乳腺数字化X线摄影辐射剂量最优化探讨

目的:分析不同摄影条件下,乳腺数字化X线摄影图像质量和辐射剂量的变化,探讨在不影响图像质量的前提下,有效降低辐射剂量的摄影方法。方法:采用全视野乳腺数字化X线机,在不同摄影条件下[手动曝光模式(manual exposure control,MEC)、自动曝光模式(automatic exposure control,AEC)]对标准乳腺模体进行重复曝光测试,记录每种摄影条件下的体表入射剂量(entrance surface dose,ESD)和平均腺体剂量(average glandular dose,AGD)。由3名高年资影像科医师,按照美国放射学院乳腺模体影像评价标准对影像进行评分,并对ESD、AGD及图像质量评分进行统计学分析。结果:固定管电压(28 k V)时,ESD和乳腺AGD随着管电流的上升而上升;固定管电流(56 m As)时,ESD和乳腺AGD随着管电压的上升而上升,固定管电压和固定管电流这2组摄影参数改变的图像评分差异均无统计学意义(χ~2=0.434,P均0.05)。结论:在乳腺数字化X射线摄影检查中,MEC模式更适合个体化诊断,能够有效降低受检者的辐射剂量,达到剂量最优化。     

胸部X线检查方法的辐射剂量控制分析

目的探讨X线检查中有效辐射剂量的控制。方法对2008年12月～2010年12月我院收治并接受胸部X线检查240例的影像资料进行分析,比较不同检查方法的平均有效辐射剂量。结果 240例中接受床边计算机X线摄影(CR)40例(CR组),接受数字X线摄影(DR)100例(DR组),接受计算机X线断层扫描检查(X-CT)100例(X-CT组)。CR组、DR组及X-CT组平均有效辐射剂量分别为0.326 mSv、0.01387 mSv和2.971 mSv。结论应重视X线检查中辐射剂量的控制问题,尽可能避免不必要的照射,尽量合理降低群体照射剂量,在为患者提供准确影像诊断的同时,将有效辐射剂量控制在最小范围内。     

数字化乳腺X线摄影评估乳腺密度、诊断乳腺癌的研究进展

乳腺密度是预测乳腺癌风险的一个指标,致密型乳腺与乳腺癌具有相关性,随着乳腺密度的增加,乳腺癌诊断敏感度下降,尤其是致密型乳腺,极大地降低了放射医师的阳性诊断率。数字化乳腺X线摄影技术可提高致密型乳腺乳腺癌的诊断敏感度。本文综述了数字化乳腺X线摄影对乳腺密度的评估及乳腺癌诊断率的影响。     

数字化乳腺X线成像系统技术进展

乳腺癌是常见的癌症之一，近年来其发病率呈上升趋势，已居我国沿海发达地区女性恶性肿瘤的首佗早期发现、早期诊断、早期治疗是目前降低乳腺癌病死率的关键。而乳腺X线摄影作为检测早期临床无症状隐匿性乳腺癌的重要手段，早已成为欧美国家公认的普查筛选的方法。据报道，乳腺X线摄影降低了约30％的50岁以上妇女的乳腺病     

乳腺癌的钼勒X线表现与病理对照分析（附42例报告）

高清晰度X线钼靶乳腺摄影是目前乳腺癌诊断应用最广泛有效的检查方法。本文目的在于探讨乳腺癌的钼靶X线影像学特点及其与病理基础，以提高诊断水平。     

CR技术在乳腺钼靶摄影中的应用价值

乳腺X线钼靶摄影是目前诊断乳腺疾病，特别是发现早期乳腺癌的一种最重要、最有效的检查方法。计算机摄影（Computed Radiography，CR）技术可以将模拟影像数字化，利用其强大的后处理功能提高图像质量。本科利用CR的IP板代替常规胶片做乳腺钼靶摄影，并利用CR技术的图像后处理功能，提高了乳腺X线摄影的图像质量。本文通过回顾性分析320例利用CR技术处理的乳腺影像，探讨CR技术在乳腺钼靶摄影中的应用价值。     

