几种乳腺疾病的电阻抗扫描的频率特性

利用电阻抗扫描技术,研究人体乳腺在疾病状态下电导参数随激励频率的变化规律,为进一步的乳腺疾病检查打下基础。获得了浸润性导管癌、瘤样增生和乳腺腺病等三种乳腺疾病的电导参数的频率特性曲线,并与病变周围正常组织进行了对比,可以得出病变组织具有与正常组织不同的频率特性,而且上述三种不同种类疾病的频率特性也各有差异。因此提示可以根据频率特性的特征,来辨别病变的种类。     

人体乳腺组织电阻抗特性的研究

以人体乳腺组织电阻抗特性为依据的乳腺电阻抗扫描成像技术的出现,为乳腺癌的早期检查与辅助诊断开辟了一个新的方向。人体乳腺组织的电阻抗特性反映了乳腺组织的病理生理状态,而对它的测量成为乳腺电阻抗扫描成像技术的前提和基础。主要讨论了人体乳腺组织电阻抗特性的测量方法、测量结果以及存在的问题,对乳腺电阻抗成像技术的应用前景进行了展望。     

乳腺癌病例多频电阻抗扫描数据特征参数的初步分析

应用上海东影EIS-1000乳腺癌电阻抗检测系统,在200Hz~20kHz相对较低的频率范围内,对乳腺癌病例进行多频电阻抗扫描测量所获得的数据进行分析,通过建立基于Cole模型的简化测量模型以及模型的拟合计算方法,从等效模型中提取出乳腺组织阻抗的多频特征参数Gs进行分析。通过对比患者患侧病变部位以及对侧正常部位测量数据,发现患侧病灶及周围区域Gs参数数值普遍较对侧正常部位值高。由此说明根据多频特征参数Gs,可判别病变所在区域。     

体外人脑胶质瘤电阻抗特性及等效电路

目的 研究人脑胶质瘤的电阻抗特性并建立其等效电路,可为进一步区分人脑胶质瘤和正常脑组织的阻抗特性差异提供依据.方法 利用英国Solartron公司的阻抗分析仪（1260）,采用四端法,在10 Hz ～ 10 MHz范围内,对4例体外人胶质瘤组织进行电阻抗测量.通过分析其频率特性并结合已有的人脑组织的等效电路,建立了体外胶质瘤的等效电路,利用阻抗分析软件Z-VIEW对其进行仿真.结果 体外人脑胶质瘤的阻抗模值在10 Hz～10 MHz范围内随频率的增大而下降,相位角在该范围内随频率的增大而增大.体外人脑胶质瘤组织在10 kHz ～ 10 MHz范围内电阻抗实部比较稳定,其中在10Hz～ 10 kHz范围内,实部随频率的增大而减小.电阻抗虚部在20 kHz ～ 10 MHz范围内较稳定,而在10Hz ～ 20 kHz范围内,虚部随频率增大而增大.样本的等效电路仿真曲线与实际曲线相比较,等效电路模型能较好地反映体外人脑胶质瘤的电阻抗特性.结论 体外人脑胶质瘤与已知的正常脑组织的电阻抗特性及等效电路差别明显,这为探索生物电阻抗技术应用于区别胶质瘤与正常脑组织的临床应用提供了研究基础.     

乳腺癌及周围组织电阻抗频谱特性与其病理学特征的研究

目的研究人体乳腺癌及其周围组织的电阻抗频谱特性，探究我国妇女乳腺组织电阻抗频谱特性的分布规律及其与病理学之间的关系。方法采用英国Solartron公司1255B型频率响应分析仪，在1Hz—1MHz频率范围内用四电极法离体测量组织电阻抗频谱特性。将每个测量标本做成病理切片用于观察比较。结果从测量数据看，乳腺癌与其周同组织电阻抗频谱特性差异显著，脂肪组织的电阻率最高，乳腺癌次之，腺体组织最低，而脂肪组织的特征频率最低．腺体组织次之．乳腺癌最高。从病理学分析看，乳腺组织病理状态不同则其电阻抗特性也存在差别。结论人体乳腺癌及其周围组织的电阻抗特性存在显著性差异，同时发现测量样本的病理状态不同，其电阻抗特性不同。     

