Simulation of mammographic breast compression in 3D MR images using ICP-based B-spline deformation for multimodality breast cancer diagnosis

Purpose

   Multimodality mammography using conventional 2D mammography and dynamic contrast-enhanced 3D magnetic resonance imaging (DCE-MRI) is frequently performed for breast cancer detection and diagnosis. Combination of both imaging modalities requires superimposition of corresponding structures in mammograms and MR images. This task is challenging due to large differences in (1) dimensionality and spatial resolution, (2) variations in tissue contrast, as well as (3) differences in breast orientation and deformation during the image acquisition. A new method for multimodality breast image registration was developed and tested.

Methods

   Combined diagnosis of mammograms and MRI datasets was achieved by simulation of mammographic breast compression to overcome large differences in breast deformation. Surface information was extracted from the 3D MR image, and back-projection of the 2D breast contour in the mammogram was done. B-spline-based 3D/3D surface-based registration was then used to approximate mammographic breast compression. This breast deformation simulation was performed on 14 MRI datasets with 19 corresponding mammograms. The results were evaluated by comparison with distances between corresponding structures identified by an expert observer.

Results

   The evaluation revealed an average distance of 6.46 mm between corresponding structures, when an optimized initial alignment between both image datasets is performed. Without the optimization, the accuracy is 9.12 mm.

Conclusion

   A new surface-based method that approximates the mammographic deformation due to breast compression without using a specific complex model needed for finite-element-based methods was developed and tested with favorable results. The simulated compression can serve as foundation for a point-to-line correspondence between 2D mammograms and 3D MR image data.     

Automatic multimodal 2D/3D breast image registration using biomechanical FEM models and intensity-based optimization

Due to their different physical origin, X-ray mammography and Magnetic Resonance Imaging (MRI) provide complementary diagnostic information. However, the correlation of their images is challenging due to differences in dimensionality, patient positioning and compression state of the breast. Our automated registration takes over part of the correlation task. The registration method is based on a biomechanical finite element model, which is used to simulate mammographic compression. The deformed MRI volume can be compared directly with the corresponding mammogram. The registration accuracy is determined by a number of patient-specific parameters. We optimize these parameters – e.g. breast rotation – using image similarity measures. The method was evaluated on 79 datasets from clinical routine. The mean target registration error was 13.2 mm in a fully automated setting. On basis of our results, we conclude that a completely automated registration of volume images with 2D mammograms is feasible. The registration accuracy is within the clinically relevant range and thus beneficial for multimodal diagnosis.     

Computerized analysis of images in the detection and diagnosis of breast cancer.

Improvements in mammographic acquisition techniques have resulted in making the early signs of breast cancer more apparent on mammograms. However, the accuracy of the overall mammographic examination depends on both the quality of the mammographic images and the ability of the radiologist to interpret those images. While mammography is the best screening method for the early detection of breast cancer, radiologists do miss lesions on mammograms. Use of output, however, from a computerized analysis of an image by a radiologist may help him/her in the detection or diagnostic tasks, and potentially improve the overall interpretation of breast images and the subsequent patient care. Computer-aided detection and diagnosis (CAD) involves the application of computer technology to the process of medical image interpretation. CAD can be defined as a diagnosis made by a radiologist, who uses the output from a computerized analysis of medical images as a "second opinion" in detecting and diagnosing lesions, with the final diagnosis being made by the radiologist. The computer output must be at a sufficient performance level, and in addition, the output must be displayed in a user-friendly format for effective and efficient use by the radiologist. This chapter reviews CAD in breast cancer detection and diagnosis, including examples of image analyses, multi-modality approaches (i.e., special-view diagnostic mammography, ultrasound, and MRI), and means of communicating the computer output to the human.     

Overuse of mammography during the first round of an organized breast cancer screening programme

Objectives  We examined the frequency of mammography screening among women who had had a screening mammogram recently and therefore generally did not need to repeat the examination.
Methods  A population-based sample of 50- to 69-year-old women were surveyed immediately before and 8 months after they received an invitation to participate in the first round of screening of the newly organized mammography screening programme in Geneva, Switzerland. These women also received a booklet that included the recommendation to have screening mammograms at 2-year intervals.
Results  The baseline survey identified 660 women who had had a mammogram within the previous 12 months. Of these, 23.2% [95% confidence interval (CI), 20.0–26.6] had an opportunistic mammogram and 4.1% (95% CI, 2.7–5.9) had an organized mammogram during follow-up. Women who had had their last mammogram 6–12 months prior to baseline (vs. more recently), intended to have a mammogram within the next 6 months, wished to receive more information on mammography screening, and had a history of surgical breast biopsy were more likely to have an unnecessary screening mammogram (either organized or opportunistic) during follow-up. Compared with women who had an opportunistic mammogram, women who had an organized mammogram were more likely to be of lower socioeconomic status, to have made their own screening decision and to have anticipated the date of their next mammogram by no more than a few months.
Conclusions  Opportunistic mammography screening in excess of recommendation is common, and persists despite explicit advice about recommended screening frequency.     

