Assessment of the uterine dose in digital mammography and digital breast tomosynthesis

IntroductionDigital Mammography (DM-2D) and more recently Digital Breast Tomosynthesis (DBT), are two of the most effective imaging modalities for breast cancer detection, often used in screening programmes. It may happen that exams using these two imaging modalities are inadvertently performed to pregnant women. The objective of this study is to assess the dose in the uterus due to DM-2D and DBT exams, according to two main irradiation scenarios: in the 1st scenario the exposure parameters were pre-selected directly by the imaging system, while in the 2nd scenario, the maximum exposure parameters were chosen.MethodsThe mammography equipment used was a Siemens Mammomat Inspiration. A physical anthropomorphic phantom, PMMA plates (simulating a breast thickness of 6 cm) and thermoluminescent dosimeters (TLDs) were used to measure entrance air kerma values on the phantom's breast and abdomen in order to successively estimate the mean glandular dose (MGD) and the dose in the uterus. For the two irradiation scenarios chosen, two-breast imaging modalities were selected: 1) DBT in Cranio-Caudal (CC) view (with 28 kV and 160 mAs as exposure parameters), 2) DBT and DM in Medio Lateral-Oblique (MLO) and CC views (with 34 kV and 250 mAs as exposure parameters).ResultsIn the 1st scenario, the TLD measurements did not detect significant dose values in the abdomen whereas the MGD estimated using the D.R. Dance model was in close agreement with data available in the literature. In the 2nd scenario, there was no significant difference in MGD estimation between the different views, whereas the air kerma values in the abdomen (in DBT mode, CC and MLO) were 0.049 mGy and 0.004 mGy respectively. In CC DM-2D mode the abdomen air kerma value was 0.026 mGy, with no significant detected value in MLO view.ConclusionsFor the dose in the uterus, the obtained values seem to indicate that DM-2D and DBT examinations inadvertently performed during pregnancy do not pose a significant radiological risk, even considering the case of overexposure in both breasts.Implications for practiceThe accurate knowledge of the doses in DM-2D and DBT will contribute to raise the awareness among medical practitioners involved in breast imaging empowering them to provide accurate information about dose levels in the uterus, improving their radiation risk communication skills and consequently helping to reduce the anxiety of pregnant women undergoing this type of examinations.     

早期乳腺导管原位癌X线表现与预后生物学标记关系的研究

目的评价乳腺导管原位癌（DCIS）及DCIS伴微浸润的X线片表现，分析X线表现与预后生物学标记的相关性。方法对50例乳腺DCIS及45例DCIS伴微浸润的患者行X线检查，共62例行预后生物学标记，分析影像表现与孕激素受体（PR）、癌基因（C—erbB-2）、抑癌基因（p53）的相关性。用卡方检验进行统计学处理，并对有意义者行优势比（OR值）分析。结果（1）单独1个X线征象表现者62例；合并2个征象26例；阴性7例。（2）各种X线征象单独分析显示，62例有钙化的病灶中恶性钙化占73％（45例），其余为中间性钙化；钙化以簇状分布最为常见（36例），其次为段样分布（18例）。22例有肿块的病灶中，以卵圆形肿块最为常见（13例）；肿块的边缘表现为浸润、小分叶、清晰和模糊各为15、1、4和2例；等密度肿块占的比例较高（55％，12例）。结构扭曲7例，除1例外多与其他征象伴行；局灶性不对称占16％（15／95），可单独发生或与其他征象伴发。（3）将病灶的X线表现分成恶性钙化、中间性钙化和非钙化3组，PR与C-erbB-2在3组中的分布有统计性意义，PR阳性表达者X线上非钙化征象发生率是中间性钙化的11．00倍[χ^2=8．571，P=0．003；95％可信区间（CI）为1．998～60．572]、恶性钙化的8．80倍（χ^2=9．748，P=0．002；95％CI为2．024～38．253）；而C—erbB-2高表达者，恶性钙化是非钙化发生的12．35倍（χ^2=7．353，P=0．007；95％CI为1．447—105．443），中间性钙化的5．74倍（χ^2=4．977，P=0．026；95％CI为1．110～29．645）。结论乳腺DCIS及DCIS伴微浸润X线征象有特征。X线征象可以作为早期乳腺DCIS的一个预后因子。     