不同个体及不同情绪状态下手臂阻抗的频率特性

目的：研究低频电流（f≤1000Hz）作用下,不同个体及同一个体在不同情绪状态下,其手臂阻抗值随电流频率变化的规律,为生物电阻抗技术的临床应用和基础医学的实验研究提供有益的借鉴。方法：在50Hz-1000Hz频率范围内,分别测量男女大学生在平静、快速阅读和快速心算三种不同情绪状态下的手臂阻抗值,并描记出其频率响应曲线。结果：（1）平静状态下,男生手臂阻抗平均值略大于女生的;交流电频率越大,人体手臂阻抗值越小;在0Hz〈f≤100Hz的低频段,手臂阻抗值受交流电频率的影响很大：在100Hz〈f≤1000Hz的频段,手臂阻抗值受交流电频率的影响变小,表明了手臂组织具有容性成分。（2）不同个体的手臂阻抗值有较大差异,但任意个体的频率特性都具有相同的变化规律。（3）在紧张情绪状态下,人体手臂阻抗值随交流电频率的变化规律与平静时的变化规律相同;但紧张情绪会引起手臂阻抗的减小,同一个体情绪越紧张,阻抗值越小。结论：人体手臂阻抗值存在较大的个体差异,同一个体的手臂阻抗值与交流电频率及情绪变化均有密切关系,对这一生理参数的测量有着重要的应用前景。     

人颅骨电阻抗频率特性

在EIT技术应用于脑部成像的研究中，颅骨的电阻抗频率特性，对驱动电流频率的选择有着重要的参考价值。本文采用离体人颅骨，二电极法，用频响分析仪（Solartron 1255B)经电阻抗接口（Solartron1294)，在0-1MHz频率范围内进行测量，描记出颅骨电阻抗频响特性曲线，并观察随时间变化的趋势，结果表明，颅骨电阻抗幅值随时间明显增大，可达200K/2h；其特征频率应在10KHz附近。     

人大脑组织复电阻抗频率特性及其等效电路模型

通过频响分析仪，用四电极测量法，在0．1Hz～1MHz频率范围内，对人大脑组织的复电阻抗频率特性进行了定量测量，经分析得到了脑整体组织的复电阻抗等效电路模型。结果显示，人脑组织同已知的动物组织相比，其复电阻抗虚部频率特性、Cole-Cole曲线均不相同，等效电路模型结构也更为复杂。但是与家兔的脑整体组织相关特性相比，两者的曲线走势、等效电路模型结构完全一致。该等效电路模型对于建立人头部的等效电路模型有重要的参考价值。     

家兔脑组织复电阻抗频率特性及其等效电路模型

目的：研究大脑组织的复电阻抗频率特性,分析缺血对大脑组织复电阻抗频率特性的影响,构建大脑组织的复电阻抗等效电路模型。方法：利用频响分析仪(1255B,英国Solartron公司),二电极测量法,对12只家兔正常、缺血状态大脑组织复电阻抗频率特性进行离体测量,脑缺血方法采用的是颈总动脉结扎法,等效电路模型分析采用阻抗分析软件(Zplot 2．1,英国Solartron公司),还经过脑组织病理学常规染色(HE染色)对脑缺血进行了验证。结果：在缺血脑损伤发生后,脑组织复电阻抗实部、虚部均明显增大,电阻率变化率受频率影响较小,但脑组织复电阻抗虚部频率特性未呈现出单峰走势,经软件分析得到了脑组织的复电阻抗等效电路模型。讨论：脑组织复电阻抗实部、虚部和电阻率变化率均可以作为成像变量;其复电阻抗等效电路模型显示整体脑组织的等效电路模型构成比较复杂,并非传统的生物组织三元件等效电路模型,在进一步的研究中应设法对各组织分别进行测量。     

