Relation between cancer cellularity and apparent diffusion coefficient values using diffusion-weighted magnetic resonance imaging in breast cancer

PURPOSE: The purpose of this study was to examine the relation between cancer cellularity and the apparent diffusion coefficient (ADC) value using diffusion-weighted magnetic resonance imaging in breast cancer. MATERIALS AND METHODS: The subjects were 27 women who had undergone operation for breast cancer. There were 27 breast cancer lesions, 24 of which were invasive ductal carcinoma (IDC) and 3 of which were noninvasive ductal carcinoma (NIDC). RESULTS: The mean ADC values of IDC, NIDC, and normal breasts were 1.07 +/- 0.19 .10(-3), 1.42 +/- 0.17 .10(-3), and 1.96 +/- 0.21 .10(-3) mm(2)/s, respectively. The mean ADC values of IDC and NIDC were significantly different from that of normal breasts (P < 0.001 each). The mean ADC values were also significantly different between IDC and NIDC (P < 0.001). There was no correlation between the ADC value and cancer cellularity. CONCLUSION: The mean ADC values for breast cancer were significantly different from that of normal breasts. The mean ADC value for breast cancer did not significantly correlate with cancer cellularity but did correlate with histological types.     

Diffusion-weighted imaging of breast cancer with the sensitivity encoding technique: analysis of the apparent diffusion coefficient value.

PURPOSE: The usefulness of diffusion-weighted imaging (DWI) in the field of neuroradiology has been established. Despite its high contrast resolution, DWI has the disadvantages of susceptibility artifact and chemical shift artifact. We performed DWI of breast cancer with the sensitivity encoding (SENSE) technique. METHODS: The subjects were 60 female patients with breast mass. All patients underwent MRI including SENSE-DWI and were diagnosed histologically. Of these patients, 55 were diagnosed with breast cancer and the remaining five were diagnosed with benign mass. The histological diagnoses of breast cancer were as follows: 39 cases of invasive ductal carcinoma (IDC); 11 cases of IDC with a predominant intraductal component and non IDC (pure or predominant NIDC); and five cases of special types of cancer. The MR system used was a Gyroscan Intera 1.5T (Philips Medical Systems). In addition to routine MRI for breast cancer, including contrast-enhanced dynamic, SENSE-DWI was obtained. The accuracy of the positional information of SENSE-DWI was visually compared with that of conventional images. The apparent diffusion coefficient (ADC) values of breast mass were analyzed with SENSE-DWI. RESULTS: The accuracy of positional information was adequate for diagnosing of all patients. The mean ADC value of breast cancer was 1.021x10(-3) mm2/s and that of benign mass was 1.488x10(-3) mm2/s (p=0.0002). The mean ADC value of IDC was 0.968x10(-3) mm2/s and that of pure or predominant NIDC was 1.218x10(-3) mm2/s (p=0.0011). CONCLUSION: SENSE-DWI was of sufficient quality to support diagnosis of breast mass. SENSE-DWI may permit the acquisition of more detailed information about lesions, including tumor cellularity, that is difficult to obtain with conventional techniques.     

Diffusion-weighted imaging of malignant breast tumors: the usefulness of apparent diffusion coefficient (ADC) value and ADC map for the detection of malignant breast tumors and evaluation of cancer extension

The authors used breast diffusion-weighted imaging (DWI) to diagnose breast cancer and identify cancer extension. Isotropic DWI was performed with EPI. The apparent diffusion coefficient (ADC) value was calculated and displayed on an ADC map. The authors compared between the distribution of low ADC values and pathologic cancer extension. The mean ADC value of breast cancer was 1.12 +/- 0.24 x 10(-3) mm/s, which was lower than that of normal breast tissue. The ADC value for invasive ductal carcinoma was lower than that of noninvasive ductal carcinoma. The sensitivity of the ADC value for breast cancer using a threshold of less than 1.6 x 10(-3) mm/s was 95%. Seventy-five percent of all cases showed precise distribution of low ADC value as cancer extension. The causes of underestimation were susceptibility artifact from bleeding and the limit of spatial resolution. Benign proliferative change showed a low ADC value. The authors conclude that DWI has a potential for clinical appreciation in detecting breast cancer.     

