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Sample records for mammographic imaging screening

  1. Journal club: molecular breast imaging at reduced radiation dose for supplemental screening in mammographically dense breasts.

    PubMed

    Rhodes, Deborah J; Hruska, Carrie B; Conners, Amy Lynn; Tortorelli, Cindy L; Maxwell, Robert W; Jones, Katie N; Toledano, Alicia Y; O'Connor, Michael K

    2015-02-01

    OBJECTIVE. The purpose of this study was to assess the diagnostic performance of supplemental screening molecular breast imaging (MBI) in women with mammographically dense breasts after system modifications to permit radiation dose reduction. SUBJECTS AND METHODS. A total of 1651 asymptomatic women with mammographically dense breasts on prior mammography underwent screening mammography and adjunct MBI performed with 300-MBq (99m)Tc-sestamibi and a direct-conversion (cadmium zinc telluride) gamma camera, both interpreted independently. The cancer detection rate, sensitivity, specificity, and positive predictive value of biopsies performed (PPV3) were determined. RESULTS. In 1585 participants with a complete reference standard, 21 were diagnosed with cancer: two detected by mammography only, 14 by MBI only, three by both modalities, and two by neither. Of 14 participants with cancers detected only by MBI, 11 had invasive disease (median size, 0.9 cm; range, 0.5-4.1 cm). Nine of 11 (82%) were node negative, and two had bilateral cancers. With the addition of MBI to mammography, the overall cancer detection rate (per 1000 screened) increased from 3.2 to 12.0 (p < 0.001) (supplemental yield 8.8). The invasive cancer detection rate increased from 1.9 to 8.8 (p < 0.001) (supplemental yield 6.9), a relative increase of 363%, while the change in DCIS detection was not statistically significant (from 1.3 to 3.2, p =0.250). For mammography alone, sensitivity was 24%; specificity, 89%; and PPV3, 25%. For the combination, sensitivity was 91% (p < 0.001); specificity, 83% (p < 0.001); and PPV3, 28% (p = 0.70). The recall rate increased from 11.0% with mammography alone to 17.6% (p < 0.001) for the combination; the biopsy rate increased from 1.3% for mammography alone to 4.2% (p < 0.001). CONCLUSION. When added to screening mammography, MBI performed using a radiopharmaceutical activity acceptable for screening (effective dose 2.4 mSv) yielded a supplemental cancer detection rate

  2. Molecular Breast Imaging at Reduced Radiation Dose for Supplemental Screening in Mammographically Dense Breasts

    PubMed Central

    Rhodes, Deborah J.; Hruska, Carrie B.; Conners, Amy Lynn; Tortorelli, Cindy L.; Maxwell, Robert W.; Jones, Katie N.; Toledano, Alicia Y.; O’Connor, Michael K.

    2015-01-01

    OBJECTIVE The purpose of this study was to assess the diagnostic performance of supplemental screening molecular breast imaging (MBI) in women with mammographically dense breasts after system modifications to permit radiation dose reduction. SUBJECTS AND METHODS A total of 1651 asymptomatic women with mammographically dense breasts on prior mammography underwent screening mammography and adjunct MBI performed with 300-MBq 99mTc-sestamibi and a direct-conversion (cadmium zinc telluride) gamma camera, both interpreted independently. The cancer detection rate, sensitivity, specificity, and positive predictive value of biopsies performed (PPV3) were determined. RESULTS In 1585 participants with a complete reference standard, 21 were diagnosed with cancer: two detected by mammography only, 14 by MBI only, three by both modalities, and two by neither. Of 14 participants with cancers detected only by MBI, 11 had invasive disease (median size, 0.9 cm; range, 0.5–4.1 cm). Nine of 11 (82%) were node negative, and two had bilateral cancers. With the addition of MBI to mammography, the overall cancer detection rate (per 1000 screened) increased from 3.2 to 12.0 (p < 0.001) (supplemental yield 8.8). The invasive cancer detection rate increased from 1.9 to 8.8 (p < 0.001) (supplemental yield 6.9), a relative increase of 363%, while the change in DCIS detection was not statistically significant (from 1.3 to 3.2, p =0.250). For mammography alone, sensitivity was 24%; specificity, 89%; and PPV3, 25%. For the combination, sensitivity was 91% (p < 0.001); specificity, 83% (p < 0.001); and PPV3, 28% (p = 0.70). The recall rate increased from 11.0% with mammography alone to 17.6% (p < 0.001) for the combination; the biopsy rate increased from 1.3% for mammography alone to 4.2% (p < 0.001). CONCLUSION When added to screening mammography, MBI performed using a radiopharmaceutical activity acceptable for screening (effective dose 2.4 mSv) yielded a supplemental cancer detection rate of

  3. A method for 3D electron density imaging using single scattered x-rays with application to mammographic screening

    NASA Astrophysics Data System (ADS)

    Van Uytven, Eric; Pistorius, Stephen; Gordon, Richard

    2008-10-01

    Screening mammography is the current standard in detecting breast cancer. However, its fundamental disadvantage is that it projects a 3D object into a 2D image. Small lesions are difficult to detect when superimposed over layers of normal, heterogeneous tissue. In this work, we examine the potential of single scattered photon electron density imaging in a mammographic environment. Simulating a low-energy (<20 keV) scanning pencil beam, we have developed an algorithm capable of producing 3D electron density images from a single projection. We have tested the algorithm by imaging parts of a simulated mammographic accreditation phantom containing lesions of various sizes. The results indicate that the group of imaged lesions differ significantly from background breast tissue (p < 0.005), confirming that electron density imaging may be a useful diagnostic test for the presence of breast cancer.

  4. 3D electron density imaging using single scattered x rays with application to breast CT and mammographic screening

    NASA Astrophysics Data System (ADS)

    van Uytven, Eric Peter

    Screening mammography is the current standard in detecting breast cancer. However, its fundamental disadvantage is that it projects a 3D object into a 2D image. Small lesions are difficult to detect when superimposed over layers of normal tissue. Commercial Computed Tomography (CT) produces a true 3D image yet has a limited role in mammography due to relatively low resolution and contrast. With the intent of enhancing mammography and breast CT, we have developed an algorithm which can produce 3D electron density images using a single projection. Imaging an object with x rays produces a characteristic scattered photon spectrum at the detector plane. A known incident beam spectrum, beam shape, and arbitrary 3D matrix of electron density values enable a theoretical scattered photon distribution to be calculated. An iterative minimization algorithm is used to make changes to the electron density voxel matrix to reduce regular differences between the theoretical and the experimentally measured distributions. The object is characterized by the converged electron density image. This technique has been validated in simulation using data produced by the EGSnrc Monte Carlo code system. At both mammographic and CT energies, a scanning polychromatic pencil beam was used to image breast tissue phantoms containing lesion-like inhomogeneities. The resulting Monte Carlo data is processed using a Nelder-Mead iterative algorithm (MATLAB) to produce the 3D matrix of electron density values. Resulting images have confirmed the ability of the algorithm to detect various 1x1x2.5 mm3 lesions with calcification content as low as 0.5% (p<0.005) at a dose comparable to mammography.

  5. Improved fracture detection using the mammographic film-screen combination

    PubMed Central

    Abdullah, BJJ; Ng, KH

    2005-01-01

    Aim The single emulsion or single screen system is usually reserved for mammography since its use in general radiography is limited. The purpose of this study is to compare the mammographic film-screen combination (MFC) and the standard film-screen combination (SFC) in terms of fracture and soft tissue injuries detection. Patients, methods and materials In this prospective study, 41 patients from Accident and Emergency suspected of having injury in the hands, wrists, ankles and feet regions were radiographed using both MFC and SFC. These were compared in terms of image quality, presence of fractures and soft tissue injuries. The two different film-screen combinations were also compared in terms of detection of bony fragments, film characteristics such as film speed, contrast and spatial resolution, dose and cost. Results The MFC gives statistically better image quality compared to SFC. In 10% of patients, fractures were detected only in the MFC, which also detects tiny bone fragments that may not be resolved by the SFC. The spatial resolution of the MFC is greater than the SFC. The film speed and contrast of the MFC are lower than that of the SFC. The doses of MFC were higher compared to SFC. Conclusions The MFC detects fractures better compared with SFC. However, the entrance skin dose for the mammographic film-screen combination was about 35% to 55% higher than the standard film-screen combination. PMID:21625275

  6. Diagnostic performance on briefly presented mammographic images

    NASA Astrophysics Data System (ADS)

    Mugglestone, Mark D.; Gale, Alastair G.; Cowley, Helen C.; Wilson, A. R. M.

    1995-04-01

    Previously an outline model of the radiological diagnostic process has been proposed which posits the importance of the initial glance at a medical image in helping to establish an appropriate diagnosis. As part of a long tern study of knowledge elicitation in mammography we examine the amount of information available to breast screening radiologists within the initial 'glance' at a mammogram. These data are compared to those from examining the same images normally. Overall, performance in a brief presentation was poorer than in normal viewing, as expected, but was also worse than found in comparable brief presentation studies using the chest radiograph. These results are discussed with regard to the inferences which can be made about the nature of mammographic knowledge which is utilized in the diagnostic process and how it is organized within the framework of a conceptual model.

  7. A new detection algorithm for microcalcification clusters in mammographic screening

    NASA Astrophysics Data System (ADS)

    Xie, Weiying; Ma, Yide; Li, Yunsong

    2015-05-01

    A novel approach for microcalcification clusters detection is proposed. At the first time, we make a short analysis of mammographic images with microcalcification lesions to confirm these lesions have much greater gray values than normal regions. After summarizing the specific feature of microcalcification clusters in mammographic screening, we make more focus on preprocessing step including eliminating the background, image enhancement and eliminating the pectoral muscle. In detail, Chan-Vese Model is used for eliminating background. Then, we do the application of combining morphology method and edge detection method. After the AND operation and Sobel filter, we use Hough Transform, it can be seen that the result have outperformed for eliminating the pectoral muscle which is approximately the gray of microcalcification. Additionally, the enhancement step is achieved by morphology. We make effort on mammographic image preprocessing to achieve lower computational complexity. As well known, it is difficult to robustly achieve mammograms analysis due to low contrast between normal and lesion tissues, there are also much noise in such images. After a serious preprocessing algorithm, a method based on blob detection is performed to microcalcification clusters according their specific features. The proposed algorithm has employed Laplace operator to improve Difference of Gaussians (DoG) function in terms of low contrast images. A preliminary evaluation of the proposed method performs on a known public database namely MIAS, rather than synthetic images. The comparison experiments and Cohen's kappa coefficients all demonstrate that our proposed approach can potentially obtain better microcalcification clusters detection results in terms of accuracy, sensitivity and specificity.

  8. Computerized measurement of mammographic display image quality

    NASA Astrophysics Data System (ADS)

    Chakraborty, Dev P.; Sivarudrappa, Mahesh; Roehrig, Hans

    1999-05-01

    Since the video monitor is widely believed to be the weak link in the imaging chain, it is critical, to include it in the total image quality evaluation. Yet, most physical measurements of mammographic image quality are presently limited to making measurements on the digital matrix, not the displayed image. A method is described to quantitatively measure image quality of mammographic monitors using ACR phantom-based test patterns. The image of the test pattern is digitized using a charge coupled device (CCD) camera, and the resulting image file is analyzed by an existing phantom analysis method (Computer Analysis of Mammography Phantom Images, CAMPI). The new method is called CCD-CAMPI and it yields the Signal-to-Noise-Ratio (SNR) for an arbitrary target shape (e.g., speck, mass or fiber). In this work we show the feasibility of this idea for speck targets. Also performed were physical image quality characterization of the monitor (so-called Fourier measures) and analysis by another template matching method due to Tapiovaara and Wagner (TW) which is closely related to CAMPI. The methods were applied to a MegaScan monitor. Test patterns containing a complete speck group superposed on a noiseless background were displayed on the monitor and a series of CCD images were acquired. These images were subjected to CCD-CAMPI and TW analyses. It was found that the SNR values for the CCD-CAMPI method tracked those of the TW method, although the latter measurements were considerably less precise. The TW SNR measure was also about 25% larger than the CCD-CAMPI determination. These differences could be understood from the manner in which the two methods evaluate the noise. Overall accuracy of the CAMPI SNR determination was 4.1% for single images when expressed as a coefficient of variance. While the SNR measures are predictable from the Fourier measures the number of images and effort required is prohibitive and it is not suited to Quality Control (QC). Unlike the Fourier

  9. Supplementary screening sonography in mammographically dense breast: pros and cons.

    PubMed

    Youk, Ji Hyun; Kim, Eun-Kyung

    2010-01-01

    Sonography is an attractive supplement to mammography in breast cancer screening because it is relatively inexpensive, requires no contrast-medium injection, is well tolerated by patients, and is widely available for equipment as compared with MRI. Sonography has been especially valuable for women with mammographically dense breast because it has consistently been able to detect a substantial number of cancers at an early stage. Despite these findings, breast sonography has known limitations as a screening tool; operator-dependence, the shortage of skilled operators, the inability to detect microcalcifications, and substantially higher false-positive rates than mammography. Further study of screening sonography is still ongoing and is expected to help establish the role of screening sonography. PMID:21076583

  10. Decision trees and integrated features for computer aided mammographic screening

    SciTech Connect

    Kegelmeyer, W.P. Jr.; Groshong, B.; Allmen, M.; Woods, K.

    1997-02-01

    Breast cancer is a serious problem, which in the United States causes 43,000 deaths a year, eventually striking 1 in 9 women. Early detection is the only effective countermeasure, and mass mammography screening is the only reliable means for early detection. Mass screening has many shortcomings which could be addressed by a computer-aided mammographic screening system. Accordingly, we have applied the pattern recognition methods developed in earlier investigations of speculated lesions in mammograms to the detection of microcalcifications and circumscribed masses, generating new, more rigorous and uniform methods for the detection of both those signs. We have also improved the pattern recognition methods themselves, through the development of a new approach to combinations of multiple classifiers.

  11. Mammographic screening for breast cancer. Overdiagnosis: an insidious adverse effect of screening.

    PubMed

    2015-07-01

    Mammographic mass screening for breast cancer sometimes detects tumours that would grow so slowly that the women concerned would die from other causes before developing noteworthy symptoms. This "overdiagnosis" unnecessarily exposes women to cancer treatments and their adverse effects. To assess the risk of overdiagnosis during mammographic mass screening for breast cancer, we conducted a review of the literature using the standard Prescrire methodology. The most reliable estimates of overdiagnosis are obtained by deduction, based on data from randomised trials with lengthy post-screening follow-up. A randomised trial in Sweden and two in Canada compared screening versus no screening, and monitored the women for an average of 15 and 17 years after the end of screening. For every 10 000 women who were screened, there were 63 cases of breast cancer overdiagnosis in the Swedish trial and 26 in the Canadian trials, representing about 25% of all cancers diagnosed by screening. This rate of overdiagnosis is probably on the low side, as about 20% of the women in the unscreened control groups had at least one mammogram. Studies of the general female population confirm that mammographic mass screening leads to overdiagnosis, but the results add little to those of randomised trials. In 2015, the most reliable estimate is that at least 25% of breast cancers detected by screening mammography are overdiagnosed. In France, at least 19 breast cancers would be overdiagnosed for every 1000 women screened during a 20-year period, corresponding to a total of about 3800 overdiagnosed cancers for each year of mass screening. Women must be informed of the risk of overdiagnosis and its consequences in terms of unnecessary treatment, along with other factors influencing the harm-benefit balance. See page 190 for our proposals on how to inform women wondering whether or not to undergo mammographic screening. PMID:26240891

  12. Texture Features from Mammographic Images and Risk of Breast Cancer

    PubMed Central

    Manduca, Armando; Carston, Michael J.; Heine, John J.; Scott, Christopher G.; Pankratz, V. Shane; Brandt, Kathy R.; Sellers, Thomas A.; Vachon, Celine M.; Cerhan, James R.

    2009-01-01

    Mammographic percent density (PD) is a strong risk factor for breast cancer, but there has been relatively little systematic evaluation of other features in mammographic images that might additionally predict breast cancer risk. We evaluated the association of a large number of image texture features with risk of breast cancer using a clinic-based case-control study of digitized film mammograms, all with screening mammograms prior to breast cancer diagnosis. The sample was split into training (123 cases, 258 controls) and validation (123 cases, 264 controls) datasets. Age and body mass index (BMI)-adjusted Odds Ratios (ORs) per standard deviation change in the feature, 95% confidence intervals, and the area under the receiver operator characteristic curve (AUC) were obtained using logistic regression. A bootstrap approach was used to identify the strongest features in the training dataset, and results for features that validated in the second half of the sample were reported using the full dataset. The mean age at mammography was 64.0 ± 10.2 years, and the mean time from mammography to breast cancer was 3.7 ± 1.0 (range 2.0-5.9 years). PD was associated with breast cancer risk (OR=1.49; 1.25-1.78). The strongest features that validated from each of several classes (Markovian, run-length, Laws, wavelet and Fourier) showed similar ORs as PD and predicted breast cancer at a similar magnitude (AUC=0.58-0.60) as PD (AUC=0.58). All of these features were automatically calculated (unlike PD), and measure texture at a coarse scale. These features were moderately correlated with PD (r = 0.39-0.64), and after adjustment for PD, each of the features attenuated only slightly and retained statistical significance. However, simultaneous inclusion of these features in a model with PD did not significantly improve the ability to predict breast cancer. PMID:19258482

  13. Mammographic breast density: effect on imaging and breast cancer risk.

    PubMed

    Pinsky, Renee W; Helvie, Mark A

    2010-10-01

    Mammographic breast density has been studied for more than 30 years. Greater breast density not only is related to decreased sensitivity of mammograms because of a masking effect but also is a major independent risk factor for breast cancer. This article defines breast density and reviews literature on quantification of mammographic density that is key to future clinical and research protocols. Important influences on breast density are addressed, including age, menopausal status, exogenous hormones, and genetics of density. Young women with dense breasts benefit from digital mammographic technique. The potential use of supplemental MRI and ultrasound screening techniques in high-risk women and women with dense breasts is explored, as are potential risk reduction strategies. PMID:20971840

  14. Automated assessment of bilateral breast volume asymmetry as a breast cancer biomarker during mammographic screening

    SciTech Connect

    Williams, Alex C; Hitt, Austin N; Voisin, Sophie; Tourassi, Georgia

    2013-01-01

    The biological concept of bilateral symmetry as a marker of developmental stability and good health is well established. Although most individuals deviate slightly from perfect symmetry, humans are essentially considered bilaterally symmetrical. Consequently, increased fluctuating asymmetry of paired structures could be an indicator of disease. There are several published studies linking bilateral breast size asymmetry with increased breast cancer risk. These studies were based on radiologists manual measurements of breast size from mammographic images. We aim to develop a computerized technique to assess fluctuating breast volume asymmetry in screening mammograms and investigate whether it correlates with the presence of breast cancer. Using a large database of screening mammograms with known ground truth we applied automated breast region segmentation and automated breast size measurements in CC and MLO views using three well established methods. All three methods confirmed that indeed patients with breast cancer have statistically significantly higher fluctuating asymmetry of their breast volumes. However, statistically significant difference between patients with cancer and benign lesions was observed only for the MLO views. The study suggests that automated assessment of global bilateral asymmetry could serve as a breast cancer risk biomarker for women undergoing mammographic screening. Such biomarker could be used to alert radiologists or computer-assisted detection (CAD) systems to exercise increased vigilance if higher than normal cancer risk is suspected.

  15. Automated assessment of bilateral breast volume asymmetry as a breast cancer biomarker during mammographic screening

    NASA Astrophysics Data System (ADS)

    Williams, Alex C.; Hitt, Austin; Voisin, Sophie; Tourassi, Georgia

    2013-03-01

    The biological concept of bilateral symmetry as a marker of developmental stability and good health is well established. Although most individuals deviate slightly from perfect symmetry, humans are essentially considered bilaterally symmetrical. Consequently, increased fluctuating asymmetry of paired structures could be an indicator of disease. There are several published studies linking bilateral breast size asymmetry with increased breast cancer risk. These studies were based on radiologists' manual measurements of breast size from mammographic images. We aim to develop a computerized technique to assess fluctuating breast volume asymmetry in screening mammograms and investigate whether it correlates with the presence of breast cancer. Using a large database of screening mammograms with known ground truth we applied automated breast region segmentation and automated breast size measurements in CC and MLO views using three well established methods. All three methods confirmed that indeed patients with breast cancer have statistically significantly higher fluctuating asymmetry of their breast volumes. However, statistically significant difference between patients with cancer and benign lesions was observed only for the MLO views. The study suggests that automated assessment of global bilateral asymmetry could serve as a breast cancer risk biomarker for women undergoing mammographic screening. Such biomarker could be used to alert radiologists or computer-assisted detection (CAD) systems to exercise increased vigilance if higher than normal cancer risk is suspected.

  16. [Sensitometry of Mammographic Screen-film System Using Bootstrap Aluminum Step-Wedge.].

    PubMed

    Abe, Shinji; Imada, Ryou; Terauchi, Takashi; Fujisaki, Tatsuya; Monma, Masahiko; Nishimura, Katsuyuki; Saitoh, Hidetoshi; Mochizuki, Yasuo

    2005-01-01

    Recently, a few types of step-wedges for bootstrap sensitometry with a mammographic screen-film system have been proposed. In this study, the bootstrap sensitometry with the mammographic screen-film system was studied for two types of aluminum step-wedges. Characteristic X-ray energy curves were determined using mammographic and general radiographic aluminum step-wedges devised to prevent scattered X-rays generated from one step penetrating into the region of another one, and dependence of the characteristic curves on the wedges was also discussed. No difference was found in the characteristic curves due to the difference in the step-wedges for mammography and general radiography although there was a slight difference in shape at the shoulder portion for the two types of step-wedges. Therefore, it was concluded that aluminum step-wedges for mammography and general radiography could be employed in bootstrap sensitometry with the mammographic screen-film system. PMID:16479054

  17. The relative effect of mammographic screening on breast cancer mortality by socioeconomic status

    PubMed Central

    Ripping, Theodora M.; van der Waal, Danielle; Verbeek, André L.M.; Broeders, Mireille J.M.

    2016-01-01

    Abstract Breast cancer incidence and mortality are higher in women with a high socioeconomic status (SES). The potential to prevent death from breast cancer is therefore greater in the high SES group. This does, however, require that the effectiveness of screening in the high SES group is equal to or greater than the effectiveness in the low SES group. The aim of this study is to assess the relative effectiveness of mammographic screening on breast cancer mortality by SES. In Nijmegen, the Netherlands, women are invited to participate in biennial mammographic screening since 1975. Postal code is collected at each round and is used to calculate the SES of each woman based on the SES indicator of the Netherlands Institute for Social Research. The Dutch average was used to classify the SES score of each woman as either high or low. We designed a case-control study to investigate the effect of mammographic screening in women aged 50 to 75, 40 to 75, and 50 to 69 years, and calculated the odds ratios (ORs) and 95% confidence intervals (CIs). Among the women invited to the mammographic screening program in Nijmegen, 10% had a high SES. In women aged 50 to 75 years, the breast cancer death rate was 38% lower in screened women than in unscreened women. The ORs for women with high SES (OR 0.82, 95% CI 0.31–2.19) and low SES did not differ significantly (OR 0.61, 95% CI 0.47–0.78). Mammographic screening reduces breast cancer mortality, but we did not observe a significant difference in the relative effectiveness of screening by SES. If the effectiveness of mammographic screening is indeed not dependent on SES status, the absolute number of breast cancer deaths prevented by mammographic screening will be greater in the high SES than low SES group, because women with a high SES have a greater risk of breast cancer death. PMID:27495038

  18. Breast MR Imaging for Equivocal Mammographic Findings: Help or Hindrance?

    PubMed

    Giess, Catherine S; Chikarmane, Sona A; Sippo, Dorothy A; Birdwell, Robyn L

    2016-01-01

    Breast magnetic resonance (MR) imaging, because of its extremely high sensitivity in detecting invasive breast cancers, is sometimes used as a diagnostic tool to evaluate equivocal mammographic findings. However, breast MR imaging should never substitute for a complete diagnostic evaluation or for biopsy of suspected, localizable suspicious mammographic lesions, whenever possible. The modality's high cost, in addition to only moderate specificity, mandate that radiologists use it sparingly and with discrimination for problematic mammographic findings. It is rare that the reality or significance of a noncalcified mammographic finding remains equivocal or problematic at diagnostic mammography evaluation, which usually includes targeted ultrasonography (US). There are several reasons for this infrequent occurrence: (a) an asymmetry may persist on diagnostic views but be visible only on craniocaudal or mediolateral oblique projections, precluding three-dimensional localization for US or biopsy, or a lesion may persist on some diagnostic spot views but dissipate or efface on others; (b) uncertainty may exist as to whether apparent change is clinically important or owing to technical factors such as compression or positioning differences; or (c) a lesion may be suspected but biopsy options are limited owing to lack of a US correlate and lesion inaccessibility for stereotactic biopsy, or biopsy of a vague or questionably real lesion has been attempted unsuccessfully. This article will discuss the indications for problem-solving MR imaging for equivocal mammographic findings, present cases illustrating appropriate and inappropriate uses of problem-solving MR imaging, and present false-positive and false-negative cases affecting the specificity of breast MR imaging. (©)RSNA, 2016. PMID:27284757

  19. Artificial-neural-network-based classification of mammographic microcalcifications using image structure features

    NASA Astrophysics Data System (ADS)

    Dhawan, Atam P.; Chitre, Yateen S.; Moskowitz, Myron

    1993-07-01

    Mammography associated with clinical breast examination and self-breast examination is the only effective and viable method for mass breast screening. It is however, difficult to distinguish between benign and malignant microcalcifications associated with breast cancer. Most of the techniques used in the computerized analysis of mammographic microcalcifications segment the digitized gray-level image into regions representing microcalcifications. We present a second-order gray-level histogram based feature extraction approach to extract microcalcification features. These features, called image structure features, are computed from the second-order gray-level histogram statistics, and do not require segmentation of the original image into binary regions. Several image structure features were computed for 100 cases of `difficult to diagnose' microcalcification cases with known biopsy results. These features were analyzed in a correlation study which provided a set of five best image structure features. A feedforward backpropagation neural network was used to classify mammographic microcalcifications using the image structure features. The network was trained on 10 cases of mammographic microcalcifications and tested on additional 85 `difficult-to-diagnose' microcalcifications cases using the selected image structure features. The trained network yielded good results for classification of `difficult-to- diagnose' microcalcifications into benign and malignant categories.

