子宫内膜癌的MRI诊断及鉴别诊断

目的:探讨子宫内膜癌的MRI表现特点,提高该病的诊断及鉴别诊断水平。方法:回顾性分析56例经手术病理证实的子宫内膜癌的临床资料及MRI表现。56例均行MRI平扫、增强扫描及DWI。结果:56例MRI平扫多表现为T_1WI呈等信号,T_2WI呈略高信号;动态增强扫描肿瘤呈轻度渐进性强化,信号强度始终低于明显强化的外肌层;DWI呈高信号,ADC呈低信号,ADC值平均为(0.904±0.185)×10~(-3)mm/s。结论:MRI能准确预测子宫内膜癌浸润肌层深度、宫颈侵犯、淋巴结和远处转移。     

磁共振弥散加权成像在子宫内膜癌的初步研究

目的 探讨磁共振弥散加权成像(diffusion weighted imaging,DWI)在子宫内膜癌中的诊断价值.方法 正常妇女子宫45例,子宫内膜癌(endometrial carcinoma,EC) 35例,均进行横断面、矢状面常规MRI扫描及不同b值下(b=500、800、1 000 s/mm2)横断面及矢状位扩散加权成像,分别测量正常子宫体3层结构和子宫内膜癌病灶的信噪比(signal to noise ratio,SNR)及表观扩散系数(appareent diffusion coefficient,ADC)值,膀胱的信号强度比(signal intensity ratio,SIR),并进行比较.结果 正常子宫三层结构的T2WI图像信号强度有差异,内膜层信号度最高,结合带最低;在DWI图像上内膜信号强度分别高于结合带和外带,结合带和外带的差异肉眼不易分辨.正常对照组子宫同一层组织在不同b值下所得ADC值之间差异无统计学意义(P>0.05);宫体内膜与结合带ADC值之间差异无统计学意义(P>0.05),而宫体内膜与肌层、结合带与肌层ADC值之间差异有统计学意义(P<0.01).扩散图像中肿瘤SNR随着b值增加而逐渐下降.b=500 s/mm2时,正常子宫内膜与子宫内膜癌ADC值之间的差异无统计学意义(P>0.05); b=800、1 000 mm2/s时,正常子宫内膜ADC分别为(1.541±0.148)×10-3mm2/s和(1.530±0.119)×10-3mm2/s,均高于EC病灶的(0.984±0.162) ×10-3mm2/s和(0.775±0.153)×10-3 mm2/s,两者之间的差异有统计学意义(F=32.919,P<0.01).但高分化子宫内膜样腺癌和中分化子宫内膜样腺癌的ADC值之间在不同b值间无统计学意义(P＞0.1).结论 b=800 s/mm2和1 000 s/mm2是子宫内膜癌成像的较佳b值.ADC值对鉴别正常子宫体内膜与子宫内膜癌有一定的参考价值,但对于鉴别不同分化程度的子宫内膜样腺癌仍有一定困难.     

The Clinical Value of Combined MRI and Diffusion Weighted Imaging in Ankylosing Spondylitis

目的 探讨MRI联合DWI对强直性脊柱炎(AS)的诊断价值.资料与方法 搜集经修订纽约标准确诊的31例AS病例和25例正常对照组,两组均行两侧骶髂关节常规MRI横断位和冠状位抑脂T2WI、T1WI联合SE/EPI扩散加权成像(DWI)横断位扫描(b值0,600 s/mm2),观察两组骶髂关节的信号改变,测量表观扩散系数(ADC)值并作统计学检验.结果 31例病例组中的24例双侧或单侧骶髂关节面下骨质抑脂T2WI呈高信号,29例DWI呈高信号,25例对照组骶髂关节面下骨质T2WI、DWI均呈等信号,测量ADC值,病变组为(0.993±0.169)×10 -3mm2/s,对照组为(0.649±0 395)×10 -3 mm2/s,病变组ADC值明显高于对照组(t=4.14,P＜0.001),两者间差异有统计学意义.结论 MRI联合DWI对AS早期诊断有重要的临床价值.     