Comparison of breast cancer detection by diffusion-weighted magnetic resonance imaging and mammography

PURPOSE: Breast cancer-detecting ability of diffusion-weighted magnetic resonance imaging (DW-MRI) was investigated by comparing the breast cancer detection rates of DW-MRI and mammography (MMG). MATERIALS AND METHODS: The subjects were 48 women who had breast cancer (53 cancer lesions) who underwent DW-MRI before surgery. Altogether, 41 lesions were invasive ductal carcinoma (IDC), 7 were noninvasive ductal carcinoma (NIDC) and 5 were "others." RESULTS: The breast cancer detection rates by MMG and DW-MRI were 84.9% and 94.3% (P < 0.001), respectively. In each classification of histology and size, the detection rate by DW-MRI was higher than that by MMG. In relation to the mammary gland density, the detection rates of fatty, scattered, heterogeneously dense, and extremely dense mammary glands were 100%, 100%, 92.0%, and 83.3%, respectively. The mean apparent diffusion coefficient values of the histologic types were 1.07 +/- 0.17 x 10(-3), 1.50 +/- 0.24 x 10(-3), 1.12 +/- 0.25 x 10(-3), and 2.01 +/- 0.29 x 10(-3) mm(2)/s for IDC, NIDC, others, and normal breast, respectively, showing that the values of IDC and NIDC were significantly different from that of the normal breast (P < 0.001 each). A significant difference was also noted between IDC and NIDC (P < 0.001). CONCLUSION: DW-MRI may be useful for detecting breast cancer in a wide age group of women, including young women with dense mammary glands.     

Differentiation of clinically benign and malignant breast lesions using diffusion-weighted imaging

PURPOSE: To evaluate the value of diffusion-weighted imaging (DWI) in distinguishing between benign and malignant breast lesions. MATERIALS AND METHODS: Fifty-two female subjects (mean age = 58 years, age range = 25-75 years) with histopathologically proven breast lesions underwent DWI of the breasts with a single-shot echo-planar imaging (EPI) sequence using large b values. The computed mean apparent diffusion coefficients (ADCs) of the breast lesions and cell density were then correlated. RESULTS: The ADCs varied substantially between benign breast lesions ((1.57 +/- 0.23) x 10(-3) mm(2)/second) and malignant breast lesions ((0.97 +/- 0.20) x 10(-3) mm(2)/second). In addition, the mean ADCs of the breast lesions correlated well with tumor cellularity (P < 0.01, r = -0.542). CONCLUSION: The ADC would be an effective parameter in distinguishing between malignant and benign breast lesions. Further, tumor cellularity has a significant influence on the ADCs obtained in both benign and malignant breast tumors.     

