磁共振扩散加权成像鉴别良恶性软组织肿瘤的价值

目的 :探讨磁共振扩散加权成像(DWI)鉴别良恶性软组织肿瘤的价值。 方法 :采用扩散加权成像分析43例软组织肿瘤,其中恶性25例,良性18例。所有病例均经手术病理证实。扩散加权成像的扩散敏感因子(b值)为0,500s/mm²。选取肿瘤实体部分最大感兴趣区,尽量避开坏死、出血、瘢痕及钙化等不均质成分。分析各病灶的扩散加权图像特点,比较良、恶性肿瘤表观扩散系数(apparent diffusion coefficient,ADC)的差异。3例恶性肿瘤患者化疗前、后进行DWI检查,分析ADC值的变化特点。 结果 :恶性肿瘤的ADC值(0.96±0.31×10^-3)mm²/s明显低于良性肿瘤的ADC值(1.92±0.63×10^-3)mm²/s和肌肉组织(1.69±0.47×10^-3)mm²/s的ADC值,差异具有统计学意义(P<0.05),良性肿瘤与肌肉的ADC值无明显差异。ADC值为(1.38×10^-3)mm²/s时,鉴别良恶性肿瘤的敏感性为92%,特异性为83%。3例恶性肿瘤患者化疗前、后进行DWI检查,其中2例化疗后ADC值升高,1例无ADC值的明显变化。 结论 :ADC值在软组织良恶性肿瘤的鉴别诊断中具有重要价值,ADC值对于化疗效果评价的作用需要进一步研究并与组织学对照加以证实。     

磁共振扩散加权成像在乳腺病变鉴别诊断中的应用价值

背景与目的:磁共振扩散加权成像(diffusion weighted imaging,DWI)是目前惟一能观察活体水分子微观运动的成像方法,能够检测出与组织含水量改变有关的形态学和病理学的早期改变,已广泛应用于脑部病变的诊断和鉴别诊断,但在乳腺病变诊断中的应用目前仍处于研究探索阶段.本文目的在于探讨DWI在乳腺病变鉴别诊断中的价值.方法:分析52例经手术病理学检查证实的乳腺疾病患者的DWI资料,包括恶性病灶27个,良性病变36个.DWI采用单次激发平面回波成像(echo planar imaging,EPI)技术.以10例正常乳腺为对照组.测量病灶的表观扩散系数(apparent diffusion coefficient,ADC)值,比较良恶性病变、正常腺体ADC值是否具有显著性差异.采用接收者工作特征曲线(receiver operating characteristic curve,ROC)确定ADC值的诊断阈值,并用于诊断.结果:DWI对乳腺病变的显示良好.良性病变平均ADC值为(1.59±0.26)×10-3 mm2/s,95%参考值范围为(1.07～2.11)×10-3 mm2/s;恶性病灶平均ADC值为(0.87±0.23)×10-3 mm2/s,95%参考值范围(0.42～1.32)×10-3 mm2/s;正常腺体ADC值为(1.98±0.31)×10-3mm2/s.95%参考值范围(1.38～2.58)×10-3 mm2/s,三组ADC值之间均有显著性差异(P＜0.05).ROC曲线下面积(Az值)为0.96(95%可信区间0.92～1.00),诊断阈值为1.22×10-3 mm2/s.以此值作为良、恶性判断标准,敏感性88.9%,特异性87.9%,准确性85.0%.结论:ADC值有助于乳腺病变的鉴别诊断,DWI在乳腺癌的诊断上具有临床应用前景.     