  20. Mammographic breast density: impact on breast cancer risk and implications for screening.

    PubMed

    Freer, Phoebe E

    2015-01-01

    Mammographic breast density is rapidly becoming a hot topic in both the medical literature and the lay press. In the United States, recent legislative changes in 19 states now require radiologists to notify patients regarding breast density as well as the possible need for supplemental screening. Federal legislation regarding breast density notification has been introduced, and its passage is likely on the horizon. An understanding of the context, scientific evidence, and controversies surrounding the topic of breast density as a risk factor for breast cancer is critical for radiologists. The current state of evidence is presented regarding supplemental screening for women with dense breasts, including the use of digital breast tomosynthesis, whole-breast ultrasonography, and gadolinium-enhanced magnetic resonance imaging. A review of current practice guidelines and additional sources of information will improve radiologists' understanding of the relevant subject of breast density and enable them to respond appropriately to questions from patients, clinicians, and the media. PMID:25763718

  1. PRONET services for distance learning in mammographic image processing.

    PubMed

    Costaridou, L; Panayiotakis, G; Efstratiou, C; Sakellaropoulos, P; Cavouras, D; Kalogeropoulou, C; Varaki, K; Giannakou, L; Dimopoulos, J

    1997-01-01

    The potential of telematics services is investigated with respect to learning needs of medical physicists and biomedical engineers. Telematics services are integrated into a system, the PRONET, which evolves around multimedia computer based courses and distance tutoring support. In addition, information database access and special interest group support are offered. System architecture is based on a component integration approach. The services are delivered in three modes: LAN, ISDN and Internet. Mammographic image processing is selected as an example content area. PMID:10179585

  2. Association of mammographic image feature change and an increasing risk trend of developing breast cancer: an assessment

    NASA Astrophysics Data System (ADS)

    Tan, Maxine; Leader, Joseph K.; Liu, Hong; Zheng, Bin

    2015-03-01

    We recently investigated a new mammographic image feature based risk factor to predict near-term breast cancer risk after a woman has a negative mammographic screening. We hypothesized that unlike the conventional epidemiology-based long-term (or lifetime) risk factors, the mammographic image feature based risk factor value will increase as the time lag between the negative and positive mammography screening decreases. The purpose of this study is to test this hypothesis. From a large and diverse full-field digital mammography (FFDM) image database with 1278 cases, we collected all available sequential FFDM examinations for each case including the "current" and 1 to 3 most recently "prior" examinations. All "prior" examinations were interpreted negative, and "current" ones were either malignant or recalled negative/benign. We computed 92 global mammographic texture and density based features, and included three clinical risk factors (woman's age, family history and subjective breast density BIRADS ratings). On this initial feature set, we applied a fast and accurate Sequential Forward Floating Selection (SFFS) feature selection algorithm to reduce feature dimensionality. The features computed on both mammographic views were individually/ separately trained using two artificial neural network (ANN) classifiers. The classification scores of the two ANNs were then merged with a sequential ANN. The results show that the maximum adjusted odds ratios were 5.59, 7.98, and 15.77 for using the 3rd, 2nd, and 1st "prior" FFDM examinations, respectively, which demonstrates a higher association of mammographic image feature change and an increasing risk trend of developing breast cancer in the near-term after a negative screening.

  3. Reduction of false-positive recalls using a computerized mammographic image feature analysis scheme

    NASA Astrophysics Data System (ADS)

    Tan, Maxine; Pu, Jiantao; Zheng, Bin

    2014-08-01

    The high false-positive recall rate is one of the major dilemmas that significantly reduce the efficacy of screening mammography, which harms a large fraction of women and increases healthcare cost. This study aims to investigate the feasibility of helping reduce false-positive recalls by developing a new computer-aided diagnosis (CAD) scheme based on the analysis of global mammographic texture and density features computed from four-view images. Our database includes full-field digital mammography (FFDM) images acquired from 1052 recalled women (669 positive for cancer and 383 benign). Each case has four images: two craniocaudal (CC) and two mediolateral oblique (MLO) views. Our CAD scheme first computed global texture features related to the mammographic density distribution on the segmented breast regions of four images. Second, the computed features were given to two artificial neural network (ANN) classifiers that were separately trained and tested in a ten-fold cross-validation scheme on CC and MLO view images, respectively. Finally, two ANN classification scores were combined using a new adaptive scoring fusion method that automatically determined the optimal weights to assign to both views. CAD performance was tested using the area under a receiver operating characteristic curve (AUC). The AUC = 0.793  ±  0.026 was obtained for this four-view CAD scheme, which was significantly higher at the 5% significance level than the AUCs achieved when using only CC (p = 0.025) or MLO (p = 0.0004) view images, respectively. This study demonstrates that a quantitative assessment of global mammographic image texture and density features could provide useful and/or supplementary information to classify between malignant and benign cases among the recalled cases, which may eventually help reduce the false-positive recall rate in screening mammography.

  4. Computerized quantitative evaluation of mammographic accreditation phantom images

    SciTech Connect

    Lee, Yongbum; Tsai, Du-Yih; Shinohara, Norimitsu

    2010-12-15

    Purpose: The objective was to develop and investigate an automated scoring scheme of the American College of Radiology (ACR) mammographic accreditation phantom (RMI 156, Middleton, WI) images. Methods: The developed method consisted of background subtraction, determination of region of interest, classification of fiber and mass objects by Mahalanobis distance, detection of specks by template matching, and rule-based scoring. Fifty-one phantom images were collected from 51 facilities for this study (one facility provided one image). A medical physicist and two radiologic technologists also scored the images. The human and computerized scores were compared. Results: In terms of meeting the ACR's criteria, the accuracies of the developed method for computerized evaluation of fiber, mass, and speck were 90%, 80%, and 98%, respectively. Contingency table analysis revealed significant association between observer and computer scores for microcalcifications (p<5%) but not for masses and fibers. Conclusions: The developed method may achieve a stable assessment of visibility for test objects in mammographic accreditation phantom image in whether the phantom image meets the ACR's criteria in the evaluation test, although there is room left for improvement in the approach for fiber and mass objects.

  5. Feature extraction from mammographic images using fast marching methods

    NASA Astrophysics Data System (ADS)

    Bottigli, U.; Golosio, B.

    2002-07-01

    Features extraction from medical images represents a fundamental step for shape recognition and diagnostic support. The present work faces the problem of the detection of large features, such as massive lesions and organ contours, from mammographic images. The regions of interest are often characterized by an average grayness intensity that is different from the surrounding. In most cases, however, the desired features cannot be extracted by simple gray level thresholding, because of image noise and non-uniform density of the surrounding tissue. In this work, edge detection is achieved through the fast marching method (Level Set Methods and Fast Marching Methods, Cambridge University Press, Cambridge, 1999), which is based on the theory of interface evolution. Starting from a seed point in the shape of interest, a front is generated which evolves according to an appropriate speed function. Such function is expressed in terms of geometric properties of the evolving interface and of image properties, and should become zero when the front reaches the desired boundary. Some examples of application of such method to mammographic images from the CALMA database (Nucl. Instr. and Meth. A 460 (2001) 107) are presented here and discussed.

  6. Computerized scheme for evaluating mammographic phantom images

    SciTech Connect

    Asahara, Masaki; Kodera, Yoshie

    2012-03-15

    Purpose: The authors developed a computer algorithm to automatically evaluate images of the American College of Radiology (ACR) mammography accreditation phantom. Methods: The developed algorithm consist of the edge detection of wax insert, nonuniformity correction of background, and correction for magnification and also calculate the cross-correlation coefficient by image matching technique. The algorithm additionally evaluates target shape for fibers, target contrast for speck groups, and target circularity for masses. To obtain an ideal template image without noise and spatial resolution loss, the wax insert containing the embedded test pattern was extracted from the phantom and radiographed. Two template images and ten test phantom images were prepared for this study. The results of evaluation using the algorithm outputs were compared with the averaged results of observer studies by six skilled observers. Results: In comparing the results from the algorithm outputs with the results of observers, the authors found that the computer outputs were well correlated with the evaluations by observers, and they indicate the quality of the phantom image. The correlation coefficients between results of observer studies and two outputs of computer algorithm, i.e., the cross-correlation coefficient by template matching and indices of target shape for fibers, were 0.89 (95% confidence interval, 0.82-0.93; hereinafter the same) and 0.85 (0.76-0.91). The correlation coefficients between observer's results and two outputs: the cross-correlation coefficient and indices of target contrast for speck groups, were 0.83 (0.79-0.86) and 0.85 (0.81-0.88) and between observer's results and two outputs: the cross-correlation coefficient and indices of target circularity for masses, were 0.90 (0.84-0.94) and 0.87 (0.77-0.92). Conclusions: Image evaluation using the ACR phantom is indispensable in quality control of a mammography system. The proposed algorithm is useful for quality control

  7. Computer-aided diagnosis of mammographic masses using scalable image retrieval.

    PubMed

    Jiang, Menglin; Zhang, Shaoting; Li, Hongsheng; Metaxas, Dimitris N

    2015-02-01

    Computer-aided diagnosis of masses in mammograms is important to the prevention of breast cancer. Many approaches tackle this problem through content-based image retrieval techniques. However, most of them fall short of scalability in the retrieval stage, and their diagnostic accuracy is, therefore, restricted. To overcome this drawback, we propose a scalable method for retrieval and diagnosis of mammographic masses. Specifically, for a query mammographic region of interest (ROI), scale-invariant feature transform (SIFT) features are extracted and searched in a vocabulary tree, which stores all the quantized features of previously diagnosed mammographic ROIs. In addition, to fully exert the discriminative power of SIFT features, contextual information in the vocabulary tree is employed to refine the weights of tree nodes. The retrieved ROIs are then used to determine whether the query ROI contains a mass. The presented method has excellent scalability due to the low spatial-temporal cost of vocabulary tree. Extensive experiments are conducted on a large dataset of 11 553 ROIs extracted from the digital database for screening mammography, which demonstrate the accuracy and scalability of our approach. PMID:25361497

  8. Mass Detection in Mammographic Images Using Wavelet Processing and Adaptive Threshold Technique.

    PubMed

    Vikhe, P S; Thool, V R

    2016-04-01

    Detection of mass in mammogram for early diagnosis of breast cancer is a significant assignment in the reduction of the mortality rate. However, in some cases, screening of mass is difficult task for radiologist, due to variation in contrast, fuzzy edges and noisy mammograms. Masses and micro-calcifications are the distinctive signs for diagnosis of breast cancer. This paper presents, a method for mass enhancement using piecewise linear operator in combination with wavelet processing from mammographic images. The method includes, artifact suppression and pectoral muscle removal based on morphological operations. Finally, mass segmentation for detection using adaptive threshold technique is carried out to separate the mass from background. The proposed method has been tested on 130 (45 + 85) images with 90.9 and 91 % True Positive Fraction (TPF) at 2.35 and 2.1 average False Positive Per Image(FP/I) from two different databases, namely Mammographic Image Analysis Society (MIAS) and Digital Database for Screening Mammography (DDSM). The obtained results show that, the proposed technique gives improved diagnosis in the early breast cancer detection. PMID:26811073

  9. Characterizing mammographic images by using generic texture features

    PubMed Central

    2012-01-01

    Introduction Although mammographic density is an established risk factor for breast cancer, its use is limited in clinical practice because of a lack of automated and standardized measurement methods. The aims of this study were to evaluate a variety of automated texture features in mammograms as risk factors for breast cancer and to compare them with the percentage mammographic density (PMD) by using a case-control study design. Methods A case-control study including 864 cases and 418 controls was analyzed automatically. Four hundred seventy features were explored as possible risk factors for breast cancer. These included statistical features, moment-based features, spectral-energy features, and form-based features. An elaborate variable selection process using logistic regression analyses was performed to identify those features that were associated with case-control status. In addition, PMD was assessed and included in the regression model. Results Of the 470 image-analysis features explored, 46 remained in the final logistic regression model. An area under the curve of 0.79, with an odds ratio per standard deviation change of 2.88 (95% CI, 2.28 to 3.65), was obtained with validation data. Adding the PMD did not improve the final model. Conclusions Using texture features to predict the risk of breast cancer appears feasible. PMD did not show any additional value in this study. With regard to the features assessed, most of the analysis tools appeared to reflect mammographic density, although some features did not correlate with PMD. It remains to be investigated in larger case-control studies whether these features can contribute to increased prediction accuracy. PMID:22490545

  10. [Clinical and mammographic screening in a district of Milan: organization, social influence and results].

    PubMed

    Pravettoni, A; Cescon, S; Moro, G; Verga, M; Saibene, F; Micheli, A

    1993-12-01

    A reduction in the mortality rate for breast cancer in women over 50 years undergoing mammographic screening has been reported in many studies. Since the first experience in Florence in 1970, mammographic screenings on a population from different areas of Italy began. We report the experience carried out in the 16th District of Milan among women from 50 to 60 years of age. A promotional activity with the use of local media supported the program. The screening was based on two-view conventional mammography and clinical examination. Immediate response was given to the women. The compliance was 60%. Mainly immigrants, with only primary school education, mothers of several children and freelancers seem to be the main features of the women in the non-attenders group. PMID:7957707

  11. What information should be given to women invited for mammographic screening for breast cancer?

    PubMed

    Duffy, Stephen W; Tabar, Laszlo; Chen, Tony Hh; Yen, Amy Mf; Dean, Peter B; Smith, Robert A

    2006-11-01

    Mammography is the only proven frontline screening method for breast cancer. Following the demonstration of a reduction in breast cancer mortality with mammography, population mammographic screening services have been instituted, and there has been discussion in the medical literature of how to convey the pros and cons of screening to invited women. Much of the discussion has focused on the negative aspects of screening, such as false-positive and negative screens, overdiagnosis and anxiety. Also, some commentators have advocated rather cumbersome amounts of quantitative information. In this article we review the original evidence on the positive and negative aspects of screening, and show that the latter may have been exaggerated in the past. We suggest a few simple and clear points that should be made to the invited women, summarizing the positive and negative aspects without a mass of confusing statistics. PMID:19804001

  12. Mammographic and clinical characteristics of different phenotypes of screen-detected and interval breast cancers in a nationwide screening program.

    PubMed

    Baré, Marisa; Torà, Núria; Salas, Dolores; Sentís, Melchor; Ferrer, Joana; Ibáñez, Josefa; Zubizarreta, Raquel; Sarriugarte, Garbiñe; Barata, Teresa; Domingo, Laia; Castells, Xavier; Sala, Maria

    2015-11-01

    In the context of a population-based screening program, we aimed to evaluate the major mammographic features and clinicopathological characteristics of breast tumors at diagnosis and the associations between them, focusing on tumors with the worst prognosis. We analyzed cancers diagnosed in a cohort of 645,764 women aged 45-69 years participating in seven population-based screening programs in Spain, between January 1, 2000 and December 31, 2006 and followed up until June 2009. We included all interval cancers and a sample of screen-detected cancers, whether invasive or in situ. We compared tumor-related information and breast density for different phenotypes (Triple-negative (TN), HER2+, Luminal B and Luminal A) in screen-detected and interval cancers. We used Chi-square or Fisher's exact test to compare major mammographic features of invasive versus in situ tumors, of screen-detected versus interval cancers, and of different types of interval cancers. We included 2582 tumors (1570 screen-detected and 1012 interval cancers). There were significant differences in the distribution of most clinicopathological variables between screen-detected and interval cancers. Invasive TN interval tumors were more common than other phenotypes in breasts with low mammographic density; three-quarters of these tumors presented as masses without associated calcifications. HER2+ tumors were more common in denser breasts and were associated with calcifications and multifocality. Architectural distortion was more common in Luminal A and Luminal B tumors. Certain radiologic findings are associated with pre-invasive lesions; these differ among invasive tumor phenotypes. We corroborate that TN and HER2+ cancers have distinctive appearances also in the context of population-based screening programs. This information can be useful for establishing protocols for diagnostic strategies in screening units. PMID:26531756

  13. Spectral analysis of mammographic images using a multitaper method

    SciTech Connect

    Wu Gang; Mainprize, James G.; Yaffe, Martin J.

    2012-02-15

    Purpose: Power spectral analysis in radiographic images is conventionally performed using a windowed overlapping averaging periodogram. This study describes an alternative approach using a multitaper technique and compares its performance with that of the standard method. This tool will be valuable in power spectrum estimation of images, whose content deviates significantly from uniform white noise. The performance of the multitaper approach will be evaluated in terms of spectral stability, variance reduction, bias, and frequency precision. The ultimate goal is the development of a useful tool for image quality assurance. Methods: A multitaper approach uses successive data windows of increasing order. This mitigates spectral leakage allowing one to calculate a reduced-variance power spectrum. The multitaper approach will be compared with the conventional power spectrum method in several typical situations, including the noise power spectra (NPS) measurements of simulated projection images of a uniform phantom, NPS measurement of real detector images of a uniform phantom for two clinical digital mammography systems, and the estimation of the anatomic noise in mammographic images (simulated images and clinical mammograms). Results: Examination of spectrum variance versus frequency resolution and bias indicates that the multitaper approach is superior to the conventional single taper methods in the prevention of spectrum leakage and variance reduction. More than four times finer frequency precision can be achieved with equivalent or less variance and bias. Conclusions: Without any shortening of the image data length, the bias is smaller and the frequency resolution is higher with the multitaper method, and the need to compromise in the choice of regions of interest size to balance between the reduction of variance and the loss of frequency resolution is largely eliminated.

  14. Monochromatic Mammographic Imaging Using X-Ray Polycapillary Optics

    NASA Astrophysics Data System (ADS)

    Sugiro, Francisca

    2002-06-01

    Monochromatic imaging is typically done with synchrotron sources. These sources are expensive and not practical for clinical settings. However, conventional laboratory sources normally have insufficient intensity. Polycapillary x-ray optics can be used to efficiently produce an intense parallel beam, which can be diffracted from a crystal to create monochromatic radiation. Monochromatic parallel beam imaging produces high subject contrast, high resolution, and low patient dose. Contrast, resolution, and intensity measurements were performed with both high and low angular acceptance crystals. Testing was first done at 8 keV with an intense copper rotating anode source. Preliminary l7.5 kev measurements were then made with a molybdenum source. At 8 keV, contrast enhancement was a factor of five relative to the polychromatic case, in good agreement with theoretical values. At l7.5 kev, monochromatic subject contrast was a factor of two times greater than the conventional polychromatic contrast. The measured angular resolution with a silicon crystal is 0.6 mrad at 8 keV, and 0.2 - 0.3 mrad at 17.5 keV. For a 50-mm thick patient, this angle corresponds to 50 lp/mm with an ideal detector. The use of polychromatic collimating optics allow monochromatic mammographic imaging measurements with a conventional x-ray source in a practical clinical setting.

  15. System performance of a prototype flat-panel imager operated under mammographic conditions.

    PubMed

    Jee, Kyung-Wook; Antonuk, Larry E; El-Mohri, Youcef; Zhao, Qihua

    2003-07-01

    The results of an empirical and theoretical investigation of the performance of a high-resolution, active matrix flat-panel imager performed under mammographic conditions are reported. The imager is based upon a prototype, indirect detection active matrix array incorporating a discrete photodiode in each pixel and a pixel-to-pixel pitch of 97 microm. The investigation involved three imager configurations corresponding to the use of three different x-ray converters with the array. The converters were a conventional Gd2O2S-based mammographic phosphor screen (Min-R) and two structured CsI:Tl scintillators: one optimized for high spatial resolution (FOS-HR) and the other for high light output (FOS-HL). Detective quantum efficiency for mammographic exposures ranging from approximately 2 to approximately 40 mR at 26 kVp were determined for each imager configuration through measurements of x-ray sensitivity, modulation transfer function (MTF), and noise power spectrum (NPS). All configurations were found to provide significant presampling MTF at frequencies beyond the Nyquist frequency of the array, approximately 5.2 mm(-1) , consistent with the high spatial resolution of the converters. In addition, the effect of additive electronic noise on the NPS was found to be significantly larger for the configuration with lower system gain (FOS-HR) than for the configurations with higher gain (Min-R, FOS-HL). The maximum DQE values obtained with the CsI:Tl scintillators were considerably greater than those obtained with the Min-R screen due to the significantly lower Swank noise of the scintillators. Moreover, DQE performance was found to degrade with decreasing exposure, although this exposure-dependence was considerably reduced for the higher gain configurations. Theoretical calculations based on the cascaded systems model were found to be in generally good agreement with these empirically determined NPS and DQE values. In this study, we provide an example of how cascaded

  16. Time-frequency analysis of functional optical mammographic images

    NASA Astrophysics Data System (ADS)

    Barbour, Randall L.; Graber, Harry L.; Schmitz, Christoph H.; Tarantini, Frank; Khoury, Georges; Naar, David J.; Panetta, Thomas F.; Lewis, Theophilus; Pei, Yaling

    2003-07-01

    We have introduced working technology that provides for time-series imaging of the hemoglobin signal in large tissue structures. In this study we have explored our ability to detect aberrant time-frequency responses of breast vasculature for subjects with Stage II breast cancer at rest and in response to simple provocations. The hypothesis being explored is that time-series imaging will be sensitive to the known structural and functional malformations of the tumor vasculature. Mammographic studies were conducted using an adjustable hemisheric measuring head containing 21 source and 21 detector locations (441 source-detector pairs). Simultaneous dual-wavelength studies were performed at 760 and 830 nm at a framing rate of ~2.7 Hz. Optical measures were performed on women lying prone with the breast hanging in a pendant position. Two class of measures were performed: (1) 20- minute baseline measure wherein the subject was at rest; (2) provocation studies wherein the subject was asked to perform some simple breathing maneuvers. Collected data were analyzed to identify the time-frequency structure and central tendencies of the detector responses and those of the image time series. Imaging data were generated using the Normalized Difference Method (Pei et al., Appl. Opt. 40, 5755-5769, 2001). Results obtained clearly document three classes of anomalies when compared to the normal contralateral breast. 1) Breast tumors exhibit altered oxygen supply/demand imbalance in response to an oxidative challenge (breath hold). 2) The vasomotor response of the tumor vasculature is mainly depressed and exhibits an altered modulation. 3) The affected area of the breast wherein the altered vasomotor signature is seen extends well beyond the limits of the tumor itself.

  17. Online mammographic images database for development and comparison of CAD schemes.

    PubMed

    Matheus, Bruno Roberto Nepomuceno; Schiabel, Homero

    2011-06-01

    Considering the difficulties in finding good-quality images for the development and test of computer-aided diagnosis (CAD), this paper presents a public online mammographic images database free for all interested viewers and aimed to help develop and evaluate CAD schemes. The digitalization of the mammographic images is made with suitable contrast and spatial resolution for processing purposes. The broad recuperation system allows the user to search for different images, exams, or patient characteristics. Comparison with other databases currently available has shown that the presented database has a sufficient number of images, is of high quality, and is the only one to include a functional search system. PMID:20480383

  18. A Comparison of the effectiveness of Mammographic Film-Screen and Standard Film-Screen in the Detection of Small Bone Fractures

    PubMed Central

    Sani, Karim Ghazikhanlou; Jafari, Mahmoodreza; Rostampoor, Nima

    2011-01-01

    The use of mammography film-screen is limited in general radiography. The purpose of this study was to compare the effectiveness of mammographic film-screen and standard film-screen systems in the detection of small bone fractures. Radiographs were taken from patients' extremities and neck areas using mammography film-screen and standard film-screen (n=57 each). Fourteen other radiographs were taken from other views (predominantly oblique views), making a total number of 128 radiographs. Paired radiographs, taken from the same areas, were compared by two radiologists in terms of image visual sharpness, presence of bony fractures, and soft tissue injuries. The surface dose received by patients in the two systems was also compared. The radiographs taken by mammography film-screen had a statistically better visual sharpness compared to those taken by the standard film-screen system. However, there was no statistically significant difference between the diagnostic accuracy of the two systems. Mammography film-screen was able to detect only one out of 57 lesions, whereas standard film-screen system did not detec any lesion. The surface dose received by patients in mammography film-screen was higher than that in standard film-screen system. The findings of the present study suggest that mammography film-screen may be recommended as a diagnostic tool for the detection of small fractures of tinny parts of body such as fingers, hand or foot. They also suggest that mammography film-screen has no advantage over standard film-screen for radiography of thick body parts such as neck and knee. PMID:23115417

  19. Mammographic quantitative image analysis and biologic image composition for breast lesion characterization and classification

    SciTech Connect

    Drukker, Karen Giger, Maryellen L.; Li, Hui; Duewer, Fred; Malkov, Serghei; Joe, Bonnie; Kerlikowske, Karla; Shepherd, John A.; Flowers, Chris I.; Drukteinis, Jennifer S.

    2014-03-15

    Purpose: To investigate whether biologic image composition of mammographic lesions can improve upon existing mammographic quantitative image analysis (QIA) in estimating the probability of malignancy. Methods: The study population consisted of 45 breast lesions imaged with dual-energy mammography prior to breast biopsy with final diagnosis resulting in 10 invasive ductal carcinomas, 5 ductal carcinomain situ, 11 fibroadenomas, and 19 other benign diagnoses. Analysis was threefold: (1) The raw low-energy mammographic images were analyzed with an established in-house QIA method, “QIA alone,” (2) the three-compartment breast (3CB) composition measure—derived from the dual-energy mammography—of water, lipid, and protein thickness were assessed, “3CB alone”, and (3) information from QIA and 3CB was combined, “QIA + 3CB.” Analysis was initiated from radiologist-indicated lesion centers and was otherwise fully automated. Steps of the QIA and 3CB methods were lesion segmentation, characterization, and subsequent classification for malignancy in leave-one-case-out cross-validation. Performance assessment included box plots, Bland–Altman plots, and Receiver Operating Characteristic (ROC) analysis. Results: The area under the ROC curve (AUC) for distinguishing between benign and malignant lesions (invasive and DCIS) was 0.81 (standard error 0.07) for the “QIA alone” method, 0.72 (0.07) for “3CB alone” method, and 0.86 (0.04) for “QIA+3CB” combined. The difference in AUC was 0.043 between “QIA + 3CB” and “QIA alone” but failed to reach statistical significance (95% confidence interval [–0.17 to + 0.26]). Conclusions: In this pilot study analyzing the new 3CB imaging modality, knowledge of the composition of breast lesions and their periphery appeared additive in combination with existing mammographic QIA methods for the distinction between different benign and malignant lesion types.

  20. Digital versus screen-film mammography: impact of mammographic density and hormone therapy on breast cancer detection.