高b值MR扩散加权成像在乳腺良恶性病变诊断中的应用价值

目的 评价高b值MR DWI及ADC值在乳腺良恶性病变诊断中的应用价值.方法 165例患者在行乳腺MR动态增强扫描前行不同b值(分别为500、1500 s/mm2)的DWI扫描,对171个怀疑或高度怀疑恶性病变者行回顾性分析.以正常乳腺组织为参考基准,选择增强图像中异常强化的高信号病变,同时在高b值(b= 1500 s/mm2)DWI中视觉判定是高信号的病变定义为恶性病变阳性结果,否则为良性病变阴性结果.对其中111个DWI视觉判定阳性结果的病变计算ADC值.依据全部病变穿刺活检病理诊断结果,应用Fisher精确检验和Wilcoxon秩和检验对比分析高b值DWI视觉评估中恶性和良性病变的阳性和阴性病灶数,以ADC值=1.13×10-3 mm2/s作为临界值,计算诊断的特异度和敏感度.结果 乳腺病变穿刺活检病理证实的171个乳腺病变中,91个恶性病变,80个良性病变.高b值DWI视觉评估,139个阳性结果中,恶性病变83个,良性病变56个;32个阴性结果中,良性病变24个,恶性病变8个(非肿块性导管原位癌),差异有统计学意义(P＜0.01).所有浸润性癌和肿块样导管原位癌(DCIS)在DWI视觉判定中为阳性,8例非肿块性DCIS判定为假阴性,总体的敏感度为91.2％ (83/91),特异性为30.0％ (24/80).110个肿块样病变和1个局灶性病变DWI视觉评估阳性结果的病变中,63个恶性病变平均ADC值为(0.73±0.24)×10-3 mm2/s,48个良性病变平均ADC值为(1.19±0.42)×10-3mm2/s,差异有统计学意义(Z=5.818,P＜0.01).以ADC值=1.13×10-3mm2/s作为临界值时,61个恶性病变为阳性结果,2个黏液癌为假阴性结果;27个良性病变为阴性结果,21个良性病变为假阳性,诊断敏感度是96.8％(61/63),特异度为56.2％ (27/48).结论 高b值DWI及ADC值对乳腺良恶性病变的鉴别诊断有一定的作用,但在诊断非肿块性乳腺病变时仍需慎重.     

The role of diffusion-weighted imaging and the apparent diffusion coefficient (ADC) values for breast tumors.

OBJECTIVE: We wanted to evaluate the role of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) for detecting breast tumors, as compared with the T1- and T2-weighted images. MATERIALS AND METHODS: Forty-one female patients underwent breast MRI, and this included the T1-, T2-, DWI and dynamic contrast-enhanced images. Sixty-five enhancing lesions were detected on the dynamic contrast-enhanced images and we used this as a reference image for detecting tumor. Fifty-six breast lesions were detected on DWI and the histological diagnoses were as follows: 43 invasive ductal carcinomas, one mucinous carcinoma, one mixed infiltrative and mucinous carcinoma, seven ductal carcinomas in situ (DCIS), and four benign tumors. First, we compared the detectability of breast lesions on DWI with that of the T1- and T2-weighted images. We then compared the ADCs of the malignant and benign breast lesions to the ADCs of the normal fibroglandular tissue. RESULTS: Fifty-six lesions were detected via DWI (detectability of 86.2%). The detectabilities of breast lesions on the T1- and T2-weighted imaging were 61.5% (40/65) and 75.4% (49/65), respectively. The mean ADCs of the invasive ductal carcinoma (0.89+/-0.18 x 10(-3)mm(2)/second) and DCIS (1.17+/-0.18 x 10(-3)mm(2)/ second) are significantly lower than those of the benign lesions (1.41+/-0.56 x 10(-3)mm(2)/second) and the normal fibroglandular tissue (1.51+/-0.29 x 10(-3)mm(2)/ second). CONCLUSION: DWI has a high sensitivity for detecting breast tumors, and especially for detecting malignant breast tumors. DWI was an effective imaging technique for detecting breast lesions, as compared to using the T1- and T2-weighted images.     

Quantitative diffusion imaging in breast cancer: a clinical prospective study

PURPOSE: To study the correlation between apparent diffusion coefficient (ADC) and pathology in patients with undefined breast lesion, to validate how accurately ADC is related to histology, and to define a threshold value of ADC to distinguish malignant from benign lesions. MATERIALS AND METHODS: Seventy-eight patients (110 lesions) were referred for positive or dubious findings. Three-dimensional fast low-angle shot (3D-FLASH) with contrast injection was applied. EPI diffusion-weighted imaging (DWI) with fat saturation was performed, and ROIs were selected on subtraction 3D-FLASH images before and after contrast injection, and copied on an ADC map. Inter- and intraobserver analyses were performed. RESULTS: At pathology 22 lesions were benign, 65 were malignant, and 23 were excluded. The ADCs of malignant and benign lesions were statistically different. In malignant tumors the ADC was (mean +/- SEM) 0.95 +/- 0.027 x 10(-3)mm(2)/second, and in benign tumors it was 1.51 +/- 0.068 x 10(-3)mm(2)/second. According to receiver operating characteristic (ROC) curves, we found a threshold between malignant and benign lesions for highest sensitivity and specificity (both 86%) around 1.13 +/- 0.10 x 10(-3)mm(2)/second. For a threshold of 0.95 +/- 0.10 x 10(-3)mm(2)/second, specificity was 100% but sensitivity was very low. Inter- and intraobserver studies showed good reproducibility. CONCLUSION: The ADC may help to differentiate benign and malignant lesions with good specificity, and may increase the overall specificity of breast MRI.     