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。     

磁共振弥散加权成像在乳腺良恶性病变鉴别中的应用价值

目的 探讨磁共振弥散加权成像（DWI）在鉴别乳腺良恶性病变中的应用价值.方法 对56例乳腺疾病患者采用3.0 T磁共振常规扫描、DWI,测量感兴趣区DWI的信号强度和表面扩散系数（ADC）值,并对得到的数据进行方差分析.结果 56例患者术后病理检查共检出122个病灶,其中乳腺癌病灶38个（31.15％）,包括浸润性导管癌32个,浸润性小叶癌2个,髓样癌4个;乳腺良性肿瘤病灶84个（68.85％）,包括纤维腺瘤55个,乳腺囊性增生病20个,乳管内乳头状瘤2个,乳管内乳头状瘤伴上皮中重度不典型增生3个,纤维脂肪瘤1个,乳腺炎症和出血3个.在ADC图上良性病灶呈相对高信号影;恶性病灶呈相对低信号影,与周围正常腺体组织分界清晰.正常乳腺腺体及良、恶性乳腺病灶在扩散敏感系数（b） =50s/mm2、b=800 s/mm2的信号强度值及ADC值比较,差异具有统计学意义（F=52.34、14.35、198.64,均P＜ 0.05）.两两比较结果显示正常乳腺腺体组与良性病变组在b=50 s/mm2、b=800 s/mm2的信号强度值及ADC值比较差异无统计学意义（均P＞0.05）,而其他各组之间两两比较差异均有统计学意义（t=23.65、12.65、13.85、24.10、5.65、6.98,均P＜0.05）.结论 DWI有助于乳腺良恶性病变的鉴别诊断,尤其ADC值是一个很有价值的参数.     

磁共振扩散加权成像在前列腺癌诊断中的价值

目的探讨磁共振扩散加权成像对前列腺癌的诊断价值并寻找诊断前列腺癌的适宜阈值。方法 74例前列腺癌疑诊患者行3.0 T MR常规平扫及DWI成像。测量ADC map图中每侧外周带的ADC低值。外周带穿刺发现腺癌为阳性组,无肿瘤证据为阴性组。比较阴性组与阳性组,分化较好腺癌组(Gleason评分2～6分)与分化较差腺癌组(Gleason评分7～10分)的ADC低值差异。以ADC低值预测外周带穿刺阳性率,绘制ROC曲线。结果74例患者中146个前列腺侧叶(阴性组50,阳性组96)获得组织学证实,其中分化较好腺癌(Gleason评分2～6分)17个,分化较差腺癌(Gleason评分7～10分)79个。阳性组与阴性组间ADC低值差异有统计学意义(0.92×10-3±0.22×10-3 mm2/s vs 1.48×10-3±0.28×10-3 mm2/s,t=12.27,P=0.00)。分化较好腺癌组与分化较差腺癌组差异有统计学意义(1.04×10-3±0.20×10-3 mm2/s vs 0.89×10-3±0.21×10-3 mm2/s,t=2.60,P=0.01)。分化较好腺癌组与阴性组ADC低值差异亦有统计学意义(t=5.91,P=0.00)。以ADC低值预测外周带穿刺阳性率,ROC曲线下面积为0.95(P=0.00),最佳临界值为1.15×10-3mm2/s,此时判断穿刺阳性的敏感度为85.4%,特异度为92.0%。结论 MR DWI出现对于前列腺癌的诊断具有较高价值,ADC低值小于1.15×10-3mm2/s可能是较适宜的诊断界值。     

磁共振扩散加权成像对子宫内膜癌的诊断价值

目的 应用高场强磁共振对子宫内膜癌进行扩散加权成像(DWI),并探讨其对子宫内膜癌的诊断价值.方法 应用3.0T磁共振扫描仪,对临床怀疑为子宫内膜癌的50例患者(病理证实子宫内膜癌35例,子宫内膜不典型增生10例,分泌期子宫内膜4例,萎缩性子宫内膜1例)以及41例正常志愿者行常规扫描和DWI,DWI选择b值为1000 s/mm~2.观察子宫内膜癌、正常子宫内膜和子宫内膜不典型增生在DWI图像上的差异,并分析三者间以及不同分化程度子宫内膜样腺癌之间表观扩散系数(ADC)值的差异.结果 与周围正常肌层相比,子宫内膜癌、子宫内膜不典型增生和正常子宫内膜在DWI图像上均呈明显高信号.子宫内膜癌、子宫内膜不典型增生和正常子宫内膜的ADC值分别为(1.08±0.23)×10~(-3)mm~2/s、(1.29±0.21)×10~(-3) mm~2/s和(1.41±0.21)×100~(-3)mm~2/s.统计分析结果显示,子宫内膜癌和正常子宫内膜的ADC值之间以及子宫内膜癌与子宫内膜不典型增生的ADC值之间的差异均有统计学意义(均P＜0.05),但高分化子宫内膜样腺癌和中分化子宫内膜样腺癌的ADC值之间的差异无统计学意义(P=0.109).结论 DWI对检出子宫内膜病变非常敏感,能够鉴别子宫内膜癌、子宫内膜不典型增生和正常子宫内膜,但对于鉴别不同分化程度的子宫内膜样腺癌仍有一定的困难.     

