中的应用价值。     

磁共振弥散加权成像在骨肿瘤诊断中的应用

磁共振弥散加权成像(DWI)是利用磁共振成像的特殊序列观察活体组织中水分子弥散运动的一种成像技术,可以用于骨转移瘤早期诊断;通过直接观察信号改变,以及表观弥散系数(ADC)值对病变进行量化分析,为良、恶性椎体压缩骨折鉴别提出了客观的诊断依据,但在该领域的应用仍处于探讨研究阶段,需要进一步深入研究活体条件下弥散机制的基础.DWI评价骨肿瘤化疗后的病理组织坏死及鉴别骨肿瘤术后瘢痕组织或肿瘤复发方面结论比较肯定,在临床上值得推广应用.     

磁共振弥散加权成像的表观弥散系数在直肠腺癌术前诊断中的应用

目的 探讨磁共振弥散加权成像(DWI)的表观弥散系数(ADC)在诊断直肠腺癌和评估直肠腺癌恶性程度中的应用.方法 比较82例经病理学检查确诊的直肠腺癌患者(观察组)与82例无直肠病变者(对照组)的ADC值,并在观察组中比较磁共振成像(MRI)和DWI对直肠腺癌T分期诊断的准确性.结果 观察组ADC平均值为(0.89±0.12)×10-3mm2/s,低于对照组ADC平均值(1.45±0.15)×10-3mm2/s,差异有统计学意义(P﹤0.05).对于直肠腺癌的诊断,ADC的最佳分界值为1.26×10-3mm2/s,敏感度为96.1%,特异度为97.5%;低分化、中分化和高分化直肠腺癌的ADC值分别为(0.80±0.10)×10-3mm2/s、(0.95±0.11)×10-3mm2/s和(1.23±0.18)×10-3mm2/s,不同分化程度的ADC值比较,差异有统计学意义(P﹤0.05).对于直肠腺癌,MRI分期诊断的准确性为74.39%,DWI分期诊断的准确性为86.59%,两者比较,差异有统计学意义(P﹤0.05).结论 直肠腺癌的不同分化程度与ADC值相关,DWI可以增加直肠腺癌术前分期诊断的准确率.     

磁共振弥散加权成像在肿瘤放射治疗中的应用研究进展

成像生物标志物是测定和表征肿瘤以及监测治疗反应的重要工具.随着技术的快速发展,新的成像方法迅速呈现,其实用性需要系统评价.磁共振弥散加权成像（diffusion-weighted magnetic resonance imaging ,DW-MRI）通过表观弥散系数（Apparent diffusion coefficient,ADC）定量反映肿瘤内部水分子的微观运动-布朗运动（Brownian motion）.放射治疗是肿瘤治疗的主要手段之一,DW-MRI在肿瘤放射治疗方面包括靶区勾画、治疗反应监测和预后评价等显示出特有的应用价值.本文就DW-MRI在肿瘤放射治疗中的应用进行综述.     

磁共振弥散加权成像在胶质瘤分级中的价值

目的 探讨磁共振弥散加权成像(DWI)及表观弥散系数(ADC)在鉴别胶质瘤瘤体区、瘤周区和正常组织中的应用及鉴别胶质瘤良、恶性的价值.方法 采用Philips 1.5T Achieva超导型磁共振成像仪,对46例胶质瘤患者行常规MRI及DWI,弥散系数b值分别取0和1 000 s/mm2,测量瘤体区、瘤周区及对侧正常组...     

磁共振动态增强成像联合弥散加权成像技术对原发性肝癌的诊断价值

目的 分析磁共振动态增强成像(DCE-MRI)联合弥散加权成像(DWI)技术在原发性肝癌中的诊断价值。方法 将81例原发性肝癌患者设为肝癌组,62例肝良性疾病患者设为良性组。两组患者均进行DCE-MRI、DWI检查,获取图像数据,对比肝癌组与良性组表观弥散系数(ADC)及DCE-MRI定量参数[容量转移常数(K^trans)、速率常数(K_ep)、血管外细胞外容积分数(V_e)]。比较DCE-MRI、DWI单独及联合检查对不同类型原发性肝癌的检出率,以病理结果为金标准,计算DCE-MRI、DWI单独及联合检查对原发性肝癌的诊断效能。结果 肝癌组患者ADC明显低于良性组,K_trans、K_ep、V_e均明显高于良性组,差异均有统计学意义(P﹤0.01)。DCE-MRI、DWI联合检查对结节型原发性肝癌的检出率高于两者单独检查,差异均有统计学意义(P﹤0.05)。DCE-MRI、DWI单独检查对原发性肝癌的诊断结果与病理结果的一致性中等(Kappa=0.678、0.71...     