    PubMed

    Chiarelli, Anna M; Prummel, Maegan V; Muradali, Derek; Shumak, Rene S; Majpruz, Vicky; Brown, Patrick; Jiang, Hedy; Done, Susan J; Yaffe, Martin J

    2015-11-01

    Most studies that have examined the effects of mammographic density and hormone therapy use on breast cancer detection have included screen-film mammography. This study further examines this association in post-menopausal women screened by digital mammography. Approved by the University of Toronto Research Ethics Board, this study identified 688,418 women of age 50-74 years screened with digital or screen-film mammography from 2008 to 2009 within the Ontario Breast Screening Program. Of 2993 eligible women with invasive breast cancer, 2450 were contacted and 1421 participated (847 screen-film mammography, 574 digital direct radiography). Mammographic density was measured by study radiologists using the standard BI-RADS classification system and by a computer-assisted method. Information on hormone therapy use was collected by a telephone-administered questionnaire. Logistic regression and two-tailed tests for significance evaluated associations between factors and detection method by mammography type. Women with >75 % radiologist-measured mammographic density compared to those with <25 % were more likely to be diagnosed with an interval than screen-detected cancer, with the difference being greater for those screened with screen-film (OR = 6.40, 95 % CI 2.30-17.85) than digital mammography (OR = 2.41, 95 % CI 0.67-8.58) and aged 50-64 years screened with screen-film mammography (OR = 10.86, 95 % CI 2.96-39.57). Recent former hormone therapy users were also at an increased risk of having an interval cancer with the association being significant for women screened with digital mammography (OR = 2.08, 95 % CI 1.17-3.71). Breast screening using digital mammography lowers the risk of having an interval cancer for post-menopausal women aged 50-64 with greater mammographic density. PMID:26518019

  1. Mammographic density descriptors of novel phantom images: effect of clustered lumpy backgrounds

    NASA Astrophysics Data System (ADS)

    Li, Yanpeng; Brennan, Patrick C.; Ryan, Elaine

    2014-03-01

    Mammographic breast density (MBD) is a risk factor for breast cancer. Both qualitative and quantitative methods have been used to evaluate MBD. However as it is impossible to measure the actual weight or volume of fibroglandular tissue evident on a mammogram, therefore it is hard to know the true correlation between measured mammographic density and the fibroglandular tissue volume. A phantom system has been developed that represents glandular tissue within an adipose tissue structure. Although a previous study has found strong correlation between the synthesised glandular mass and several image descriptors, it is not known if the correlation is still present when a high level of background noise is introduced. The background noise is required to more realistically simulate clinical image appearance. The aim of this study is to investigate if the correlation between percentage density, integrated density, and standard deviation of mean grey value of the whole phantom and simulated glandular tissue mass is affected by background noise being added to the phantom images. For a set of one hundred phantom mammographic images, clustered lumpy backgrounds were synthesised and superimposed onto phantom images. The correlation between the synthesised glandular mass and the image descriptors were calculated. The results showed the correlation is strong and statistically significant for the above three descriptors with r is 0.7597, 0.8208, and 0.7167 respectively. This indicates these descriptors may be used to assess breast fibroglandular tissue content of the breast using mammographic images.

  2. Mammographic Imaging Studies Using the Monte Carlo Image Simulation-Differential Sampling (MCMIS-DS) Code

    SciTech Connect

    Kuruvilla Verghese

    2002-04-05

    This report summarizes the highlights of the research performed under the 1-year NEER grant from the Department of Energy. The primary goal of this study was to investigate the effects of certain design changes in the Fisher Senoscan mammography system and in the degree of breast compression on the discernability of microcalcifications in calcification clusters often observed in mammograms with tumor lesions. The most important design change that one can contemplate in a digital mammography system to improve resolution of calcifications is the reduction of pixel dimensions of the digital detector. Breast compression is painful to the patient and is though to be a deterrent to women to get routine mammographic screening. Calcification clusters often serve as markers (indicators ) of breast cancer.

  3. A novel phantom system facilitating better descriptors of density within mammographic images

    NASA Astrophysics Data System (ADS)

    Li, Yanpeng; Brennan, Patrick C.; Nickson, Carolyn; Pietrzyk, Mariusz W.; Al Mousa, Dana; Ryan, Elaine

    2013-03-01

    High mammographic density is a risk factor for breast cancer. As it is impossible to measure actual weight or volume of fibroglandular tissue evident within a mammogram, it is hard to know the correlation between measured mammographic density and the actual fibroglandular tissue volume. The aim of this study is to develop a phantom that represents glandular tissue within an adipose tissue structure so that correlations between image feature descriptors and the synthesised glandular structure can be accurately quantified. In this phantom study, ten different weights of fine steel wool were put into gelatine to simulate breast structure. Image feature descriptors are investigated for both the whole phantom image and the simulated density. Descriptors included actual area and percentage area of density, mean pixel intensity for the whole image and dense area, standard deviation of mean intensity, and integrated pixel density which is the production of area and mean intensity. The results show high level correlation between steel-wool weight and percentage density measured on images (r = 0.8421), and the integrated pixel density of dense area (r = 0.8760). The correlation is significant for mean intensity standard deviation for the whole phantom (r = 0.8043). This phantom study may help identify more accurate descriptors of mammographic density, thus facilitating better assessments of fibroglandular tissue appearances.

  4. A GaAs pixel detectors-based digital mammographic system: Performances and imaging tests results

    NASA Astrophysics Data System (ADS)

    Annovazzi, A.; Amendolia, S. R.; Bigongiari, A.; Bisogni, M. G.; Catarsi, F.; Cesqui, F.; Cetronio, A.; Colombo, F.; Delogu, P.; Fantacci, M. E.; Gilberti, A.; Lanzieri, C.; Lavagna, S.; Novelli, M.; Passuello, G.; Paternoster, G.; Pieracci, M.; Poletti, M.; Quattrocchi, M.; Rosso, V.; Stefanini, A.; Testa, A.; Venturelli, L.

    2007-06-01

    The prototype presented in this paper is based on GaAs pixel detectors read-out by the PCC/MEDIPIX I circuit. The active area of a sensor is about 1 cm 2 therefore to cover the typical irradiation field used in mammography (18×24 cm 2), 18 GaAs detection units have been organized in two staggered rows of nine chips each and moved by a stepper motor in the orthogonal direction. The system is integrated in a mammographic equipment which comprehends the X-ray tube, the bias and data acquisition systems and the PC-based control system. The prototype has been developed in the framework of the Integrated Mammographic Imaging (IMI) project, an industrial research activity aiming to develop innovative instrumentation for morphologic and functional imaging. The project has been supported by the Italian Ministry of Education, University and Research (MIUR) and by five Italian High Tech companies, Alenia Marconi Systems (AMS), CAEN, Gilardoni, LABEN and Poli.Hi.Tech., in collaboration with the universities of Ferrara, Roma "La Sapienza", Pisa and the Istituto Nazionale di Fisica Nucleare (INFN). In this paper, we report on the electrical characterization and the first imaging test results of the digital mammographic system. To assess the imaging capability of such a detector we have built a phantom, which simulates the breast tissue with malignancies. The radiographs of the phantom, obtained by delivering an entrance dose of 4.8 mGy, have shown particulars with a measured contrast below 1%.

  5. Efficiency of Lu 2SiO 5:Ce (LSO) powder phosphor as X-ray to light converter under mammographic imaging conditions

    NASA Astrophysics Data System (ADS)

    David, S.; Michail, C.; Valais, I.; Nikolopoulos, D.; Liaparinos, P.; Kalivas, N.; Kalatzis, I.; Toutountzis, A.; Efthimiou, N.; Loudos, G.; Sianoudis, I.; Cavouras, D.; Dimitropoulos, N.; Nomicos, C. D.; Kandarakis, I.; Panayiotakis, G. S.

    2007-02-01

    The aim of the present study was to examine the light emission efficiency of Lu 2SiO 5:Ce (LSO) powder scintillator under X-ray mammographic imaging conditions. Powder LSO scintillator has never been used in X-ray imaging. For the purposes of the present study, a 25 mg/cm 2 thick scintillating screen was prepared in our laboratory, by sedimentation of Lu 2SiO 5:Ce powder. Absolute luminescence efficiency measurements were performed within the range of X-ray tube voltages (22-49 kVp) used in mammographic applications. Parameters related to X-ray detection, i.e. the energy absorption efficiency (EAE) and the quantum detection efficiency (QDE) were calculated. A theoretical model, describing radiation and light transfer, was employed to fit experimental data and to estimate values of the intrinsic conversion efficiency and the light attenuation coefficients of the screen. The spectral compatibility of the LSO powder scintillator to mammographic X-ray films and to various electronic optical detectors was determined by performing light emission spectrum measurements and by taking into account the spectral sensitivity of the optical detectors. Results in the voltage range used in mammography showed that Lu 2SiO 5:Ce powder scintillator has approximately 10% higher values of QDE and 4.5% higher values of EAE than Gd 2O 2S:Tb.

  6. Combined photoacoustic and ultrasound imaging of human breast in vivo in the mammographic geometry

    NASA Astrophysics Data System (ADS)

    Xie, Zhixing; Lee, Won-Mean; Hooi, Fong Ming; Fowlkes, J. Brian; Pinsky, Renee W.; Mueller, Dean; Wang, Xueding; Carson, Paul L.

    2013-03-01

    This photoacoustic volume imaging (PAVI) system is designed to study breast cancer detection and diagnosis in the mammographic geometry in combination with automated 3D ultrasound (AUS). The good penetration of near-infrared (NIR) light and high receiving sensitivity of a broad bandwidth, 572 element, 2D PVDF array at a low center-frequency of 1MHz were utilized with 20 channel simultaneous acquisition. The feasibility of this system in imaging optically absorbing objects in deep breast tissues was assessed first through experiments on ex vivo whole breasts. The blood filled pseudo lesions were imaged at depths up to 49 mm in the specimens. In vivo imaging of human breasts has been conducted. 3D PAVI image stacks of human breasts were coregistered and compared with 3D ultrasound image stacks of the same breasts. Using the designed system, PAVI shows satisfactory imaging depth and sensitivity for coverage of the entire breast when imaged from both sides with mild compression in the mammographic geometry. With its unique soft tissue contrast and excellent sensitivity to the tissue hemodynamic properties of fractional blood volume and blood oxygenation, PAVI, as a complement to 3D ultrasound and digital tomosynthesis mammography, might well contribute to detection, diagnosis and prognosis for breast cancer.

  7. Do screen-detected lobular and ductal carcinoma present with different mammographic features?

    PubMed

    Garnett, S; Wallis, M; Morgan, G

    2009-01-01

    The aim of this study is to investigate any difference in the shape and location of infiltrating lobular carcinoma (ILC) with respect to the parenchymal density between the cranio-caudal (CC) and medio-lateral oblique (MLO) mammographic views. Six film-readers independently re-read 59 ILC mammograms and a matched sample of 59 infiltrating ductal carcinoma (IDC) mammograms from one 3-year screening round to quantify lesion characteristics. There is fair to moderate reader agreement for parenchymal pattern, lesion shape and location (kappa = 0.41-0.60). Both ILC (33/60, 55%) and IDC (22/65, 37%) appear as a spiculate mass more often on the CC view than on the MLO view. 41% (25/60) of the ILC spiculate masses become architectural distortions or asymmetric densities on the MLO view. No more ILC lesions (4/60, 7%) are seen in dense breasts than IDC (5/65, 8%), but ILC is mainly associated with (58/60, 97%), and rarely isolated from (2/60, 3%), the main glandular density. The appearance of ILC is significantly different between the MLO and CC views (paired Wilcoxon test: z = -17.059; significance level

  8. Mammographic equipment, technique, and quality control

    SciTech Connect

    Friedrich, M.A. )

    1991-08-01

    The most important improvements in mammographic technique were the introduction of single- or double-emulsion high-contrast film-screen combinations for mammography, the use of a specially designed low-kilovoltage Bucky grid to reduce scattered radiation, and the introduction of smaller focal spots to improve imaging geometry. Magnification techniques, especially the spot-film technique, yields clearer delineation of high-contrast microcalcifications. Dedicated mammographic equipment with specially designed x-ray tubes is necessary for modern high-quality mammography. However, in many modern mammographic units, the automatic exposure controller still fails to provide appropriate and constant optical film density over a wide range of tissue thickness and absorption. Extended-cycle processing of single-emulsion mammographic films can yield better image contrast and reduce exposure by up to 30%. Exposure times of less than 1 second are recommended to avoid the unnecessary higher doses caused by longer exposure times and reciprocity law failure. The wide dynamic range in mammography can be reduced by a beam equalization filter, and thus be better adapted to the decreased latitude of modern high-contrast mammographic screen-film systems. Mammographic film reading (detection of subtle microcalcifications) can be facilitated by modern computer evaluation of previously digitized mammograms. Standardization and assurance of image quality have been major challenges in the technical development of mammography. Different technical and anthropomorphic phantoms have been designed to measure and compare practical image quality. Detailed quality control measures have been developed. The benefit of a single or annual screening mammography, calculated in gained life expectancy, by far outweighs the relative risk for radiation-induced breast cancer. 22 references.

  9. Association Between Changes in Mammographic Image Features and Risk for Near-Term Breast Cancer Development.

    PubMed

    Tan, Maxine; Zheng, Bin; Leader, Joseph K; Gur, David

    2016-07-01

    The purpose of this study is to develop and test a new computerized model for predicting near-term breast cancer risk based on quantitative assessment of bilateral mammographic image feature variations in a series of negative full-field digital mammography (FFDM) images. The retrospective dataset included series of four sequential FFDM examinations of 335 women. The last examination in each series ("current") and the three most recent "prior" examinations were obtained. All "prior" examinations were interpreted as negative during the original clinical image reading, while in the "current" examinations 159 cancers were detected and pathologically verified and 176 cases remained cancer-free. From each image, we initially computed 158 mammographic density, structural similarity, and texture based image features. The absolute subtraction value between the left and right breasts was selected to represent each feature. We then built three support vector machine (SVM) based risk models, which were trained and tested using a leave-one-case-out based cross-validation method. The actual features used in each SVM model were selected using a nested stepwise regression analysis method. The computed areas under receiver operating characteristic curves monotonically increased from 0.666±0.029 to 0.730±0.027 as the time-lag between the "prior" (3 to 1) and "current" examinations decreases. The maximum adjusted odds ratios were 5.63, 7.43, and 11.1 for the three "prior" (3 to 1) sets of examinations, respectively. This study demonstrated a positive association between the risk scores generated by a bilateral mammographic feature difference based risk model and an increasing trend of the near-term risk for having mammography-detected breast cancer. PMID:26886970

  10. Analysis of mammographic microcalcifications using gray-level image structure features

    SciTech Connect

    Dhawan, A.P.; Chitre, Y.; Kaiser-Bonasso, C.; Moskowitz, M.

    1996-06-01

    Most of the techniques used in the computerized analysis of mammographic microcalcifications use shape features on the segmented regions of microcalcifications extracted from the digitized mammograms. Since mammographic images usually suffer from poorly defined microcalcification features, the extraction of shape features based on a segmentation process may not accurately represent microcalcifications. In this paper, the authors define a set of image structure features for classification of malignancy. Two categories of correlated gray-level image structure features are defined for classification of difficult-to-diagnose cases. The first category of features includes second-order histogram statistics-based features representing the global texture and the wavelet decomposition-based features representing the local texture of the microcalcification area of interest. The second category of features represents the first-order gray-level histogram-based statistics of the segmented microcalcification regions and the size, number, and distance features of the segmented microcalcification cluster. Various features in each category were correlated with the biopsy examination results of 191 difficult-to-diagnose cases for selection of the best set of features representing the complete gray-level image structure information. The selection of the best features was performed using the multivariate cluster analysis as well as a genetic algorithm (GA)-based search method. The selected features were used for classification using backpropagation neural network and parametric statistical classifiers. Receiver operating characteristic (ROC) analysis was performed to compare the neural network-based classification with linear and k-nearest neighbor (KNN) classifiers.

  11. A novel approach to computer-aided diagnosis of mammographic images

    SciTech Connect

    Sari-Sarraf, H.; Gleason, S.S.; Hudson, K.T.; Hubner, K.F.

    1996-08-01

    This is a work-in-progress report of a research endeavor that deals with the design and development of a novel approach to computer-aided diagnosis (CAD) of mammographic images. With the initial emphasis being on the analysis of microcalcifications, the proposed approach defines a synergistic paradigm that utilizes new methodologies together with previously developed techniques. The new paradigm is intended to promote a higher degree of accuracy in CAD of mammograms with an increased overall throughput. The process of accomplishing these goals is initiated by the fractal encoding of the input image, which gives rise to the generation of focus-of-attention regions (FARs), that is, regions that contain anomalies. The primary thrust of this work is to demonstrate that by considering FARs, rather than the entire input image, the performances of the ensuing processes (i.e., segmentation, feature extraction, and classification) are enhanced in terms of accuracy and speed. After presenting the proposed approach to CAD of mammographic images, the paper describes the generation of FARs. Furthermore, an experimental study is included that demonstrates the impact of this front-end procedure on the process of microcalcification segmentation. Specifically, the experimentation reveals a dramatic decrease (increase) in the amount of input data (throughput), as well as a reduction in the number of false detections.

  12. Feature and Contrast Enhancement of Mammographic Image Based on Multiscale Analysis and Morphology

    PubMed Central

    Wu, Shibin; Xie, Yaoqin

    2013-01-01

    A new algorithm for feature and contrast enhancement of mammographic images is proposed in this paper. The approach bases on multiscale transform and mathematical morphology. First of all, the Laplacian Gaussian pyramid operator is applied to transform the mammography into different scale subband images. In addition, the detail or high frequency subimages are equalized by contrast limited adaptive histogram equalization (CLAHE) and low-pass subimages are processed by mathematical morphology. Finally, the enhanced image of feature and contrast is reconstructed from the Laplacian Gaussian pyramid coefficients modified at one or more levels by contrast limited adaptive histogram equalization and mathematical morphology, respectively. The enhanced image is processed by global nonlinear operator. The experimental results show that the presented algorithm is effective for feature and contrast enhancement of mammogram. The performance evaluation of the proposed algorithm is measured by contrast evaluation criterion for image, signal-noise-ratio (SNR), and contrast improvement index (CII). PMID:24416072

  13. Mammographic system performance using an image reading qualification method.

    PubMed

    Pires, Silvio R; Medeiros, Regina B

    2012-07-01

    Our goal was to evaluate mammography systems based on microcalcifications and fiber detection using a statistical phantom (ALVIM, model TRM 18-209, Nuclear Associates) image readings. ALVIM phantom images were acquired under diverse exposure conditions with various equipments, and 5 radiologists with similar expertise reported their findings. The reading performance in the detection of microcalcifications and fibers of different sizes was measured by simulation of equivalent breast tissue with 4.5 and 6.5 cm thicknesses. We determined kappa values, ROC curves, and kappa probability density and detection rates with dedicated software developed locally. The statistical results generated three kappa (K) ranges that allowed quantification of the detection performance at three quality levels: unacceptable (K ≤ 0.64), achievable (K ≥ 0.70) and acceptable (0.64 < K < 0.70). An extensive database permitted a comparison of the reading performance with 99.5% reliability (p < 0.005). The comparison showed a larger dispersion of the kappa values for the images with low contrast generated with mammography equipment which was not properly calibrated, showing that the method is able to detect the performance changes associated with the loss of image quality. PMID:22547266

  14. The impact of mammographic imaging systems on density measurement

    NASA Astrophysics Data System (ADS)

    Damases, Christine N.; Brennan, Patrick C.; McEntee, Mark F.

    2015-03-01

    The purpose of this study is to investigate whether having a mammogram on differing manufacturer equipment will affect a woman's breast density (BD) measurement. The data set comprised of 40 cases, each containing a combined image of the left craniocaudal (LCC) and left mediolateral oblique (LMLO). These images were obtained from 20 women age between 42-89 years. The images were acquired on two imaging systems (GE and Hologic) one year apart. Volumetric BD was assessed by using Volpara Density Grade (VDG) and average BD% (AvBD%). Twenty American Board of Radiology (ABR) examiners assessed the same images using the BIRADS BD scale 1-4. Statistical comparisons were performed on the means using Mann-Whitney, on correlation using Spearman's rank coefficient of correlation and agreement using Cohen's Kappa. The absolute median BIRADS difference between GE and Hologic was 0.225 (2.00 versus 2.00; p<0.043). The VDG measures for GE was not statistically different to Hologic (2.00 versus 2.00; p<0.877), likewise the median AvBD% for the GE and Hologic systems showed no difference (6.51 versus 6.79; p<0.935). BIRADS for GE and Hologic systems showed strong positive correlation (ρ=0.904; p<0.001), while the VDG (ρ=0.978; p<0.001) and AvBD% (ρ=0.973; p<0.001) showed very strong positive correlations. There was a substantial agreement between GE and Hologic systems for BIRADS density shown with Cohen's Kappa (κ=0.692; p<0.001), however the systems demonstrated an almost perfect agreement for VDG (κ=0.933; p<0.001).

  15. Assessment of change in breast density: reader performance using synthetic mammographic images

    NASA Astrophysics Data System (ADS)

    Astley, Sue; Swayamprakasam, Chitra; Berks, Michael; Sergeant, Jamie; Morris, Julie; Wilson, Mary; Barr, Nicky; Boggis, Caroline

    2012-02-01

    A recent study has shown that breast cancer risk can be reduced by taking Tamoxifen, but only if this results in at least a 10% point reduction in mammographic density. When mammographic density is quantified visually, it is impossible to assess reader accuracy using clinical images as the ground truth is unknown. Our aim was to compare three models of assessing density change and to determine reader accuracy in identifying reductions of 10% points or more. We created 100 synthetic, mammogram-like images comprising 50 pairs designed to simulate natural reduction in density within each pair. Model I: individual images were presented to readers and density assessed. Model II: pairs of images were displayed together, with readers assessing density for each image. Model III: pairs of images were displayed together, and readers asked whether there was at least a 10% point reduction in density. Ten expert readers participated. Readers' estimates of percentage density were significantly closer to the truth (6.8%-26.4%) when images were assessed individually rather than in pairs (9.6%-29.8%). Measurement of change was significantly more accurate in Model II than Model I (p<0.005). Detecting density changes of at least 10% points in image pairs, mean accuracy was significantly (p<0.005) lower (58%-88%) when change was calculated from density assessments than in Model III (74%-92%). Our results suggest that where readers need to identify change in density, images should be displayed alongside one another. In our study, less accurate assessors performed better when asked directly about the magnitude of the change.

  16. Breast imaging using an amorphous silicon-based full-field digital mammographic system: stability of a clinical prototype.

    PubMed

    Vedantham, S; Karellas, A; Suryanarayanan, S; D'Orsi, C J; Hendrick, R E

    2000-11-01

    An amorphous silicon-based full-breast imager for digital mammography was evaluated for detector stability over a period of 1 year. This imager uses a structured CsI:TI scintillator coupled to an amorphous silicon layer with a 100-micron pixel pitch and read out by special purpose electronics. The stability of the system was characterized using the following quantifiable metrics: conversion factor (mean number of electrons generated per incident x-ray), presampling modulation transfer function (MTF), detector linearity and sensitivity, detector signal-to-noise ratio (SNR), and American College of Radiology (ACR) accreditation phantom scores. Qualitative metrics such as flat field uniformity, geometric distortion, and Society of Motion Picture and Television Engineers (SMPTE) test pattern image quality were also used to study the stability of the system. Observations made over this 1-year period indicated that the maximum variation from the average of the measurements were less than 0.5% for conversion factor, 3% for presampling MTF over all spatial frequencies, 5% for signal response, linearity and sensitivity, 12% for SNR over seven locations for all 3 target-filter combinations, and 0% for ACR accreditation phantom scores. ACR mammographic accreditation phantom images indicated the ability to resolve 5 fibers, 4 speck groups, and 5 masses at a mean glandular dose of 1.23 mGy. The SMPTE pattern image quality test for the display monitors used for image viewing indicated ability to discern all contrast steps and ability to distinguish line-pair images at the center and corners of the image. No bleeding effects were observed in the image. Flat field uniformity for all 3 target-filter combinations displayed no artifacts such as gridlines, bad detector rows or columns, horizontal or vertical streaks, or bad pixels. Wire mesh screen images indicated uniform resolution and no geometric distortion. PMID:11110258

  17. Extra patient movement during mammographic imaging: an experimental study

    PubMed Central

    Brettle, D; Howard, D; Kelly, J; Millington, S; Hogg, P

    2014-01-01

    Objective: To determine if movement external to the patient occurring during mammography may be a source of image blur. Methods: Four mammography machines with eight flexible and eight fixed paddles were evaluated. In the first stage, movement at the paddle was measured mechanically using two calibrated linear potentiometers. A deformable breast phantom was used to mimic a female breast. For each paddle, the movement in millimetres and change in compression force in Newton was recorded at 0.5- and 1-s intervals, respectively, for 40 s with the phantom in an initially compressed state under a load of 80 N. In the second stage, clinical audit on 28 females was conducted on one mammography machine with the 18 × 24- and 24 × 29-cm flexible paddles. Results: Movement at the paddle followed an exponential decay with a settling period of approximately 40 s. The compression force readings for both fixed and flexible paddles decreased exponentially with time, while fixed paddles had a larger drop in compression force than did flexible paddles. There is a linear relationship between movement at the paddle and change in compression force. Conclusion: Movement measured at the paddle during an exposure can be represented by a second order system. The amount of extra patient movement during the actual exposure can be estimated using the linear relationship between movement at the paddle and the change in compression force. Advances in knowledge: This research provides a possible explanation to mammography image blurring caused by extra patient movement and proposes a theoretical model to analyse the movement. PMID:25348098

  18. Influence of monitor characteristics on the signals detection present in the mammographic phantom image

    NASA Astrophysics Data System (ADS)

    Pires, Silvio R.; Medeiros, Regina B.

    2008-03-01

    The objective of this study was to compare the detection of microcalcifications and fibers on phantom images based on monitor readings versus analog image readings. 180 films were obtained with 3 different mammographic equipment under different exposure conditions and digitized using the Lumiscan75 scanner. It was used the ALVIM statistical phantom (4,5cm) and 2 acrylic plates of 1cm (6,5cm) over it. The software named QualIM was developed to manager the images and the database which storages the specialist's readings allowing them digital tools manipulation. The images were displayed on 4 monitors: CRT Philips 19" (2,9Mpixels/8bits), CRT Philips 22" (3,0Mpixels/8bits), LCD Clinton (3,0Mpixels/10bits) and LCD Barco (5,0Mpixels/14bits). The same images group was also displayed on the appropriated view box to mammograms (3200cd/m2) and the readings performance was taken as reference parameter. The software generates on real time Kappa values to microcalcifications and fibers detection, histogram, ROC curve and true/false positive parameters. Barco monitor readings produced superior results when compared with all the others suggesting that there weren't losses in the digitalizing process. Clinton monitor readings were similar the view box results and superior on both Philips monitors when compared the detection of objects on phantom images (6,5cm). The specialist performance results using Philips 22" were only comparable to view box and Clinton for images of 4,5cm. It was possible to verify that the monitors' spatial and contrast resolutions have influenced on the readings performance of specialists, suggesting these characteristics are relevant at lesions detection performance in mammographic exams.