基于体外阻抗测量的恶性胶质瘤介电特性

目的研究脑胶质瘤生物电阻抗特性,探索出恶性胶质瘤组织与正常脑组织的特征性电参数,为区分恶性胶质瘤与正常脑组织提供依据。方法基于四电极法阻抗测量设计了一种体外阻抗测量传感器,利用普林斯顿阻抗分析仪Versa STAT3对10例裸鼠脑胶质瘤和脑组织进行阻抗测量,并对20Hz~250 k Hz范围内阻抗频谱特性曲线进行定量分析;结合生物阻抗谱理论,建立体外脑胶质瘤等效电路模型,并利用ZSimp Win对等效阻抗电路进行拟合仿真,以探讨脑胶质瘤在阻抗电路中的特性。结果胶质瘤的阻抗模值在20 Hz~250 k Hz范围内随频率的增大而减小,幅值曲线在200 Hz和50 k Hz附近各存在一个斜坡,这两个斜坡的斜度都小于对应的正常鼠脑组织的斜度。10组裸鼠体外实验中,胶质瘤和脑组织的虚部-实部图中有两个时间环节,可以用两个时间常数的等效电路代替,并且电路元件中的参数R1对于胶质瘤和脑组织差异明显。结论体外鼠脑胶质瘤与正常脑组织可以用阻抗特性曲线的斜坡值进行定量区别。此外,等效电路电参数中的R1也可以作为一个区分胶质瘤和脑组织的指标,这为临床检测和区分胶质瘤组织开拓了新的研究思路。     

Cellular composition of the nipple aspirate specimen of breast fluid. I. The benign cells.

A nipple aspirator device was used to obtain breast secretions for cytologic examination, as well as for viral and biochemical analysis. Examination of the first 1,456 specimens from 796 women revealed ductal epithelium in 54%. Ductal epithelial cells were often absent in specimens from normal women; however, 78.5% of women with benign breast disease on tissue biopsy had specimens containing ductal epithelium. Apocrine metaplastic cells were a further indication of the presence of breast disease, and were rarely found in specimens from asymptomatic women. Foam cells were often abundant in specimens from normal breasts, but were found in decreased numbers in specimens from women benign breast disease. Differences in the occurrence of ductal epithelial cells, apocrine metaplastic cells, and foam cells suggest an alteration in the rate of maturation of ductal epithelium in women with both benign and malignant breast disease. The finding of a relative abundance of cells in nipple aspirate specimens from women with breast disease and few or no cells in specimens from women with normal breasts is believed to be of great importance in the cytologic evaluation of nipple aspirate specimens.     

Assessment of utility of ductal lavage and ductoscopy in breast cancer-a retrospective analysis of mastectomy specimens.

Early detection of breast lesions continues to be an important goal in the management of breast cancer. At present, mammographic imaging in addition to physical examination is the main screening method for the detection of cancer. Fiberoptic ductoscopy and duct lavage are being recently used to evaluate patients at risk for breast cancer. Both techniques examine the nipple and central duct area to identify intraductal lesions. In this study, we examined the frequency of involvement of these structures in mastectomy specimens as a surrogate marker to estimate the utility of these methods in breast cancer patients. The presence and type of involvement of the nipple and central duct area was retrospectively evaluated in 801 mastectomy specimens from a 4-year period that had been performed for infiltrating or in situ carcinoma. Atypical proliferation or cells, when seen in the ducts of this region, was considered as evidence of nipple involvement, even if definite evidence of malignancy was lacking. The review of 801 mastectomies showed nipple and central duct involvement in 179 (22%) cases. Among the 665 cases of infiltrating carcinoma, 17% did not have an intraductal component. The relative rarity of nipple and central duct in mastectomy specimens and the lack of an in situ component in many cases raise questions about the utility of fiberoptic ductoscopy and duct lavage as methods for screening of breast cancer. Additionally, as these methods examine only 1-2 ducts of the 15-20 ducts that open at the nipple, they might fail to detect focal abnormalities.     

Escaping from Flatland: clinical and biological aspects of human mammary duct anatomy in three dimensions

