MR imaging findings of benign and malignant circumscribed breast masses: part 2. Cystic circumscribed masses

The purpose of our study was to review the magnetic resonance (MR) imaging findings and pathological characteristics of benign and malignant cystic circumscribed breast masses. This article reviews the MR imaging findings of cystic circumscribed breast masses. Intracystic papillomas typically show a single mural nodule with a washout enhancement pattern. Intracystic papillary carcinomas show multiple mural nodules or grow as a solid mass that obliterates the cystic space with a washout enhancement pattern. Despite the MR imaging findings, however, many circumscribed breast masses are impossible to differentiate without performing a biopsy.     

MR扩散加权成像在眼眶良恶性肿块鉴别诊断中的应用

目的 分析眶内良恶性肿块的扩散加权成像(DWI)特征,评价表观扩散系数(ADC)值对其诊断价值.方法 对77例眶内肿块进行常规MRI及DWI,其中良性肿块55例,恶性肿块22例.扩散敏感系数(b)值=0、1000 s/mm2,测量病变对侧颞叶脑白质感兴趣区DWI信号,获得相应的肿块区ADC(ADCM)值、病变对侧颞叶脑白质ADC(ADCw)值,计算二者比值(ADCR).以不同ADCM值及ADCR作为临界点区分眶内良恶性肿块绘制出受试者工作特征曲线(ROC).结果 眶内良性肿块ADCM值及ADCR分别为(1.56±0.75)×10-3mm2/s、1.85±0.91;恶性肿块ADCM值及ADCR分别为(1.09±0.42)×10-3mm2/s、1.28±0.53;良性肿块ADCM值及ADCR显著高于恶性肿块(t值分别为2.803、2.735,P值均＜0.01).以不同ADCM值、ADCR作为临界点判断眶内良恶性肿块绘制ROC,曲线下面积均为0.71±0.07.以ADCM值为1.05×10-3mm2/s作为判断眶内良恶性肿块的决定值,灵敏度、特异度和准确率分别为59.1%(13/22)、78.2%(43/55)和72.7%(56/77);以ADCR为1.24作为决定值,灵敏度、特异度和准确率分别为59.1%(13/22)、76.4%(42/55)和71.4%(55/77).结论 DWI可揭示眼眶肿块的扩散特征,ADC值对于良恶性肿块的鉴别诊断具有辅助诊断价值.     

Diagnosis of soft-tissue masses with MR imaging: can benign masses be differentiated from malignant ones?

A blinded, retrospective review of 83 soft-tissue masses (49 benign and 34 malignant) was performed to evaluate the ability to distinguish benign from malignant soft-tissue masses with magnetic resonance (MR) imaging. The correct histologic diagnosis was reached in 31% of cases by one reader and in 16% of cases by the second reader. Mean sensitivity was 50% for benign masses and 80% for malignant masses. The majority of both benign and malignant masses had inhomogeneous signal intensity and at least partially irregular borders. Malignant masses uncommonly had smooth borders and homogeneous signal intensity. MR imaging can be used to evaluate the extent of soft-tissue masses, but most masses will require biopsy to determine if they are benign or malignant.     

Quantitative differentiation of benign and malignant mammographic circumscribed masses using intensity histograms

Purpose

To investigate the usefulness of density gradient of mammographic masses for differentiating benign from malignant lesions, particularly circumscribed masses, which are difficult to diagnose by shape.

Materials and methods

Phantom experiments were performed and diagnostic mammography examinations were reviewed. Mammograms of three acrylic resin globes differing in hardness were acquired with/without applied pressure, and density gradients were examined on intensity histograms with standard deviation (SD) as a hardness index. Similar analyses were performed using clinical mammographic examinations of circumscribed mass lesions. The usefulness of SD for differentiating between benign and malignant lesions was investigated by ROC curve analysis and minimum/maximum values of malignant and benign lesions, respectively.

Results

For circumscribed masses (n = 196, benign, n = 176; malignant, n = 20), ROC analysis showed AUC = 0.786, with sensitivity = 70.0 %, specificity = 70.5 %, accuracy = 70.4 %, positive predictive value = 21.1 %, and negative predictive value = 95.4 % at SD = 64.46. Minimum and maximum SD of malignant and benign masses were 39.1 and 241.7, respectively.

Conclusion

On mammography, circumscribed masses can be diagnosed with moderate accuracy using the intensity histogram SD. Masses with SD below the minimum of breast cancer can be roughly diagnosed as clinically benign.