乳腺X线数字摄影中压力对辐射剂量的影响分析

目前,乳腺疾病呈上升趋势,需要做到早发现、早诊断、早治疗,以提高治愈率。乳腺X线数字钼靶摄片能更早地显示微小病变,特别是在乳腺癌早期筛查中,具有其他检查方法不可比拟的优越性。我国正常人群普查时,40岁以上妇女每年需做一次乳腺X线检查,所以降低受检者摄片过程中的辐射剂量是非常关键和重要的。     

X线引导下三维立体定位技术对乳腺疾病的诊断价值

乳腺钼靶X线摄影技术仍是目前乳腺检查的首选,尤其是早期乳腺癌诊断最有效的方法之一[1,2]。乳腺X线立体定位术能够准确定位、手术一次完成;乳腺穿刺活检能直接取得活体组织,进行病理诊断。本次研究旨在探讨X线引导下三维立体定位术的技术方法及在诊断临床乳腺微小病变中的价值。     

初步讨论乳腺钼靶投照体位和压迫技术的技巧与体会

迅速普及的乳腺钼靶X线摄影成像技术可以大大提高早期乳腺癌的检出率，从而降低乳腺癌的死亡率，这种成像技术的效用和成功取决于一份高质量的摄影照片的恒定产生，投照体位的选择和乳房压迫技术是获取高质量乳腺摄影照片的最重要因素。在现有乳腺X线成像设备的基础上，掌握和控制乳腺X线摄影中乳腺投照位置、压迫技术的技术要点是提高临床影像质量、提高X线检查利用率的前提和关键。作者结合实际工作中频繁实用的实施要点及传统的质量控制要求，作以下阐述。     

乳腺癌影像学诊断研究进展

乳腺癌是当前威胁妇女生命健康最常见的恶性肿瘤。我国乳腺癌的发病率也呈逐年上升。随着现代医学的发展,乳腺癌可以通过乳腺影像学检查方法如乳腺X线摄影等首先发现,进而提高了乳腺癌的诊断准确性和降低了死亡率。特别是近几十年,新的乳腺影像诊断技术的飞速发展更是为不断提高乳腺癌诊断的准确率奠定了基础。本文就乳腺X线摄影、乳腺超声声像图、CT和MRI等影像学检查方法对乳腺癌的诊断价值及其最新进展做综述评价。     

Mammography and early breast cancer detection

Screening mammography has been shown to reduce breast cancer mortality. Both film-screen mammography and xeromammography are highly sensitive and specific. Mammography accreditation programs assure physicians and patients that a facility provides mammography of the highest quality, using the lowest possible radiation dose. Mammographic signs of early cancer include a small mass, calcifications, architectural distortion and a neodensity. Dense tissue may result in a false-negative examination even when a cancer is palpable, with adverse effects if biopsy is delayed.     

The regulation of mammography

There has been a long history of public and professional concern about the safety and quality of mammography. Whereas concerns about radiation dose levels dominated the 1970s, the type of equipment used in mammography was the focus of the 1980s. In the early 1990s, there was a lack of confidence in the overall quality of mammography. These problems have stood in the way of the widespread utilization of mammography to reduce mortality from breast cancer. The Mammography Accreditation Program of the American College of Radiology, state regulations, and the Mammography Quality Standards Act of 1992 came about to ensure a minimum level of quality that would encourage women to participate in breast cancer screening programs. Designing regulations that ensure quality mammography for women, without burdening mammography facilities with unnecessary costs and depletion of their resources, is one of the most difficult challenges facing the U.S. Food and Drug Administration.     

A review of screening mammography: The benefits and radiation risks put into perspective

Introduction/BackgroundIn medical imaging a benefit to risk analysis is required when justifying or implementing diagnostic procedures. Screening mammography is no exception and in particular concerns around the use of radiation to help diagnose cancer must be addressed.MethodsThe Medline database and various established reports on breast screening and radiological protection were utilised to explore this review.Results/DiscussionThe benefit of screening is well argued; the ability to detect and treat breast cancer has led to a 91% 5-year survival rate and 497 deaths prevented from breast cancer amongst 100,000 screened women. Subsequently, screening guidelines by various countries recommend annual, biennial or triennial screening from ages somewhere between 40–74 years. Whilst the literature presents different perspectives on screening younger and older women, the current evidence of benefit for screening women <40 and ≥75 years is currently not strong. The radiation dose and associated risk delivered to each woman for a single examination is dependent upon age, breast density and breast thickness, however the average mean glandular dose is around 2.5–3 mGy, and this would result in 65 induced cancers and 8 deaths per 100,000 women over a screening lifetime from 40–74 years. This results in a ratio of lives saved to deaths from induced cancer of 62:1.ConclusionTherefore, compared to the potential mortality reduction achievable with screening mammography, the risk is small.     