Personalized targeted mailing increases mammography among long-term noncompliant medicare beneficiaries: a randomized trial

OBJECTIVES: The study purpose was to increase mammography screening among older women by identifying female Medicare beneficiaries without a recent mammogram and assesses the cost-effectiveness of a personalized targeted mailing encouraging them to have a mammogram. METHODS: A randomized paired controlled trial included 1229 pairs of women matched on zip code, race, and urban or rural county. Postintervention mammography claims were measured from November 1997 through December 1998. The subjects were female Medicare beneficiaries age > or = 70, living in Michigan for > or = 5 years, having no significant comorbidity likely to affect screening, and no mammogram for > or = 5 years. Intervention subjects received a personally addressed letter from the Medical Director of Michigan Medicare with materials emphasizing the individual's lack of use of the Medicare mammography screening benefit, reasons for screening, and how to be screened. RESULTS: Women who received the mailing were 60% more likely to have a subsequent mammogram (OR 1.6, P <0.005), with diagnostic mammograms increasing more than screening mammograms (2.8% vs. 0.8%). The absolute increase was greatest for women age 70 to 79, 10.6% in the intervention group versus 6.5% for controls, odds ratio 1.7 (P <0.02). A statewide Medicare intervention in Michigan would cost of 108,000 US dollars to 238,000 US dollars, producing 3500 to 4300 additional mammograms at 31 US dollars to 55 US dollars per additional mammogram. CONCLUSION: The intervention increased mammography among long-term noncompliant older women, particularly increasing diagnostic mammograms. This approach can be directly implemented in other states and nationally. It may also be useful for other preventive services.     

Mammography at a crossroad. How do physicians reconcile conflicting study results with the biologic truths of breast cancer?

The value of routine mammography screening for breast cancer has been the subject of heated debate for much of the last decade. Ten years ago, a baseline mammogram was recommended for women at age 35, and annual mammograms were recommended after age 40. These guidelines were based on the results of mammography trials in Europe and the United States in which a 30% reduction in breast cancer deaths was seen among women who underwent screening.     

The role of mammography in male patients with breast symptoms

OBJECTIVE: To determine the contribution of mammography to the comprehensive clinical evaluation of men with breast symptoms. PATIENTS AND METHODS: We retrospectively reviewed the records of all men who underwent mammography between January 1, 2001, and December 31, 2004, at the Mayo Clinic In Jacksonville, Fla. Medical history, mammographic findings, and breast cancer diagnoses were assessed. RESULTS: A total of 198 men had 212 mammograms. Nine mammograms (from 9 different men) (4%) showed suspicious findings. Eight men underwent biopsy, which yielded a breast cancer diagnosis in 2 (1%). Of the 212 mammograms, 203 (96%) showed benign findings, including gynecomastia on 132 (62%). One patient with a benign-appearing mammogram later underwent breast biopsy, and malignant disease was diagnosed. All the men with breast cancer had a dominant mass on clinical examination and other findings suggestive of breast cancer. Of the 132 mammograms showing gynecomastia, 110 (83%) were from men who had taken predisposing medications or who had predisposing medical conditions. CONCLUSIONS: Mammography added little information to the initial patient evaluation. Breast cancer may be suspected by the presence of a dominant mass. Gynecomastia can be predicted on the basis of the patient's symptoms or preexisting condition. Patients with suspicious findings on examination warrant appropriate clinical management regardless of mammographic findings. Mammography in men may be of benefit only for image guidance of percutaneous biopsy of a suspicious mass.     