  19. Breast screening: visual search as an aid for digital mammographic interpretation training

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Turnbull, Ann; James, Jonathan; Gale, Alastair; Scott, Hazel

    2010-02-01

    Digital mammography is gradually being introduced across all breast screening centres in the UK during 2010. This provides increased training opportunities using lower resolution, lower cost and more widely available devices, in addition to the clinical digital mammography workstations. This study examined how experienced breast screening personnel performed when they examined sets of difficult DICOM two-view screening cases in three conditions: on GE digital mammography workstations, on a standard LCD monitor (using a DICOM viewer) and an iPhone (running Osirix software). In each condition they either viewed the full images unaided or were permitted to use the post-processing manipulations of pan, zoom and window level/width adjustments. For each case they had to report the feature type, rate their confidence on the presence of abnormality, classify the case and specify case density. Their visual search behaviour was recorded throughout using a head mounted eye tracker. Additionally aspects of their real life screening performance and performance on a national self assessment scheme were examined. Data indicate that screening experience plays a major role in doing well on the self assessment scheme. Task performance was best on the clinical workstation. However, the data also suggest that a DICOM viewer that runs on a PC or laptop with a standard LCD display allows viewing digital images in full resolution support impressive cancer detection performance. The iPhone is not ideal for examining full images due to the amount of scrolling and zooming required. Overall, the results indicate that low cost devices could be used to provide additional tailored training as long as device resolution and HCI aspects are carefully considered.

  20. Roles of biologic breast tissue composition and quantitative image analysis of mammographic images in breast tumor characterization

    NASA Astrophysics Data System (ADS)

    Drukker, Karen; Giger, Maryellen L.; Duewer, Fred; Malkov, Serghei; Flowers, Christopher I.; Joe, Bonnie; Kerlikowske, Karla; Drukteinis, Jennifer S.; Shepherd, John

    2014-03-01

    Purpose. Investigate whether knowledge of the biologic image composition of mammographic lesions provides imagebased biomarkers above and beyond those obtainable from quantitative image analysis (QIA) of X-ray mammography. Methods. The dataset consisted of 45 in vivo breast lesions imaged with the novel 3-component breast (3CB) imaging technique based on dual-energy mammography (15 malignant, 30 benign diagnoses). The 3CB composition measures of water, lipid, and protein thicknesses were assessed and mathematical descriptors, `3CB features', were obtained for the lesions and their periphery. The raw low-energy mammographic images were analyzed with an established in-house QIA method obtaining `QIA features' describing morphology and texture. We investigated the correlation within the `3CB features', within the `QIA features', and between the two. In addition, the merit of individual features in the distinction between malignant and benign lesions was assessed. Results. Whereas many descriptors within the `3CB features' and `QIA features' were, often by design, highly correlated, correlation between descriptors of the two feature groups was much weaker (maximum absolute correlation coefficient 0.58, p<0.001) indicating that 3CB and QIA-based biomarkers provided potentially complementary information. Single descriptors from 3CB and QIA appeared equally well-suited for the distinction between malignant and benign lesions, with maximum area under the ROC curve 0.71 for a protein feature (3CB) and 0.71 for a texture feature (QIA). Conclusions. In this pilot study analyzing the new 3CB imaging modality, knowledge of breast tissue composition appeared additive in combination with existing mammographic QIA methods for the distinction between benign and malignant lesions.

  1. Predicted image quality of a CMOS APS X-ray detector across a range of mammographic beam qualities

    NASA Astrophysics Data System (ADS)

    Konstantinidis, A.

    2015-09-01

    Digital X-ray detectors based on Complementary Metal-Oxide- Semiconductor (CMOS) Active Pixel Sensor (APS) technology have been introduced in the early 2000s in medical imaging applications. In a previous study the X-ray performance (i.e. presampling Modulation Transfer Function (pMTF), Normalized Noise Power Spectrum (NNPS), Signal-to-Noise Ratio (SNR) and Detective Quantum Efficiency (DQE)) of the Dexela 2923MAM CMOS APS X-ray detector was evaluated within the mammographic energy range using monochromatic synchrotron radiation (i.e. 17-35 keV). In this study image simulation was used to predict how the mammographic beam quality affects image quality. In particular, the experimentally measured monochromatic pMTF, NNPS and SNR parameters were combined with various mammographic spectral shapes (i.e. Molybdenum/Molybdenum (Mo/Mo), Rhodium/Rhodium (Rh/Rh), Tungsten/Aluminium (W/Al) and Tungsten/Rhodium (W/Rh) anode/filtration combinations at 28 kV). The image quality was measured in terms of Contrast-to-Noise Ratio (CNR) using a synthetic breast phantom (4 cm thick with 50% glandularity). The results can be used to optimize the imaging conditions in order to minimize patient's Mean Glandular Dose (MGD).

  2. Evolution of mammographic image quality in the state of Rio de Janeiro*

    PubMed Central

    Villar, Vanessa Cristina Felippe Lopes; Seta, Marismary Horsth De; de Andrade, Carla Lourenço Tavares; Delamarque, Elizabete Vianna; de Azevedo, Ana Cecília Pedrosa

    2015-01-01

    Objective To evaluate the evolution of mammographic image quality in the state of Rio de Janeiro on the basis of parameters measured and analyzed during health surveillance inspections in the period from 2006 to 2011. Materials and Methods Descriptive study analyzing parameters connected with imaging quality of 52 mammography apparatuses inspected at least twice with a one-year interval. Results Amongst the 16 analyzed parameters, 7 presented more than 70% of conformity, namely: compression paddle pressure intensity (85.1%), films development (72.7%), film response (72.7%), low contrast fine detail (92.2%), tumor mass visualization (76.5%), absence of image artifacts (94.1%), mammography-specific developers availability (88.2%). On the other hand, relevant parameters were below 50% conformity, namely: monthly image quality control testing (28.8%) and high contrast details with respect to microcalcifications visualization (47.1%). Conclusion The analysis revealed critical situations in terms of compliance with the health surveillance standards. Priority should be given to those mammography apparatuses that remained non-compliant at the second inspection performed within the one-year interval. PMID:25987749

  3. Fine-needle aspiration cytology in nonpalpable mammographic abnormalities in breast cancer screening: results from the breast cancer screening programme in Oslo 1996-2001.

    PubMed

    Sauer, Torin; Myrvold, Kristina; Lømo, Jon; Anderssen, Karin Yvonne; Skaane, Per

    2003-10-01

    Fine-needle aspiration cytology (FNAC) of nonpalpable mammographic lesions has been under attack from two sides for some years. There has been much discussion and controversy as to the ability to differentiate between in situ and invasive carcinomas in cytological material. A further issue is that of optimal sampling to obtain adequate cell material in sufficient quantity. We present the results of FNAC from 832 nonpalpable mammographic abnormalities detected in the course of the breast cancer screening programme in Oslo during 1996-2001. In 11.6% of cases the smears were inadequate, and there were 7% false negatives (FN) and 1.3% false positives. Of the FN, 64% represented microcalcifications and 86% were due to sampling errors. Absolute sensitivity was 74%, complete sensitivity 88% and specificity 88%. In 255 carcinomas a cytological diagnosis of them as in situ or invasive was made. In 93% of the invasive cases (190/205) these had been correctly identified as invasive on FNAC. In 78% of cases proper follow-up could be resolved by cytology/radiology alone. Suboptimal sampling and localization remains the main cause of FN FNAC results. Problems in differentiating between in situ and invasive breast carcinomas can be significantly reduced by applying strict criteria for in situ lesions. PMID:14659146

  4. Similarity of Fibroglandular Breast Tissue Content Measured from Magnetic Resonance and Mammographic Images and by a Mathematical Algorithm

    PubMed Central

    Ju, Hyunsu; Brunder, Donald G.; Anderson, Karl E.; Khamapirad, Tuenchit; Lu, Lee-Jane W.

    2014-01-01

    Women with high breast density (BD) have a 4- to 6-fold greater risk for breast cancer than women with low BD. We found that BD can be easily computed from a mathematical algorithm using routine mammographic imaging data or by a curve-fitting algorithm using fat and nonfat suppression magnetic resonance imaging (MRI) data. These BD measures in a strictly defined group of premenopausal women providing both mammographic and breast MRI images were predicted as well by the same set of strong predictor variables as were measures from a published laborious histogram segmentation method and a full field digital mammographic unit in multivariate regression models. We also found that the number of completed pregnancies, C-reactive protein, aspartate aminotransferase, and progesterone were more strongly associated with amounts of glandular tissue than adipose tissue, while fat body mass, alanine aminotransferase, and insulin like growth factor-II appear to be more associated with the amount of breast adipose tissue. Our results show that methods of breast imaging and modalities for estimating the amount of glandular tissue have no effects on the strength of these predictors of BD. Thus, the more convenient mathematical algorithm and the safer MRI protocols may facilitate prospective measurements of BD. PMID:25132995

  5. Mammographic parenchymal texture as an imaging marker of hormonal activity: a comparative study between pre- and post-menopausal women

    NASA Astrophysics Data System (ADS)

    Daye, Dania; Bobo, Ezra; Baumann, Bethany; Ioannou, Antonios; Conant, Emily F.; Maidment, Andrew D. A.; Kontos, Despina

    2011-03-01

    Mammographic parenchymal texture patterns have been shown to be related to breast cancer risk. Yet, little is known about the biological basis underlying this association. Here, we investigate the potential of mammographic parenchymal texture patterns as an inherent phenotypic imaging marker of endogenous hormonal exposure of the breast tissue. Digital mammographic (DM) images in the cranio-caudal (CC) view of the unaffected breast from 138 women diagnosed with unilateral breast cancer were retrospectively analyzed. Menopause status was used as a surrogate marker of endogenous hormonal activity. Retroareolar 2.5cm2 ROIs were segmented from the post-processed DM images using an automated algorithm. Parenchymal texture features of skewness, coarseness, contrast, energy, homogeneity, grey-level spatial correlation, and fractal dimension were computed. Receiver operating characteristic (ROC) curve analysis was performed to evaluate feature classification performance in distinguishing between 72 pre- and 66 post-menopausal women. Logistic regression was performed to assess the independent effect of each texture feature in predicting menopause status. ROC analysis showed that texture features have inherent capacity to distinguish between pre- and post-menopausal statuses (AUC>0.5, p<0.05). Logistic regression including all texture features yielded an ROC curve with an AUC of 0.76. Addition of age at menarche, ethnicity, contraception use and hormonal replacement therapy (HRT) use lead to a modest model improvement (AUC=0.78) while texture features maintained significant contribution (p<0.05). The observed differences in parenchymal texture features between pre- and post- menopausal women suggest that mammographic texture can potentially serve as a surrogate imaging marker of endogenous hormonal activity.

  6. A Review on Automatic Mammographic Density and Parenchymal Segmentation

    PubMed Central

    He, Wenda; Juette, Arne; Denton, Erika R. E.; Oliver, Arnau; Martí, Robert; Zwiggelaar, Reyer

    2015-01-01

    Breast cancer is the most frequently diagnosed cancer in women. However, the exact cause(s) of breast cancer still remains unknown. Early detection, precise identification of women at risk, and application of appropriate disease prevention measures are by far the most effective way to tackle breast cancer. There are more than 70 common genetic susceptibility factors included in the current non-image-based risk prediction models (e.g., the Gail and the Tyrer-Cuzick models). Image-based risk factors, such as mammographic densities and parenchymal patterns, have been established as biomarkers but have not been fully incorporated in the risk prediction models used for risk stratification in screening and/or measuring responsiveness to preventive approaches. Within computer aided mammography, automatic mammographic tissue segmentation methods have been developed for estimation of breast tissue composition to facilitate mammographic risk assessment. This paper presents a comprehensive review of automatic mammographic tissue segmentation methodologies developed over the past two decades and the evidence for risk assessment/density classification using segmentation. The aim of this review is to analyse how engineering advances have progressed and the impact automatic mammographic tissue segmentation has in a clinical environment, as well as to understand the current research gaps with respect to the incorporation of image-based risk factors in non-image-based risk prediction models. PMID:26171249

  7. Risk of breast cancer after false-positive results in mammographic screening.

    PubMed

    Román, Marta; Castells, Xavier; Hofvind, Solveig; von Euler-Chelpin, My

    2016-06-01

    Women with false-positive results are commonly referred back to routine screening. Questions remain regarding their long-term outcome of breast cancer. We assessed the risk of screen-detected breast cancer in women with false-positive results. We conducted a joint analysis using individual level data from the population-based screening programs in Copenhagen and Funen in Denmark, Norway, and Spain. Overall, 150,383 screened women from Denmark (1991-2008), 612,138 from Norway (1996-2010), and 1,172,572 from Spain (1990-2006) were included. Poisson regression was used to estimate the relative risk (RR) of screen-detected cancer for women with false-positive versus negative results. We analyzed information from 1,935,093 women 50-69 years who underwent 6,094,515 screening exams. During an average 5.8 years of follow-up, 230,609 (11.9%) women received a false-positive result and 27,849 (1.4%) were diagnosed with screen-detected cancer. The adjusted RR of screen-detected cancer after a false-positive result was 2.01 (95% CI: 1.93-2.09). Women who tested false-positive at first screen had a RR of 1.86 (95% CI: 1.77-1.96), whereas those who tested false-positive at third screening had a RR of 2.42 (95% CI: 2.21-2.64). The RR of breast cancer at the screening test after the false-positive result was 3.95 (95% CI: 3.71-4.21), whereas it decreased to 1.25 (95% CI: 1.17-1.34) three or more screens after the false-positive result. Women with false-positive results had a twofold risk of screen-detected breast cancer compared to women with negative tests. The risk remained significantly higher three or more screens after the false-positive result. The increased risk should be considered when discussing stratified screening strategies. PMID:26916154

  8. A new and fast image feature selection method for developing an optimal mammographic mass detection scheme

    PubMed Central

    Tan, Maxine; Pu, Jiantao; Zheng, Bin

    2014-01-01

    Purpose: Selecting optimal features from a large image feature pool remains a major challenge in developing computer-aided detection (CAD) schemes of medical images. The objective of this study is to investigate a new approach to significantly improve efficacy of image feature selection and classifier optimization in developing a CAD scheme of mammographic masses. Methods: An image dataset including 1600 regions of interest (ROIs) in which 800 are positive (depicting malignant masses) and 800 are negative (depicting CAD-generated false positive regions) was used in this study. After segmentation of each suspicious lesion by a multilayer topographic region growth algorithm, 271 features were computed in different feature categories including shape, texture, contrast, isodensity, spiculation, local topological features, as well as the features related to the presence and location of fat and calcifications. Besides computing features from the original images, the authors also computed new texture features from the dilated lesion segments. In order to select optimal features from this initial feature pool and build a highly performing classifier, the authors examined and compared four feature selection methods to optimize an artificial neural network (ANN) based classifier, namely: (1) Phased Searching with NEAT in a Time-Scaled Framework, (2) A sequential floating forward selection (SFFS) method, (3) A genetic algorithm (GA), and (4) A sequential forward selection (SFS) method. Performances of the four approaches were assessed using a tenfold cross validation method. Results: Among these four methods, SFFS has highest efficacy, which takes 3%–5% of computational time as compared to GA approach, and yields the highest performance level with the area under a receiver operating characteristic curve (AUC) = 0.864 ± 0.034. The results also demonstrated that except using GA, including the new texture features computed from the dilated mass segments improved the AUC

  9. Misclassification of Breast Imaging Reporting and Data System (BI-RADS) Mammographic Density and Implications for Breast Density Reporting Legislation.

    PubMed

    Gard, Charlotte C; Aiello Bowles, Erin J; Miglioretti, Diana L; Taplin, Stephen H; Rutter, Carolyn M

    2015-01-01

    USA states have begun legislating mammographic breast density reporting to women, requiring that women undergoing screening mammography who have dense breast tissue (Breast Imaging Reporting and Data System [BI-RADS] density c or d) receive written notification of their breast density; however, the impact that misclassification of breast density will have on this reporting remains unclear. The aim of this study was to assess reproducibility of the four-category BI-RADS density measure and examine its relationship with a continuous measure of percent density. We enrolled 19 radiologists, experienced in breast imaging, from a single integrated health care system. Radiologists interpreted 341 screening mammograms at two points in time 6 months apart. We assessed intra- and interobserver agreement in radiologists'; interpretations of BI-RADS density and explored whether agreement depended upon radiologist characteristics. We examined the relationship between BI-RADS density and percent density in a subset of 282 examinations. Intraradiologist agreement was moderate to substantial, with kappa varying across radiologists from 0.50 to 0.81 (mean = 0.69, 95% CI [0.63, 0.73]). Intraradiologist agreement was higher for radiologists with ≥10 years experience interpreting mammograms (difference in mean kappa = 0.10, 95% CI [0.01, 0.24]). Interradiologist agreement varied widely across radiologist pairs from slight to substantial, with kappa ranging from 0.02 to 0.72 (mean = 0.46, 95% CI [0.36, 0.55]). Of 145 examinations interpreted as "nondense" (BI-RADS density a or b) by the majority of radiologists, 82.8% were interpreted as "dense" (BI-RADS density c or d) by at least one radiologist. Of 187 examinations interpreted as "dense" by the majority of radiologists, 47.1% were interpreted as "nondense" by at least one radiologist. While the examinations of almost half of the women in our study were interpreted clinically as having BI-RADS density c or d, only about 10% of

  10. Image simulation and a model of noise power spectra across a range of mammographic beam qualities

    SciTech Connect

    Mackenzie, Alistair Dance, David R.; Young, Kenneth C.; Diaz, Oliver

    2014-12-15

    Purpose: The aim of this work is to create a model to predict the noise power spectra (NPS) for a range of mammographic radiographic factors. The noise model was necessary to degrade images acquired on one system to match the image quality of different systems for a range of beam qualities. Methods: Five detectors and x-ray systems [Hologic Selenia (ASEh), Carestream computed radiography CR900 (CRc), GE Essential (CSI), Carestream NIP (NIPc), and Siemens Inspiration (ASEs)] were characterized for this study. The signal transfer property was measured as the pixel value against absorbed energy per unit area (E) at a reference beam quality of 28 kV, Mo/Mo or 29 kV, W/Rh with 45 mm polymethyl methacrylate (PMMA) at the tube head. The contributions of the three noise sources (electronic, quantum, and structure) to the NPS were calculated by fitting a quadratic at each spatial frequency of the NPS against E. A quantum noise correction factor which was dependent on beam quality was quantified using a set of images acquired over a range of radiographic factors with different thicknesses of PMMA. The noise model was tested for images acquired at 26 kV, Mo/Mo with 20 mm PMMA and 34 kV, Mo/Rh with 70 mm PMMA for three detectors (ASEh, CRc, and CSI) over a range of exposures. The NPS were modeled with and without the noise correction factor and compared with the measured NPS. A previous method for adapting an image to appear as if acquired on a different system was modified to allow the reference beam quality to be different from the beam quality of the image. The method was validated by adapting the ASEh flat field images with two thicknesses of PMMA (20 and 70 mm) to appear with the imaging characteristics of the CSI and CRc systems. Results: The quantum noise correction factor rises with higher beam qualities, except for CR systems at high spatial frequencies, where a flat response was found against mean photon energy. This is due to the dominance of secondary quantum noise

  11. Justifying age thresholds for mammographic screening: an application of pragma-dialectical argumentation theory.

    PubMed

    Schulz, Peter J; Meuffels, Bert

    2012-01-01

    Information campaigns on breast cancer screening in the Netherlands need to convince women above 50 years of age to have biannual mammography, and women below 50 years of age that regular mammograms are not recommended for them. This article reports the results of two experiments in which the construction of the persuasive messages was informed by argumentation-theoretical insights. No differences were found between either statistical and anecdotal evidence or gain- and loss-framing in the attempt to convince women under 50 that they normally do not need regular mammography. A striking contrast emerged, however, between the overwhelming acceptance of breast cancer screening for women above 50 and the relative restraint and reluctance to consent that mammography is usually not recommended for women under 50. The reluctance to accept that regular mammography is not recommended for women under 50 is traced back to ego involvement. PMID:21823968

  12. Mammographic interpretation training: how useful is handheld technology?

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Gale, Alastair G.; Scott, Hazel

    2008-03-01

    In the UK a national self-assessment scheme (PERFORMS) for mammographers is undertaken as part of the National Health Search Breast Screening Programme. Where appropriate, further training is suggested to improve performance. Ideally, such training would be on-demand; that is whenever and wherever an individual decides to undertake it. To use a portable device for such a purpose would be attractive on many levels. However, it is not known whether handheld technology can be used effectively for viewing mammographic images. Previous studies indicate the potential for viewing medical images with fairly low spatial resolution (e.g. CT, MRI) on PDAs. In this study, we set out to investigate factors that might affect the feasibility of using PDAs as a training technology for examining large, high resolution mammographic images. Two studies are reported: 20 mammographers examined a series of mammograms presented on a PDA, specifying the location of any abnormality. Secondly, a group of technologists examined a series of mammograms presented at different sizes and resolutions to mimic presentation on a PDA and their eye movements were recorded. The results indicate the potential for using PDAs to show such large, high resolution images if suitable Human-computer Interaction (HCI) techniques are employed.

  13. Image quality and breast dose of 24 screen-film combinations for mammography.

    PubMed

    Dimakopoulou, A D; Tsalafoutas, I A; Georgiou, E K; Yakoumakis, E N

    2006-02-01

    In this study the effect of different mammographic screen-film combinations on image quality and breast dose, and the correlation between the various image quality parameters, breast dose and the sensitometric parameters of a film were investigated. Three Agfa (MR5-II, HDR, HT), two Kodak (Min-R M, Min-R 2000), one Fuji (AD-M), one Konica (CM-H) and one Ferrania (HM plus) single emulsion mammographic films were combined with three intensifying screens (Agfa HDS, Kodak Min-R 2190 and Fuji AD-MA). The film characteristics were determined by sensitometry, while the image quality and the dose to the breast of the resulting 24 screen-film combinations were assessed using a mammography quality control phantom. For each combination, three images of the phantom were acquired with optical density within three different ranges. Two observers assessed the quality of the 72 phantom images obtained, while the breast dose was calculated from the exposure data required for each image. Large differences among screen-film combinations in terms of image quality and breast dose were identified however, that, could not be correlated with the film's sensitometric characteristics. All films presented the best resolution when combined with the HDS screen at the expense of speed, and the largest speed when combined with the AD-MA screen, without degradation of the overall image quality. However, an ideal screen-film combination presenting the best image quality with the least dose was not identified. It is also worth mentioning that the best performance for a film was not necessarily obtained when this was combined with the screen provided by the same manufacturer. The results of this study clearly demonstrate that comparison of films based on their sensitometric characteristics are of limited value for clinical practice, as their performance is strongly affected by the screens with which they are combined. PMID:16489193

  14. Validation of no-reference image quality index for the assessment of digital mammographic images

    NASA Astrophysics Data System (ADS)

    de Oliveira, Helder C. R.; Barufaldi, Bruno; Borges, Lucas R.; Gabarda, Salvador; Bakic, Predrag R.; Maidment, Andrew D. A.; Schiabel, Homero; Vieira, Marcelo A. C.

    2016-03-01

    To ensure optimal clinical performance of digital mammography, it is necessary to obtain images with high spatial resolution and low noise, keeping radiation exposure as low as possible. These requirements directly affect the interpretation of radiologists. The quality of a digital image should be assessed using objective measurements. In general, these methods measure the similarity between a degraded image and an ideal image without degradation (ground-truth), used as a reference. These methods are called Full-Reference Image Quality Assessment (FR-IQA). However, for digital mammography, an image without degradation is not available in clinical practice; thus, an objective method to assess the quality of mammograms must be performed without reference. The purpose of this study is to present a Normalized Anisotropic Quality Index (NAQI), based on the Rényi entropy in the pseudo-Wigner domain, to assess mammography images in terms of spatial resolution and noise without any reference. The method was validated using synthetic images acquired through an anthropomorphic breast software phantom, and the clinical exposures on anthropomorphic breast physical phantoms and patient's mammograms. The results reported by this noreference index follow the same behavior as other well-established full-reference metrics, e.g., the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM). Reductions of 50% on the radiation dose in phantom images were translated as a decrease of 4dB on the PSNR, 25% on the SSIM and 33% on the NAQI, evidencing that the proposed metric is sensitive to the noise resulted from dose reduction. The clinical results showed that images reduced to 53% and 30% of the standard radiation dose reported reductions of 15% and 25% on the NAQI, respectively. Thus, this index may be used in clinical practice as an image quality indicator to improve the quality assurance programs in mammography; hence, the proposed method reduces the subjectivity

  15. Association of Mammographic Density with Pathologic Findings

    PubMed Central

    Ahmadinejad, Nasrin; Movahedinia, Samaneh; Movahedinia, Sajjadeh; Shahriari, Mona

    2013-01-01

    Background Breast cancer is one of the most common cancers in the world and is the first cause of death due to cancer among women. Mammography is the best screening method and mammographic density, which determines the percentage of fibro glandular tissue of breast, is one of the strongest risk factors of breast cancer. Because benign and malignant lesions may present as dense lesions in mammography so it is necessary to take a core biopsy of any suspicious lesions to evaluate pathologic findings. Objectives The aim of this study was to assess the association between mammographic density and histopathological findings in Iranian population. Moreover, we assessed the correlation between mammographic density and protein expression profile. We indeed, determined the accuracy and positive predictive value and negative predictive value of mammographic reports in our center. Patients and Method This study is a cross-sectional study carried out among 131 eligible women who had referred to imaging center for mammographic examination and had been advised to take biopsy of breast tissue. All participants of the study had filled out the informed consent. Pathologic review was performed blinded to the density status. Patients were divided into low density breast tissue group (ACR density group 1-2) and high density breast tissue group (ACR 3, 4) and data was compared between these two groups. Statistical analysis performed using SPSS for windows, version 11.5. We used chi-square, t-test, and logistic regression test for analysis and Odds Ratio calculated where indicated. Results In patients with high breast densities, malignant cases (61.2%) were significantly more in comparison to patients with low breast densities (37.3%) (P= 0.007, OR=2.66 95% CI=1.29-5.49). After adjusting for age, density was associated with malignancy in age groups <46 years (P=0.007), and 46-60 years (P=0.024) but not in age group >60yrs (P=0.559). Adjusting for menopausal status, density showed

  16. Consistency of visual assessments of mammographic breast density from vendor-specific "for presentation" images.

    PubMed

    Abdolell, Mohamed; Tsuruda, Kaitlyn; Lightfoot, Christopher B; Barkova, Eva; McQuaid, Melanie; Caines, Judy; Iles, Sian E

    2016-01-01

    Discussions of percent breast density (PD) and breast cancer risk implicitly assume that visual assessments of PD are comparable between vendors despite differences in technology and display algorithms. This study examines the extent to which visual assessments of PD differ between mammograms acquired from two vendors. Pairs of "for presentation" digital mammography images were obtained from two mammography units for 146 women who had a screening mammogram on one vendor unit followed by a diagnostic mammogram on a different vendor unit. Four radiologists independently visually assessed PD from single left mediolateral oblique view images from the two vendors. Analysis of variance, intra-class correlation coefficients (ICC), scatter plots, and Bland-Altman plots were used to evaluate PD assessments between vendors. The mean radiologist PD for each image was used as a consensus PD measure. Overall agreement of the PD assessments was excellent between the two vendors with an ICC of 0.95 (95% confidence interval: 0.93 to 0.97). Bland-Altman plots demonstrated narrow upper and lower limits of agreement between the vendors with only a small bias (2.3 percentage points). The results of this study support the assumption that visual assessment of PD is consistent across mammography vendors despite vendor-specific appearances of "for presentation" images. PMID:26870747

  17. Diagnosis of breast cancer in light microscopic and mammographic images textures using relative entropy via kernel estimation.