磁共振动态增强、扩散加权成像联合应用对乳腺疾病的诊断价值

目的 探讨磁共振动态增强（dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI）、扩散加权成像（diffusion weighted imaging,DWI）及其联合应用对乳腺疾病诊断的价值.方法 乳腺病变患者75例,共80个病灶.观察病灶形态、信号特征、时间信号强度曲线（time signal intensity curve,TIC）、早期强化率.联合诊断采用序列诊断及平行诊断两种方法.评价DCE-MRI、DWI及联合成像对乳腺疾病定性诊断的价值.结果 恶性病变形状不规则或呈分叶状、多见毛刺或棘状突起、不均匀强化或环状强化、早期强化明显、TIC多为Ⅲ型.乳腺良性病变多形态规则、边缘清晰、呈均匀强化、早期强化率低、TIC多为Ⅰ型.DCE-MRI联合DWI平行诊断,提高了诊断的灵敏度及准确率,有助于对病变进行定性诊断.结论 DCE-MRI及DWI诊断均有较高的灵敏度、特异度及准确率,推荐作为常规检查序列.联合DCE-MRI和DWI平行诊断,为疾病的诊断提供更丰富、更有价值的信息,诊断的灵敏度和准确率较高,有助于病变性质的判定.     

三种不同磁共振扩散加权成像模型在鉴别乳腺良恶性病灶中的价值研究

背景与目的：近年来扩散加权成像(diffusion-weighted imaging,DWI)技术的开展及应用,大大提高了磁共振（magnetic resonance,MR）的特异度,其中体素内不相干运动（intravoxel incoherent motion,IVIM）模型和扩散峰度成像（diffusion kurtosis imaging,DKI）模型作为新兴技术,已在临床研究中取得一定的进展。该研究探讨DWI的单指数模型、IVIM模型和DKI模型在乳腺良恶性病灶中的鉴别诊断价值。方法：该研究为前瞻性研究,纳入标准：超声或X线BI-RADS 4类及以上患者。排除标准：① 乳腺MR检查前已进行穿刺检查、新辅助化疗或手术的患者;② 图像运动伪影较重。所有患者术前均行双侧乳腺MR检查,扫描序列包括快速反转恢复（turbo inversion recovery magnitude,TIRM）、多b值DWI（RS-EPI）和T1W动态增强扫描。选取病灶实性成分最大层面且避开明显坏死、囊变液化区绘制感兴趣区（region of interest,ROI）,分别测量单指数模型参数表观弥散系数（apparent diffusion coefficient,D_ADC）值、IVIM模型参数[真实扩散系数（tissue diffusivity coefficient,D_DT）、灌注相关扩散系数（perfusion-related diffusivity coefficient,D^*）、灌注分数（perfusion fraction,f）]和DKI模型参数[峰度系数（kurtosis coefficient,K）、扩散系数（diffusivity coefficient,D_DK）]。采用独立样本t检验分别比较乳腺良恶性病灶组织上述参数的差异。采用受试者工作特征（receiver operating characteristic,ROC）曲线评价3种模型参数的诊断效能。采用Z检验比较各参数曲线下面积（area under curve,AUC）的差异。结果：依据上述标准共纳入80例患者（83个病灶）,其中良性病灶38个,恶性病灶45个。3种不同扩散模型中D_ADC值、D_DT值、K值及D_DK值在鉴别乳腺良恶性病灶中差异均有统计学意义（P均＜0.05）,其最佳阈值分别为D_ADC值1.08×10^-3 mm²/s、D_DT值1.06×10^-3 mm²/s、K值0.756及D_DK值1.36×10^-3 mm²/s。而D*值和f值在良恶性病灶之间存在较大重叠,差异无统计学意义（P＞0.05）。ROC曲线显示,K值和DDT值在鉴别乳腺良恶性病灶的AUC值最高,分别为0.956和0.947,K值的灵敏度和特异度为91.1%和89.5%,D_DT值的灵敏度和特异度为93.3%和84.2%;D_ADC值和D_DK值其次,AUC分别为0.933和0.923,DADC值的灵敏度和特异度为88.9%和84.2%,D_DK值的灵敏度和特异度为91.1%和84.2%。最后,D_ADC值、D_DT值、K值及D_DK值在鉴别乳腺良恶性病灶中的ROC曲线的AUC差异均无统计学意义（P均＞0.05）。结论：三种不同扩散加权成像模型在鉴别乳腺良恶性病灶中均有较好的诊断价值,其中IVIM和DKI的诊断效能较单指数模型略高,但 三者间差异无统计学意义。单指数模型扫描时间短,后处理简单,在临床应用价值很高。     