磁共振弥散加权成像在肺癌患者诊断中的应用研究

目的 探讨磁共振弥散加权成像(DWI)在肺癌患者诊断中的应用价值研究.方法 选取2016年5月至2019年8月间大连市第三人民医院收治的经病理检查确诊的89例肺癌患者,均行DWI检查,分析DWI在肺癌诊断中的应用价值.结果 随着b值升高,肺癌不同病理类型下表面弥散系数(ADC)值呈下降趋势,其中腺癌在不同b值下ADC值...     

磁共振弥散加权成像对鼻咽癌靶区勾画和复发转移预测的临床价值研究

目的 探讨磁共振弥散加权成像(DWMRI)能否预测鼻咽癌调强放疗后复发和转移以及判断靶区范围的价值。方法 回顾 2008年6月起初次调强放疗的鼻咽癌病历资料,选择有复发或转移 36例和无复发转移 36例作对照。对两组病例在DWMRI上测量其疗前肿瘤表观弥散系数(ADC值),并行成组t检验推测ADC值是否能预测鼻咽癌复发和转移。回顾分析局部区域复发病例放疗前MRI,从影像学角度分析DWMRI是否有助于判断靶区范围。结果 复发或转移组、对照组疗前ADC均值分别为(0.753±0.091)×10^－3、(0.793±0.094)×10^－3 mm²/s (t=－1.79,P=0.078)。影像学回顾分析显示DWMRI在低本底上突显了肿瘤侵犯范围,局部区域复发共 16例,15例疗前常规MRI弥散序列在病变范围上一致,1例复发患者DWMRI序列较常规序列更准确地预测了病变复发部位。结论 DWMRI结合常规MRI可更准确地判断鼻咽癌靶区范围,但其疗前ADC值的高低与鼻咽癌复发或转移并无关联。     

MRI联合CT影像学在肺癌中的诊断效能

目的探讨磁共振成像(MRI)联合计算机断层扫描(CT)影像学检查对肺癌的诊断效能。方法选取疑似肺癌患者88例,均给予MRI常规序列、弥散加权成像扫描和CT检查。观察MRI、CT单独及联合检查诊断肺癌的效能,并对不同临床特征肺癌患者的表观弥散系数(ADC)进行比较。结果88例疑似肺癌患者中,最终确诊肺癌患者51例;MRI联合CT检查诊断肺癌的灵敏度和阴性预测值均高于MRI检查,特异度和阳性预测值均高于CT检查,差异均有统计学意义(P﹤0.05)。小细胞癌患者的ADC值明显低于鳞癌和腺癌患者(P﹤0.01);低分化肺癌患者的ADC值低于高分化和中分化肺癌患者(P﹤0.01)。结论MRI联合CT检查在肺癌中有较高的诊断价值,其中MRI弥散加权成像ADC值与肺癌患者的病理类型和分化程度有关。     

Diffusion weighted MR imaging in the differential diagnosis of haemangiomas and metastases of the liver

Background

The purpose of the study was to evaluate the value of diffusion-weighted imaging in the differential diagnosis of haemangiomas from metastases of the liver.

Patients and methods.

We analyzed 69 lesions in 38 patients (33 haemangiomas; 36 metastases) in the retrospective study. Diffusion-weighted imaging was performed using a breath-hold single-shot echo-planar spin echo sequence with three b factors (0, 500 and 1000 sec/mm²), and apparent diffusion coefficients (ADCs) were calculated. For the quantitative evaluation, signal intensity of the lesions, lesion-to-liver signal intensity ratios, ADC of the lesions, and lesion-to-liver ADC ratios were compared between the groups. The statistical significance was determined by student’s-t test.

Results

With the b factor 500 sec/mm², no statistical significance was achieved (p>0.05). With the b factor of 1000 sec/mm², both the signal intensity and lesion-to-liver signal intensity ratio of the metastases were significantly higher than those for haemangiomas (p<0.001). The cut-off value at 2.6 yielded a sensitivity of 86% and a specificity of 82% for the lesion-to-liver signal intensity ratio. The ADC, and lesion-to-liver ADC ratio of the metastases were significantly lower than those of haemangiomas (p<0.001). With cut-off value of 1.7, ADC ratio had a sensitivity of 88% and a specificity of 72% for ADC lesion/liver.