计算机辅助检测系统对数字化乳腺X线图像检测的可重复性

目的 观察计算机辅助检测系统(CAD)检出全数字化乳腺X线图像中良恶性肿块及钙化灶的可重复性。 方法 454例乳腺疾病患者经手术病理证实,其中67例乳腺癌患者于3个月内接受两次乳腺X线检查。比较数字化图像直接获得的CAD结果(CAD1)与两次重新回输原始数据生成的CAD结果(CAD2、CAD3)的一致性,评价CAD系统短期内对乳腺X线图像检测结果的可重复性。 结果 CAD1、CAD2、CAD3在肿块及钙化灶检出的数目及所标记的位置上完全相同。67例短期内两次乳腺X线检查病例中,32例病灶大小、密度未见变化,初次和再次CAD发现恶性病灶的敏感度分别为87.50%(28/32)和90.63%(29/32)。 结论 对于相同的数字化图像,CAD标记的重复率为100%。对于相同乳腺短期内两次X线检查图像,CAD系统检出乳腺癌具有较高的可重复性。     

Do cultural factors predict mammography behaviour among Korean immigrants in the USA?

Title. Do cultural factors predict mammography behaviour among Korean immigrants in the USA? Aim. This paper is a report of a study of the correlates of mammogram use among Korean American women. Background. Despite the increasing incidence of and mortality from breast cancer, Asian women in the United States of America report consistently low rates of mammography screening. A number of health beliefs and sociodemographic characteristics have been associated with mammogram participation among these women. However, studies systematically investigating cultural factors in relation to mammogram experience have been scarce. Methods. We measured screening‐related health beliefs, modesty and use of Eastern medicine in 100 Korean American women in 2006. Hierarchical logistic regression was used to examine the unique contribution of the study variables, after accounting for sociodemographic characteristics. Findings. Only 51% reported past mammogram use. Korean American women who had previously had mammograms were statistically significantly older and had higher perceived benefit scores than those who had not. Perceived benefits (odds ratio = 6·3, 95% confidence interval = 2·12, 18·76) and breast cancer susceptibility (odds ratio = 3·18, 95% confidence interval = 1·06, 9·59) were statistically significant correlates of mammography experience, whereas cultural factors did not correlate. Post hoc analysis showed that for women with some or good English skills, cultural factors statistically significantly correlated with health beliefs and breast cancer knowledge (P < 0·05). Conclusion. Nurses should consider the inclusion in culturally tailored interventions of more targeted outreach and healthcare system navigation assistance for promoting mammography screening in Korean American women. Further research is needed to unravel the interplay between acculturation, cultural factors and health beliefs related to cancer screening behaviours of Korean American women.     

Classification of mammographic breast density and its correlation with BI-RADS in elder women using machine learning approach

IntroductionMammographic breast density (MBD) is a known risk factor for breast cancer and older women have higher incidence rates of breast cancer occurrence. The Breast Imaging Reporting and Data System (BI-RADS) is a commonly used MBD classification tool for mammogram reporting. However, they have limitations since there are reading inconsistencies between different radiologists with the visual assessment of breast density.MethodsDigitised film-screen mammographic images were extracted from the Digital Database for Screening Mammography (DDSM). A machine learning project was developed using commercially available software with several predictive models applied to classify different amount of MBD on mammograms into different density groups. The effectiveness of different predictive models used in classifying the mammograms were tested by receiver operator characteristics (ROC) curve with comparison to the gold standard of BI-RADS classification.ResultsThree predictive models, Decision Tree (Tree), Support Vector Model (SVM) and k-Nearest Neighbour (kNN) showed high AUC values of 0.801, 0.805 and 0.810 respectively. High AUC values for the three predictive models indicates that the accuracy of the model is approaching that of the BI-RADS method.DiscussionOur machine learning project showed to have capabilities to be potentially used in the clinical settings to help categorise mammograms into extremely dense breasts (BI-RADS Group A) from entirely fatty breasts (BI-RADS Group D).ConclusionFindings from the present study suggest that the machine learning method is potentially useful to quantify the amount of MBD in mammograms.     

Application of vibro-acoustography for detection of calcified arteries in breast tissue.

OBJECTIVE: The relationship between breast arterial calcification and coronary artery calcification and stenosis is currently an area of active research. It has been suggested in the literature that calcified arteries in the breast may be positively correlated with coronary artery disease. The sensitivity of x-ray mammography, the main breast imaging method, is reduced in radiologically dense breasts. In a recent study, we showed that vibro-acoustography, a novel noninvasive imaging technique that is based on the dynamic response of the object to a vibrating force, can detect microcalcifications in the breast regardless of breast density. In this study, we examined the application of vibro-acoustography in detecting calcified arteries in breast tissue. METHODS: Experiments were conducted on 207 postsurgical excised human breast tissue samples. Tissues specimens were imaged with a high-resolution x-ray mammography unit. Each sample with confirmed arterial calcification was then scanned by the vibro-acoustography system, and the resulting image was compared with the corresponding mammogram. We also studied the histologic characteristics of each sample to positively identify the disease and the presence of arterial calcification. RESULTS: Initial mammograms clearly showed 14 calcified arteries. The corresponding vibro-acoustographic images showed all calcified arteries as fragmented linear structures. The vibro-acoustographic appearance of the arteries was highly correlated with their distinctive radiographic appearance, which allowed us to identify all the calcified arteries in the vibro-acoustographic images. CONCLUSIONS: Vibro-acoustography can be used to detect calcified arteries in excised breast tissue. This method may eventually play a role in identifying individuals with an increased risk of coronary artery disease.     