Diffusion-weighted imaging of the prostate at 3 T for differentiation of malignant and benign tissue in transition and peripheral zones: preliminary results

OBJECTIVE: To evaluate prospectively the use of apparent diffusion coefficients (ADCs) for the differentiation of malignant and benign tissue in the transition (TZ) and peripheral (PZ) zones of the prostate diffusion-weighted imaging (DWI) at 3 T magnetic resonance imaging (MRI) using a phased-array coil. METHODS: The DWI at 3-T MRI was performed on a total of 35 patients before radical prostatectomy. A single-shot echo-planar imaging DWI technique with b = 0 and b = 1000 s/mm2 was used. The ADC values were measured in both benign and malignant tissues in the PZ and TZ using regions of interest. Differences between PZ and TZ ADC values were estimated using a paired Student t test. Presumed ADC cutoff values in the PZ and TZ for the diagnosis of cancer were assessed by receiver operating characteristic analysis. RESULTS: The ADC values of malignant tissues were significantly lower than those of benign tissues in the PZ and TZ (P < 0.001; 1.32 +/- 0.24 x 10(-3) mm2/s vs 1.97 +/- 0.25 x 10(-3) mm2/s, and 1.37 +/- 0.29 x 10(-3) mm2/s vs 1.79 +/- 0.19 x 10(-3) mm2/s, respectively). For tumor diagnosis, cutoff values of 1.67 x 10(-3) mm2/s (PZ) and 1.61 x 10(-3) mm2/s (TZ) resulted in sensitivities and specificities of 94% and 91% and 90% and 84%, respectively. CONCLUSIONS: The DWI of the prostate at 3T MRI using a phased-array coil was useful for the differentiation of malignant and benign tissues in the TZ and PZ.     

不同扩散梯度因子值的乳腺MR扩散加权成像对比研究

目的 确定一个最佳的用于乳腺MR DWI的b值.方法 按照前瞻性设计,选取怀疑乳腺癌的乳腺可触性包块患者40例,术前行双侧乳腺MR和DWI扫描,b值分别取1000、800和600 s/mm2,肉眼判断DWI图像等级,采用单因素方差分析比较3组b值的DWI像信噪比和病灶ADC值,采用ROC曲线评价ADC值诊断价值.结果40例患者中乳腺癌26例,良性肿块14例,DWI显示36例,共42个病灶.3组b值下的DWI图像质量均较好,加例中视觉分级达A级的分别占75.0%(30例)、77.5%(31例)和77.5%(31例).3组b值DWI图像对病灶的检出能力相同.b=1000、800和600 s/mm2的信噪比平均值分别为63±22、82±27和96±29,3组间比较差异具有统计学意义(P<0.01).良性病变平均ADC值分别为(1.44±0.28)× 10-3、(1.50±0.32)×10-3和(1.52±0.29)×10-3mm2/s,3组间比较差异无统计学意义(P=0.725).恶性病变平均ADC值分别为(1.00±0.25)×10-3、(0.98±0.19)×10-3和(1.07±0.22)×10-3mm2/s,3组间比较差异也无统计学意义(P=0.358).3组b值的ADC值诊断乳腺良恶性病变的ROC曲线下面积分别为0.879、0.885和0.865;诊断良恶性病变的阈值分别为1.295×10-3、1.435×10-3和1.335×10-3mm2/s;诊断乳腺癌的敏感性分别为80.0%、92.0%和84.0%,特异性均为90.0%;阳性预测值分别为95.2%,95.8%和95.5%.结论综合图像信噪比和ADC值诊断价值,认为在乳腺DWI中,b=800 s/mm2是乳腺DWI成像的最佳b值.     