    PubMed

    Korkmaz, Sevcan Aytac; Korkmaz, Mehmet Fatih; Poyraz, Mustafa

    2016-04-01

    The aim of this article was to provide early detection of breast cancer by using both mammography and histopathology images of the same patient. When the studies in the literature are examined, it is seen that the mammography and histopathology images of the same patient are not used together for early diagnosis of breast cancer. Mammographic and microscopic images can be limited when using only one of them for the early detection of the breast cancer. Therefore, multi-modality solutions that give more accuracy results than single solutions have been realized in this paper. 3 × 50 microscopic (histopathology) and 3 × 50 mammography image sets have been taken from Firat University Medicine Faculty Pathology and Radiology Laboratories, respectively. Optimum feature space has been obtained by minimum redundancy and maximum relevance via mutual information method applying to the 3 × 50 microscopic and mammography images. Then, probabilistic values of suspicious lesions in the image for selected features have been found by exponential curve fitting. Jensen Shannon, Hellinger, and Triangle measurements have been used for the diagnosis of breast cancer. It has been proved that these measures have been related to each other. Weight values for selected each feature have been found using these measures. These weight values have been used in object function. Afterward, histopathology and mammography images have been classified as normal, malign, and benign utilizing object function. In the result of this classifier, the accuracy of diagnosis of breast cancer has been estimated probabilistically. Furthermore, classifications have been probabilistically visualized on a pie chart. Consequently, the performances of Jensen Shannon, Hellinger, and Triangle measures have been compared with ROC analysis using histopathology and mammography test images. It has been observed that Jensen Shannon measure has higher performance than Hellinger and Triangle measures. Accuracy rates of

  18. Assessment of two mammographic density related features in predicting near-term breast cancer risk

    NASA Astrophysics Data System (ADS)

    Zheng, Bin; Sumkin, Jules H.; Zuley, Margarita L.; Wang, Xingwei; Klym, Amy H.; Gur, David

    2012-02-01

    In order to establish a personalized breast cancer screening program, it is important to develop risk models that have high discriminatory power in predicting the likelihood of a woman developing an imaging detectable breast cancer in near-term (e.g., <3 years after a negative examination in question). In epidemiology-based breast cancer risk models, mammographic density is considered the second highest breast cancer risk factor (second to woman's age). In this study we explored a new feature, namely bilateral mammographic density asymmetry, and investigated the feasibility of predicting near-term screening outcome. The database consisted of 343 negative examinations, of which 187 depicted cancers that were detected during the subsequent screening examination and 155 that remained negative. We computed the average pixel value of the segmented breast areas depicted on each cranio-caudal view of the initial negative examinations. We then computed the mean and difference mammographic density for paired bilateral images. Using woman's age, subjectively rated density (BIRADS), and computed mammographic density related features we compared classification performance in estimating the likelihood of detecting cancer during the subsequent examination using areas under the ROC curves (AUC). The AUCs were 0.63+/-0.03, 0.54+/-0.04, 0.57+/-0.03, 0.68+/-0.03 when using woman's age, BIRADS rating, computed mean density and difference in computed bilateral mammographic density, respectively. Performance increased to 0.62+/-0.03 and 0.72+/-0.03 when we fused mean and difference in density with woman's age. The results suggest that, in this study, bilateral mammographic tissue density is a significantly stronger (p<0.01) risk indicator than both woman's age and mean breast density.

  19. Novel multiresolution mammographic density segmentation using pseudo 3D features and adaptive cluster merging

    NASA Astrophysics Data System (ADS)

    He, Wenda; Juette, Arne; Denton, Erica R. E.; Zwiggelaar, Reyer

    2015-03-01

    Breast cancer is the most frequently diagnosed cancer in women. Early detection, precise identification of women at risk, and application of appropriate disease prevention measures are by far the most effective ways to overcome the disease. Successful mammographic density segmentation is a key aspect in deriving correct tissue composition, ensuring an accurate mammographic risk assessment. However, mammographic densities have not yet been fully incorporated with non-image based risk prediction models, (e.g. the Gail and the Tyrer-Cuzick model), because of unreliable segmentation consistency and accuracy. This paper presents a novel multiresolution mammographic density segmentation, a concept of stack representation is proposed, and 3D texture features were extracted by adapting techniques based on classic 2D first-order statistics. An unsupervised clustering technique was employed to achieve mammographic segmentation, in which two improvements were made; 1) consistent segmentation by incorporating an optimal centroids initialisation step, and 2) significantly reduced the number of missegmentation by using an adaptive cluster merging technique. A set of full field digital mammograms was used in the evaluation. Visual assessment indicated substantial improvement on segmented anatomical structures and tissue specific areas, especially in low mammographic density categories. The developed method demonstrated an ability to improve the quality of mammographic segmentation via clustering, and results indicated an improvement of 26% in segmented image with good quality when compared with the standard clustering approach. This in turn can be found useful in early breast cancer detection, risk-stratified screening, and aiding radiologists in the process of decision making prior to surgery and/or treatment.

  20. Development of an imaging-planning program for screen/film and computed radiography mammography for breasts with short chest wall to nipple distance

    PubMed Central

    Dong, S L; Su, J L; Yeh, Y H; Chu, T C; Lin, Y C; Chuang, K S

    2011-01-01

    Objective Imaging breasts with a short chest wall to nipple distance (CWND) using a traditional mammographic X-ray unit is a technical challenge for mammographers. The purpose of this study is the development of an imaging-planning program to assist in determination of imaging parameters of screen/film (SF) and computed radiography (CR) mammography for short CWND breasts. Methods A traditional mammographic X-ray unit (Mammomat 3000, Siemens, Munich, Germany) was employed. The imaging-planning program was developed by combining the compressed breast thickness correction, the equivalent polymethylmethacrylate thickness assessment for breasts and the tube loading (mAs) measurement. Both phantom exposures and a total of 597 exposures were used for examining the imaging-planning program. Results Results of the phantom study show that the tube loading rapidly decreased with the CWND when the automatic exposure control (AEC) detector was not fully covered by the phantom. For patient exposures with the AEC fully covered by breast tissue, the average fractional tube loadings, defined as the ratio of the predicted mAs using the imaging-planning program and mAs of the mammogram, were 1.10 and 1.07 for SF and CR mammograms, respectively. The predicted mAs values were comparable to the mAs values, as determined by the AEC. Conclusion By applying the imaging-planning program in clinical practice, the experiential dependence of the mammographer for determination of the imaging parameters for short CWND breasts is minimised. PMID:21123310

  1. Disparities in mammographic screening for Asian women in California: a cross-sectional analysis to identify meaningful groups for targeted intervention

    PubMed Central

    Gomez, Scarlett Lin; Tan, Susanna; Keegan, Theresa HM; Clarke, Christina A

    2007-01-01

    Background Breast cancer is the most commonly diagnosed cancer among the rapidly growing population of Asian Americans; it is also the most common cause of cancer mortality among Filipinas. Asian women continue to have lower rates of mammographic screening than women of most other racial/ethnic groups. While prior studies have described the effects of sociodemographic and other characteristics of women on non-adherence to screening guidelines, they have not identified the distinct segments of the population who remain at highest risk of not being screened. Methods To better describe characteristics of Asian women associated with not having a mammogram in the last two years, we applied recursive partitioning to population-based data (N = 1521) from the 2001 California Health Interview Survey (CHIS), for seven racial/ethnic groups of interest: Chinese, Japanese, Filipino, Korean, South Asian, Vietnamese, and all Asians combined. Results We identified two major subgroups of Asian women who reported not having a mammogram in the past two years and therefore, did not follow mammography screening recommendations: 1) women who have never had a pap exam to screen for cervical cancer (68% had no mammogram), and 2) women who have had a pap exam, but have no women's health issues (osteoporosis, using menopausal hormone therapies, and/or hysterectomy) nor a usual source of care (62% had no mammogram). Only 19% of Asian women who have had pap screening and have women's health issues did not have a mammogram in the past two years. In virtually all ethnic subgroups, having had pap or colorectal screening were the strongest delineators of mammography usage. Other characteristics of women least likely to have had a mammogram included: Chinese non-U.S. citizens or citizens without usual source of health care, Filipinas with no health insurance, Koreans without women's health issues and public or no health insurance, South Asians less than age 50 who were unemployed or non

  2. Relationship between breast sound speed and mammographic percent density

    NASA Astrophysics Data System (ADS)

    Sak, Mark; Duric, Nebojsa; Boyd, Norman; Littrup, Peter; Myc, Lukasz; Faiz, Muhammad; Li, Cuiping; Bey-Knight, Lisa

    2011-03-01

    Despite some shortcomings, mammography is currently the standard of care for breast cancer screening and diagnosis. However, breast ultrasound tomography is a rapidly developing imaging modality that has the potential to overcome the drawbacks of mammography. It is known that women with high breast densities have a greater risk of developing breast cancer. Measuring breast density is accomplished through the use of mammographic percent density, defined as the ratio of fibroglandular to total breast area. Using an ultrasound tomography (UST) prototype, we created sound speed images of the patient's breast, motivated by the fact that sound speed in a tissue is proportional to the density of the tissue. The purpose of this work is to compare the acoustic performance of the UST system with the measurement of mammographic percent density. A cohort of 251 patients was studied using both imaging modalities and the results suggest that the volume averaged breast sound speed is significantly related to mammographic percent density. The Spearman correlation coefficient was found to be 0.73 for the 175 film mammograms and 0.69 for the 76 digital mammograms obtained. Since sound speed measurements do not require ionizing radiation or physical compression, they have the potential to form the basis of a safe, more accurate surrogate marker of breast density.

  3. Modeling error in assessment of mammographic image features for improved computer-aided mammography training: initial experience

    NASA Astrophysics Data System (ADS)

    Mazurowski, Maciej A.; Tourassi, Georgia D.

    2011-03-01

    In this study we investigate the hypothesis that there exist patterns in erroneous assessment of BI-RADS image features among radiology trainees when performing diagnostic interpretation of mammograms. We also investigate whether these error making patterns can be captured by individual user models. To test our hypothesis we propose a user modeling algorithm that uses the previous readings of a trainee to identify whether certain BI-RADS feature values (e.g. "spiculated" value for "margin" feature) are associated with higher than usual likelihood that the feature will be assessed incorrectly. In our experiments we used readings of 3 radiology residents and 7 breast imaging experts for 33 breast masses for the following BI-RADS features: parenchyma density, mass margin, mass shape and mass density. The expert readings were considered as the gold standard. Rule-based individual user models were developed and tested using the leave one-one-out crossvalidation scheme. Our experimental evaluation showed that the individual user models are accurate in identifying cases for which errors are more likely to be made. The user models captured regularities in error making for all 3 residents. This finding supports our hypothesis about existence of individual error making patterns in assessment of mammographic image features using the BI-RADS lexicon. Explicit user models identifying the weaknesses of each resident could be of great use when developing and adapting a personalized training plan to meet the resident's individual needs. Such approach fits well with the framework of adaptive computer-aided educational systems in mammography we have proposed before.

  4. Using computer-extracted image features for modeling of error-making patterns in detection of mammographic masses among radiology residents

    SciTech Connect

    Zhang, Jing Ghate, Sujata V.; Yoon, Sora C.; Lo, Joseph Y.; Kuzmiak, Cherie M.; Mazurowski, Maciej A.

    2014-09-15

    Purpose: Mammography is the most widely accepted and utilized screening modality for early breast cancer detection. Providing high quality mammography education to radiology trainees is essential, since excellent interpretation skills are needed to ensure the highest benefit of screening mammography for patients. The authors have previously proposed a computer-aided education system based on trainee models. Those models relate human-assessed image characteristics to trainee error. In this study, the authors propose to build trainee models that utilize features automatically extracted from images using computer vision algorithms to predict likelihood of missing each mass by the trainee. This computer vision-based approach to trainee modeling will allow for automatically searching large databases of mammograms in order to identify challenging cases for each trainee. Methods: The authors’ algorithm for predicting the likelihood of missing a mass consists of three steps. First, a mammogram is segmented into air, pectoral muscle, fatty tissue, dense tissue, and mass using automated segmentation algorithms. Second, 43 features are extracted using computer vision algorithms for each abnormality identified by experts. Third, error-making models (classifiers) are applied to predict the likelihood of trainees missing the abnormality based on the extracted features. The models are developed individually for each trainee using his/her previous reading data. The authors evaluated the predictive performance of the proposed algorithm using data from a reader study in which 10 subjects (7 residents and 3 novices) and 3 experts read 100 mammographic cases. Receiver operating characteristic (ROC) methodology was applied for the evaluation. Results: The average area under the ROC curve (AUC) of the error-making models for the task of predicting which masses will be detected and which will be missed was 0.607 (95% CI,0.564-0.650). This value was statistically significantly different

  5. [Dose requirement and definition of the image with new types of mammographic systems (author's transl)].

    PubMed

    Frost, D; Krause, R A

    1980-11-01

    Several film-screen-systems have been tested under clinical conditions in order to check their utility for mammography (Dupont, Kodak, 3M, Agfa, Auer). The aim was to find the balance between the resolution of the details and the minimal radiation dose. PMID:7434387

  6. An Examination of Sexual Orientation Group Patterns in Mammographic and Colorectal Screening in a Cohort of U.S. Women

    PubMed Central

    Austin, S. Bryn; Pazaris, Mathew J.; Nichols, Lauren P.; Bowen, Deborah; Wei, Esther K.; Spiegelman, Donna

    2014-01-01

    Purpose Underutilization of cancer screening has been found especially to affect socially marginalized groups. We investigated sexual orientation group patterns in breast and colorectal cancer screening adherence. Methods Data on breast and colorectal cancer screening, sexual orientation, and sociodemographics were gathered prospectively from 1989 through 2005 from 85,759 U.S. women in the Nurses' Health Study II. Publicly available data on state-level health care quality and sexual orientation-related legal protections were also gathered. Multivariable models were used to estimate sexual orientation-group differences in breast and colorectal cancer screening, controlling for sociodemographics and state-level health care quality and legal protections for sexual minorities. Results Receipt of a mammogram in the past two years was common though not universal and differed only slightly by sexual orientation: heterosexual 84%; bisexual 79%; lesbian 82%. Fewer than half of eligible women had ever received a colonoscopy or sigmoidoscopy, and rates did not differ by sexual orientation: heterosexual 39%; bisexual 39%; lesbian 42%. In fully adjusted models, state-level health care quality score, though not state-level legal protections for sexual minorities, was positively associated with likelihood of being screened for all women regardless of sexual orientation. Conclusions Concerns have been raised that unequal health care access for sexual orientation minorities may adversely affect cancer screening. We found small disparities in mammography and none in colorectal screening, though adherence to colorectal screening recommendations was uniformly very low. Interventions are needed to increase screening in women of all sexual orientation groups, particularly in areas with poor health care policies. PMID:22729931

  7. Training system for digital mammographic diagnoses of breast cancer

    NASA Astrophysics Data System (ADS)

    Thomaz, R. L.; Nirschl Crozara, M. G.; Patrocinio, A. C.

    2013-03-01

    As the technology evolves, the analog mammography systems are being replaced by digital systems. The digital system uses video monitors as the display of mammographic images instead of the previously used screen-film and negatoscope for analog images. The change in the way of visualizing mammographic images may require a different approach for training the health care professionals in diagnosing the breast cancer with digital mammography. Thus, this paper presents a computational approach to train the health care professionals providing a smooth transition between analog and digital technology also training to use the advantages of digital image processing tools to diagnose the breast cancer. This computational approach consists of a software where is possible to open, process and diagnose a full mammogram case from a database, which has the digital images of each of the mammographic views. The software communicates with a gold standard digital mammogram cases database. This database contains the digital images in Tagged Image File Format (TIFF) and the respective diagnoses according to BI-RADSTM, these files are read by software and shown to the user as needed. There are also some digital image processing tools that can be used to provide better visualization of each single image. The software was built based on a minimalist and a user-friendly interface concept that might help in the smooth transition. It also has an interface for inputting diagnoses from the professional being trained, providing a result feedback. This system has been already completed, but hasn't been applied to any professional training yet.

  8. A feasibility study of X-ray phase-contrast mammographic tomography at the Imaging and Medical beamline of the Australian Synchrotron.

    PubMed

    Nesterets, Yakov I; Gureyev, Timur E; Mayo, Sheridan C; Stevenson, Andrew W; Thompson, Darren; Brown, Jeremy M C; Kitchen, Marcus J; Pavlov, Konstantin M; Lockie, Darren; Brun, Francesco; Tromba, Giuliana

    2015-11-01

    Results are presented of a recent experiment at the Imaging and Medical beamline of the Australian Synchrotron intended to contribute to the implementation of low-dose high-sensitivity three-dimensional mammographic phase-contrast imaging, initially at synchrotrons and subsequently in hospitals and medical imaging clinics. The effect of such imaging parameters as X-ray energy, source size, detector resolution, sample-to-detector distance, scanning and data processing strategies in the case of propagation-based phase-contrast computed tomography (CT) have been tested, quantified, evaluated and optimized using a plastic phantom simulating relevant breast-tissue characteristics. Analysis of the data collected using a Hamamatsu CMOS Flat Panel Sensor, with a pixel size of 100 µm, revealed the presence of propagation-based phase contrast and demonstrated significant improvement of the quality of phase-contrast CT imaging compared with conventional (absorption-based) CT, at medically acceptable radiation doses. PMID:26524316

  9. New mammography screen/film combinations: Imaging characteristics and radiation dose

    SciTech Connect

    Kimme-Smith, C.; Bassett, L.W.; Gold, R.H.; Zheutlin, J.; Gornbein, J.A. )

    1990-04-01

    Five types of film (Kodak OM, Kodak OM-SO177, Konica CM, Dupont Microvision, and Fuji MiMa) exposed in combination with seven different intensifying screens (Min R, Min R Medium, Siemens Orthox MA, Kyokka HR Mammo Fine, Agfa Gevaert Detail S (old and new), and Konica Monarch) were processed for either 90 sec (at 33.3{degrees}C) or 3 min (at 35.0 degrees C). The films imaged a Computerized Imaging Reference System phantom with additional detail test objects placed on its surface to produce four groups of objects with which to evaluate resolution and contrast. For objects that tested resolution, the Kyokka HR Mammo Fine (Fuji) screen was statistically significantly superior; for objects that tested contrast, the Konica Monarch screen was statistically significantly superior. Extended processing did not affect Dupont and Kodak OM film as much as it affected the other films. It did affect contrast for the other films tested. The mean glandular doses from gridless exposures ranged from 32 to 80 mrad (0.32-0.80 mGy) over all film/screen/processing combinations for a 4.5-cm-thick test object. Several new film/screen combinations can provide images superior to the Kodak Min R/OM combination at a reduced radiation dose. The Kyokka HR Mammo Fine (Fuji) screen was found statistically superior in radiographic resolution of mammographic test objects and the Konica Monarch screen was found to be superior in defining contrast.

  10. New mammography screen/film combinations: imaging characteristics and radiation dose.

    PubMed

    Kimme-Smith, C; Bassett, L W; Gold, R H; Zheutlin, J; Gornbein, J A

    1990-04-01

    Five types of film (Kodak OM, Kodak OM-SO177, Konica CM, Dupont Microvision, and Fuji MiMa) exposed in combination with seven different intensifying screens (Min R, Min R Medium, Siemens Orthox MA, Kyokka HR Mammo Fine, Agfa Gevaert Detail S (old and new), and Konica Monarch) were processed for either 90 sec (at 33.3 degrees C) or 3 min (at 35.0 degrees C). The films imaged a Computerized Imaging Reference System phantom with additional detail test objects placed on its surface to produce four groups of objects with which to evaluate resolution and contrast. For objects that tested resolution, the Kyokka HR Mammo Fine (Fuji) screen was statistically significantly superior; for objects that tested contrast, the Konica Monarch screen was statistically significantly superior. Extended processing did not affect Dupont and Kodak OM film as much as it affected the other films. It did affect contrast for the other films tested. The mean glandular doses from gridless exposures ranged from 32 to 80 mrad (0.32-0.80 mGy) over all film/screen/processing combinations for a 4.5-cm-thick test object. Several new film/screen combinations can provide images superior to the Kodak Min R/OM combination at a reduced radiation dose. The Kyokka HR Mammo Fine (Fuji) screen was found statistically superior in radiographic resolution of mammographic test objects and the Konica Monarch screen was found to be superior in defining contrast. PMID:2107663

  11. Mammographic density measurements are not affected by mammography system

    PubMed Central

    Damases, Christine N.; Brennan, Patrick C.; McEntee, Mark F.

    2015-01-01

    Abstract. Mammographic density (MD) is a significant risk factor for breast cancer and has been shown to reduce the sensitivity of mammography screening. Knowledge of a woman’s density can be used to predict her risk of developing breast cancer and personalize her imaging pathway. However, measurement of breast density has proven to be troublesome with wide variations in density recorded using radiologists’ visual Breast Imaging Reporting and Data System (BIRADS). Several automated methods for assessing breast density have been proposed, each with their own source of measurement error. The use of differing mammographic imaging systems further complicates MD measurement, especially for the same women imaged over time. The purpose of this study was to investigate whether having a mammogram on differing manufacturer’s equipment affects a woman’s MD measurement. Raw mammographic images were acquired on two mammography imaging systems (General Electric and Hologic) one year apart and processed using VolparaDensity™ to obtain the Volpara Density Grade (VDG) and average volumetric breast density percentage (AvBD%). Visual BIRADS scores were also obtained from 20 expert readers. BIRADS scores for both systems showed strong positive correlation (ρ=0.904; p<0.001), while the VDG (ρ=0.978; p<0.001) and AvBD% (ρ=0.973; p<0.001) showed stronger positive correlations. Substantial agreement was shown between the systems for BIRADS (κ=0.692; p<0.001), however, the systems demonstrated an almost perfect agreement for VDG (κ=0.933; p<0.001). PMID:26158085

  12. Mammographic computer-aided detection systems.

    PubMed

    2003-04-01

    While mammography is regarded as the best means available to screen for breast cancer, reading mammograms is a tedious, error-prone task. Given the repetitiveness of the process and the fact that less than 1% of mammograms in the average screening population contain cancer, it's no wonder that a significant number of breast cancers--about 28%--are missed by radiologists. The fact that human error is such a significant obstacle makes mammography screening an ideal application for computer-aided detection (CAD) systems. CAD systems serve as a "second pair of eyes" to ensure that radiologists don't miss a suspect area on an image. They analyze patterns on a digitized mammographic image, identify regions that may contain an abnormality indicating cancer, and mark these regions. The marks are then inspected and classified by a radiologist. But CAD systems provide no diagnosis of any kind--it's up to the radiologist to analyze the marked area and decide if it shows cancer. In this Evaluation, we describe the challenges posed by screening mammography, the operating principles and overall efficacy of CAD systems, and the characteristics to consider when purchasing a system. We also compare the performance of two commercially available systems, iCAD's MammoReader and R2's ImageChecker. Because the two systems offer comparable sensitivity, our judgments are based on other performance characteristics, including their ease of use, the number of false marks they produce, the degree to which they can integrate with hospital information systems, and their processing speed. PMID:12760158

  13. Influence of factors on mammographic density in premenopausal Chinese women.

    PubMed

    Yang, Yaping; Liu, Jieqiong; Gu, Ran; Hu, Yue; Liu, Fengtao; Yun, Miaomiao; Xiao, Qiaozhen; Wu, Mei; Liu, Qiang; Su, Fengxi

    2016-07-01

    Mammographic density is an independent strong risk factor for breast cancer. However, the influence of factors on mammographic density in premenopausal women remains unclear. In the Southern Professional Women Breast Cancer Screening Project, we assessed the associations between mammographic density and its influential factors using multivariate logistic regression in premenopausal women adjusting for BMI, age, duration of breastfeeding, number of live births, and breast size. A total of 1699 premenopausal women aged 27 to 57 years, who had been screened by mammography, were enrolled in this cross-sectional study. Overall, 85.2% were categorized as having dense breasts (BI-RADS density 3 and 4) and 14.8% as having fatty breasts (BI-RADS density 1 and 2). In multivariate and logistic regression analysis, only BMI and age were significantly negatively correlated with mammographic density in premenopausal women (P<0.001). No significant associations between mammographic density and number of deliveries, breastfeeding duration, education level, family history of breast cancer, as well as breast size and sleep quality, were identified in the study. Age and BMI are negatively associated with mammographic density in premenopausal Chinese women. Information on the influential factors of mammographic density in premenopausal women might provide meaningful insights into breast cancer prevention. PMID:26075657

  14. Variable Shadow Screens for Imaging Optical Devices

    NASA Technical Reports Server (NTRS)

    Lu, Ed; Chretien, Jean L.