MRI联合DWI在强直性脊柱炎诊断中的价值

目的探讨MRI联合DWI对强直性脊柱炎(AS)的诊断价值。资料与方法搜集经修订纽约标准确诊的31例AS病例和25例正常对照组,两组均行两侧骶髂关节常规MRI横断位和冠状位抑脂T2WI、T1WI联合SE/EPI扩散加权成像(DWI)横断位扫描(b值0,600 s/mm2),观察两组骶髂关节的信号改变,测量表观扩散系数(ADC)值并作统计学检验。结果 31例病例组中的24例双侧或单侧骶髂关节面下骨质抑脂T2WI呈高信号,29例DWI呈高信号,25例对照组骶髂关节面下骨质T2WI、DWI均呈等信号,测量ADC值,病变组为(0.993±0.169)×10-3mm2/s,对照组为(0.649±0.395)×10-3mm2/s,病变组ADC值明显高于对照组(t=4.14,P<0.001),两者间差异有统计学意义。结论 MRI联合DWI对AS早期诊断有重要的临床价值。     

3.0T磁共振扩散加权成像在子宫内膜癌诊断中的价值

目的 探讨3.0T MR扩散加权成像(DWI)在子宫内膜癌诊断中的临床应用价值.方法 对48例子宫内膜癌患者和20例无子宫内膜病变者行盆腔T2WI和DWI,由2名MRI诊断医师采用盲法随机进行MRI阅片后,采用5分制评分,以受试者工作特征曲线(ROC)对比分析单纯T2WI与DWI结合T2WI诊断子宫内膜癌的敏感性和特异性,并对内膜癌和正常内膜的表观扩散系数(ADC)值进行定量分析.结果 2名医师单纯应用T2WI与DWI结合T2WI检出子宫内膜癌的ROC曲线下面积(Az)值分别为0.831与0.944、0.877与0.954,2名医师DWI结合T2WI对内膜癌诊断的准确性均高于单纯应用T2WI(P<0.05).Kappa一致性检验表明2名医师具有良好的一致性(Kappa值分别为0.843和0.898,P<0.01).子宫内膜癌和正常内膜的ADC值分别为(0.954±0.139)×10-3mm2/s、(1.468±0.161)×10-3mm2/s,子宫 内膜癌与正常内膜的ADC值间差异有统计学意义(t=-13.217,P<0.01).结论 3.0T MR-DWI作为常规T2WI的补充检查序列可以明显提高对子宫内膜癌的检出率.     

MR弥散加权成像在子宫内膜良恶性病变中的鉴别价值

目的 探讨MR弥散加权成像(DWI)及其表观弥散系数(ADC)在子宫内膜良恶性病变中的鉴别价值.方法 回顾性分析55例经病理证实的子宫内膜病变,其中良性组14例(6例内膜增生、8例内膜息肉),恶性组41例(39例内膜癌、2例癌肉瘤).所有病例行常规MRI平扫和增强检查,以及DWI(弥散敏感因子b值为0、1000s/mm2),分析病变的DWI信号特点和测定ADC值.结果 良性组DWI图12例表现为稍高信号、2例表现为等信号、平均ADC值为(1.34±0.19)×103mm2/s;恶性组DWI图34例表现为明显高信号,余下7例表现为稍高信号,平均ADC值为(0.84±0.14)×103 mm2/s;恶性组ADC值明显小于良性组(P=0.042),以1.07×103 mm2/s为临界值诊断子宫内膜良恶性病变的敏感性、特异性、准确性高达92.9％、97.6％、96.4％.结论 DWI及ADC值测定有助于子宫内膜良恶性病变的鉴别诊断.     