多参数磁共振成像对乳腺良恶性病变的诊断价值

目的 探讨扩散加权成像(DWI)、T2加权成像(T2WI)和动态对比增强(DCE)-MRI对乳腺癌的诊断价值.方法 对136例患者的169个乳腺病变进行分析,所有患者同时接受了DCE-MRI和DWI(b值为1000 s/mm2)检查.按检查方法分为三组,第一组DCE-MRI,第二组DWI-T2WI,第三组DCE-MRI联合DWI-T2WI.计算三组检查对乳腺良恶性病变的诊断价值.结果 169个乳腺病变中,良性48个,恶性121个.第二组DWI-T2WI和第三组DCE-MRI联合DWI-T2WI的特异度、阳性预测值和曲线下面积(AUC)均优于第一组DCE-MRI.低ADC值和边缘强化与组织学分级较高的肿瘤有关.结论 与DCE-MRI相比,结合DWI、T2WI和ADC值可提高鉴别乳腺癌良恶性病变的准确度.ADC值越低,肿瘤的组织学分级越高.     

Diffusion-Weighted Imaging for the Left Hepatic Lobe has Higher Diagnostic Accuracy for Malignant Focal Liver Lesions

Background: This study was conducted to investigate whether apparent diffusion coefficient (ADC) measurements by dividing the liver into left and right hepatic lobes may be utilized to improve the accuracy of differential diagnosis of benign and malignant focal liver lesions. Materials and Methods: A total of 269 consecutive patients with 429 focal liver lesions were examined by 3-T magnetic resonance imaging that included diffusion-weighted imaging. For 58 patients with focal liver lesions of the same etiology in left and right hepatic lobes, ADCs of normal liver parenchyma and focal liver lesions were calculated and compared using the paired t-test. For all 269 patients, ADC cutoffs for focal liver lesions and diagnostic accuracy in the left hepatic lobe, right hepatic lobe and whole liver were evaluated by receiver operating characteristic curve analysis. Results:For the group of 58 patients, mean ADCs of normal liver parenchyma and focal liver lesions in the left hepatic lobe were significantly higher than those in the right hepatic lobe. For differentiating malignant lesions from benign lesions in all patients, the sensitivity and specificity were 92.6% and 92.0% in the left hepatic lobe, 94.4% and 94.4% in the right hepatic lobe, and 90.4% and 94.7% in the whole liver, respectively. The area under the curve of the right hepatic lobe, but not the left hepatic lobe, was higher than that of the whole liver. Conclusions: ADCs of normal liver parenchyma and focal liver lesions in the left hepatic lobe were significantly higher than those in the right hepatic lobe. Optimal ADC cutoff for focal liver lesions in the right hepatic lobe, but not in the left hepatic lobe, had higher diagnostic accuracy compared with that in the whole liver.     