    2004-01-01

    Variable shadow screens have been proposed for reducing the apparent brightnesses of very bright light sources relative to other sources within the fields of view of diverse imaging optical devices, including video and film cameras and optical devices for imaging directly into the human eye. In other words, variable shadow screens would increase the effective dynamic ranges of such devices. Traditionally, imaging sensors are protected against excessive brightness by use of dark filters and/or reduction of iris diameters. These traditional means do not increase dynamic range; they reduce the ability to view or image dimmer features of an image because they reduce the brightness of all parts of an image by the same factor. On the other hand, a variable shadow screen would darken only the excessively bright parts of an image. For example, dim objects in a field of view that included the setting Sun or bright headlights could be seen more readily in a picture taken through a variable shadow screen than in a picture of the same scene taken through a dark filter or a narrowed iris. The figure depicts one of many potential variations of the basic concept of the variable shadow screen. The shadow screen would be a normally transparent liquid-crystal matrix placed in front of a focal-plane array of photodetectors in a charge-coupled-device video camera. The shadow screen would be placed far enough from the focal plane so as not to disrupt the focal-plane image to an unacceptable degree, yet close enough so that the out-of-focus shadows cast by the screen would still be effective in darkening the brightest parts of the image. The image detected by the photodetector array itself would be used as feedback to drive the variable shadow screen: The video output of the camera would be processed by suitable analog and/or digital electronic circuitry to generate a negative partial version of the image to be impressed on the shadow screen. The parts of the shadow screen in front of

  15. Retinal Imaging Techniques for Diabetic Retinopathy Screening.

    PubMed

    Goh, James Kang Hao; Cheung, Carol Y; Sim, Shaun Sebastian; Tan, Pok Chien; Tan, Gavin Siew Wei; Wong, Tien Yin

    2016-03-01

    Due to the increasing prevalence of diabetes mellitus, demand for diabetic retinopathy (DR) screening platforms is steeply increasing. Early detection and treatment of DR are key public health interventions that can greatly reduce the likelihood of vision loss. Current DR screening programs typically employ retinal fundus photography, which relies on skilled readers for manual DR assessment. However, this is labor-intensive and suffers from inconsistency across sites. Hence, there has been a recent proliferation of automated retinal image analysis software that may potentially alleviate this burden cost-effectively. Furthermore, current screening programs based on 2-dimensional fundus photography do not effectively screen for diabetic macular edema (DME). Optical coherence tomography is becoming increasingly recognized as the reference standard for DME assessment and can potentially provide a cost-effective solution for improving DME detection in large-scale DR screening programs. Current screening techniques are also unable to image the peripheral retina and require pharmacological pupil dilation; ultra-widefield imaging and confocal scanning laser ophthalmoscopy, which address these drawbacks, possess great potential. In this review, we summarize the current DR screening methods using various retinal imaging techniques, and also outline future possibilities. Advances in retinal imaging techniques can potentially transform the management of patients with diabetes, providing savings in health care costs and resources. PMID:26830491

  16. Evaluation of Doses and Image Quality in Mammography with Screen-Film, CR, and DR Detectors – Application of the ACR Phantom

    PubMed Central

    Ślusarczyk-Kacprzyk, Wioletta; Skrzyński, Witold; Fabiszewska, Ewa

    2016-01-01

    Summary Background Different methods of image quality evaluation are routinely used for analogue and digital mammography systems in Poland. In the present study, image quality for several screen-film (SF), computed radiography (CR), and fully digital (DR) mammography systems was compared directly with the use of the ACR mammography accreditation phantom. Material/Methods Image quality and mean glandular doses were measured and compared for 47 mammography systems in the Mazovia Voivodeship in Poland, including 26 SF systems, 12 CR systems, and 9 DR systems. The mean glandular dose for the breast simulated by 4.5 cm of PMMA was calculated with methods described in the “European guidelines for quality assurance in breast cancer screening and diagnosis”. Visibility of the structures in the image (fibers, microcalcifications, and masses) was evaluated with the mammographic accreditation ACR phantom. Results Image quality for DR systems was significantly higher than for SF and CR systems. Several SF systems failed to pass the image quality tests because of artifacts. The doses were within acceptable limits for all of the systems, but the doses for the CR systems were significantly higher than for the SF and DR systems. Conclusions The best image quality, at a reasonably low dose, was observed for the DR systems. The CR systems are capable of obtaining the same image quality as the SF systems, but only at a significantly higher dose. The ACR phantom can be routinely used to evaluate image quality for all types of mammographic systems.

  17. Shapelet analysis of pupil dilation for modeling visuo-cognitive behavior in screening mammography

    NASA Astrophysics Data System (ADS)

    Alamudun, Folami; Yoon, Hong-Jun; Hammond, Tracy; Hudson, Kathy; Morin-Ducote, Garnetta; Tourassi, Georgia

    2016-03-01

    Our objective is to improve understanding of visuo-cognitive behavior in screening mammography under clinically equivalent experimental conditions. To this end, we examined pupillometric data, acquired using a head-mounted eye-tracking device, from 10 image readers (three breast-imaging radiologists and seven Radiology residents), and their corresponding diagnostic decisions for 100 screening mammograms. The corpus of mammograms comprised cases of varied pathology and breast parenchymal density. We investigated the relationship between pupillometric fluctuations, experienced by an image reader during mammographic screening, indicative of changes in mental workload, the pathological characteristics of a mammographic case, and the image readers' diagnostic decision and overall task performance. To answer these questions, we extract features from pupillometric data, and additionally applied time series shapelet analysis to extract discriminative patterns in changes in pupil dilation. Our results show that pupillometric measures are adequate predictors of mammographic case pathology, and image readers' diagnostic decision and performance with an average accuracy of 80%.

  18. Evaluation of the image quality in digital breast tomosynthesis (DBT) employed with a compressed-sensing (CS)-based reconstruction algorithm by using the mammographic accreditation phantom

    NASA Astrophysics Data System (ADS)

    Park, Yeonok; Cho, Heemoon; Je, Uikyu; Cho, Hyosung; Park, Chulkyu; Lim, Hyunwoo; Kim, Kyuseok; Kim, Guna; Park, Soyoung; Woo, Taeho; Choi, Sungil

    2015-12-01

    In this work, we have developed a prototype digital breast tomosynthesis (DBT) system which mainly consists of an x-ray generator (28 kVp, 7 mA s), a CMOS-type flat-panel detector (70-μm pixel size, 230.5×339 mm2 active area), and a rotational arm to move the x-ray generator in an arc. We employed a compressed-sensing (CS)-based reconstruction algorithm, rather than a common filtered-backprojection (FBP) one, for more accurate DBT reconstruction. Here the CS is a state-of-the-art mathematical theory for solving the inverse problems, which exploits the sparsity of the image with substantially high accuracy. We evaluated the reconstruction quality in terms of the detectability, the contrast-to-noise ratio (CNR), and the slice-sensitive profile (SSP) by using the mammographic accreditation phantom (Model 015, CIRS Inc.) and compared it to the FBP-based quality. The CS-based algorithm yielded much better image quality, preserving superior image homogeneity, edge sharpening, and cross-plane resolution, compared to the FBP-based one.

  19. Screening MR imaging versus screening ultrasound: pros and cons.

    PubMed

    Mahoney, Mary C; Newell, Mary S

    2013-08-01

    Data support greater sensitivity of MR imaging compared with mammography and ultrasound in high-risk populations, in particular BRCA 1 and BRCA 2 carriers. Screening ultrasound improves cancer yield versus mammography alone in high-risk patients and in patients with dense breasts and is less expensive. Drawbacks include low positive predictive value, operator dependence, and significant physician time expenditure. Advances, such as refinement of automated whole-breast ultrasound, new outcomes data from ultrasound-detected masses in BI-RADS 3 and 4a categories, and development of new MR imaging sequences that allow rapid screening, potentially without use of contrast, will likely reveal the most appropriate tool over time. PMID:23928240

  20. Breast cancer screening controversies: who, when, why, and how?

    PubMed

    Chetlen, Alison; Mack, Julie; Chan, Tiffany

    2016-01-01

    Mammographic screening is effective in reducing mortality from breast cancer. The issue is not whether mammography is effective, but whether the false positive rate and false negative rates can be reduced. This review will discuss controversies including the reduction in breast cancer mortality, overdiagnosis, the ideal screening candidate, and the optimal imaging modality for breast cancer screening. The article will compare and contrast screening mammography, tomosynthesis, whole-breast screening ultrasound, magnetic resonance imaging, and molecular breast imaging. Though supplemental imaging modalities are being utilized to improve breast cancer diagnosis, mammography still remains the gold standard for breast cancer screening. PMID:26093511

  1. Intagliated phosphor screen image tube project

    NASA Technical Reports Server (NTRS)

    Hertzel, R. J.

    1982-01-01

    The production and evaluation of a magnetic focus image tube for astronomical photography that has an intagliated phosphor screen is described. The modulation transfer function of such a tube was measured by electronic means and by film tests, and the results compared with tubes of more conventional construction. The physical properties of the image tube and film combination, the analytical model of the optical interface, and the salient features of the intagliated screen tube are described. The results of electronic MTF tests of the intagliated image tube and of the densitometry of the tube and film test samples are presented. It is concluded that the intagliated screen is a help, but that the thickness of the photographic film is also important.

  2. Hyperspectral imaging for melanoma screening

    NASA Astrophysics Data System (ADS)

    Martin, Justin; Krueger, James; Gareau, Daniel

    2014-03-01

    The 5-year survival rate for patients diagnosed with Melanoma, a deadly form of skin cancer, in its latest stages is about 15%, compared to over 90% for early detection and treatment. We present an imaging system and algorithm that can be used to automatically generate a melanoma risk score to aid clinicians in the early identification of this form of skin cancer. Our system images the patient's skin at a series of different wavelengths and then analyzes several key dermoscopic features to generate this risk score. We have found that shorter wavelengths of light are sensitive to information in the superficial areas of the skin while longer wavelengths can be used to gather information at greater depths. This accompanying diagnostic computer algorithm has demonstrated much higher sensitivity and specificity than the currently commercialized system in preliminary trials and has the potential to improve the early detection of melanoma.

  3. Lung cancer screening: from imaging to biomarker.

    PubMed

    Xiang, Dong; Zhang, Bicheng; Doll, Donald; Shen, Kui; Kloecker, Goetz; Freter, Carl

    2013-01-01

    Despite several decades of intensive effort to improve the imaging techniques for lung cancer diagnosis and treatment, primary lung cancer is still the number one cause of cancer death in the United States and worldwide. The major causes of this high mortality rate are distant metastasis evident at diagnosis and ineffective treatment for locally advanced disease. Indeed, approximately forty percent of newly diagnosed lung cancer patients have distant metastasis. Currently, the only potential curative therapy is surgical resection of early stage lung cancer. Therefore, early detection of lung cancer could potentially increase the chance of cure by surgery and underlines the importance of screening and detection of lung cancer. In the past fifty years, screening of lung cancer by chest X-Ray (CXR), sputum cytology, computed tomography (CT), fluorescence endoscopy and low-dose spiral CT (LDCT) has not improved survival except for the recent report in 2010 by the National Lung Screening Trial (NLST), which showed a 20 percent mortality reduction in high risk participants screened with LDCT compared to those screened with CXRs. Furthermore, serum biomarkers for detection of lung cancer using free circulating DNA and RNA, exosomal microRNA, circulating tumor cells and various lung cancer specific antigens have been studied extensively and novel screening methods are being developed with encouraging results. The history of lung cancer screening trials using CXR, sputum cytology and LDCT, as well as results of trials involving various serum biomarkers, are reviewed herein. PMID:24252206

  4. Lung cancer screening: from imaging to biomarker

    PubMed Central

    2013-01-01

    Despite several decades of intensive effort to improve the imaging techniques for lung cancer diagnosis and treatment, primary lung cancer is still the number one cause of cancer death in the United States and worldwide. The major causes of this high mortality rate are distant metastasis evident at diagnosis and ineffective treatment for locally advanced disease. Indeed, approximately forty percent of newly diagnosed lung cancer patients have distant metastasis. Currently, the only potential curative therapy is surgical resection of early stage lung cancer. Therefore, early detection of lung cancer could potentially increase the chance of cure by surgery and underlines the importance of screening and detection of lung cancer. In the past fifty years, screening of lung cancer by chest X-Ray (CXR), sputum cytology, computed tomography (CT), fluorescence endoscopy and low-dose spiral CT (LDCT) has not improved survival except for the recent report in 2010 by the National Lung Screening Trial (NLST), which showed a 20 percent mortality reduction in high risk participants screened with LDCT compared to those screened with CXRs. Furthermore, serum biomarkers for detection of lung cancer using free circulating DNA and RNA, exosomal microRNA, circulating tumor cells and various lung cancer specific antigens have been studied extensively and novel screening methods are being developed with encouraging results. The history of lung cancer screening trials using CXR, sputum cytology and LDCT, as well as results of trials involving various serum biomarkers, are reviewed herein. PMID:24252206

  5. Virtual display: unidirectional diffusing image screen for extension of screen region using mirror image

    NASA Astrophysics Data System (ADS)

    Sakamoto, Kunio; Adachi, Mariko

    2008-03-01

    A liquid crystal display (LCD) recently comes into common use. It is possible for this display unit to provide the same size of displaying area as the image screen on the panel. Thus the conventional display can show only one screen, but it is impossible to enlarge the size of a screen, for example twice. To enlarge the display area, the authors have developed an enlarging method of display area using a mirror. Our extension method enables the observers to show the virtual image plane and to enlarge a screen area twice. In the developed display unit, we made use of an image separating technique using polarized glasses, a parallax barrier or a lenticular lens screen for 3D imaging. However, each technique has a defect at viewing an image. In the glasses method, an observer needs to wear the special glasses for a viewing screen. The slit or lens sheet reduces the resolution in half. To solve these problems, we develop a new virtual display system using a unidirectional diffusing image screen.

  6. Magnetic resonance imaging for lung cancer screen.

    PubMed

    Wang, Yi-Xiang J; Lo, Gladys G; Yuan, Jing; Larson, Peder E Z; Zhang, Xiaoliang

    2014-09-01

    Lung cancer is the leading cause of cancer related death throughout the world. Lung cancer is an example of a disease for which a large percentage of the high-risk population can be easily identified via a smoking history. This has led to the investigation of lung cancer screening with low-dose helical/multi-detector CT. Evidences suggest that early detection of lung cancer allow more timely therapeutic intervention and thus a more favorable prognosis for the patient. The positive relationship of lesion size to likelihood of malignancy has been demonstrated previously, at least 99% of all nodules 4 mm or smaller are benign, while noncalcified nodules larger than 8 mm diameter bear a substantial risk of malignancy. In the recent years, the availability of high-performance gradient systems, in conjunction with phased-array receiver coils and optimized imaging sequences, has made MR imaging of the lung feasible. It can now be assumed a threshold size of 3-4 mm for detection of lung nodules with MRI under the optimal conditions of successful breath-holds with reliable gating or triggering. In these conditions, 90% of all 3-mm nodules can be correctly diagnosed and that nodules 5 mm and larger are detected with 100% sensitivity. Parallel imaging can significantly shorten the imaging acquisition time by utilizing the diversity of sensitivity profile of individual coil elements in multi-channel radiofrequency receive coil arrays or transmit/receive coil arrays to reduce the number of phase encoding steps required in imaging procedure. Compressed sensing technique accelerates imaging acquisition from dramatically undersampled data set by exploiting the sparsity of the images in an appropriate transform domain. With the combined imaging algorithm of parallel imaging and compressed sensing and advanced 32-channel or 64-channel RF hardware, overall imaging acceleration of 20 folds or higher can then be expected, ultimately achieve free-breathing and no ECG gating acquisitions

  7. Magnetic resonance imaging for lung cancer screen

    PubMed Central

    Lo, Gladys G.; Yuan, Jing; Larson, Peder E. Z.

    2014-01-01

    Lung cancer is the leading cause of cancer related death throughout the world. Lung cancer is an example of a disease for which a large percentage of the high-risk population can be easily identified via a smoking history. This has led to the investigation of lung cancer screening with low-dose helical/multi-detector CT. Evidences suggest that early detection of lung cancer allow more timely therapeutic intervention and thus a more favorable prognosis for the patient. The positive relationship of lesion size to likelihood of malignancy has been demonstrated previously, at least 99% of all nodules 4 mm or smaller are benign, while noncalcified nodules larger than 8 mm diameter bear a substantial risk of malignancy. In the recent years, the availability of high-performance gradient systems, in conjunction with phased-array receiver coils and optimized imaging sequences, has made MR imaging of the lung feasible. It can now be assumed a threshold size of 3-4 mm for detection of lung nodules with MRI under the optimal conditions of successful breath-holds with reliable gating or triggering. In these conditions, 90% of all 3-mm nodules can be correctly diagnosed and that nodules 5 mm and larger are detected with 100% sensitivity. Parallel imaging can significantly shorten the imaging acquisition time by utilizing the diversity of sensitivity profile of individual coil elements in multi-channel radiofrequency receive coil arrays or transmit/receive coil arrays to reduce the number of phase encoding steps required in imaging procedure. Compressed sensing technique accelerates imaging acquisition from dramatically undersampled data set by exploiting the sparsity of the images in an appropriate transform domain. With the combined imaging algorithm of parallel imaging and compressed sensing and advanced 32-channel or 64-channel RF hardware, overall imaging acceleration of 20 folds or higher can then be expected, ultimately achieve free-breathing and no ECG gating acquisitions

  8. Power spectral analysis of mammographic parenchymal patterns

    NASA Astrophysics Data System (ADS)

    Li, Hui; Giger, Maryellen L.; Olopade, Olufunmilayo I.

    2006-03-01

    Mammographic density and parenchymal patterns have been shown to be associated with the risk of developing breast cancer. Two groups of women: gene-mutation carriers and low-risk women were included in this study. Power spectral analysis was performed within parenchymal regions of 172 digitized craniocaudal normal mammograms of the BRCA1/BRCA2 gene-mutation carriers and those of women at low-risk of developing breast cancer. The power law spectrum of the form, P(f)=B/f β was evaluated for the mammographic patterns. Receiver Operating Characteristic (ROC) analysis was used to assess the performance of exponent β as a decision variable in the task of distinguishing between high and low-risk subjects. Power spectral analysis of mammograms demonstrated that mammographic parenchymal patterns have a power-law spectrum of the form, P(f)=B/f β where f is radial spatial frequency, with the average β values of 2.92 and 2.47 for the gene-mutation carriers and for the low-risk women, respectively. A z values of 0.90 and 0.89 were achieved in distinguishing between the gene-mutation carriers and the low-risk women with the individual image β value as the decision variable in the entire database and the age-matched group, respectively.

  9. Ghosted images: old lesbians on screen.

    PubMed

    Krainitzki, Eva

    2015-01-01

    Screen images of old lesbians combine modes of representing female gender, lesbian sexuality, and old age, all of which contain layers of otherness within a hetero-patriarchal and youth-centered society. Analyzing a range of films, from independent to mainstream cinema, this article explores how the ghosted lesbian paradigm intersects with narratives of aging as decline in representations of lesbian characters who are over the age of sixty. The spectral matters of illness, death, mourning, and widowhood inevitably culminate in an unhappy ending. Removed from a lesbian community context, intergenerational continuity vanishes and the old lesbian emerges as the cultural other. PMID:25575318

  10. Factors associated with mammographic decisions of Chinese-Australian women.

    PubMed

    Kwok, Cannas; Cant, Rosemary; Sullivan, Gerard

    2005-12-01

    BreastScreen (a free breast cancer screening service) has been implemented in Australia since 1991. Surveys conducted overseas consistently report that women of Chinese ancestry have low participation rates in breast cancer screening. Although Chinese women's use of breast cancer screening services has been investigated abroad, to date there are few studies of mammographic screening behavior among Chinese-Australian women. The purpose of this study is to explore and investigate the factors associated with mammographic decisions of Chinese-Australian women. Using a qualitative approach, in-depth interviews were conducted with 20 Chinese-Australian women. These were augmented by additional data from ethnographic observations. The findings show two facilitators: organizational factors (an invitation letter from BreastScreen and seniors' clubs arrangements) and the influence of 'significant others'. Barriers identified were fear perceptions of mammography, modesty and fear of stigmatization. This study provides a useful framework for designing and implementing mammographic screening services for Chinese-Australian women that may improve their participation rates. PMID:15888474

  11. Mammographic imaging with a small format CCD-based digital cassette: Physical characteristics of a clinical systema

    PubMed Central

    Vedantham, Srinivasan; Karellas, Andrew; Suryanarayanan, Sankararaman; Levis, Ilias; Sayag, Michel; Kleehammer, Robert; Heidsieck, Robert; D’Orsi, Carl J.

    2008-01-01

    The physical characteristics of a clinical charge coupled device (CCD)-based imager (Senovision, GE Medical Systems, Milwaukee, WI) for small-field digital mammography have been investigated. The imager employs a MinR 2000™ (Eastman Kodak Company, Rochester, NY) scintillator coupled by a 1:1 optical fiber to a front-illuminated 61×61 mm CCD operating at a pixel pitch of 30 microns. Objective criteria such as modulation transfer function (MTF), noise power spectrum (NPS), detective quantum efficiency (DQE), and noise equivalent quanta (NEQ) were employed for this evaluation. The results demonstrated a limiting spatial resolution (10% MTF) of 10 cy/mm. The measured DQE of the current prototype utilizing a 28 kVp, Mo–Mo spectrum beam hardened with 4.5 cm Lucite is ~40% at close to zero spatial frequency at an exposure of 8.2 mR, and decreases to ~28% at a low exposure of 1.1 mR. Detector element nonuniformity and electronic gain variations were not significant after appropriate calibration and software corrections. The response of the imager was linear and did not exhibit signal saturation under tested exposure conditions. PMID:10984230

  12. Use of border information in the classification of mammographic masses

    NASA Astrophysics Data System (ADS)

    Varela, C.; Timp, S.; Karssemeijer, N.

    2006-01-01

    We are developing a new method to characterize the margin of a mammographic mass lesion to improve the classification of benign and malignant masses. Towards this goal, we designed features that measure the degree of sharpness and microlobulation of mass margins. We calculated these features in a border region of the mass defined as a thin band along the mass contour. The importance of these features in the classification of benign and malignant masses was studied in relation to existing features used for mammographic mass detection. Features were divided into three groups, each representing a different mass segment: the interior region of a mass, the border and the outer area. The interior and the outer area of a mass were characterized using contrast and spiculation measures. Classification was done in two steps. First, features representing each of the three mass segments were merged into a neural network classifier resulting in a single regional classification score for each segment. Secondly, a classifier combined the three single scores into a final output to discriminate between benign and malignant lesions. We compared the classification performance of each regional classifier and the combined classifier on a data set of 1076 biopsy proved masses (590 malignant and 486 benign) from 481 women included in the Digital Database for Screening Mammography. Receiver operating characteristic (ROC) analysis was used to evaluate the accuracy of the classifiers. The area under the ROC curve (Az) was 0.69 for the interior mass segment, 0.76 for the border segment and 0.75 for the outer mass segment. The performance of the combined classifier was 0.81 for image-based and 0.83 for case-based evaluation. These results show that the combination of information from different mass segments is an effective approach for computer-aided characterization of mammographic masses. An advantage of this approach is that it allows the assessment of the contribution of regions rather

  13. Urinary Cadmium and Mammographic Density in Premenopausal Women

    PubMed Central

    Adams, Scott V.; Newcomb, Polly A.; Shafer, Martin M.; Atkinson, Charlotte; Aiello Bowles, Erin J.; Newton, Katherine M.; Lampe, Johanna W.

    2011-01-01

    Purpose Mammographic density (MD), a strong marker of breast cancer risk, is influenced by genetic, environmental, and hormonal factors. Cadmium, a persistent and widespread environmental pollutant, has been associated with risk of breast cancer, and laboratory evidence suggests cadmium is a carcinogen in the breast. We investigated the hypothesis that cadmium exposure is associated with higher MD. Methods In a cross-sectional study of MD and urinary cadmium concentration, percentage MD (MD%) and Breast Imaging-Reporting and Data Systems (BI-RADS ®) density category were determined from screening mammograms of 190 premenopausal women ages 40–45 years. Women completed a health questionnaire, and the cadmium content of spot urine samples was measured with inductively-coupled plasma mass spectrometry and corrected for urine creatinine. Urinary cadmium concentrations are thought to reflect exposure to cadmium over a period of 20–30 years. Multivariable linear regression and logistic regression were used to estimate the strength of association between urinary cadmium and mammographic breast density. Results Adjusted mean MD% among women in the upper tertile of creatinine-corrected urine cadmium was 4.6% higher (95% confidence interval (CI): −2.3 to 11.6%) than in women in the lowest cadmium tertile. Each two-fold increase in urine cadmium was associated with higher odds of MD% in the upper tertile (odds ratio(OR): 1.29, 95% CI: 0.82–2.02) or a BI-RADS category rating of “extremely dense” (OR: 1.75, 95% CI: 1.14–2.70). Stronger associations were observed among nulliparous women, and current or former smokers. Conclusions Exposure to cadmium may be associated with increased breast density in premenopausal women. PMID:21327468

  14. Impact of deprivation on breast cancer survival among women eligible for mammographic screening in the West Midlands (UK) and New South Wales (Australia): Women diagnosed 1997-2006.

    PubMed

    Woods, Laura M; Rachet, Bernard; O'Connell, Dianne; Lawrence, Gill; Coleman, Michel P

    2016-05-15

    Women diagnosed with breast cancer in the UK display marked differences in survival between categories defined by socio-economic deprivation. Timeliness of diagnosis is one of the possible explanations for these patterns. Women whose cancer is screen-detected are more likely to be diagnosed at an earlier stage. We examined deprivation and screening-specific survival in order to evaluate the role of early diagnosis upon deprivation-specific survival differences in the West Midlands (UK) and New South Wales (Australia). We estimated net survival for women aged 50-65 years at diagnosis and whom had been continuously eligible for screening from the age of 50. Records for 5,628 women in West Midlands (98.5% of those eligible, mean age at diagnosis 53.7 years) and 6,396 women in New South Wales (99.9% of those eligible, mean age at diagnosis 53.8 years). In New South Wales, survival was similar amongst affluent and deprived women, regardless of whether their cancer was screen-detected or not. In the West Midlands, there were large and persistent differences in survival between affluent and deprived women. Deprivation differences were similar between the screen-detected and non-screen detected groups. These differences are unlikely to be solely explained by artefact, or by patient or tumour factors. Further investigations into the timeliness and appropriateness of the treatments received by women with breast cancer across the social spectrum in the UK are warranted. PMID:26756181

  15. Image-quality performance of an a-Si : H-based X-ray imaging system for digital mammography

    NASA Astrophysics Data System (ADS)

    Darambara, D. G.; Taibi, A.; Speller, R. D.