Conclusions

Diffusion-weighted imaging with high b value may help in the differential diagnosis of metastases from haemangiomas of the liver.     

弥散加权成像表观弥散系数预测肺癌放疗疗效与预后分析

目的 磁共振弥散加权成像可反映放疗前后肿瘤内部的功能变化及肿瘤细胞的存活情况,从而为肺癌疗效评价及预后评估提供重要参考信息.本研究通过测量肺癌患者放疗前后磁共振弥散加权成像(diffusion-weighted magnetic resonance imaging,DWI)表观弥散系数(apparent diffusion coefficient,ADC)的大小及变化情况,探讨该技术在预测肺癌放疗疗效及预后评估中的应用价值.方法 选取2011-01-01-2013-10-31河北医科大学第四医院收治接受三维适形或调强放疗的Ⅲ期肺癌患者34例.处方剂量50～66 Gy,单次2～2.2 Gy.放疗前后l周内行CT扫描及磁共振检查,应用CT、DWI ADC表观弥散系数评价放疗疗效,并与生存相结合进行预后分析.结果 全组患者治疗前后可测量原发灶ADC值分别为(1.03±0.12)×10-3和(1.41±0.10)×10-3 mm2/s,治疗后ADC值明显高于治疗前,z=-4.541,P＜0.001.非小细胞癌组与小细胞癌组肿瘤退缩率差异有统计学意义,z=-3.038,P=0.002.非小细胞癌组与小细胞癌组治疗前(z=-0.527,P=0.598)及治疗后(z=-1.353,P=0.176)原发灶ADC值差异均无统计学意义;小细胞癌组治疗前后ADC值变化更显著,z=-3.337,P=0.001.非小细胞癌组治疗前ADC值、△ADC与肿瘤退缩率之间存在关联性,r值分别为-0.432和0.604,P值分别为0.016和0.001.治疗前低ADC值组(≤1.03×10-3 mm2/s)和高ADC值组(＞1.03×10-3 mm2/s)1年生存率分别为69.2％和17.7％,2年为23.1％和0,3年为23.1％和0,x2=5.577,P=0.018.低△ADC值组(≤0.41×10 3 mm2/s)和高△ADC值组(＞0.41×10-3 mm2/s)1年生存率分别为29.4％和62.5％,2年为0和37.5％,3年为0和37.5％,x2=6.989,P=0.008.治疗后低ADC值和高ADC值组,1年生存率分别为27.3％和57.1％,2年为0和21.4％,3年为0和21.4％,x2=7.626,P=0.006.Cox回归模型单因素分析显示,非小细胞癌患者放疗前和放疗后ADC值大小、治疗前后ADC值变化为预后影响因素.小细胞癌组仅△ADC值与肿瘤退缩率存在负相关,r=-0.840,P=0.005;Cox回归模型单因素分析显示,治疗前后ADC值变化、治疗后ADC值大小为预后影响因素,Wald=3.935和4.495,P=0.047和0.034.结论 肺癌患者放疗前后ADC值变化、治疗末ADC值大小为预后影响因素,经治疗后ADC值变化显著者及治疗末高ADC值表达者提示预后良好,对于非小细胞癌患者治疗前高ADC值表达者提示预后不良.     

Differentiation of malignant and benign lung lesions with diffusion-weighted MR imaging

Background

The aim of the study was to evaluate the role of diffusion-weighted magnetic resonance imaging in the differential diagnosis of lung lesions.

Patients and methods.

Sixty-seven patients with lung lesions (48 malignant, 19 benign) were included in this prospective study. Signal intensities (SIs) were measured in diffusion-weighted MR images that were obtained with b=0, 500 and 1000 s/mm² values. Apparent diffusion coefficient (ADC) maps were calculated by using images with b=0 and 1000 s/mm² values. The statistical significance was determined using the Student-t test.

Results

The SIs of malignant lesions were significantly higher than those of benign lesions (p<0.004 for b=0 s/mm² and p<0.000 for the other b values). Using b=500 s/mm², SI≥391 indicated a malignant lesion with a sensitivity of 95%, specificity of 73% and positive predictive value of 87%. Using b=1000 s/mm², SI≥277 indicated a malignant lesion with a sensitivity of 93%, specificity of 69% and positive predictive value of 85%. There was no significant difference between malignant and benign lesions regarding ADC values (p=0.675). There was no significant difference in SIs or ADC values between small cell carcinoma and non-small cell carcinoma. When comparing undifferentiated with well- partially differentiated cancers, SIs were higher with all b values, but the difference was statistically significant only with b=1000 s/mm² (p<0.04).