Differentiation of Benign from Malignant Adnexal Masses by Functional 3 Tesla MRI Techniques: Diffusion-Weighted Imaging and Time-Intensity Curves of Dynamic Contrast-Enhanced MRI

Background: The aim of this study was to evaluate and compare the accuracy of diffusion-weighted imaging(DWI), apparent diffusion coefficient (ADC) value, and time-intensity curve (TIC) type analysis derived fromdynamic contrast-enhanced MR imaging (DCE-MRI) in differentiating benign from malignant adnexal masses.Materials and Methods: 47 patients with 56 adnexal masses (27 malignant and 29 benign) underwent DWI andDCE-MRI examinations, prior to surgery. DWI signal intensity, mean ADC value, and TIC type were determinedfor all the masses. Results: High signal intensity on DWI and type 3 TIC were helpful in differentiating benignfrom malignant adnexal masses (p<0.001). The mean ADC value was significantly lower in malignant adnexalmasses (p<0.001). An ADC value<1.20×10-3 mm2/s may be the optimal cutoff for differentiating between benignand malignant tumors. The negative predictive value for low signal intensity on DWI, and type 1 TIC were 100%.The pairwise comparison among the receiver operating characteristic (ROC) curves showed that the area underthe curve (AUC) of TIC was significantly larger than the AUCs of DWI and ADC (p<0.001 for comparison ofTIC and DWI, p<0.02 for comparison of TIC and ADC value). Conclusions: DWI, ADC value and TIC typederived from DCE-MRI are all sensitive and relatively specific methods for differentiating benign from malignantadnexal masses. By comparing these functional MR techniques, TIC was found to be more accurate than DWIand ADC.     

移植骨肉瘤磁共振弥散加权成像特点及价值

目的探讨大鼠骨肉瘤磁共振弥散加权成像(DWI)特点及其判断骨肉瘤坏死区的价值。方法将UMR-106细胞接种于SD大鼠背部皮下成瘤,对肿瘤行MRI常规扫描及DWI成像并做病理对照。结果活肿瘤细胞区血管横断面积百分比与ADC值无相关性。增强扫描确定肿瘤坏死区的敏感性为86.7%(13/15),特异性为38.5%(15/39),准确性为51.9%(28/54)。ADC值确定肿瘤坏死区的敏感性为93.3%(14/15),特异性为94.9%(37/39),准确性为94.4%(51/54)。结论b值较大时,组织微灌注对大鼠骨肉瘤ADC值影响很小。DWI较传统MRI序列及增强扫描能更早期分辨骨肉瘤坏死区。     

Two Different Methods of Region-of-Interest Placement for Differentiation of Benign and Malignant Breast Lesions by Apparent Diffusion Coefficient Value

Purpose: We aimed to investigate the influence of different methods of region-of-interest (ROI) placement onapparent diffusion coefficient (ADC) values in breast tumours and their accuracy in differentiating benign versusmalignant tumors in mass and nonmass lesions. Methods and Materials: In this prospective study, 79 patients with98 breast lesions, from 2015 until 2017, were investigated by 1.5-T breast MRI. Histopathology evaluation were donefor all malignant lesions and most of the benign ones. ADC values were measured in normal breast tissue and by twoways of ROI placement in the breast lesions (mass and non-mass): 1- ROI covering the whole lesion, 2- ROI in thehighest part (most restricted area) of the lesion in DWI images. The accuracy of these two approaches were compared.Results: The age range was 17-68 years with mean age 43.3 ± 9.9 years. 49% of the lesions were benign and 51% oftumors were malignant. Our results revealed that the measured ADC values in normal breast tissue were higher thanbreast lesions (P≤0.01). Appropriate cut off determination in non-mass was not valid by both methods, but in mass inthe first way was 1.45×10 -³mm²/s and in the most restricted part was 1.16×10-³ mm²/s. ADC values differed significantlybetween the two ways of ROI placement in mass lesions (P<.001). Most restricted part ADC showed the best diagnosticperformance in mass lesions with area under curve 0.88 versus 0.82. Conclusion: ROI placement has significant impacton the meseaured ADC values of breast lesions and ROIs in most restricted parts were more accurate than whole-lesionROIs. Cut-off values differed significantly based on the methods of measurement.     