    2002-01-01

    We have been investigating the potential of large area active matrix flat-panel a-Si : H imaging arrays for full-field digital X-ray mammography. To optimise the overall performance of such an imaging system under mammographic conditions, four different Gd 2O 2S : Tb phosphor screens (i.e. Lanex Fast-Back, Regular, Fine and MinR-2000) were employed and our full-field detector was integrated with the Feinfocus DIMA (Direct Magnification) PLUS MII mammographic unit. The spatial resolution and the image noise of the digital detector were measured and the X-ray imaging performance of the whole system was also evaluated with two mammographic phantoms. It was deduced from the results of this study that Regular screen offers the best compromise between sensitivity and spatial resolution and exhibits better overall image-quality performance than that of a conventional mammography system.

  16. Breast Cancers Detected at Screening MR Imaging and Mammography in Patients at High Risk: Method of Detection Reflects Tumor Histopathologic Results.

    PubMed

    Sung, Janice S; Stamler, Sarah; Brooks, Jennifer; Kaplan, Jennifer; Huang, Tammy; Dershaw, D David; Lee, Carol H; Morris, Elizabeth A; Comstock, Christopher E

    2016-09-01

    Purpose To compare the clinical, imaging, and histopathologic features of breast cancers detected at screening magnetic resonance (MR) imaging, screening mammography, and those detected between screening examinations (interval cancers) in women at high risk. Materials and Methods This retrospective institutional review board-approved, HIPAA-compliant review of 7519 women at high risk for breast cancer who underwent screening with MR imaging and mammography between January 2005 and December 2010 was performed to determine the number of screening-detected and interval cancers diagnosed. The need for informed consent was waived. Medical records were reviewed for age, risk factors (family or personal history of breast cancer, BRCA mutation status, history of high-risk lesion or mantle radiation), tumor histopathologic results, and time between diagnosis of interval cancer and most recent screening examination. The χ(2) test and logistic regression methods were used to compare the features of screening MR imaging, screening mammography, and interval cancers. The Wilcoxon signed-rank test was used to calculate P values. Results A total of 18 064 screening MR imaging examinations and 26 866 screening mammographic examinations were performed. Two hundred twenty-two cancers were diagnosed in 219 women, 167 (75%) at MR imaging, 43 (19%) at mammography, and 12 (5%) interval cancers. Median age at diagnosis was 52 years. No risk factors were associated with screening MR imaging, screening mammography, or interval cancer (P > .06). Cancers found at screening MR imaging were more likely to be invasive cancer (118 of 167 [71%]; P < .0001). Of the 43 cancers found at screening mammography, 38 (88%) manifested as calcifications and 28 (65%) were ductal carcinoma in situ. Interval cancers were associated with nodal involvement (P = .005) and the triple-negative subtype (P = .03). Conclusion In women at high risk for breast cancer who underwent screening with mammography and MR

  17. An approach for tissue density classification in mammographic images using artificial neural network based on wavelet and curvelet transforms

    NASA Astrophysics Data System (ADS)

    Yaşar, Hüseyin; Ceylan, Murat

    2015-03-01

    Breast cancer is one of the types of cancer which is most commonly seen in women. Density of breast is an important indicator for the risk of cancer. In addition, densities of tissue may harden the diagnosis by hiding the abnormalities occurring on the breast. For this reason, during the process of diagnosis, the process of automatic classification of breast density has a significant importance. In this study, a new system with the base of Artificial Neural Network (ANN) and multiple resolution analysis is suggested. Wavelet and curvelet analyses having the most common use have been used as multi resolution analysis. 4 pieces of statistics which are minimum value, maximum value, mean value and standard deviation have been extracted from the images which have been eluted to their sub-bands via multi resolution analysis. For the purpose of testing the success of the system, 322 pieces of images which are in MIAS database have been used. The obtained results for different backgrounds are so satisfying; and the highest classification values have been obtained as 97.16 % with Wavelet transform and ANN for fatty background and 79.80 % with Wavelet transform and ANN for fatty-glanduar background. The same results have been obtained using Wavelet transform and ANN and Curvelet transform and ANN for dense background and accuracy rate of 84.82 % have been reached. The results of mean classification have been obtained, for three pieces of tissue types (fatty, fatty-glanduar, dense), in sequence as 84.47 % with the use of ANN, 85.71 % with the use of curvelet analysis and ANN; and 87.26 % with the use of wavelet analysis and ANN.

  18. Local mammographic density as a predictor of breast cancer

    NASA Astrophysics Data System (ADS)

    Otsuka, Mayu; Harkness, Elaine F.; Chen, Xin; Moschidis, Emmanouil; Bydder, Megan; Gadde, Soujanya; Lim, Yit Y.; Maxwell, Anthony J.; Evans, Gareth D.; Howell, Anthony; Stavrinos, Paula; Wilson, Mary; Astley, Susan M.

    2015-03-01

    High overall mammographic density is associated with both an increased risk of developing breast cancer and the risk of cancer being masked. We compared local density at cancer sites in diagnostic images with corresponding previous screening mammograms (priors), and matched controls. VolparaTM density maps were obtained for 54 mammograms showing unilateral breast cancer and their priors which had been previously read as normal. These were each matched to 3 controls on age, menopausal status, hormone replacement therapy usage, body mass index and year of prior. Local percent density was computed in 15mm square regions at lesion sites and similar locations in the corresponding images. Conditional logistic regression was used to predict case-control status. In diagnostic and prior images, local density was increased at the lesion site compared with the opposite breast (medians 21.58%, 9.18%, p<0.001 diagnostic; 18.82%, 9.45%, p <0.001 prior). Women in the highest tertile of local density in priors were more likely to develop cancer than those in the lowest tertile (OR 42.09, 95% CI 5.37-329.94). Those in the highest tertile of VolparaTM gland volume were also more likely to develop cancer (OR 2.89, 95% CI 1.30-6.42). Local density is increased where cancer will develop compared with corresponding regions in the opposite breast and matched controls, and its measurement could enhance computer-aided mammography.

  19. iScreen: Image-Based High-Content RNAi Screening Analysis Tools.

    PubMed

    Zhong, Rui; Dong, Xiaonan; Levine, Beth; Xie, Yang; Xiao, Guanghua

    2015-09-01

    High-throughput RNA interference (RNAi) screening has opened up a path to investigating functional genomics in a genome-wide pattern. However, such studies are often restricted to assays that have a single readout format. Recently, advanced image technologies have been coupled with high-throughput RNAi screening to develop high-content screening, in which one or more cell image(s), instead of a single readout, were generated from each well. This image-based high-content screening technology has led to genome-wide functional annotation in a wider spectrum of biological research studies, as well as in drug and target discovery, so that complex cellular phenotypes can be measured in a multiparametric format. Despite these advances, data analysis and visualization tools are still largely lacking for these types of experiments. Therefore, we developed iScreen (image-Based High-content RNAi Screening Analysis Tool), an R package for the statistical modeling and visualization of image-based high-content RNAi screening. Two case studies were used to demonstrate the capability and efficiency of the iScreen package. iScreen is available for download on CRAN (http://cran.cnr.berkeley.edu/web/packages/iScreen/index.html). The user manual is also available as a supplementary document. PMID:25548139

  20. Impact of deprivation on breast cancer survival among women eligible for mammographic screening in the West Midlands (UK) and New South Wales (Australia): Women diagnosed 1997–2006

    PubMed Central

    Rachet, Bernard; O'Connell, Dianne; Lawrence, Gill; Coleman, Michel P.

    2016-01-01

    Women diagnosed with breast cancer in the UK display marked differences in survival between categories defined by socio‐economic deprivation. Timeliness of diagnosis is one of the possible explanations for these patterns. Women whose cancer is screen‐detected are more likely to be diagnosed at an earlier stage. We examined deprivation and screening‐specific survival in order to evaluate the role of early diagnosis upon deprivation‐specific survival differences in the West Midlands (UK) and New South Wales (Australia). We estimated net survival for women aged 50–65 years at diagnosis and whom had been continuously eligible for screening from the age of 50. Records for 5,628 women in West Midlands (98.5% of those eligible, mean age at diagnosis 53.7 years) and 6,396 women in New South Wales (99.9% of those eligible, mean age at diagnosis 53.8 years). In New South Wales, survival was similar amongst affluent and deprived women, regardless of whether their cancer was screen‐detected or not. In the West Midlands, there were large and persistent differences in survival between affluent and deprived women. Deprivation differences were similar between the screen‐detected and non‐screen detected groups. These differences are unlikely to be solely explained by artefact, or by patient or tumour factors. Further investigations into the timeliness and appropriateness of the treatments received by women with breast cancer across the social spectrum in the UK are warranted. PMID:26756181

  1. Mammographic breast density and serum phytoestrogen levels.

    PubMed

    Lowry, Sarah J; Sprague, Brian L; Aiello Bowles, Erin J; Hedman, Curtis J; Hemming, Jocelyn; Hampton, John M; Burnside, Elizabeth S; Sisney, Gale A; Buist, Diana S M; Trentham-Dietz, Amy

    2012-08-01

    Some forms of estrogen are associated with breast cancer risk as well as with mammographic density (MD), a strong marker of breast cancer risk. Whether phytoestrogen intake affects breast density, however, remains unclear. We evaluated the association between serum levels of phytoestrogens and MD in postmenopausal women. We enrolled 269 women, ages 55-70 yr, who received a screening mammogram and had no history of postmenopausal hormone use. Subjects completed a survey on diet and factors related to MD and provided a blood sample for analysis of 3 phytoestrogens: genistein, daidzein, and coumestrol. We examined whether mean percent MD was related to serum level of phytoestrogens, adjusting for age and body mass index. Genistein and daidzein levels correlated with self-reported soy consumption. Mean percent MD did not differ across women with different phytoestrogen levels. For example, women with nondetectable genistein levels had mean density of 11.0% [95% confidence intervals (CI) = 9.9-12.4], compared to 10.5% (95% CI = 8.0-13.7) and 11.2% (95% CI = 8.7-14.6) for < and ≥ median detectable levels, respectively. In a population with relatively low soy intake, serum phytoestrogens were not associated with mammographic density. Additional studies are needed to determine effects of higher levels, particularly given patterns of increasing phytoestrogen intake. PMID:22860715

  2. Dynamic infrared imaging for skin cancer screening

    NASA Astrophysics Data System (ADS)

    Godoy, Sebastián E.; Ramirez, David A.; Myers, Stephen A.; von Winckel, Greg; Krishna, Sanchita; Berwick, Marianne; Padilla, R. Steven; Sen, Pradeep; Krishna, Sanjay

    2015-05-01

    Dynamic thermal imaging (DTI) with infrared cameras is a non-invasive technique with the ability to detect the most common types of skin cancer. We discuss and propose a standardized analysis method for DTI of actual patient data, which achieves high levels of sensitivity and specificity by judiciously selecting pixels with the same initial temperature. This process compensates the intrinsic limitations of the cooling unit and is the key enabling tool in the DTI data analysis. We have extensively tested the methodology on human subjects using thermal infrared image sequences from a pilot study conducted jointly with the University of New Mexico Dermatology Clinic in Albuquerque, New Mexico (ClinicalTrials ID number NCT02154451). All individuals were adult subjects who were scheduled for biopsy or adult volunteers with clinically diagnosed benign condition. The sample size was 102 subjects for the present study. Statistically significant results were obtained that allowed us to distinguish between benign and malignant skin conditions. The sensitivity and specificity was 95% (with a 95% confidence interval of [87.8% 100.0%]) and 83% (with a 95% confidence interval of [73.4% 92.5%]), respectively, and with an area under the curve of 95%. Our results lead us to conclude that the DTI approach in conjunction with the judicious selection of pixels has the potential to provide a fast, accurate, non-contact, and non-invasive way to screen for common types of skin cancer. As such, it has the potential to significantly reduce the number of biopsies performed on suspicious lesions.

  3. Automatic image classification for the urinoculture screening.

    PubMed

    Andreini, Paolo; Bonechi, Simone; Bianchini, Monica; Garzelli, Andrea; Mecocci, Alessandro

    2016-03-01

    Urinary tract infections (UTIs) are considered to be the most common bacterial infection and, actually, it is estimated that about 150 million UTIs occur world wide yearly, giving rise to roughly $6 billion in healthcare expenditures and resulting in 100,000 hospitalizations. Nevertheless, it is difficult to carefully assess the incidence of UTIs, since an accurate diagnosis depends both on the presence of symptoms and on a positive urinoculture, whereas in most outpatient settings this diagnosis is made without an ad hoc analysis protocol. On the other hand, in the traditional urinoculture test, a sample of midstream urine is put onto a Petri dish, where a growth medium favors the proliferation of germ colonies. Then, the infection severity is evaluated by a visual inspection of a human expert, an error prone and lengthy process. In this paper, we propose a fully automated system for the urinoculture screening that can provide quick and easily traceable results for UTIs. Based on advanced image processing and machine learning tools, the infection type recognition, together with the estimation of the bacterial load, can be automatically carried out, yielding accurate diagnoses. The proposed AID (Automatic Infection Detector) system provides support during the whole analysis process: first, digital color images of Petri dishes are automatically captured, then specific preprocessing and spatial clustering algorithms are applied to isolate the colonies from the culture ground and, finally, an accurate classification of the infections and their severity evaluation are performed. The AID system speeds up the analysis, contributes to the standardization of the process, allows result repeatability, and reduces the costs. Moreover, the continuous transition between sterile and external environments (typical of the standard analysis procedure) is completely avoided. PMID:26780249

  4. Obstructive sleep apnea screening by NIRS imaging

    NASA Astrophysics Data System (ADS)

    Kashefi, Feraydune; Watenpaugh, Donald E.; Liu, Hanli

    2007-02-01

    This study aimed at determining cerebral hemodynamic parameters in human subjects during breath holding using near infrared spectroscopy (NIRS). Breath holding serves as a method of simulation OSA (Obstructive Sleep Apnea). Data was acquired non-invasively from 40 subjects, twenty OSA sufferers (10 females, 10 males, age 20-70 years), and twenty normal volunteers (10 females, 10 males, age 20-65 years). Measurements were conducted using a LED Imager (LEDI) during breath holding. In comparing OSA subjects with controls during breath holding, a consistent increase or even a decrease in oxy- ([O IIHb]), deoxy- ([HHb]), total hemoglobin ([tHb]) concentrations, and tissue hemoglobin oxygen saturation (SO II) in the regional brain tissue were observed. The LEDI probe consists of 4 sources and 10 detectors serving as 4 sets of 1 source and 4 detectors each. A three wavelength (730, 805, and 850 nm) LED was used and the wavelengths were switched sequentially. The distance between sources and the source-detector separation were 2.5 cm. Data acquisition consisted of three segments, baseline for one minute, followed by a period of breath holding, and then 2 minutes of recovery time. The duration of the breath holding was subject-dependent. Our investigation proves that NIR spectroscopy could be used as a tool for detecting cerebral hemodynamics and also serves as a method of screening patients with OSA.

  5. The impact of mammographic density and lesion location on detection

    NASA Astrophysics Data System (ADS)

    Al Mousa, Dana; Ryan, Elaine; Lee, Warwick; Nickson, Carolyn; Pietrzyk, Mariusz; Reed, Warren; Poulos, Ann; Li, Yanpeng; Brennan, Patrick

    2013-03-01

    The aim of this study is to examine the impact of breast density and lesion location on detection. A set of 55 mammographic images (23 abnormal images with 26 lesions and 32 normal images) were examined by 22 expert radiologists. The images were classified by an expert radiologist according to the Synoptic Breast Imaging Report of the National Breast Cancer Centre (NBCC) as having low mammographic density (D1<25% glandular and D2> 25-50% glandular) or high density (D3 51-75% glandular and D4> 75-glandular). The observers freely examined the images and located any malignancy using a 5-point confidence. Performance was defined using the following metrics: sensitivity, location sensitivity, specificity, receiver operating characteristic (ROC Az) curves and jackknife free-response receiver operator characteristics (JAFROC) figures of merit. Significant increases in sensitivity (p= 0.0174) and ROC (p=0.0001) values were noted for the higher density compared with lower density images according to NBCC classification. No differences were seen in radiologists' performance between lesions within or outside the fibroglandular region. In conclusion, analysis of our data suggests that radiologists scored higher using traditional metrics in higher mammographic density images without any improvement in lesion localisation. Lesion location whether within or outside the fibroglandular region appeared to have no impact on detection abilities suggesting that if a masking effect is present the impact is minimal. Eye-tracking analyses are ongoing.

  6. Classification of mammographic masses using generalized dynamic fuzzy neural networks

    NASA Astrophysics Data System (ADS)

    Lim, Wei Keat; Er, Meng Joo

    2003-05-01

    In this paper, computer-aided classification of mammographic masses using generalized dynamic fuzzy neural networks (GDFNN) is presented. The texture parameters, derived from first-order gradient distribution and gray-level co-occurrence matrices (GCMs), were computed from the regions of interest (ROIs). A total of 77 images containing 38 benign cases and 39 malignant cases from the Digital Database for Screening Mammography (DDSM) were analyzed. A fast approach of automatically generating fuzzy rules from training samples was implemented to classify tumors. The novelty of this work is that it alleviates the problem of the conventional computer-aided diagnosis (CAD) system that requires a designer to examine all the input-output relationships of a training database in order to obtain the most appropriate structure for the classifier. In this approach, not only the connection weights can be adjusted, but also the structure can be self-adaptive during the learning process. With the classifier automatically generated by the GDFNN learning algorithm, the area under the receiver-operating characteristic (ROC) curve, Az, reached 0.9289, which corresponded to a true-positive fraction of 94.9% at a false positive fraction of 73.7%. The corresponding accuracy was 84.4%, the positive predictive value was 78.7% and the negative predictive value was 93.3%.

  7. Mammographic feature type and reader variability by occupation: an ROC study

    NASA Astrophysics Data System (ADS)

    Scott, Hazel J.; Gale, Alastair G.

    2010-02-01

    Previous work has outlined that certain mammographic appearances feature more prominently in reader's false negative responses on a self-assessment scheme. Bi-annually 600 breast-screening film-readers complete at least one round of the Personal Performance in Mammographic Screening (PERFORMS) self-assessment scheme in the UK. The main occupational groups in UK Breast Screening can be categorised thus, Radiologist, Technologists and Symptomatics. Previous work has shown that these groups can vary in their reading 'style' and accuracy on self-assessed cases. These groups could be said to contain individuals each with (arguably) pronounced differences in their real life reading experience, symptomatic readers routinely read a large number of cases with abnormal appearances and Technologists (specially trained to read films) do not have the same medical background as breast-screening Radiologists. We aimed to examine overall (national) and group (occupational) differences in terms of ROC analysis on those mammographic cases with different mammographic appearance (feature type). Several main feature types were identified namely; Well Defined Mass (WDM), Ill Defined Mass (IDM), Spiculate Mass (SPIC), Architectural Distortions (AD), Asymmetry (ASYM) and Calcification (CALC). Results are discussed in light of differences in real-life practice for each of the occupational groups and how this may impact on accuracy over certain mammographic appearances.

  8. Impedance mammograph 3D phantom studies.

    PubMed

    Wtorek, J; Stelter, J; Nowakowski, A

    1999-04-20

    The results obtained using the Technical University of Gdansk Electroimpedance Mammograph (TUGEM) of a 3D phantom study are presented. The TUGEM system is briefly described. The hardware contains the measurement head and DSP-based identification modules controlled by a PC computer. A specially developed reconstruction algorithm, Regulated Correction Frequency Algebraic Reconstruction Technique (RCFART), is used to obtain 3D images. To visualize results, the Advance Visualization System (AVS) is used. It allows a powerful image processing on a fast workstation or on a high-performance computer. Results of three types of 3D conductivity perturbations used in the study (aluminum, Plexiglas, and cucumber) are shown. The relative volumes of perturbations less than 2% of the measurement chamber are easily evidenced. PMID:10372188

  9. Characterization of difference of Gaussian filters in the detection of mammographic regions

    SciTech Connect

    Catarious, David M. Jr.; Baydush, Alan H.; Floyd, Carey E. Jr.

    2006-11-15

    In this article, we present a characterization of the effect of difference of Gaussians (DoG) filters in the detection of mammographic regions. DoG filters have been used previously in mammographic mass computer-aided detection (CAD) systems. As DoG filters are constructed from the subtraction of two bivariate Gaussian distributions, they require the specification of three parameters: the size of the filter template and the standard deviations of the constituent Gaussians. The influence of these three parameters in the detection of mammographic masses has not been characterized. In this work, we aim to determine how the parameters affect (1) the physical descriptors of the detected regions (2) the true and false positive rates, and (3) the classification performance of the individual descriptors. To this end, 30 DoG filters are created from the combination of three template sizes and four values for each of the Gaussians' standard deviations. The filters are used to detect regions in a study database of 181 craniocaudal-view mammograms extracted from the Digital Database for Screening Mammography. To describe the physical characteristics of the identified regions, morphological and textural features are extracted from each of the detected regions. Differences in the mean values of the features caused by altering the DoG parameters are examined through statistical and empirical comparisons. The parameters' effects on the true and false positive rate are determined by examining the mean malignant sensitivities and false positives per image (FPpI). Finally, the effect on the classification performance is described by examining the variation in FPpI at the point where 81% of the malignant masses in the study database are detected. Overall, the findings of the study indicate that increasing the standard deviations of the Gaussians used to construct a DoG filter results in a dramatic decrease in the number of regions identified at the expense of missing a small number of

  10. Cellular imaging: a key phenotypic screening strategy for predictive toxicology

    PubMed Central

    Xu, Jinghai J.

    2015-01-01

    Incorporating phenotypic screening as a key strategy enhances predictivity and translatability of drug discovery efforts. Cellular imaging serves as a “phenotypic anchor” to identify important toxicologic pathology that encompasses an array of underlying mechanisms, thus provides an effective means to reduce drug development failures due to insufficient safety. This mini-review highlights the latest advances in hepatotoxicity, cardiotoxicity, and genetic toxicity tests that utilized cellular imaging as a screening strategy, and recommends path forward for further improvement. PMID:26441648

  11. Fluorescent and Lanthanide Labeling for Ligand Screens, Assays, and Imaging

    PubMed Central

    Josan, Jatinder S.; De Silva, Channa R.; Yoo, Byunghee; Lynch, Ronald M.; Pagel, Mark D.; Vagner, Josef; Hruby, Victor J.

    2012-01-01

    The use of fluorescent (or luminescent) and metal contrast agents in high-throughput screens, in vitro assays, and molecular imaging procedures has rapidly expanded in recent years. Here we describe the development and utility of high-affinity ligands for cancer theranostics and other in vitro screening studies. In this context, we also illustrate the syntheses and use of heteromultivalent ligands as targeted imaging agents. PMID:21318902

  12. Optoelectronic image processing for cervical cancer screening

    NASA Astrophysics Data System (ADS)

    Narayanswamy, Ramkumar; Sharpe, John P.; Johnson, Kristina M.

    1994-05-01

    Automation of the Pap-smear cervical screening method is highly desirable as it relieves tedium for the human operators, reduces cost and should increase accuracy and provide repeatability. We present here the design for a high-throughput optoelectronic system which forms the first stage of a two stage system to automate pap-smear screening. We use a mathematical morphological technique called the hit-or-miss transform to identify the suspicious areas on a pap-smear slide. This algorithm is implemented using a VanderLugt architecture and a time-sequential ANDing smart pixel array.

  13. Grid-enabled mammographic auditing and training system

    NASA Astrophysics Data System (ADS)

    Yap, M. H.; Gale, A. G.

    2008-03-01

    Effective use of new technologies to support healthcare initiatives is important and current research is moving towards implementing secure grid-enabled healthcare provision. In the UK, a large-scale collaborative research project (GIMI: Generic Infrastructures for Medical Informatics), which is concerned with the development of a secure IT infrastructure to support very widespread medical research across the country, is underway. In the UK, there are some 109 breast screening centers and a growing number of individuals (circa 650) nationally performing approximately 1.5 million screening examinations per year. At the same, there is a serious, and ongoing, national workforce issue in screening which has seen a loss of consultant mammographers and a growth in specially trained technologists and other non-radiologists. Thus there is a need to offer effective and efficient mammographic training so as to maintain high levels of screening skills. Consequently, a grid based system has been proposed which has the benefit of offering very large volumes of training cases that the mammographers can access anytime and anywhere. A database, spread geographically across three university systems, of screening cases is used as a test set of known cases. The GIMI mammography training system first audits these cases to ensure that they are appropriately described and annotated. Subsequently, the cases are utilized for training in a grid-based system which has been developed. This paper briefly reviews the background to the project and then details the ongoing research. In conclusion, we discuss the contributions, limitations, and future plans of such a grid based approach.

  14. MR Imaging as an Additional Screening Modality for the Detection of Breast Cancer in Women Aged 50-75 Years with Extremely Dense Breasts: The DENSE Trial Study Design.