DWI结合MRI动态增强扫描在肝脏炎性肌纤维母细胞瘤鉴别诊断中的应用

目的:探讨DWI结合MRI动态增强扫描对肝脏炎性肌纤维母细胞瘤与恶性肿瘤的鉴别诊断价值。方法:对经手术或病理证实的肝脏炎性肌纤维母细胞瘤及恶性肿瘤患者行腹部MRI平扫、DWI和动态增强扫描,分析病变的影像特点,并测量分析ROI的ADC值。结果:肝脏炎性肌纤维母细胞瘤增强扫描不强化或边缘纤维组织呈环状强化。原发性肝癌动态增强扫描曲线呈快进快出的特点;转移瘤及胆管细胞癌呈延迟强化。15例炎性肌纤维母细胞瘤中,8例DWI表现为等信号,ADC图表现为稍高信号,平均ADC值(1.21±0.05)×10-3 mm2/s;4例DWI表现为低信号,ADC图表现为低信号,平均ADC值(0.61±0.07)×10-3 mm2/s;3例DWI表现为高信号,ADC图表现为稍高信号,平均ADC值(1.14±0.06)×10-3 mm2/s。原发性肝癌14例中11例DWI表现为高信号,ADC图表现为低信号,平均ADC值(1.27±0.03)×10-3 mm2/s;3例DWI表现为等信号,ADC图表现为稍高信号,平均ADC值(1.38±0.05)×10-3 mm2/s。转移瘤13例DWI表现为高信号,ADC图表现为低信号,平均ADC值(1.27±0.03)×10-3 mm2/s。12例胆管细胞癌DWI表现为稍高信号,ADC图表现为稍低信号,平均ADC值(1.65±0.03)×10-3 mm2/s。结论:DWI结合动态增强扫描对肝脏炎性肌纤维母细胞瘤与恶性肿瘤具有一定的鉴别诊断价值。     

Meckel腔病变的常规MRI和扩散加权成像表现

目的：探讨各种Meckel腔病变的常规MRI和扩散加权成像（DWI）特点.方法：回顾性分析30例Meckel腔病变（31处病变）的MRI表现,且与临床资料、病理诊断及手术结果进行对照分析.结果：31处Meckel腔病变中以肿瘤（n=28）最常见.病变T1WI呈等信号（n=18）、不均匀信号（n=11）、稍低信号（n=1）或稍高信号（n=1）;T2WI呈稍高信号（n=8）、等信号（n=7）、高信号（n=6）及不均匀信号（n=10）;所有病变增强扫描均显著强化.30例病变DWI上呈高信号,且31例呈不同的ADC值,平均ADC值为（1.09±0.22）×10-3mm2/s,最小值为（0.59±0.11）×10-3mm2/s（小细胞型神经内分泌癌）,最大值为（2.09±0.41）×10-3mm2/s（软骨肉瘤）.结论：常规MRI与DWI和ADC值相结合,对诊断各种Meckel腔病变具有重要价值.     

DWI联合MRI常规序列对宫颈癌的诊断及分期与病理对照分析

目的探讨扩散加权成像(DWI)联合MRI常规序列在宫颈癌诊断及分期中的价值。方法收集46例经病理证实的宫颈癌患者,术前行MRI常规序列及DWI检查,测量肿瘤实性部分及宫颈或宫体残留正常肌层的ADC值,并将宫颈癌的MRI分期与手术病理结果进行比较。结果宫颈癌在T1WI呈等低信号,T2WI呈中高信号,DWI呈明显高信号,肿瘤实性部分及残留正常宫颈或宫体ADC值分别为(0.89±0.12)×10-3mm2/s和(1.76±0.13)×10-3mm2/s,两者差异有统计学意义(t=34.164,P=0)。宫颈癌MRI分期与手术病理分期符合率为84.8%。结论 DWI联合MRI常规序列能清晰显示宫颈癌病变及侵犯范围,分期诊断有较高的准确率,在宫颈癌的诊断及分期中具有重要价值。     

扩散加权成像在胰腺癌诊断中的价值初探

目的探讨MR扩散加权成像(DWI)在胰腺癌诊断中的价值。资料与方法健康自愿者20名,经手术病理和随访证实的胰腺癌患者21例、慢性胰腺炎患者12例,分别行常规MRI和DWI检查。应用自旋回波-回波平面成像(SE-EPI)并采用采集空间敏感性编码技术(ASSET),取b=0和600s/mm2获得DWI图像。分别测量感兴趣区(ROI)的表观扩散系数(ADC)值,行配对t检验。结果健康自愿者胰腺DWI呈中等信号,胰头、胰体尾部ADC值分别为(1.535±0.247)×10-3mm2/s、(1.643±0.375)×10-3mm2/s。21例胰腺癌肿瘤区DWI呈均匀或稍不均匀高信号,ADC值为(1.192±0.117)×10-3mm2/s。健康自愿者胰头与胰体尾部ADC值差异无统计学意义(P>0.05),胰头及胰颈部肿瘤患者胰体尾部ADC值与健康自愿者间差异有统计学意义(P<0.001),胰腺肿瘤ADC值与胰头及体尾部之间差异有统计学意义(P<0.001)。慢性胰腺炎DWI呈不均匀等或稍高信号,ADC值为(1.437±0.385)×10-3mm2/s,与胰腺癌间差异有统计学意义(P<0.05)。结论DWI可以清楚显示肿瘤病灶及范围,ADC值的测定在一定程度上有助于胰腺癌的诊断。     