     

MR diffusion imaging in mediastinal masses the differentiation between benign and malignant lesions

Background

Diffusion-weighted imaging is a fundamental tool integrated in MR protocols useful in differentiating benign from malignant mediastinal masses, assessing mediastinal lymphadenopathy and investigating central bronchogenic carcinoma. This method is an excellent alternative to CT or PET/CT in the investigation of mediastinal masses. Current applications of diffusion MRI in malignancies include monitoring the treatment response and detecting recurrent cancer.

Diffusion-weighted MR imaging of intracerebral masses: comparison with conventional MR imaging and histologic findings

BACKGROUND AND PURPOSE: The purposes of this study were to find the role of diffusion-weighted MR imaging in characterizing intracerebral masses and to find a correlation, if any, between the different parameters of diffusion-weighted imaging and histologic analysis of tumors. The usefulness of diffusion-weighted imaging and apparent diffusion coefficient (ADC) maps in tumor delineation was evaluated. Contrast with white matter and ADC values for tumor components with available histology were also evaluated. METHODS: Twenty patients with clinical and routine MR imaging/CT evidence of intracerebral neoplasm were examined with routine MR imaging and echo-planar diffusion-weighted imaging. The routine MR imaging included at least the axial T2-weighted fast spin-echo and axial T1-weighted spin-echo sequences before and after contrast enhancement. The diffusion-weighted imaging included an echo-planar spin-echo sequence with three b values (0, 300, and 1200 s/mm(2)), sensitizing gradient in the z direction, and calculated ADC maps. The visual comparison of routine MR images with diffusion-weighted images for tumor delineation was performed as was the statistical analysis of quantitative diffusion-weighted imaging parameters with histologic evaluation. RESULTS: For tumors, the diffusion-weighted images and ADC maps of gliomas were less useful than the T2-weighted spin-echo and contrast-enhanced T1-weighted spin-echo images in definition of tumor boundaries. Additionally, in six cases of gliomas, neither T2-weighted spin-echo nor diffusion-weighted images were able to show a boundary between tumor and edema, which was present on contrast-enhanced T1-weighted and/or perfusion echo-planar images. The ADC values of solid gliomas, metastases, and meningioma were in the same range. In two cases of lymphomas, there was a good contrast with white matter, with strongly reduced ADC values. For infection, the highest contrast on diffusion-weighted images and lowest ADC values were observed in association with inflammatory granuloma and abscess. CONCLUSION: Contrary to the findings of previous studies, we found no clear advantage of diffusion-weighted echo-planar imaging in the evaluation of tumor extension. The contrast between gliomas, metastases, meningioma, and white matter was generally lower on diffusion-weighted images and ADC maps compared with conventional MR imaging. Unlike gliomas, the two cases of lymphomas showed hyperintense signal on diffusion-weighted images whereas the case of cerebral abscess showed the highest contrast on diffusion-weighted images with very low ADC values. Further study is required to find out whether this may be useful in the differentiation of gliomas and metastasis from lymphoma and abscess.     

MR imaging assessment of the breast after breast conservation therapy: distinguishing benign from malignant lesions

Dynamic contrast material-enhanced magnetic resonance (MR) imaging has emerged as a valuable tool in evaluation of women who have undergone lumpectomy and whole-breast radiation therapy for breast cancer. Early diagnosis of local recurrence by means of close clinical and imaging follow-up is an important component of a breast-conserving strategy, as it may improve survival. In the post-breast conservation therapy (BCT) breast, resolving edema, fat necrosis, a small focal area of non-masslike enhancement (NMLE), and thin linear NMLE at the lumpectomy site can all be expected findings. In contrast, masslike enhancement or NMLE of ductal or segmental distribution can indicate recurrence. Therefore, at MR imaging of the post-BCT breast, it is important to identify lesions that are benign or appropriate for short-interval imaging surveillance to minimize unnecessary intervention, as well as to discern suspicious lesions and optimize the diagnosis of recurrence.     

Differentiation of benign from malignant solid breast masses: conventional US versus spatial compound imaging