Accurate knowledge of breast duct anatomy in three dimensions is needed to understand normal breast development, how intraepithelial neoplasia may spread through a breast, and the potential for diagnostic and therapeutic access to breast parenchyma via the nipple. This paper reports three related exploratory studies. In study 1, the median number of milk-collecting ducts in the nipple was determined in 72 breasts excised for cancer; in study 2, the volumes of all 20 complete duct systems ("lobes") in an autopsy breast were measured from 2 mm serial "subgross" sections; and in study 3, a 3D digital model of all collecting ducts in a mastectomy nipple was made from 68 100 micro m serial sections. The mastectomy nipples contained 11-48 central ducts (median 27, inter-quartile range 21-30). In the autopsy breast, the largest "lobe" drained 23% of breast volume; half of the breast was drained by three ducts and 75% by the largest six. Conversely, eight small duct systems together accounted for only 1.6% of breast volume. The 3D model of the nipple revealed three distinct nipple duct populations. Seven ducts maintained a wide lumen up to the skin surface (population A); 20 ducts tapered to a minute lumen at their origin in the vicinity of skin appendages (population B) on the apex of the nipple; and a minor duct population (C) arose around the base of the papilla. Major variations in duct morphology and extent define highly variable territories in which intraepithelial neoplasia could grow. While population A ducts appear accessible to duct endoscopy or lavage, population B and population C ducts may be less accessible.     

Scalp-ear-nipple syndrome: Additional manifestations

Scalp-ear-nipple (SEN) syndrome is a rare, autosomal dominant condition that causes aplasia cutis congenita of the scalp, alteration of the shape of the external ear, and hypoplasia of the nipple. Women in a new family, the fifth to be described, had virtually complete aplasia of the breast and a small skin dimple without any pigmentation instead of a normal nipple, although other affected women had normal breast and nipple development. Dental changes included widely spaced or missing secondary teeth; the ears were cupped or folded and stood out from the head, axillary apocrine secretion and axillary hair growth were reduced; and finger nails were brittle. There was no generalized abnormality of sweating. Some patients had partial syndactyly of the 3rd and 4th fingers, and complete cutaneous syndactyly of the 2nd and 3rd toes. © 1994 Wiley-Liss, Inc.     

Characterization of foam cells in nipple aspirate fluid

Foam cells with abundant vacuolated cytoplasm are prominent in most samples of spontaneous nipple discharge, nipple aspirate fluid, and ductal lavage. Although several investigators have attempted to characterize these cells, there is no consensus about whether these cells are derived entirely from macrophages or from both ductal epithelial cells and macrophages. Using immunocytochemical methods, we studied 20 paired specimens of nipple aspirate fluid containing abundant foam cells obtained from the involved breast of women with in situ or invasive carcinoma and from the contralateral normal breast. We used a cocktail of anticytokeratin antibodies including AE1, AE3, and CAM5.2 and the macrophage marker KP1 (CD68). In addition, we examined samples by electron microscopy. The foam cells were consistently negative for cytokeratin and positive for CD68. In every case electron microscopy of these cells revealed irregular outlines with short cytoplasmic processes. The cytoplasm was abundant and contained numerous lysosomes, a small Golgi complex, lipid droplets, mitochondria, and short profiles of rough endoplasmic reticulum. There was no evidence, however, of cell junctions or tonofilaments. The immunocytochemical and electron microscopic findings of our study together clearly support a macrophage derivation for foam cells in nipple aspirate fluid.     

Computerized nipple identification for multiple image analysis in computer-aided diagnosis

Correlation of information from multiple-view mammograms (e.g., MLO and CC views, bilateral views, or current and prior mammograms) can improve the performance of breast cancer diagnosis by radiologists or by computer. The nipple is a reliable and stable landmark on mammograms for the registration of multiple mammograms. However, accurate identification of nipple location on mammograms is challenging because of the variations in image quality and in the nipple projections, resulting in some nipples being nearly invisible on the mammograms. In this study, we developed a computerized method to automatically identify the nipple location on digitized mammograms. First, the breast boundary was obtained using a gradient-based boundary tracking algorithm, and then the gray level profiles along the inside and outside of the boundary were identified. A geometric convergence analysis was used to limit the nipple search to a region of the breast boundary. A two-stage nipple detection method was developed to identify the nipple location using the gray level information around the nipple, the geometric characteristics of nipple shapes, and the texture features of glandular tissue or ducts which converge toward the nipple. At the first stage, a rule-based method was designed to identify the nipple location by detecting significant changes of intensity along the gray level profiles inside and outside the breast boundary and the changes in the boundary direction. At the second stage, a texture orientation-field analysis was developed to estimate the nipple location based on the convergence of the texture pattern of glandular tissue or ducts towards the nipple. The nipple location was finally determined from the detected nipple candidates by a rule-based confidence analysis. In this study, 377 and 367 randomly selected digitized mammograms were used for training and testing the nipple detection algorithm, respectively. Two experienced radiologists identified the nipple locations which were used as the gold standard. In the training data set, 301 nipples were positively identified and were referred to as visible nipples. Seventy six nipples could not be positively identified and were referred to as invisible nipples. The radiologists provided their estimation of the nipple locations in the latter group for comparison with the computer estimates. The computerized method could detect 89.37% (269/301) of the visible nipples and 69.74% (53/76) of the invisible nipples within 1 cm of the gold standard. In the test data set, 298 and 69 of the nipples were classified as visible and invisible, respectively. 92.28% (275/298) of the visible nipples and 53.62% (37/69) of the invisible nipples were identified within 1 cm of the gold standard. The results demonstrate that the nipple locations on digitized mammograms can be accurately detected if they are visible and can be reasonably estimated if they are invisible. Automated nipple detection will be an important step towards multiple image analysis for CAD.     