扩散张量成像导出量对扩散时间依赖关系的实验研究

目的研究扩散张量导出量与扩散时间的关系。方法保持扩散敏感梯度磁场强度不变,使用8个不同的扩散时间对11名被试者进行扩散张量成像扫描得到脑部的各向异性与各向同性信息,计算出各个感兴趣区的平均扩散率与各向异性分数后进行比较。结果不同扩散时间对应的平均扩散率有显著性差异（P〈0．05）,而各向异性分数无显著性差异（P〉0．05）。结论扩散时间对扩散张量成像导出量中的各向异性分数无影响,对平均扩散率有影响。原因是细胞内外水分子扩散性质不同。     

Diffusion Weighting by the Trace of the Diffusion Tensor within a Single Scan

The anisotropy of the water diffusion tensor inside brain causes contrast in diffusion images, which depends on the relative orientation of the diffusion gradients and the subject. Because the trace of a tensor is invariant upon rotation, measurement of this trace can reduce the orientation effect. A family of imaging pulse sequences is presented in which the signal intensity is weighted by the trace of the diffusion tensor in a single scan. The methods are demonstrated for chicken gizzard in several orientations with respect to the gradient frame of reference, and for ischemic injury in cat brain after middle cerebral artery occlusion. The sensitivity of the techniques to the presence of background gradients is measured and discussed in detail. As a result, pulse sequences are suggested that provide reliable diffusion constants in both homogeneous and inhomogeneous magnetic fields. The efficiency of the techniques for clinical application is also evaluated.     

Diffusion of myelin water.

We studied compartmentally specific characteristics of water diffusion in excised frog sciatic nerve by combining T1 or T2 selective acquisitions with pulse-gradient spin-echo (PGSE) diffusion weighting, with the specific objective of characterizing myelin water diffusion. Combining a PGSE with a Carr-Purcell-Meiboom-Gill (CPMG) acquisition provided apparent diffusion coefficients (ADCs) for each of the three T2 components found in nerve, including the short-lived component believed to be derived from myelin water. Double-inversion-recovery (DIR) preparation provided an alternate means of discriminating myelin water, and in combination with PGSE provided somewhat different measures of ADC. The DIR measures yielded myelin water ADCs of 0.37 microm2/ms (parallel to nerve) and 0.13 microm2/ms (perpendicular to nerve). These ADC estimates were postulated to be more accurate than those based on T2 discrimination, although the difference between the two findings is not clear.     

Echo-Planar Diffusion Spectroscopic Imaging

High-speed diffusion spectroscopic imaging based on an echo-planar technique is presented. A pair of diffusion gradients is applied prior to a rapidly oscillating magnetic field gradient which encodes both chemical shift and spatial information. By applying this technique to a phantom consisting of acetone and water, a diffusion spectroscopic image is obtained in about 15 min, about 64 times faster than the time required in the conventional method. The measured diffusion coefficients show good agreement with previously reported values. This kind of diffusion spectroscopic imaging is expected to provide a way to observe more specific metabolism.     

基于磁共振扩散加权波谱技术的水分子扩散测量方法

目的 在常规医用磁共振机上利用扩散加权波谱技术测量水分子的扩散系数.方法 在受激回波采集模式序列中第二个π/2射频脉冲之前及第三个π/2射频脉冲之后加入两个强扩散梯度磁场,在3.0特斯拉医用磁共振机上运行此脉冲序列扫描磁共振波谱模体,扩散梯度磁场强度固定,通过改变两扩散梯度磁场间隔得到不同的扩散权重,扫描过程中不抑制水信号.结果 在重扩散权重条件下得到的波谱中水信号信噪比依然较高,扩散权重对水分子表观扩散系数的影响不显著(P＞0.05).结论 在常规医用磁共振机上利用扩散加权波谱技术测量水分子扩散系数是可行的,而且结果不受扩散权重的影响.     