Mammography screening behavior in older women caregivers

The purposes of this study are to explore older caregivers' mammography participation and the facilitators and barriers to mammography screening. Of the 52 older female caregivers with a mean age of 65 years (range 50-90) interviewed by telephone, 80.8% had had a mammogram within 12 months. Significant facilitators included health care provider recommendation and beliefs in the efficacy of treatment. Significant barriers included health care providers' failure to recommend mammograms, caregiver procrastination, fear of pain, and lack of symptoms. Caregivers with higher burden reported less frequent self- and provider-conducted breast examinations.     

Phantom-based comparison of conventional versus phase-contrast mammography for LCD soft-copy diagnosis

Purpose

Liquid crystal display (LCD) of mammograms provides soft-copy results that differ in conventional and phase contrast mammography (PCM). PCM potentially offers the highest quality of sharpness and graininess, an edge emphasis effect on the object, and the highest image resolution. However, when the image is displayed on an LCD, the resolution depends on the pixel pitch and the PCM image data must be diminished. We investigated the observed effect on spatial resolution and contrast when conventional or phase contrast mammograms are viewed on an LCD.

Methods

Using the tissue-equivalent phantom (Model 1011A), a conventional mammogram and a magnification radiography image were obtained with a PCM system. This phantom contains simulated fibers, microcalcifications, and masses. The PCM image was reduced 1/1.75 to render it consistent with life size mammography using the nearest neighbor, bilinear, and bicubic interpolation methods. The images were displayed on a five million (5M)-pixel LCD with 100 % magnification. Ten mammography technicians observed the reduction images displayed on LCDs and reported their results.

Results

In the detectability of the microcalcifications, there was no significant difference between conventional mammograms and reduced PCM images. Regarding fibers and masses, detectability using reduced images was higher than those of conventional images. The detectability using images reduced by the nearest-neighbor method was lower than those of images reduced by two other interpolation methods. Bilinear interpolation was affected by the smoothing effect, while CNR was increased. In addition, since the noise of PCM image was reduced by an air gap effect, high detectability of key image features was found.

Conclusions

Soft-copy display of phase-contrast mammograms is feasible with LCDs, while detectability of fibers and masses was best with bilinear interpolation and use of an air gap.     

Efficacy of a simple, low-cost educational intervention in improving knowledge about risks and benefits of screening mammography

OBJECTIVES: To assess the efficacy of a minimal cost and involvement educational intervention in improving women's knowledge about screening mammography and to explore patient perceptions of the educational intervention. PARTICIPANTS AND METHODS: During the study period (March 10, 2005, to July 1, 2005), 1446 participants in the Mayo Mammography Health Study scheduled for a mammogram within 4 weeks at the Mayo Clinic in Rochester, Minn, were randomized to 2 study groups and mailed surveys about mammograms. The 2 groups received separate surveys; both surveys contained knowledge-based questions about mammography, but the educational intervention group survey also contained qualitative questions that assessed the educational pamphlets. RESULTS: Of the 668 surveys returned (responders), 248 (34.4%) were from the control group, and 420 (58.3%) were from the intervention group. Approximately 80% of responders had had more than 7 prior mammograms. Significant increases in knowledge about mammography were found in the educational intervention compared with the control group on questions regarding age to begin screening mammography (67.9% vs 54.4%; P < .001), recommended frequency of mammograms (86.4% vs 75.4%; P < .001), overall reduction in mortality due to screening mammography (55.2% vs 8.9%; P < .001), and proportions of women who required follow-up mammograms (35.5% vs 14.9%; P < .001) or biopsy (59.5% vs 13.3%; P < .001). Qualitative data results indicated that most women who received the educational intervention found the pamphlets helpful and informative despite having had many previous mammograms. CONCLUSION: The results suggest that providing women scheduled for screening mammograms with physician-approved educational material before their appointment significantly increases knowledge about screening mammography, risks and benefits, and possible follow-up.     