Value of diffusion-weighted imaging for the prediction of prostate cancer location at 3T using a phased-array coil: preliminary results

OBJECTIVES: To retrospectively evaluate the imaging quality of diffusion-weighted imaging (DWI), compare the apparent diffusion coefficient (ADC) values for malignant and benign tissues in the peripheral zone (PZ) and transition zone (TZ), and evaluate whether T2-weighted imaging (T2WI) with DWI could improve the prediction of prostate cancer location when compared with T2WI at 3T using a phased-array coil. MATERIALS AND METHODS: Thirty-seven patients underwent T2WI and DWI before radical prostatectomy. The DWI technique with b = 0 and b = 1000 s/mm2 was used. ADC values were measured in benign and malignant tissues in the PZ or TZ. The prediction of prostate cancer location was evaluated in the PZ and TZ using T2WI and T2WI with DWI, respectively. Two readers in consensus recorded the presence of prostate cancer at magnetic resonance imaging and rated the imaging quality of DWI. RESULTS: For the prediction of 68 prostate tumors, the overall sensitivity and positive predictive value of T2WI with DWI were 84% and 86%, whereas those of T2WI were 66% and 63%, respectively (P < 0.05). The mean ADC values of malignant and benign tissues in the PZ and TZ were 1.30 +/- 0.26 and 1.96 +/- 0.20, and 1.35 +/- 0.24 and 1.75 +/- 0.23 x 10(-3)mm2/s, respectively (P < 0.01). The overall imaging quality was satisfactory or better in 97% of patients. CONCLUSION: DWI is a feasible technique that can be used for the differentiation of malignant and benign tissues in the PZ and TZ. Additionally, T2WI with DWI is superior to T2WI alone for the prediction of prostate cancer location.     

扩散加权成像与MRI动态增强检测小乳腺癌的比较研究

目的 比较扩散加权成像(DWI)与动态对比增强MR成像(DCE MRI)对小乳腺癌的检出敏感性,并评价DWI的临床应用价值.方法 经病理证实的48例共70个乳腺小病灶(最大径≤2 cm)被纳入研究对象,其中恶性病灶45个,良性25个.所有患者均行DWI和DCE MRI,DCEMRI采用快速小角度激发(FLASH)序列,绘制病灶的时间.信号强度曲线(TIC),DWI采用回波平面成像(EPI)序列加用全局自动校准部分并行采集(GRAPPA)技术,取2个扩散敏感因子(b)值(800、1000 s/mm2)行横断面扫描,测量病灶的表观扩散系数(ADC)值.对2种检查方法 的诊断结果 进行比较.结果 DCE MRI正确诊断了40个小乳腺癌及19个良性小病灶,TIC显示小乳腺癌的敏感性及阳性预测值分别为88.9%(40/45)及87.0%(40/46).DWI中,在2种b值(800、1000 s/mm2)条件下小乳腺癌平均ADC值分别为(1.153±0.192)×10-3和(1.079±0.186)×10-3 mm2/s,而良性小病灶的平均ADC值为(1.473±0.252)×10-3和(1.419±0.255)×10-3 mm2/s;同组患者在2种b值条件下的ADC值差异无统计学意义(P＞0.05),而良恶性2组小病灶的ADC值差异有统计学意义(P＜0.01);b值取1000 s/mm2 时,根据DWI信号结合ADC值测量结果 可以正确诊断39个小乳腺癌及19个良性小病灶,其对小乳腺癌检出的敏感性及阳性预测值均为86.7%(39/45).DWI与DCEMRI的诊断结果 有很好的一致性,DWI联合DCE MRI可以提高检出的敏感性及阳性预测值,分别达93.3%(42/45))及91.3%(42/46).结论 DWI对小乳腺癌具有较高的检出率,且ADC值的测量可以为良恶性病变的鉴别提供有价值的诊断信息.     