磁共振扩散加权成像和ADC值在前列腺癌诊断中的应用价值

目的探讨磁共振扩散加权成像（DWI）及表观扩散系数（ADC）在前列腺癌诊断中的应用价值。资料与方法回顾分析经组织病理学证实的前列腺癌49例患者资料,DWI采用单次激发平面回波序列（EPI）。感兴趣区（ROI）包括前列腺癌、前列腺良性增生（BPH）和正常前列腺周围带,并计算相应的ADC值。结果49例前列腺癌患者血清前列腺特异抗原（PSA）平均为49.1ng/ml。肿瘤病灶ROI的ADC值在X、Y和Z轴方向分别有41、9和13例获得;前列腺良性增生分别在3个方向为39、11和13例;正常前列腺周围带为31、9和10例。前列腺癌在X、Y和Z轴方向平均ADC值分别为2.282×10^-3mm^2/s、2.293×10^-3mm^2/s和3.017×10^-3mm^2/s;BPH各个方向平均ADC值分别为2.559×10^-3mm^2/s、2.812×10^-3mm^2/s和3.585×10^-3mm^2/s;正常前列腺外周区组织3个方向的平均ADC值分别为2.892×10^-3mm^2/s、3.303×10^-3mm^2/s和4.112×10^-3mm^2/s。前列腺癌在X轴方向的ADC值明显低于相同方向前列腺增生和正常周围带的ADC值（P〈0.005）。结论DWI和ADC值在前列腺癌的诊断中应用方便、易行,ADC值是区别前列腺癌组织和非肿瘤组织的可靠指标。     

Diffusion and perfusion of the breast

This article is a review of the current published clinical applications of DWI and perfusion of breast MR explaining possibilities and limits of both techniques.DWI in a fast time acquisition and without contrast medium gives information as regards cellularity of breast lesions. The technique can be used for distinguishing between benign and malignant breast lesions and monitoring therapies in locally advanced breast cancer.Perfusion can give additional information as regards vascularization of breast lesions, useful in the characterization of breast lesions doubt at DCE-MRI and also in monitoring chemotherapic effect.     

Diffusion and perfusion of the breast

This article is a review of the current published clinical applications of DWI and perfusion of breast MR explaining possibilities and limits of both techniques.DWI in a fast time acquisition and without contrast medium gives information as regards cellularity of breast lesions. The technique can be used for distinguishing between benign and malignant breast lesions and monitoring therapies in locally advanced breast cancer.Perfusion can give additional information as regards vascularization of breast lesions, useful in the characterization of breast lesions doubt at DCE-MRI and also in monitoring chemotherapic effect.     

Diffusion weighted MRI of spine tumors

PURPOSE: To evaluate the contribution of diffusion weighted MR imaging in malignant spine pathology. Materials and methods. Between February 2004 and January 2005, 49 patients (43 to 86 years old) were included. Three groups were made: osteoporotic collapses (n = 13), malignant collapses (n = 15) and malignant spine lesions (n = 21). The MRI (Symphony 1.5T) allowed SENSE imaging. After conventional MRI examination (T1, T2 fat sat, T1 with Gadolinium), all patients underwent diffusion weighted imaging (Spin Echo) with variable b values: 0, 250, 500, 750 and 1000. The diffusion sequence lasted 2 min 29 s. The Apparent Diffusion Coefficient (ADC) was calculated automatically. The analysis was qualitative (signal study b = 1,000 mm2/s) and quantitative (ADC measurement). RESULTS: The image quality was good except for some cervical examinations. Qualitative analysis did not show a difference between benign and malignant lesions. Quantitative results are: malignant spine lesion (mean ADC = 0.826 10-3 s/mm2), malignant spinal collapses (mean ADC = 0.912 10-3 s/mm2) and benign spinal collapses (mean ADC = 1.497 10-3 s/mm2). There was overlapping results between benign and malignant lesion. The statistical study showed a significant difference (t test with p < 1/10 000). For an ADC threshold value of 1.089 (malignant lesion ADC < 1.089), ROC curve showed a specificity = 80% and a sensitivity = 83.3%. CONCLUSION: Performing diffusion weighted imaging of the spine is easy with new MR technology. The ADC measurement of spine lesion provides important additional information, but does not serve as a substitute for the routine MRI sequences. In the future, it could become an important point in this difficult diagnosis.