Trends in breast cancer screening and diagnosis

Screening mammography is the single most effective method of early breast cancer detection and is recommended on an annual basis beginning at age 40 for women at average risk of breast cancer. In addition to traditional film-screen mammograms, digital mammograms now offer digital enhancement to aid interpretation, which is especially helpful in women with dense breast tissue. Useful emerging adjuncts to mammography include ultrasonography, which is particularly helpful for further assessment of known areas of interest, and magnetic resonance imaging, which shows promise for use in high-risk populations. Image-guided biopsy--directed by ultrasonograpy or stereotactic mammography views--plays a critical role in histologic confirmation of suspected breast cancer.     

乳腺黏液癌的影像学特征分析

目的 评价乳腺黏液癌的超声、X线等影像学特征及其与病理组织类型的相关性.方法 回顾性分析21例经手术病理证实的乳腺黏液癌患者(22个病灶)的超声、X线特征及与病理组织类型之间的关系.结果 病理组织学分类包括14个单纯型(6个富细胞型,8个少细胞型)和8个混合型病灶.超声:所有病例均存在实性肿块,85.71％(12/14)的单纯型肿块境界清晰,回声等或略低于皮下脂肪,92.86％(13/14)的单纯型病灶后方回声增强;75.00％(6/8)的混合型和14.29％(2/14)的单纯型肿块边界较模糊并细小毛刺,内部回声较脂肪回声低.超声和X线片术前怀疑恶性的比例均为63.64％(14/22).恶性X线表现包括肿块(10个)、局限性不对称致密影(2个)、结构扭曲并恶性钙化和单纯不定性钙化(各1个).肿块主要为高密度,单纯型边界清楚或呈浅分叶状,混合型边界不规则和毛刺改变.81.82％(18/22)的病灶被超声或X线之一疑诊恶性,45.45％(10/22)的病灶术前超声和X线均疑为恶性.结论 乳腺黏液癌尤其单纯型影像学特征不典型,超声和X线诊断均可能诊断为良性病变;肿块边缘特征是鉴别良恶性的重要依据,混合型肿块较单纯型更具有浸润性特征;超声和X线联合诊断有利于避免误诊,两者之一怀疑恶性时,即应行穿刺活检以明确诊断.     

Pacemaker Interference with Screening Mammography

In female pacemaker recipients undergoing screening mammography, the impact of a pulse generator placed in the pectoral region has yet to be reviewed. We evaluated mammograms from 74 female pacemaker patients aged 40 years and older. The pulse generator obscured a portion of the mammogram in 7 patients (12%). During pacemaker implantation in women, the potential for the pulse generator to interfere with screening mammography should be considered. Baseline mammography should be obtained or reviewed; in high risk patients a nonconventional location for the pulse generator may be appropriate.     

Registration and difference analysis of corresponding mammogram images

An automated technique is proposed for identifying differences between corresponding mammogram images. The technique recovers an approximate deformation between a pair of mammograms based on identifying corresponding features across the two images. The registration process is completed using an unwarping technique for transforming one image into the coordinate system of the other. A difference image is generated using intensity-weighted subtraction in order to identify regions of large difference. Evaluation of the technique is performed using 124 bilateral image pairs which contain a total of 77 abnormalities of different types. The purpose of this paper is to measure the extent to which the mammogram registration technique is able to provide useful information for identifying abnormalities in mammograms.     

Health beliefs, health locus of control, and women's mammography behavior

Research has shown that routine mammography screening can significantly reduce mortality from breast cancer. The use of mammography screening, however, remains well below national goals. In an effort to understand the factors that influence women's mammography behaviors, this study explored the relation between health beliefs, locus of control, and women's mammography practice. Survey instruments used were Champion's health belief scales and the Multidimensional Health Locus of Control (MHLC) scales. The study used a convenience sample of 25 African Americans and 72 white women ages 35 to 84. Findings showed that women who participated in mammography screening were significantly more likely to perceive greater benefits, greater health motivation, and fewer barriers to screening than those who did not participate. These same three variables were similarly associated with greater frequency of receiving mammograms. It also was found that perceived benefits and health motivation were significantly correlated with shorter duration of time since the last mammogram. No support was found for perceived susceptibility, perceived seriousness, and health locus of control as predictors of women's mammography behavior. Implications for nursing research in further examining the MHLC and the Health Belief Model construct of susceptibility as they relate to mammography behavior are identified. Practice implications for nurses are suggested.