磁共振扩散加权成像及动态增强MRI在乳腺病变中的应用价值

目的 探讨月经周期对正常乳腺实质磁共振扩散加权成像(DWI)表观扩散系数(ADC)值的影响,并评价动态增强MRI(DCE-MRI)及DWI在乳腺病变鉴别诊断中的价值。方法 选取健康女性志愿者34例、乳腺病变患者96例,所有病例均经外科手术或针吸病理证实,其中良性病变者36例,共44个病灶;恶性病变者60例,共70个病灶...     

IVIM成像与DWI在乳腺良恶性病变鉴别诊断中的比较

目的 比较体素内不相干运动(IVIM)成像双指数模型、拉伸指数模型与扩散加权成像(DWI)单指数模型各参数在乳腺良恶性病变鉴别诊断中的价值.方法 回顾性分析257例经病理证实的乳腺病变患者(共276个病灶,包括197个恶性病变,79个良性病变).所有患者均行MRI常规检查及多b值DWI检查,获得传统DWI及IVIM各参数.比较各参数在正常乳腺组织、乳腺良性病变及恶性病变中的统计学差异,采用受试者工作特征(ROC)曲线确定各参数诊断乳腺恶性病变的阈值以及曲线下面积(AUC)、诊断敏感性和特异性.结果 正常乳腺组织、乳腺良性病变及恶性病变的表观扩散系数(ADC)、慢速表观扩散系数(slow ADC)、快速表观扩散系数(fast ADC)、灌注分数(f)、扩散分布指数(DDC)及扩散异质性指数(α)值均有统计学差异(P<0.001).ADC、slow ADC、f、DDC和α的AUC分别为0.865、0.861、0.742、0.85和0.735;ADC、slow ADC、DDC和α的最佳诊断阈值分别为1.105×10-3 mm2/s,0.883×10-3 mm2/s,1.025×10-3 mm2/s和0.842,slow ADC敏感性最高(90.3%),DDC特异性最高(79.5%).双指数模型中slow ADC与fast ADC联合诊断的AUC为0.882;拉伸指数模型DDC与α联合诊断的AUC为0.853.结论 3种模型对于乳腺病变良恶性的鉴别都具有较高的价值,传统ADC的诊断准确性较高,slow ADC敏感性较高,DDC特异性较高.双指数模型中slow ADC与fast ADC联合诊断具有较高的价值.     

弥散加权成像鉴别乳腺良恶性病变的价值初探

目的　探讨弥散加权成像（diffusionweightedimaging,DWI）的表面弥散系数（apparentdiffusioncoefficients,ADC）鉴别乳腺良恶性病变的价值。方法　健康志愿者10人,经手术病理证实的乳腺病变49例,其中恶性肿瘤26例,良性病变23例。DWI采用单次激发回波平面成像（echo-planarimaging,EPI）技术,14例取5个b值（b为扩散敏感度）,余者取2个b值,计算ADC值。以恶性肿瘤ADC值单侧上界95%容许区间为界限判断病灶的良恶性,诊断结果与动态增强比较。结果　除1例原位癌和1例小腺瘤外,DWI显示所有良恶性病变。恶性肿瘤组ADC值为(0.9608±0.2043)×10     