PURPOSE: To compare prospectively the diagnostic performance of radiologists who used conventional ultrasonography (US) with that of radiologists who used spatial compound imaging for the differentiation of benign from malignant solid breast masses. MATERIALS AND METHODS: The study was approved by the institutional review board, and informed consent was obtained. Before excisional or needle biopsy was performed, conventional US and spatial compound images were obtained in 67 patients (age range, 25-67 years; mean age, 45 years) with 75 solid breast masses (21 cancers and 54 benign lesions). Three experienced radiologists who did not perform the examinations independently analyzed US findings and indicated the probability of malignancy. Results were evaluated with kappa statistics and receiver operating characteristic (ROC) analysis. RESULTS: For US findings, the presence of calcifications was the most discordant feature (kappa = 0.372) between conventional US and spatial compound imaging, followed by echotexture (kappa = 0.439), boundary echo (kappa = 0.496), orientation (kappa = 0.518), echogenicity (kappa = 0.523), shape (kappa = 0.526), margin (kappa = 0.569), and posterior acoustic transmission (kappa = 0.669). The area under the ROC curve for conventional US was 0.79 for reader 1, 0.88 for reader 2, and 0.82 for reader 3, and the area under the ROC curve for spatial compound imaging was 0.85 for reader 1, 0.88 for reader 2, and 0.89 for reader 3. The partial area index for conventional US was 0.29 for reader 1, 0.69 for reader 2, and 0.39 for reader 3, and the partial area index for spatial compound imaging was 0.29 for reader 1, 0.65 for reader 2, and 0.39 for reader 3. The difference between the diagnostic performances of the two techniques was not significant (P > .05). CONCLUSION: The performance of the radiologists with respect to the characterization of solid breast masses was not significantly improved with spatial compound imaging.     

The postconservation breast: part 1, Expected imaging findings

OBJECTIVE: The objectives of this article are to discuss the conventional imaging algorithms after breast-conserving surgery and radiation therapy and to review the expected chronologic imaging appearances of the conservatively treated breast. CONCLUSION: Imaging the treated breast presents challenges because of its limited compressibility and the overlapping features of benign posttreatment alterations and tumor recurrence. After lumpectomy and radiation therapy, mammographic findings such as breast edema, skin thickening, fluid collections, architectural distortion, and calcifications have characteristic sequences of evolution toward stability. Awareness of these normal chronologic imaging findings for the conservatively treated breast minimizes unnecessary recall from screening and permits early detection of recurrent breast carcinoma.     

MRI扩散加权成像对乳腺良恶性病变的诊断

目的:探讨磁共振扩散加权成像(DWI)对乳腺良恶性疾病的诊断价值。方法:回顾性分析40例经病理确诊的乳腺疾病,其中良性病变22个,恶性病变18个;均行DWI检查,测定病灶区表观扩散系数(ADC值),与正常组织进行比较,计算相对表观扩散系数(rADC值),应用SPSS 16.0软件比较其平均值,并以病理结果为金标准,作ROC曲线,求其最佳诊断阈值。结果:良性病变及恶性病变的ADC值分别为(1.55±0.35)×10-3和1.00±0.18)×10-3 mm2/s,其rADC值分别为(0.82±0.19)和(0.52±0.08)。良恶性病变组间均有统计学差异,以ADC值及rADC值为诊断标准作受试者工作特征曲线(ROC曲线),其中ADC值的曲线下面积(AUC)为(0.927±0.04),rADC值的AUC为(0.965±0.03),诊断阈值分别为1.17×10-3 mm2/s、0.66,相应敏感度及特异度分别为(90.9%、88.9%)和(95.5%、94.4%),rADC值的AUC、敏感度及特异度均高于ADC值。结论:DWI对乳腺良恶性病变的的诊断具有重要作用,其中rADC值有更好诊断效能。     

Inflammatory breast cancer: MR imaging findings

Purpose

This paper describes the magnetic resonance (MR) imaging features of primary inflammatory breast cancer (IBC).

Materials and methods

Two radiologists reviewed the MR examinations of 14 women with a pathological diagnosis of IBC. Images were assessed for skin thickening, oedema, nipple retraction, architectural distortion, type and extent of parenchymal and cutaneous enhancement and enhancement kinetics over time, axillary and internal mammary lymphadenopathy, pectoral muscle enhancement and additional findings.

Results

Skin thickening was identified in eight patients (58%), oedema in nine (64%), nipple retraction in two (14%), architectural distortion in eight (58%), mass-like enhancement in five (36%), non-mass-like enhancement in nine (64%) with washout enhancement curve in 12 (86%) and plateau curve in two (14%), axillary lymphadenopathy in 12 (86%) and internal mammary artery lymphadenopathy in two (14%), and pectoral muscle enhancement in one (7%). Additional findings included increased breast volume in two patients (14%), prepectoral fluid in four (28%) and hypertrophic internal mammary artery in three (21%).

Conclusions

The most characteristic MR findings of IBC are skin thickening, oedema, architectural distortion, masslike enhancement with washout curve and axillary lymphadenopathy; less frequent ones are nipple retraction, mass-like enhancement and internal mammary lymphadenopathy. Prepectoral fluid is frequent but is not a sign of infiltration.     