Mammography Dose Survey Using International Quality Standards

Digital mammography is the current standard for breast cancer screening. The absence of any dosimetric data, the quality standards, and the fear of radiation detriment, sometimes, hampers the smooth introduction of this technology and the launch of breast cancer screening programmes. As the breast cancer screening programmes are in development in Morocco, quality standards have been set in this study, so that any new breast cancer screening service could get started with their first analysis. The purpose of this study was to report the first Moroccan breast dose and to test quality standards compared with European guidelines. A dosimetric study is conducted by calculating mean glandular dose (MGD) for patients' breasts and polymethyl methacrylate (PMMA) for each thickness from recorded radiographic factors and X-ray tube (output and half-value layer) measurements using Dance's model for a digital mammography system. This is carried out to determine the correlation between phantom and patient measurements.The mean MGD for patient data was 1.02 ± 0.5 mGy and the compressed breast thickness was 55 ± 14 mm. For compressed breast thickness range of 50–60 mm, the MGD was 0.94 ± 0.3 mGy and the dose calculated with PMMA phantom for the same range thickness was 1.33 mGy. The results of MGD as a function of PMMA thickness is lower than the achievable limit curve proposed in the European guidelines. The average doses, which depend on the technical parameters of the mammography equipment, are in line with values obtained in European guidelines. In addition, an investigation is needed throughout the Moroccan territory, in the sense of optimization of radiological practices and techniques in mammographic centres aligning with the international recommendations.     

Radiation dose from digital breast tomosynthesis screening – A comparison with full field digital mammography

ObjectivesTo compare Mean Glandular Dose (MGD) and effective dose from digital breast tomosynthesis (DBT) screening with that from full field digital mammography (FFDM) screening.MethodTo simulate compressed breasts, two Perspex-polyethylene breast phantoms were used, one phantom for compressed breast in craniocaudal and the other for compressed breast in mediolateral oblique. An adult ATOM dosimetry phantom was loaded with high sensitivity thermoluminescence dosimeters; the phantom was then positioned on Hologic Selenia Dimensions mammographic machine to imitate DBT and 4-view FFDM screening. Organ radiation doses were measured from 4-view DBT and 4-view FFDM (craniocaudal and mediolateral oblique views for each breast). Organ radiation doses were used to calculate effective dose from one screening session.ResultsMGD for DBT was 3.6 mGy; MGD for FFDM was 2.8 mGy. For DBT, other organs (e.g. thymus, lungs, salivary glands, thyroid, contralateral breast and bone marrow) radiation dose was also higher than for FFDM. The use of DBT for breast cancer screening increases the effective dose (E) of one screening session by 22%. E for DBT was 0.44 mSv; E for FFDM was 0.34 mSv.ConclusionThe use of DBT for breast cancer screening increases the radiation dose to screening clients.     

计算机乳腺摄影影像处理参数的探讨

目的　探讨通过对计算机乳腺摄影影像处理参数的合理的选择和运用 ,以提高乳腺摄影的图像质量及降低X线剂量。方法　对 3 0 0例不同乳腺类型患者进行常规乳腺摄影和计算机乳腺摄影 ,对二者摄影参数进行比较 ;对计算机乳腺摄影影像处理参数修改前后的乳腺照片进行对比分析 ,确定最佳的乳腺影像处理参数。结果　计算机乳腺摄影能显著降低受检者的辐射量 ,不同乳腺类型的X线剂量是常规乳腺摄影的 1/3～ 1/2 ;最适宜的计算机乳腺摄影影像处理参数为 :GA =1.2 ;GT =G ;GC =0 .6;GS =0 .3 ;RN =5 ;RT =P ;RE =1.0。结论　计算机乳腺摄影因其具有大的曝光宽容度和高的检测敏感性 ,通过合理的选择影像处理参数可获得高质量的图像 ,降低辐射量。     