Study of the Reduced Field-of-View Diffusion-Weighted Imaging of the Breast

BackgroundThis study aimed to compare the imaging quality, apparent diffusion coefficient (ADC) values, and application values between reduced field-of-view diffusion-weighted imaging (rFOV DWI) and single-shot echo-planar–imaging diffusion-weighted imaging (SS-EPI DWI) of breast tissue.Patients and MethodsFor 87 cases (75 with normal breast tissue, 12 with mammary cancer), breasts were scanned with SS-EPI DWI and rFOV DWI (b values, 800 s/mm²). Image quality and ADC values of breast tissue images were compared between SS-EPI DWI and rFOV DWI.ResultsThe average image quality score for the 87 cases was 4.73 in rFOV DWI and 3.62 in SS-EPI DWI. The difference was statistically significant (P < .01). The resolution of rFOV DWI was 2.25 mm × 1.23 mm, which was higher than the resolution of SS-EPI DWI (2.25 mm × 2.25 mm). The mean ADC value of 75 cases with normal breast tissue was 1.696 × 10^-3 mm²/s by rFOV DWI and 1.832 × 10^-3 mm²/s by SS-EPI DWI, and the difference was statistically significant (P < .01). The mean ADC value for the 12 cases with breast cancer was 1.065 × 10^-3 mm²/s by rFOV DWI and 1.192 × 10^-3 mm²/s by SS-EPI DWI, which was a statistically significant difference (P < .05).ConclusionrFOV DWI presented images with higher resolution and less distortion than SS-EPI DWI, and this difference may be helpful in disease diagnosis.     

Diffusion Weighted Imaging Can Distinguish Benign from Malignant Mediastinal Tumors and Mass Lesions: Comparison with Positron Emission Tomography

Background: Diffusion-weighted magnetic resonance imaging (DWI) makes it possible to detect malignanttumors based on the diffusion of water molecules. It is uncertain whether DWI is more useful than positronemission tomography-computed tomography (PET-CT) for distinguishing benign from malignant mediastinaltumors and mass lesions. Materials and Methods: Sixteen malignant mediastinal tumors (thymomas 7, thymiccancers 3, malignant lymphomas 3, malignant germ cell tumors 2, and thymic carcinoid 1) and 12 benignmediastinal tumors or mass lesions were assessed in this study. DWI and PET-CT were performed before biopsyor surgery. Results: The apparent diffusion coefficient (ADC) value (1.51±0.46 ×10-3mm2/sec) of malignantmediastinal tumors was significantly lower than that (2.96±0.86 ×10-3mm2/sec) of benign mediastinal tumors andmass lesions (P<0.0001). Maximum standardized uptake value (SUVmax) (11.30±11.22) of malignant mediastinaltumors was significantly higher than that (2.53±3.92) of benign mediastinal tumors and mass lesions (P=0.0159).Using the optimal cutoff value (OCV) 2.21×10-3mm2/sec for ADC and 2.93 for SUVmax, the sensitivity (100%) byDWI was not significantly higher than that (93.8%) by PET-CT for malignant mediastinal tumors. The specificity(83.3%) by DWI was not significantly higher than that (66.7%) for benign mediastinal tumors and mass lesions.The accuracy (92.9%) by DWI was not significantly higher than that (82.1%) by PET-CT for mediastinal tumorsand mass lesions. Conclusions: There was no significant difference between diagnostic capability of DWI andthat of PET-CT for distinguishing mediastinal tumors and mass lesions. DWI is useful in distinguishing benignfrom malignant mediastinal tumors and mass lesions.     