群集钙化对鉴别乳腺良恶性病变的意义

目的评价乳腺钼靶片群集钙化对鉴别乳腺良恶性病变的意义。方法分析76例乳腺X线钼靶片群集钙化病例,全部经手术病理证实,其中,乳腺恶性病变52例,良性病变24例。采用下列4项指标分析上述76例群集钙化的特征并进行良恶性对照研究:a)病灶钙化总数;b)每平方厘米钙化数目(N/S);c)钙化灶的大小、形态;d)钙化灶合并肿块。结果76例群集钙化病例中钙化总数大于30个、N/S大于等于10个、钙化灶大小形态不一致、钙化合并肿块,这4项指标诊断恶性钙化的特异性和敏感性分别为83.3%和69.2%,79.2%和76.9%,62.5%和92.3%,62.5%和53.8%。结论N/S大于等于10个、钙化总数大于30个及钙化灶大小、形态不一致这3个特征对恶性钙化最具有诊断价值。     

Detection of primary breast cancer in women with known adenocarcinoma metastatic to the axilla: Use of MRI after negative clinical and mammographic examination

The purpose of this study was to evaluate the ability of MRI to identify a primary site of malignancy in the breast of patients who present clinically with ipsilateral lymph nodes containing metastatic carcinoma but whose physical and mammographic examination are negative. MRI of the breast was performed on four patients using a variety of imaging parameters, all with and without gadolinium contrast. All patients had biopsy-proven adenocarcinoma of the ipsilateral axilla, with negative physical and mammographic examinations. Foci of enhancement assessed visually on precontrast and postcontrast scans (n = 1) and on substraction studies (n = 3) were considered suspicious under the clinical circumstances defined for this study. Lesions identified on MRI were re-identified on ultrasound examination and either preoperative localization for excisional biopsy or tissue sampling was performed. Surgery was performed and histopathologic correlation was obtained in all cases. Primary sites of breast carcinoma were identified in all four patients, with multiple sites of malignancy identified in three of four patients. Breast conservation therapy was made possible for three of four patients based on the results of the MRI study showing sites of malignancy and no features of cancer elsewhere in the breast. Follow-up data of 1, 2, and 5 years of these patients show no evidence of recurrent disease. MRI of the breast is a useful technique for identifying primary sites of malignancy in patients presenting with ipsilateral lymph nodes positive for metastatic adenocarcinoma when the physical and mammographic examinations are negative.     

乳腺隐匿性病灶切除术前简易X线定位方法的应用

目的探讨应用简易X线定位方法对乳腺隐匿性病灶切除的应用价值。方法在普通钼靶乳腺机上应用简易X线定位法,对31例乳腺隐匿性可疑病变进行病灶切除术前定位。结果30例一次定位成功,1例二次定位成功,定位满意度96.8%,病灶切除率为100%。结论简易X线定位方法可以指导临床准确切除病灶,并且安全可靠、价格低廉、创伤性小,具有临床应用价值。     

Standardization for image characteristics in telemammography using genetic and nonlinear algorithms

As the soft copy reading and computer assisted diagnosis (CAD) in mammography become more and more important, the standardization of digital images becomes paramount. Telemammography and telemedicine requires the standardization for image characteristics, such as image resolution, bit-depth and intensity response. Soft copy reading and CAD in mammography are both dependent on the characteristics of the source of the digital data, either direct digital mammography or digitized screen-film mammography. An algorithm developed on images from one database may not perform well as on images from another database (with a different digitization). In this paper, we describe two methods based on a genetic algorithm and a nonlinear algorithm for standardization of digitized and digital mammography. The proposed standardization techniques are based on geometric and intensity transformations that are discovered using a set of calibration images. A set of transformation algorithm is used to search for the best standardization.     