Conclusions

Diffusion-weighteted MR trace image SI is useful for the differentiation of malignant versus benign lung lesions.     

全身扩散加权成像在恶性淋巴瘤诊断与疗效评估中的价值

Objective  

The aim was to evaluate the role of whole body diffusion weighted imaging (WB-DWI) of magnetic resonance in the diagnosis and efficacy evaluation of malignant lymphoma.     

磁共振扩散加权成像鉴别诊断良恶性乳腺肿瘤价值的Meta分析

目的:对磁共振扩散加权成像鉴别诊断良恶性乳腺肿瘤的价值进行Meta分析。方法:选择对关于磁共振扩散加权成像鉴别诊断良恶性乳腺肿瘤的国内外文献(2005年-2013年)进行检索与分析,分析磁共振扩散加权成像鉴别诊断的敏感度与特异度。结果:检索符合纳入标准的为60篇文章,其中a级文献10篇。所有文献资料都有很好的异质性,偏倚性也比较好。磁共振扩散加权成像鉴别诊断的平均敏感度与特异度分别为92.0%和79.5%。结论:磁共振扩散加权成像鉴别诊断良恶性乳腺肿瘤有很好的敏感度,特异度也比较好。     

Challenges for the functional diffusion map in pediatric brain tumors

Background

The functional diffusion map (fDM) has been suggested as a tool for early detection of tumor treatment efficacy. We aim to study 3 factors that could act as potential confounders in the fDM: areas of necrosis, tumor grade, and change in tumor size.

Methods

Thirty-four pediatric patients with brain tumors were enrolled in a retrospective study, approved by the local ethics committee, to examine the fDM. Tumors were selected to encompass a range of types and grades. A qualitative analysis was carried out to compare how fDM findings may be affected by each of the 3 confounders by comparing fDM findings to clinical image reports.

Results

Results show that the fDM in areas of necrosis do not discriminate between treatment response and tumor progression. Furthermore, tumor grade alters the behavior of the fDM: a decrease in apparent diffusion coefficient (ADC) is a sign of tumor progression in high-grade tumors and treatment response in low-grade tumors. Our results also suggest using only tumor area overlap between the 2 time points analyzed for the fDM in tumors of varying size.

Conclusions

Interpretation of fDM results needs to take into account the underlying biology of both tumor and healthy tissue. Careful interpretation of the results is required with due consideration to areas of necrosis, tumor grade, and change in tumor size.     

原发性软组织恶性纤维组织细胞瘤的MRI影像诊断（附15例报告）

目的：探讨原发性软组织恶性纤维组织细胞瘤（MFH）的MRI影像诊断。方法：回顾性分析15例经手术病理证实的原发于软组织的恶性纤维组织细胞瘤患者的影像学资料,15例患者均行MRI检查,有7例行CT检查,8例行增强扫描。结果：原发于软组织恶性纤维组织细胞瘤15例,肿瘤形态多样,以卵圆形、分叶状多见。病变于T1WI呈低信号或等信号,T2WI呈高信号或等信号为主混杂信号影,7例病变内可见低信号之分隔影。13例病变内见坏死或黏液样改变,2例伴出血。明确有包膜3例。增强扫描均呈显著不均匀强化。结论：MRI对原发性软组织恶性纤维组织细胞瘤的诊断具有重要价值,是首选的影像学检查方法。     

原发性软组织恶性纤维组织细胞瘤的MRI影像诊断(附15例报告)

目的:探讨原发性软组织恶性纤维组织细胞瘤(MFH)的MRI影像诊断。方法:回顾性分析15例经手术病理证实的原发于软组织的恶性纤维组织细胞瘤患者的影像学资料,15例患者均行MRI检查,有7例行CT检查,8例行增强扫描。结果:原发于软组织恶性纤维组织细胞瘤15例,肿瘤形态多样,以卵圆形、分叶状多见。病变于T1WI呈低信号或等信号,T2WI呈高信号或等信号为主混杂信号影,7例病变内可见低信号之分隔影。13例病变内见坏死或黏液样改变,2例伴出血。明确有包膜3例。增强扫描均呈显著不均匀强化。结论:MRI对原发性软组织恶性纤维组织细胞瘤的诊断具有重要价值,是首选的影像学检查方法。