MR表观扩散系数预测鼻咽癌放疗敏感度及相关因素分析

目的 探讨利用MR扩散加权成像的表观扩散系数（ADC值）预测鼻咽癌放疗敏感度的可行性。 方法 97例鼻咽癌患者在放疗前行MR扩散加权成像检查,并测量肿瘤灶ADC值。根据放射治疗后的效果将鼻咽癌患者按放疗敏感度进行分组,放疗敏感组74例、放疗抗拒组23例。分析放疗敏感度与ADC值、病理分型、T分期的相互关系。 结果 放疗敏感组的ADC值为（0.792±0.121）×10^-3mm²/s,其中非角化型分化型癌23例,非角化型未分化癌51例,T1期10例,T2期33例,T3期22例,T4期9例。放疗抗拒组的ADC值为（0.730±0.104）×10^-3 mm²/s,其中非角化型分化型癌8例,非角化型未分化癌15例,T1期3例,T2期4例,T3期7例,T4期9例。两组间在ADC值、T分期方面差异均有统计学意义（t=2.199, P=0.030; χ ²=10.287,P=0.016）,在病理分型方面差异无统计学意义（χ ²=0.111, P=0.740）。各T分期的ADC值整体上差异有统计学意义（F=8.597, P=0.000）,随着T分期的增高,ADC值呈现下降趋势。ADC值、T分期预测鼻咽癌放疗敏感度的ROC曲线下的面积（Az）值分别为0.657、0.661。当ADC值取0.737×10^-3 mm²/s为诊断阈值时,其诊断价值最大,敏感度为68.9%,特异性为69.6%。结论 ADC值可以预测鼻咽癌放疗敏感度,其价值接近于Ｔ分期,最佳诊断阈值为0.737×10^-3 mm²/s。     

乳腺超声BI-RADS评分系统结合超声造影对乳腺肿块良恶性判断的价值

[目的]评价超声乳腺影像学报告及数据系统fBI．RADS）诊断标准结合超声造影（CEUS）诊断乳腺肿块良恶性的价值。[方法]对120例患者共122个实性肿块行常规超声检查,按照BI．RADS评分标准进行分级诊断,然后行超声造影（CEUS）并做出诊断。比较BI—RADS分级、CEUS、BI—RADS分级＋CEUS三种方法诊断的差异。[结果]BI—RADS分级诊断与CEUS诊断组间比较,其灵敏度、特异性、准确率无统计学差异（P〉0．05）,BI．RADS分级＋CEUS诊断与单独CEUS诊断比较其灵敏度、特异性、准确率亦无统计学差异（P〉0．05）。BI—RADS分级＋CEUS诊断与单独BI—RADS分级诊断比较,其特异性、准确率差异有统计学意义（P均〈0．05）。[结论]BI-RADS分级诊断与CEUS结合可以提高超声对乳腺肿瘤的诊断效率。     

Diffusion-Weighted MRI as Non-Invasive Diagnostic Tool for Rectal Cancer Aggressiveness and Correlation with KI-67 Expression in Tumor Tissue

Background and aim: Apparent diffusion coefficient (ADC) was suggested as a prognostic marker in rectal carcinoma (RC). However, reported data are inconsistent. The present study aimed to assess the relation between ADC value and Ki-67 expression index and other pathological parameters in Egyptian RC patients. Materials and Methods: The study included 39 patients with newly diagnosed RC (non-mucinous adenocarcinoma). All patients underwent magnetic resonance imaging (MRI) scan by 1.5T magnet. Mean ADC value was calculated. Pathological features were assessed and Ki- 67 immunohistochemical expression was applied as a proliferative index (PI) biomarker. Results: It was shown that patients with T4 tumors had significantly lower ADC values when compared with patients with T2 and T3 (0.903 ± 0.24 versus 1.157 ± 0.31 and 0.971 ± 0.26 respectively, p<0.001). Also, patients with circumferential resection margin (CRM) involvement had significantly lower ADC values when compared with patients without (0.905 ± 0.24 versus 1.109 ± 0.30, p=0.036). Patients with T4 tumors expressed significantly higher ki-67 PI when compared with patients with T2 and T3 tumors (75.71 ± 5.14 versus 46.25 ± 5.18 and 75.71 ± 5.14 respectively, p<0.001). Pearson’s correlation coefficient identified a significant inverse correlation between ADC values and ki-67 PI (r=-367, p=0.027). Conclusion: ADC values of RC may reflect tumor staging and Ki-67 is closely related to the ADC value confirm this result.