MR背景抑制扩散加权成像在乳腺癌的应用

目的 探讨MR扩散加权成像(DWI)结合短时间反转恢复回波成像(STIR-EPI)背景抑制(BS)技术在乳腺癌成像的技术参数及其可行性.方法 回顾性分析26例乳腺癌的MR DWIBS测得各组织的表观扩散系数(ADC),利用三维最大强度投影(3D-MIP)重组及黑白反转技术,观察病变显示效果.观察乳腺痛DWI及DWIBS两种方法的显示率.对乳腺各组织的ADC值进行随机区组设计的方差分析,在乳腺癌与良性病变ADC值的比较中,采用t检验.对两种成像方法乳腺癌的显示率进行配对资料X2检验.结果 在扩散敏感因子(b)=800 mm2/s的图像中,乳腺癌多表现为高信号,其ADC值分别为:肿瘤实质(0.93±0.25)×10-3 mm2/s、瘤内坏死灶(2.06±0.17)×10-3 mm2/s、正常腺体(1.92±0.23)×10-3 mm2/s、转移性淋巴结(1.10 ± 0.14)×10-3mm2/s,各种组织间两两比较,差异具有统计学意义(P值均＜0.01).DWIBS经MIP重组及黑白反转技术,病变周围组织信号被抑制,得到类正电子发射体层成像(PET)图像.在乳腺癌中,DWIBS对肿瘤实质(92.3/)及转移性淋巴结(88.4/)的显示率要高于DWI序列(分别为57.6/和42.3/),差异有统计学意义(x2值分别为8.307、12.235,P均＜0.05).乳腺癌与良性病变ADC值分别为(1.092±0·17)×10-3和(2.154±0.53)×10-3mm2/s,差异有统计学意义(t=8.626,P＜0.05).结论 MRDWIBS在显示病灶方面有一定优势,应用DWI结合ADC值对乳腺癌的诊断具有临床应用前景.     

MR扩散加权成像表观扩散系数在乳腺结节病变诊断中的应用价值

目的 评价ADC值及相对ADC值(rADC)在乳腺结节病灶检查中的应用价值.方法 对52例66个乳腺结节病灶行MR DWI扫描,b值分别为0、800、1000 s/mm2,测量乳腺结节及同侧、对侧乳头层面未受累乳腺实质组织ADC值,计算rADC1(病灶ADC值/同侧未受累乳腺实质ADC值)及rADC2(病灶ADC值/对侧未受累乳腺实质ADC值),对所获资料采用两独立样本t检验、x2检验进行统计学分析.所有病灶均经穿刺活检或手术病理证实.结果 52例患者中,浸润性导管癌18例,纤维腺瘤34例,DWI显示50例,共64个病灶.b=800s/mm2时,良、恶性结节平均ADC值、同侧rADC800-1及对侧rADC800-2分别为(1.54±0.28)×10-3、(1.01±0.09)×10-3 mm2/s和0.77±0.15、0.52±0.07,0.76±0.14、0.51±0.06;其差异均有统计学意义(t值分别为8.217、9.339、10.394,P值均＜0.01);以乳腺浸润性导管癌平均值95％参考值范围上限界值作为恶性病变上限阈值点,ADC值、rADC8o0-1及rADC800-2分别为1.05×10-3 mm2/s、0.55、0.53,诊断的敏感度分别为75.0％、65.0％、60.0％,特异度分别为100.0％、95.7％、97.8％,阳性预测值分别为100.0％、86.7％、92.3％,阴性预测值分别为90.2％、86.3％、84.9％,诊断符合率分别为92.4％、86.4％、86.4％.b=1000 s/mm2时,良、恶性结节平均ADC值、rADC1000-1及rADC1000-2分别为(1.45±0.28)×10-3、(0.93±0.08)×10-3mm2/s和0.75±0.16、0.53±0.09,0.74±0.15、0.52±0.07;其差异有统计学意义(t值分为11.844、5.820、8.082;P值均＜0.01);ADC值、rADC1ooo-1及rADC1000-2阈值点分别为0.97×10-3 mm2/s、0.58、0.55,诊断的敏感度均为70.0％,特异度分别为100.0％、95.7％、93.5％,阳性预测值分别为100.0％、87.5％、82.4％,阴性预测值分别为88.5％、88.0％、87.8％,诊断符合率分别为90.9％、87.9％、86.5％.以上6种诊断方法的敏感度及诊断符合率差异无统计学意义(x2值分别为1.232、2.263,P值分别为0.942、0.812).结论 ADC值与rADC值均为鉴别良恶性乳腺病变的重要参数,尤其是b= 800 s/mm2时的ADC值临床应用价值最高.     