Nodular hidradenoma of the breast: Report of two cases with literature review

Two cases of nodular hidradenoma of the breast with possibly different origins are reported. Case 1 is of a 58 year-old female wlth a breast mass in the left, outer lower-quadrant. A histogenetical origin in the skin adnexal glands was suspected due to its superficial location and immuno-histochemical findlngs. Case 2 is of a 44-yearold male with a subareolar nodule and nipple discharge. Histological examlnation demonstrated that the tumor was located deep in the breast tissue, was surrounded by dilated mammary ducts and exhibited intraductal extenslons, which are all features mlmicking those of breast cancer. Immunohlsto-chemical positivity against gross cystic disease fluid protein-15 was weakly Identified and negativity for endo-plasrnic reticulum was observed. This case can be interpreted as arising In the mammary ducts. It is well known that various kinds of skin adnexal tumors arise in the breast tissue; however, nodular hidradenoma of the breast is still a rare benign neoplasm. Cllnically, nodular hidradenoma of the breast tends to occur in the nipple or subareolar region of the female breast. It should be kept in mind that nodular hidradenoma may occur in mammary ducts and it should be included when differential diagnoses are made of subare olar breast tumors.     

Syringomatous adenoma of the nipple: a case report

We present a case of a 33-year-old woman who underwent excisional breast biopsy due to a left nipple mass. Histological examination revealed the morphologic and immunohistochemical pattern of syringomatous adenoma of the nipple. This is a rare lesion of the breast that can clinically mimic breast carcinoma, but harbors a benign and only locally aggressive course. Awareness of both the clinician and the pathologist for the possibility of diagnosing this tumor in the nipple region is mandatory to avoid mastectomy and lymph node dissection.     

Power Spectral Analysis of Mammographic Parenchymal Patterns for Breast Cancer Risk Assessment

PURPOSE: The purpose of the study was to evaluate the usefulness of power law spectral analysis on mammographic parenchymal patterns in breast cancer risk assessment. MATERIALS AND METHODS: Mammograms from 172 subjects (30 women with the BRCA1/BRCA2 gene mutation and 142 low-risk women) were retrospectively collected and digitized. Because age is a very important risk factor, 60 low-risk women were randomly selected from the 142 low-risk subjects and were age matched to the 30 gene mutation carriers. Regions of interest were manually selected from the central breast region behind the nipple of these digitized mammograms and subsequently used in power spectral analysis. The power law spectrum of the form P(f) = B/f(beta) was evaluated for the mammographic patterns. The performance of exponent beta as a decision variable for differentiating between gene mutation carriers and low-risk women was assessed using receiver operating characteristic analysis for both the entire database and the age-matched subset. RESULTS: Power spectral analysis of mammograms demonstrated a statistically significant difference between the 30 BRCA1/BRCA2 gene mutation carriers and the 142 low risk women with an average beta values of 2.92 (+/-0.28) and 2.47(+/-0.20), respectively. An A (z) value of 0.90 was achieved in distinguishing between gene mutation carriers and low-risk women in the entire database, with an A (z) value of 0.89 being achieved on the age-matched subset. CONCLUSIONS: The BRCA1/BRCA2 gene mutation carriers and low-risk women have different mammographic parenchymal patterns. It is expected that women identified as high risk by computerized feature analyses might potentially be more aggressively screened for breast cancer.