Distinguishing benign from malignant bowel obstruction in patients with malignancy: findings at MR imaging

PURPOSE: To retrospectively evaluate the features of benign versus malignant bowel obstruction on unenhanced and gadolinium-enhanced spoiled gradient-echo magnetic resonance (MR) images in patients with malignancy. MATERIALS AND METHODS: Forty-eight patients with malignancy and bowel obstruction underwent abdominal and pelvic MR imaging. Two blinded radiologists independently evaluated each study for dilated bowel, transition point, level of obstruction, obstructing mass, mural thickening and enhancement, and peritoneal disease. Benign obstruction was recorded if no mass was present and if mural thickening (when present) was segmental or diffuse. Malignant bowel obstruction was recorded if there was a mass, a disseminated abdominal tumor, or focal mural thickening. MR images were compared with surgical findings, follow-up imaging studies, and clinical outcome. chi2 test and Fisher exact test were used to assess the relationship between the MR features and benign versus malignant obstruction. RESULTS: Bowel obstruction had a benign cause in 19 patients and a malignant cause in 29 patients. Observer 1 correctly characterized benign bowel obstruction in 17 of 19 patients and malignant bowel obstruction in 27 of 29 patients. The sensitivity of observer 1 for characterizing malignant obstruction was 93%, specificity was 89%, and accuracy was 92%. Observer 2 correctly characterized benign bowel obstruction in 18 of 19 patients and malignant bowel obstruction in 26 of 29 patients. The sensitivity of observer 2 for characterizing malignant obstruction was 90%, specificity was 95%, and accuracy was 92%. Malignant bowel obstruction was present in 24 of 25 patients with an obstructing mass (P <.001). All 16 patients with focal mural thickening had malignant obstruction. Benign obstruction was present in four of five patients with diffuse mural thickening. Segmental mural thickening occurred in four patients with serosal metastases and in 11 patients with benign bowel obstruction. More extensive peritoneal thickening and enhancement correlated with malignant obstruction. CONCLUSION: In patients with malignancy who have symptoms indicative of bowel obstruction, gadolinium-enhanced MR imaging can help distinguish benign from malignant causes of bowel obstruction.     

Characterization of benign and malignant solid breast masses in harmonic 3D power Doppler imaging

Purpose

The authors assessed the characteristics of benign and malignant solid breast tumors in harmonic three-dimensional (3D) power Doppler imaging and proposed decision models to classify benign and malignant breast tumors.

Materials and methods

A total of 86 malignant and 97 benign harmonic 3D power Doppler US images were analyzed. All the harmonic 3D power Doppler images were obtained using a Voluson730 US system (GE, Zipf, Austria) equipped with a RSP 6-12 transducer and tissue harmonic imaging modalities. Imaging analysis was performed using the Virtual Organ Computer-aided Analysis (VOCAL)-imaging program. Histogram indices, the vascularization index (VI), flow index (FI) and vascularization-flow index (VFI), were calculated for the intra-tumor and for shells with an outside thickness of 3 mm surrounding the breast tumors. The receiver operating characteristic (ROC) curves were calculated to estimate the diagnostic performances.

Results

The results revealed that the choice of decision model comprised the parameters of patient age, intra-tumor VI, and tumor volume to classify benign and malignant breast tumors. The area under the ROC curve (Az) was 0.910, accuracy was 81.4%, and sensitivity and specificity were 81.4% and 81.4%, respectively. The parameter intra-tumor VI was the choice for all of the histogram indices in differentiating between malignant and benign lesions.

Conclusion

The decision model, which was composed of patient age, tumor volume and intra-tumor VI, and a cut-off value for intra-tumor VI at the upper end of patient age and tumor volume, was recommended in clinical application.     

乳腺错构瘤MRI表现

目的 探讨MRI对乳腺错构瘤诊断的价值.方法 收集经手术病理证实的乳腺错构瘤8例,回顾性分析其临床及MRI表现,并复习相关文献.结果 发病年龄42~52岁,平均48岁,病程2 d~15年不等,均为无痛性肿块,其中1例15年来逐渐增大,挤压双乳后有乳汁分泌.8例中椭圆形5例,圆形3例,直径4~10 cm不等.混合型5例,脂肪型2例,致密型1例.MRI表现为T1WI、T2W SPIR高低混杂信号影,即肿块内混杂的成熟脂肪组织和纤维腺体组织,2种成分按不同比例相间分布,边界清,均可见完整的包膜.动态增强后纤维腺体成分呈渐进性强化,强化曲线呈缓慢上升型.结论 明确的脂肪成分与纤维腺体组织不同比例混合的混杂信号及完整的包膜是乳腺错构瘤MRI特征性表现,最后确诊有赖于病理.     

超快速动态对比增强MR成像鉴别良恶性乳腺病变

目的评估超快速模式与标准模式动态对比增强MR成像的药代动力学分析方法对乳腺癌诊断的准确性。材料与方法本研究通过机构伦理委员会审核且符合HIPAA规定。89名高危妇女     

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.