Usefulness of the calculated apparent diffusion coefficient value in the differential diagnosis of retroperitoneal masses

PURPOSE: To elucidate whether or not the apparent diffusion coefficient (ADC) values calculated from echo-planar diffusion-weighted (EPDW) MR images are useful in the differential diagnosis of retroperitoneal masses. MATERIALS AND METHODS: In 50 patients with known retroperitoneal masses, EPDW images were performed with b-factors of 0-1100 seconds/mm2. The final histologic diagnoses of these lesions were as follows: 12 malignant lymphomas, four other malignant mesenchymal neoplasms, 25 malignant epithelial neoplasms, seven benign mesenchymal neoplasms, and two nonneoplastic lesions. The ADC values obtained for the solid portion of the lesions were used to represent each lesion, and the values of the histologic groups were compared. RESULTS: The respective value of ADC for 12 malignant lymphomas, four other mesenchymal neoplasms, seven benign mesenchymal neoplasms, and two nonneoplastic lesions were as follows: 0.66 +/- 0.26, 1.26 +/- 0.50, 0.90 +/- 0.20, 1.87 +/- 0.48, 1.32 +/- 0.20 x 10(-3) mm2/second. The ADC value of the malignant lymphoma was significantly lower than that of the other malignant mesenchymal lesions, and was also lower than the ADC of the benign lesions. The ADC value of the malignant epithelial neoplasms was lower than that of the benign mesenchymal tumors. The ADC values of the malignant and benign lesions were 0.94 +/- 0.30 and 1.75 +/- 0.49 x 10(-3) mm2/second, respectively, which also demonstrated a significant difference. CONCLUSION: ADC values calculated from EPDW MR images may provide useful information in the differential diagnosis of retroperitoneal masses.     

1.5TMR乳腺扩散加权成像b值的优化

目的 通过分析水模、正常乳腺腺体、乳腺良性及恶性病变的ADC值及图像信噪比(SNR)随b值的变化规律,探讨1.5 TMR乳腺DWI合理的b值取值范围.方法 对32例经病理证实的乳腺病变(恶性18例,良性14例)及对侧正常腺体进行乳腺MR检查,采用EPI-DWI序列;b值分别采用0、50、100、200、400、600、800、1000、1200、1400、1600、1800、2000、2200、2400、2600 s/mm2.测量不同b值下水模、正常乳腺腺体、乳腺良性及恶性病变的平均ADC值和图像SNR,采用Pearson相关分析法分析不同b值时的变化规律.结果 DWI的SNR均随b值的增加逐渐下降,二者呈负相关(r=-0.802,P＜0.01),乳腺良、恶性病变的ADC值均随着b值的增加而下降(r=-0.923和-0.855,P＜0.01);当b值取800～1000 s/mm2时,恶性病变与良性病变和正常腺体之间的ADC值差异最大(0.7×10-3mm2/s);当b值＞1400 s/mm2,差异逐渐减小.结论 取b值800～ 1000 s/mm2时,既能取得良好的图像质量,又能有效地鉴别乳腺良、恶性病变,是1.5 TMR乳腺DWI最合理的b值取值范围.     

Comparison between malignant and benign abdominal lymph nodes on diffusion-weighted imaging

RATIONALE AND OBJECTIVES: The purpose of this study is to review the apparent diffusion coefficient (ADC) values of benign and metastatic abdominal lymph nodes on diffusion-weighted imaging (DWI). MATERIALS AND METHODS: Twenty-eight patients with a total of 40 benign (20 patients) and 16 malignant (8 patients) lymph nodes who underwent DWI MRI of the abdomen (b = 0.600) were enrolled in the study. ADC values of the lymph nodes were measured and comparison was made between benign and malignant groups. RESULTS: Mean ADC value of lymph nodes was 2.38 +/- 0.29 and 1.84 +/- 0.37 x 10(-3) mm(2)/sec in the benign and malignant groups, respectively. There was a significant statistical difference between the ADC values of benign and malignant lymph nodes (P < .0005). CONCLUSION: A wide range of ADC values exist in patients with metastatic abdominal lymph nodes, with a tendency of higher ADC values in benign lymph nodes.