Can supplementary contrast-enhanced MRI of the breast avoid needle biopsies in suspicious microcalcifications seen on mammography? A systematic review and meta-analysis

PurposeTo analyze the rate of potentially avoidable needle biopsies in mammographically suspicious calcifications if supplementary Contrast-Enhanced MRI (CE-MRI) is negative.MethodsUsing predefined criteria, a systematic review was performed. Studies investigating the use of supplemental CE-MRI in the setting of mammographically suspicious calcifications undergoing stereotactic biopsy and published between 2000 and 2020 were eligible. Two reviewers extracted study characteristics and true positives (TP), false positives, true negatives and false negatives (FN). Specificity, in this setting equaling the number of avoidable biopsies and FN rates were calculated. The maximum pre-test probability at which post-test probabilities of a negative CE-MRI met with BI-RADS benchmarks was determined by a Fagan nomogram. Random-effects models, I²-statistics, Deek’s funnel plot testing and meta-regression were employed. P-values <0.05 were considered significant.ResultsThirteen studies investigating 1414 lesions with a cancer prevalence of 43.6% (range: 22.7–66.9%) were included. No publication bias was found (P = 0.91). CE-MRI performed better in pure microcalcification studies compared to those also including associate findings (P < 0.001). In the first group, the pooled rate of avoidable biopsies was 80.6% (95%-CI: 64.6–90.5%) while the overall and invasive cancer FN rates were 3.7% (95%-CI: 1.2–6.2%) and 1.6% (95%-CI 0–3.6%), respectively. Up to a pre-test probability of 22%, the post-test probability did not exceed 2%.ConclusionA negative supplementary CE-MRI could potentially avoid 80.6% of unnecessary stereotactic biopsies in BI-RADS 4 microcalcifications at a cost of 3.7% missed breast cancers, 1.6% invasive. BI-RADS benchmarks for downgrading mammographic calcifications would be met up to a pretest probability of 22%.     

提高乳腺癌早期诊断水平的研究

目的：评价育龄妇女乳腺疾病普查、乳腺钼靶摄片及^99mTc-MIBI核素显像在乳腺癌早期诊断中的价值，探索提高乳腺癌早期诊断的方法。方法：对徐州地区10万例育龄妇女进行乳腺疾病的普查，筛选出的乳腺癌高危人群及门诊就诊的乳腺疾{戎患者行乳腺钼靶摄片及^99mTc-MIB核素显像检查。结果：普查乳腺癌检出率为28．9／10万。乳腺钼靶摄片诊断乳腺癌的灵敏度为90．2％、特异性为31.4％。^99mTc-MIBI核素显像灵敏度为82．5％，特异性为90．2％。联合应用乳腺钼靶摄片与^99mTc-MIBI核素显像，对乳腺癌诊断的灵敏性为100％，特异性为99．3％。结论：育龄妇女乳腺疾病普查，结合乳腺钼靶摄片及^99mTc-MIBI核素显像可以明显提高乳腺癌的诊断率。     

Ultrasound variables and their prognostic value in a population of 1103 patients with 272 breast cancers

In a prospective two-centre study targeted US was performed as an adjunct to mammography in a population of 1103 patients with 272 breast cancers, 517 benign lesions and no abnormalities in 314 patients. The purpose of the study was to analyse the distribution of the different US variables among the breast lesions and to determine the prognostic value of these variables with respect to the diagnosis of malignancy. The following variables were analysed: border; contour; orientation; structure; echogenicity; sound transmission; and size. These variables were correlated with the definitive diagnosis and univariate analysis was performed. A statistically significant association with breast cancer (p < 0.001) was present for irregular border; ill-defined contour; indeterminate or vertical orientation; homogeneous, complex or heterogeneous structure; hypoechogenicity; and unchanged or decreased sound transmission. Multivariate analysis showed a high independent prognostic value for malignancy for irregular border, followed by ill-defined contour and unchanged or decreased sound transmission. However, their discriminative power was not absolute: in 38 cancers none of the malignant US variables were present, and in 11 benign lesions all variables were present. There were hardly any benign-looking lesions that proved to be malignant. Received: 6 October 1999; Revised: 3 March 2000; Accepted: 26 June 2000