The role of magnetic resonance imaging in screening women at high risk of breast cancer

Most women at very high risk of breast cancer because of a mutation in the genes BRCA1 or BRCA2, or a very strong family history of breast cancer, opt for intensive breast screening rather than bilateral prophylactic mastectomy. Annual screening mammography has low sensitivity in this population in part because of the greater breast density and faster tumor growth of younger women, resulting in cancers being detected at a suboptimal stage. In 11 prospective comparative studies, the addition of annual contrast-enhanced magnetic resonance imaging (MRI) of the breast to mammography demonstrated more than 90% sensitivity, more than twice that of mammography alone. False-positive rates were higher with the addition of MRI, but specificity improved on successive rounds of screening. Although survival data are not yet available, the stage distribution of these tumors predicts a significant reduction in breast cancer mortality rate compared with that of screening without MRI. Accordingly, annual MRI plus mammography is now the standard of care for screening women aged 30 years or older who are known or likely to have inherited a strong predisposition to breast cancer (based on the above evidence) and for women who received radiation therapy to the chest before the age of 30 years (based on expert opinion). Further research is necessary to define the optimal screening schedule for different subgroups. Formal studies of other high-risk populations (eg, biopsy showing lobular neoplasia or atypical ductal hyperplasia, dense breasts, and personal history of breast cancer at a young age) should be done before MRI screening is routinely adopted for these women.     

Radiographers’ Reflections on Women With High Breast Density Tissue—An Interview Study

Women aged between 40 and 74 years are called to do mammography screening in Sweden with the aim of early detection of breast cancer, which is the most common type of cancer in women. Women with dense breast tissue are more likely to develop breast cancer, and mammography is not an optimal diagnostic method for them because of reduced sensitivity. Radiographers who work in mammography departments are exposed to ethical dilemma daily, which is whether they should inform women about the density of their breast. The purpose of the study is to illustrate thoughts that radiographers have on breast density during mammography examination. The study was performed with qualitative method, where semistructured interviews were conducted. The material from the interviews was analyzed, condensed into different units and afterward in different codes that became different categories. The informants had separate opinions about if women in Sweden should be informed about breast density. On the other hand, radiographers considered that women should not be informed if there are no guidelines for the assessment and follow-up of breast density. With regard to supplementary examinations, all informants consider that it would be good for women with high-dense breast tissue to be offered supplementary examinations during mammography screening.     

Screening Mammography and Breast Cancer Reduction: Examining the Evidence

Better treatment and awareness may explain much of the decline in breast cancer deaths in recent years, not mammography. For women without a family history of breast cancer, the risks of screening mammography may outweigh the benefits, particularly for women younger than age 50. Mammography carries the risk of overdiagnosis of tumors that would not have caused death. Nurse practitioners are advised to educate their patients on mammography risks and benefits while increasing their emphasis on the clinical symptoms of breast cancer and ways to reduce risk, including weight control, decreased alcohol use, and decreased use of menopausal estrogen.     

Mammography Pain in Women Treated Conservatively for Breast Cancer

In this study, pain during mammography in women treated conservatively for breast cancer was examined. It studied pain intensity and its relation to a variety of demographic, medical, and pain coping variables as well as to objective measures of breast compression. Ninety-nine women, treated with lumpectomy (with or without radiation) and undergoing follow-up screening mammography, were asked about strategies they use to cope with everyday pain and then were asked to report pain experienced during the mammogram. Treated and untreated breasts were rated separately and compared with a sample of 125 control women with no history of breast cancer. Women reported significantly greater pain in the treated breast (41% greater than the untreated breast and 32% greater than the control group). There was no consistent relationship between mammography pain and pain coping. Average intensity of pain at last mammogram was the best predictor of pain in both breasts. Women treated conservatively for breast cancer experience significantly greater pain during mammography of their treated breast. Radiologists and technologists can identify women at risk for a painful mammogram by asking about the pain at last mammogram. By applying pain-reducing interventions, they might be able to make the mammography experience more tolerable for these women.