    PubMed

    Emaus, Marleen J; Bakker, Marije F; Peeters, Petra H M; Loo, Claudette E; Mann, Ritse M; de Jong, Mathijn D F; Bisschops, Robertus H C; Veltman, Jeroen; Duvivier, Katya M; Lobbes, Marc B I; Pijnappel, Ruud M; Karssemeijer, Nico; de Koning, Harry J; van den Bosch, Maurice A A J; Monninkhof, Evelyn M; Mali, Willem P Th M; Veldhuis, Wouter B; van Gils, Carla H

    2015-11-01

    Women with extremely dense breasts have an increased risk of breast cancer and lower mammographic tumor detectability. Nevertheless, in most countries, these women are currently screened with mammography only. Magnetic resonance (MR) imaging has the potential to improve breast cancer detection at an early stage because of its higher sensitivity. However, MR imaging is more expensive and is expected to be accompanied by an increase in the number of false-positive results and, possibly, an increase in overdiagnosis. To study the additional value of MR imaging, a randomized controlled trial (RCT) design is needed in which one group undergoes mammography and the other group undergoes mammography and MR imaging. With this design, it is possible to determine the proportion of interval cancers within each study arm. For this to be an effective screening strategy, the additional cancers detected at MR imaging screening must be accompanied by a subsequent reduction in interval cancers. The Dense Tissue and Early Breast Neoplasm Screening, or DENSE, trial is a multicenter RCT performed in the Dutch biennial population-based screening program (subject age range, 50-75 years). The study was approved by the Dutch Minister of Health, Welfare and Sport. In this study, mammographic density is measured by using a fully automated volumetric method. Participants with extremely dense breasts (American College of Radiology breast density category 4) and a negative result at mammography (Breast Imaging Recording and Data System category 1 or 2) are randomly assigned to undergo additional MR imaging (n = 7237) or to be treated according to current practice (n = 28 948). Participants provide written informed consent before the MR imaging examination, which consists of dynamic breast MR imaging with gadolinium-based contrast medium and is intended to be performed for three consecutive screening rounds. The primary outcome is the difference in the proportions of interval cancers between the

  15. The effect of image size on screen-positive rates for nuchal translucency screening.

    PubMed

    Teoh, M; Meagher, S E; Choong, S; Shekleton, P; Wallace, E M

    2006-04-01

    It has been shown previously that the absolute measurement of nuchal translucency (NT) thickness, one of the most effective screening tests for fetal Down syndrome, significantly decreases with increasing image size. We undertook a prospective study to assess whether this effect materially alters the NT-derived risk estimation for fetal Down syndrome. In 350 women, NT was measured at both 100 and 200% image sizes. The median NT measurement at 200% was 8% smaller than at 100%. The screen-positive rates at 100 and 200% image sizes were 5.1% (18/350) and 2.3% (8/350), respectively (P= 0.048). Altering the image magnification settings is likely to decrease the sensitivity of NT-derived Down syndrome risk estimation. Further study is required to test the effect of our finding on the sensitivity of NT screening and to assess whether adjustments in gain settings mitigate the effect. PMID:16489936

  16. Hiding a checkered-pattern carrier-screen image in a camouflaged halftone image

    NASA Astrophysics Data System (ADS)

    Shogenji, Rui; Ohtsubo, Junji

    2014-05-01

    As carrier-screen images, we have developed checkered-pattern carrier-screen images, which can be physically decoded by superimposing a checkered pattern. We also proposed a decoding method by image sampling with an ordinary compact digital camera. To obtain a better decoding result, each carrier-screen image should be output at a low resolution. However, secret information can be detected when you observe the image carefully. Thus, a hiding process is an important technique. In this paper, we propose an advanced hiding method by embedding the carrier-screen image into another significant image to generate a camouflaged halftone image. The proposed embedding method can be performed through a simple sequential process of blending and halftoning.

  17. Fabrication and characteristics of experimental radiographic amplifier screens. [image transducers with improved image contrast and resolution

    NASA Technical Reports Server (NTRS)

    Szepesi, Z.

    1978-01-01

    The fabrication process and transfer characteristics for solid state radiographic image transducers (radiographic amplifier screens) are described. These screens are for use in realtime nondestructive evaluation procedures that require large format radiographic images with contrast and resolution capabilities unavailable with conventional fluoroscopic screens. The screens are suitable for in-motion, on-line radiographic inspection by means of closed circuit television. Experimental effort was made to improve image quality and response to low energy (5 kV and up) X-rays.

  18. Improving imaging to optimize screening strategies for carotid artery stenosis.

    PubMed

    Pandya, Ankur; Gupta, Ajay

    2016-01-01

    Carotid stenosis is a major risk factor for ischemic stroke. Recently, the United States Preventive Services Task Force issued a recommendation against screening for carotid stenosis in the general population. There is the potential for efficient risk-stratifying or staged screening approaches that identify individuals at highest risk for carotid stenosis and stroke, but these tools have yet to be proven effective in external validation studies. In this paper, we review how medical imaging can be used to detect carotid stenosis and highlight several areas that could be improved to identify potentially efficient screening strategies for carotid stenosis. PMID:26275846

  19. Fundus Autofluorescence Imaging in an Ocular Screening Program

    PubMed Central

    Kolomeyer, A. M.; Nayak, N. V.; Szirth, B. C.; Khouri, A. S.

    2012-01-01

    Purpose. To describe integration of fundus autofluorescence (FAF) imaging into an ocular screening program. Methods. Fifty consecutive screening participants were included in this prospective pilot imaging study. Color and FAF (530/640 nm exciter/barrier filters) images were obtained with a 15.1MP Canon nonmydriatic hybrid camera. A clinician evaluated the images on site to determine need for referral. Visual acuity (VA), intraocular pressure (IOP), and ocular pathology detected by color fundus and FAF imaging modalities were recorded. Results. Mean ± SD age was 47.4 ± 17.3 years. Fifty-two percent were female and 58% African American. Twenty-seven percent had a comprehensive ocular examination within the past year. Mean VA was 20/39 in the right eye and 20/40 in the left eye. Mean IOP was 15 mmHg bilaterally. Positive color and/or FAF findings were identified in nine (18%) individuals with diabetic retinopathy or macular edema (n = 4), focal RPE defects (n = 2), age-related macular degeneration (n = 1), central serous retinopathy (n = 1), and ocular trauma (n = 1). Conclusions. FAF was successfully integrated in our ocular screening program and aided in the identification of ocular pathology. Larger studies examining the utility of this technology in screening programs may be warranted. PMID:23316224

  20. Computer Simulation Of Radiographic Screen-Film Images

    NASA Astrophysics Data System (ADS)

    Metter, Richard V.; Dillon, Peter L.; Huff, Kenneth E.; Rabbani, Majid

    1986-06-01

    A method is described for computer simulation of radiographic screen-film images. This method is based on a previously published model of the screen-film imaging process.l The x-ray transmittance of a test object is sampled at a pitch of 50 μm by scanning a high-resolution, low-noise direct-exposure radiograph. This transmittance is then used, along with the x-ray exposure incident upon the object, to determine the expected number of quanta per pixel incident upon the screen. The random nature of x-ray arrival and absorption, x-ray quantum to light photon conversion, and photon absorption by the film is simulated by appropriate random number generation. Standard FFT techniques are used for computing the effects of scattering. Finally, the computed film density for each pixel is produced on a high-resolution, low-noise output film by a scanning printer. The simulation allows independent specification of x-ray exposure, x-ray quantum absorption, light conversion statistics, light scattering, and film characteristics (sensitometry and gran-ularity). Each of these parameters is independently measured for radiographic systems of interest. The simulator is tested by comparing actual radiographic images with simulated images resulting from the independently measured parameters. Images are also shown illustrating the effects of changes in these parameters on image quality. Finally, comparison is made with a "perfect" imaging system where information content is only limited by the finite number of x-rays.

  1. From Planetary Imaging to Enzyme Screening

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Based in San Diego, KAIROS Scientific develops molecular biology methods, instrumentation, and computer algorithms to create solutions to challenging problems in the medical and chemical industries. company s pioneering efforts in digital imaging spectroscopy (DIS) enable researchers to obtain spectral and/or time-dependent information for each pixel or group of pixels in a two-dimensional scene. In addition to having Yang s NASA experience at its foundation, KAIROS Scientific was established with the support of many government grants and contracts. Its first was a NASA Small Business Innovation Research (SBIR) grant, from Ames Research Center, to develop HIRIM, a high-resolution imaging microscope embodying both novel hardware and software that can be used to simultaneously acquire hundreds of individual absorbance spectra from microscopic features. Using HIRIM s graphical user interface, MicroDIS, scientists and engineers are presented with a revolutionary new tool which enables them to point to a feature in an image and recall its associated spectrum in real time.

  2. Diabetic Rethinopathy Screening by Bright Lesions Extraction from Fundus Images

    NASA Astrophysics Data System (ADS)

    Hanđsková, Veronika; Pavlovičova, Jarmila; Oravec, Miloš; Blaško, Radoslav

    2013-09-01

    Retinal images are nowadays widely used to diagnose many diseases, for example diabetic retinopathy. In our work, we propose the algorithm for the screening application, which identifies the patients with such severe diabetic complication as diabetic retinopathy is, in early phase. In the application we use the patient's fundus photography without any additional examination by an ophtalmologist. After this screening identification, other examination methods should be considered and the patient's follow-up by a doctor is necessary. Our application is composed of three principal modules including fundus image preprocessing, feature extraction and feature classification. Image preprocessing module has the role of luminance normalization, contrast enhancement and optical disk masking. Feature extraction module includes two stages: bright lesions candidates localization and candidates feature extraction. We selected 16 statistical and structural features. For feature classification, we use multilayer perceptron (MLP) with one hidden layer. We classify images into two classes. Feature classification efficiency is about 93 percent.

  3. Dose comparisons for mammographic systems

    SciTech Connect

    Speiser, R.C.; Zanrosso, E.M.; Jeromin, L.S.; Carlson, R.A.

    1986-09-01

    Dose estimates were made for Kodak Min-R screens combined with Kodak Min-R film and Kodak Ortho M film, both with and without a 5:1 Bucky grid; for standard xeroradiographic techniques in negative development mode; and for the new, higher sensitivity xeroradiographic process of the Xerox 175 System. The estimates were derived from exposure versus depth measurements in phantoms made of BR12 breast simulation material using thermoluminescent detectors. A molybdenum target source with molybdenum filtration, at a half-value layer of 0.37-mm Al, was used for the screen-film measurements. All xeroradiographic measurements were made with a tungsten target source with aluminum filtration at half-value layers of 1.5 to 1.56 mm Al. Mean glandular dose estimates for the Min-R screen/Ortho M film combination with Bucky grid and for the new xeroradiographic process were found to be similar. Dose reduction with the new xeroradiographic system was achieved through a more sensitive photoreceptor and more sensitive development, which also improved the unique imaging characteristics of xeroradiography.

  4. Can mammographic assessments lead to consider density as a risk factor for breast cancer?

    PubMed

    Colin, C; Prince, V; Valette, P J

    2013-03-01

    Admitting that mammographic breast density is an important independent risk factor for breast cancer in the general population, has a crucial economical health care impact, since it might lead to increasing screening frequency or reinforcing additional modalities. Thus, the impact of density as a risk factor has to be carefully investigated and might be debated. Some authors suggested that high density would be either a weak factor or confused with a masking effect. Others concluded that most of the studies have methodological biases in basic physics to quantify percentage of breast density, as well as in mammographic acquisition parameters. The purpose of this review is to evaluate mammographic procedures and density assessments in published studies regarding density as a breast cancer risk. No standardization was found in breast density assessments and compared density categories. High density definitions varied widely from 25 to 75% of dense tissues on mammograms. Some studies showed an insufficient follow-up to reveal masking effect related to mammographic false negatives. Evaluating breast density impact needs thorough studies with consensual mammographic procedures, methods of density measurement, breast density classification as well as a standardized definition of high breast density. Digital mammography, more effective in dense breasts, should help to re-evaluate the issue of density as a risk factor for breast cancer. PMID:20133095

  5. The Diabetic Retinopathy Screening Workflow: Potential for Smartphone Imaging.

    PubMed

    Bolster, Nigel M; Giardini, Mario E; Bastawrous, Andrew

    2015-01-01

    Complications of diabetes mellitus, namely diabetic retinopathy and diabetic maculopathy, are the leading cause of blindness in working aged people. Sufferers can avoid blindness if identified early via retinal imaging. Systematic screening of the diabetic population has been shown to greatly reduce the prevalence and incidence of blindness within the population. Many national screening programs have digital fundus photography as their basis. In the past 5 years several techniques and adapters have been developed that allow digital fundus photography to be performed using smartphones. We review recent progress in smartphone-based fundus imaging and discuss its potential for integration into national systematic diabetic retinopathy screening programs. Some systems have produced promising initial results with respect to their agreement with reference standards. However further multisite trialling of such systems' use within implementable screening workflows is required if an evidence base strong enough to affect policy change is to be established. If this were to occur national diabetic retinopathy screening would, for the first time, become possible in low- and middle-income settings where cost and availability of trained eye care personnel are currently key barriers to implementation. As diabetes prevalence and incidence is increasing sharply in these settings, the impact on global blindness could be profound. PMID:26596630

  6. Screening CEST contrast agents using ultrafast CEST imaging

    NASA Astrophysics Data System (ADS)

    Xu, Xiang; Yadav, Nirbhay N.; Song, Xiaolei; McMahon, Michael T.; Jerschow, Alexej; van Zijl, Peter C. M.; Xu, Jiadi

    2016-04-01

    A chemical exchange saturation transfer (CEST) experiment can be performed in an ultrafast fashion if a gradient field is applied simultaneously with the saturation pulse. This approach has been demonstrated for studying dia- and para-magnetic CEST agents, hyperpolarized Xe gas and in vivo spectroscopy. In this study we present a simple method for the simultaneous screening of multiple samples. Furthermore, by interleaving a number of saturation and readout periods within the TR, a series of images with different saturation times can be acquired, allowing for the quantification of exchange rates using the variable saturation time (QUEST) approach in a much accelerated fashion, thus enabling high throughput screening of CEST contrast agents.

  7. Digital mammography, cancer screening: Factors important for image compression

    NASA Technical Reports Server (NTRS)

    Clarke, Laurence P.; Blaine, G. James; Doi, Kunio; Yaffe, Martin J.; Shtern, Faina; Brown, G. Stephen; Winfield, Daniel L.; Kallergi, Maria

    1993-01-01

    The use of digital mammography for breast cancer screening poses several novel problems such as development of digital sensors, computer assisted diagnosis (CAD) methods for image noise suppression, enhancement, and pattern recognition, compression algorithms for image storage, transmission, and remote diagnosis. X-ray digital mammography using novel direct digital detection schemes or film digitizers results in large data sets and, therefore, image compression methods will play a significant role in the image processing and analysis by CAD techniques. In view of the extensive compression required, the relative merit of 'virtually lossless' versus lossy methods should be determined. A brief overview is presented here of the developments of digital sensors, CAD, and compression methods currently proposed and tested for mammography. The objective of the NCI/NASA Working Group on Digital Mammography is to stimulate the interest of the image processing and compression scientific community for this medical application and identify possible dual use technologies within the NASA centers.

  8. Conversion of mammographic images to appear with the noise and sharpness characteristics of a different detector and x-ray system

    SciTech Connect

    Mackenzie, Alistair; Dance, David R.; Workman, Adam; Yip, Mary; Wells, Kevin; Young, Kenneth C.

    2012-05-15

    Purpose: Undertaking observer studies to compare imaging technology using clinical radiological images is challenging due to patient variability. To achieve a significant result, a large number of patients would be required to compare cancer detection rates for different image detectors and systems. The aim of this work was to create a methodology where only one set of images is collected on one particular imaging system. These images are then converted to appear as if they had been acquired on a different detector and x-ray system. Therefore, the effect of a wide range of digital detectors on cancer detection or diagnosis can be examined without the need for multiple patient exposures. Methods: Three detectors and x-ray systems [Hologic Selenia (ASE), GE Essential (CSI), Carestream CR (CR)] were characterized in terms of signal transfer properties, noise power spectra (NPS), modulation transfer function, and grid properties. The contributions of the three noise sources (electronic, quantum, and structure noise) to the NPS were calculated by fitting a quadratic polynomial at each spatial frequency of the NPS against air kerma. A methodology was developed to degrade the images to have the characteristics of a different (target) imaging system. The simulated images were created by first linearizing the original images such that the pixel values were equivalent to the air kerma incident at the detector. The linearized image was then blurred to match the sharpness characteristics of the target detector. Noise was then added to the blurred image to correct for differences between the detectors and any required change in dose. The electronic, quantum, and structure noise were added appropriate to the air kerma selected for the simulated image and thus ensuring that the noise in the simulated image had the same magnitude and correlation as the target image. A correction was also made for differences in primary grid transmission, scatter, and veiling glare. The method was

  9. CVD diamond screens for photon beam imaging at PETRA III

    NASA Astrophysics Data System (ADS)

    Degenhardt, M.; Aprigliano, G.; Schulte-Schrepping, H.; Hahn, U.; Grabosch, H.-J.; Wörner, E.

    2013-03-01

    PETRA III, the most brilliant storage-ring-based synchrotron radiation source in the world, started its operation in 2009. It features 14 undulator beamlines and will be extended by further 10 beamlines in the PETRA III extension project. During the startup phase of the 14 PETRA III beamlines, fluorescence monitors based on CVD diamond screens have proven to be a very powerful tool for the monitoring of the attenuated undulator beams and for the commissioning of the optical components, e.g. slit systems and monochromators. They served as the essential instrument for the initial setup of the positron beam orbit to align the undulator photon beam along the beamline. The application of CVD diamond screens for the beam imaging at PETRA III beamlines is presented. Images taken during the beam adjustment and the beamline commissioning are shown.

  10. Amount of stroma is associated with mammographic density and stromal expression of oestrogen receptor in normal breast tissues.

    PubMed

    Gabrielson, Marike; Chiesa, Flaminia; Paulsson, Janna; Strell, Carina; Behmer, Catharina; Rönnow, Katarina; Czene, Kamila; Östman, Arne; Hall, Per

    2016-07-01

    Following female sex and age, mammographic density is considered one of the strongest risk factors for breast cancer. Despite the association between mammographic density and breast cancer risk, little is known about the underlying histology and biological basis of breast density. To better understand the mechanisms behind mammographic density we assessed morphology, proliferation and hormone receptor status in relation to mammographic density in breast tissues from healthy women. Tissues were obtained from 2012-2013 by ultrasound-guided core needle biopsy from 160 women as part of the Karma (Karolinska mammography project for risk prediction for breast cancer) project. Mammograms were collected through routine mammography screening and mammographic density was calculated using STRATUS. The histological composition, epithelial and stromal proliferation status and hormone receptor status were assessed through immunohistochemical staining. Higher mammographic density was significantly associated with a greater proportion of stromal and epithelial tissue and a lower proportion of adipose tissue. Epithelial expression levels of Ki-67, oestrogen receptor (ER) and progesterone receptor (PR) were not associated with mammographic density. Epithelial Ki-67 was associated with a greater proportion of epithelial tissue, and epithelial PR was associated with a greater proportion of stromal and a lower proportion of adipose tissue. Epithelial ER was not associated with any tissues. In contrast, expression of ER in the stroma was significantly associated with a greater proportion of stroma, and negatively associated with the amount of adipose tissue. High mammographic density is associated with higher amount of stroma and epithelium and less amount of fat, but is not associated with a change in epithelial proliferation or receptor status. Increased expressions of both epithelial PR and stromal ER are associated with a greater proportion of stroma, suggesting hormonal involvement

  11. Imaging of acute thoracic injury: the advent of MDCT screening.

    PubMed

    Mirvis, Stuart E

    2005-10-01

    Chest radiography remains the primary screening study for the assessment of victims of chest trauma, but computed tomography (CT), particularly multidetector CT (MDCT), has progressively changed the imaging approach to these patients. MDCT acquires thinner sections with greater speed, allowing higher quality axial images and nonaxial reformations than conventional or single-detector helical CT. The speed of MDCT, both in acquiring data and in reconstructing images, makes the performance of total body surveys in the blunt polytrauma patient practicable. In general, CT has been well documented to offer major advantages over chest radiography in both screening for thoracic injuries and in characterizing such injuries. This capacity has been enhanced by the application of multichannel data acquisition. The greater sensitivity of MDCT has been well demonstrated in diagnosing vascular and diaphragmatic injuries. This article reviews current concepts of diagnostic imaging in acute chest trauma from blunt force and penetrating mechanisms emphasizing the spectrum of diagnostic imaging findings for various injuries, based primarily on radiographic and CT appearances. The advantages of MDCT for selected injuries are emphasized. PMID:16274001

  12. Multiresolution neural networks for mammographic mass detection

    NASA Astrophysics Data System (ADS)

    Spence, Clay D.; Sajda, Paul

    1999-01-01

    We have previously presented a hierarchical pyramid/neural network (HPNN) architecture which combines multi-scale image processing techniques with neural networks. This coarse-to- fine HPNN was designed to learn large-scale context information for detecting small objects. We have developed a similar architecture to detect mammographic masses (malignant tumors). Since masses are large, extended objects, the coarse-to-fine HPNN architecture is not suitable for the problem. Instead we constructed a fine-to- coarse HPNN architecture which is designed to learn small- scale detail structure associated with the extended objects. Our initial result applying the fine-to-coarse HPNN to mass detection are encouraging, with detection performance improvements of about 30%. We conclude that the ability of the HPNN architecture to integrate information across scales, from fine to coarse in the case of masses, makes it well suited for detecting objects which may have detail structure occurring at scales other than the natural scale of the object.

  13. The TOMMY trial: a comparison of TOMosynthesis with digital MammographY in the UK NHS Breast Screening Programme--a multicentre retrospective reading study comparing the diagnostic performance of digital breast tomosynthesis and digital mammography with digital mammography alone.

    PubMed Central

    Gilbert, Fiona J; Tucker, Lorraine; Gillan, Maureen Gc; Willsher, Paula; Cooke, Julie; Duncan, Karen A; Michell, Michael J; Dobson, Hilary M; Lim, Yit Yoong; Purushothaman, Hema; Strudley, Celia; Astley, Susan M; Morrish, Oliver; Young, Kenneth C; Duffy, Stephen W

    2015-01-01

    BACKGROUND Digital breast tomosynthesis (DBT) is a three-dimensional mammography technique with the potential to improve accuracy by improving differentiation between malignant and non-malignant lesions. OBJECTIVES The objectives of the study were to compare the diagnostic accuracy of DBT in conjunction with two-dimensional (2D) mammography or synthetic 2D mammography, against standard 2D mammography and to determine if DBT improves the accuracy of detection of different types of lesions. STUDY POPULATION Women (aged 47-73 years) recalled for further assessment after routine breast screening and women (aged 40-49 years) with moderate/high of risk of developing breast cancer attending annual mammography screening were recruited after giving written informed consent. INTERVENTION All participants underwent a two-view 2D mammography of both breasts and two-view DBT imaging. Image-processing software generated a synthetic 2D mammogram from the DBT data sets. RETROSPECTIVE READING STUDY In an independent blinded retrospective study, readers reviewed (1) 2D or (2) 2D + DBT or (3) synthetic 2D + DBT images for each case without access to original screening mammograms or prior examinations. Sensitivities and specificities were calculated for each reading arm and by subgroup analyses. RESULTS Data were available for 7060 subjects comprising 6020 (1158 cancers) assessment cases and 1040 (two cancers) family history screening cases. Overall sensitivity was 87% [95% confidence interval (CI) 85% to 89%] for 2D only, 89% (95% CI 87% to 91%) for 2D + DBT and 88% (95% CI 86% to 90%) for synthetic 2D + DBT. The difference in sensitivity between 2D and 2D + DBT was of borderline significance (p = 0.07) and for synthetic 2D + DBT there was no significant difference (p = 0.6). Specificity was 58% (95% CI 56% to 60%) for 2D, 69% (95% CI 67% to 71%) for 2D + DBT and 71% (95% CI 69% to 73%) for synthetic 2D + DBT. Specificity was significantly

  14. Circularly polarized millimeter-wave imaging for personnel screening

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; McMakin, Douglas L.; Lechelt, Wayne M.; Griffin, Jeffrey W.

    2005-05-01

    A novel polarimetric millimeter-wave imaging technique has been developed at the Pacific Northwest National Laboratory (PNNL) for concealed weapon detection applications. Wideband millimeter-wave imaging systems developed at PNNL utilize low-power, coherent, millimeter-wave illumination in the 10-100 GHz range to form high-resolution images of personnel. Electromagnetic waves in these frequency ranges easily penetrate most clothing materials and are reflected from the body and any concealed items. Three-dimensional images are formed using computer image reconstruction algorithms developed to mathematically focus the received wavefronts scattered from the target. Circular polarimetric imaging can be employed to obtain additional information from the target. Circularly polarized waves incident on relatively smooth reflecting targets are typically reversed in their rotational handedness, e.g. left-hand circular polarization (LHCP) is reflected to become right-hand circular polarization (RHCP). An incident wave that is reflected twice (or any even number) of times prior to returning to the transceiver, has its handedness preserved. Sharp features such as wires and edges tend to return linear polarization, which can be considered to be a sum of both LHCP and RHCP. These characteristics can be exploited for personnel screening by allowing differentiation of smooth features, such as the body, and sharper features present in many concealed items. Additionally, imaging artifacts due to multipath can be identified and eliminated. Laboratory imaging results have been obtained in the 10-20 GHz frequency range and are presented in this paper.

  15. Circularly Polarized Millimeter-Wave Imaging for Personnel Screening

    SciTech Connect

    Sheen, David M.; McMakin, Douglas L.; Lechelt, Wayne M.; Griffin, Jeffrey W.

    2005-08-01

    A novel polarimetric millimeter-wave imaging technique has been developed at the Pacific Northwest National Laboratory (PNNL) for concealed weapon detection applications. Wideband millimeter-wave imaging systems developed at PNNL utilize low-power, coherent, millimeter-wave illumination in the 10-100 GHz range to form high-resolution images of personnel. Electromagnetic waves in these frequency ranges easily penetrate most clothing materials and are reflected from the body and any concealed items. Three-dimensional images are formed using computer image reconstruction algorithms developed to mathematically focus the received wavefronts scattered from the target. Circular polarimetric imaging can be employed to obtain additional information from the target. Circularly polarized waves incident on relatively smooth reflecting targets are typically reversed in their rotational handedness, e.g. left-hand circular polarization (LHCP) is reflected to become right-hand circular polarization (RHCP). An incident wave that is reflected twice (or any even number) of times prior to returning to the transceiver, has its handedness preserved. Sharp features such as wires and edges tend to return linear polarization, which can be considered to be a sum of both LHCP and RHCP. These characteristics can be exploited for personnel screening by allowing differentiation of smooth features, such as the body, and sharper features present in many concealed items. Additionally, imaging artifacts due to multipath can be identified and eliminated. Laboratory imaging results have been obtained in the 10-20 GHz frequency range and are presented in this paper.

  16. The Problem of Mammographic Breast Density - The Position of the DEGUM Working Group on Breast Ultrasound.

    PubMed

    Mueller-Schimpfle, M P; Brandenbusch, V C; Degenhardt, F; Duda, V; Madjar, H; Mundinger, A; Rathmann, R; Hahn, M

    2016-04-01

    Mammographic breast density correlates with breast cancer risk and also with the number of false-negative calls. In the USA these facts lead to the "Breast Density and Mammography Reporting Act" of 2011. In the case of mammographically dense breasts, the Working Group on Breast Ultrasound in Germany recommends explaining the advantages of adjunct imaging to women, depending on the individual breast cancer risk. Due to the particular structure of German healthcare, quality-assured breast ultrasound would be the first choice. Possible overdiagnosis, costs, potentially increased emotional stress should be addressed. In high familial breast cancer risk, genetic counselling and an intensified early detection program should be performed. PMID:26882482

  17. Angular dependence of mammographic dosimeters in digital breast tomosynthesis

    NASA Astrophysics Data System (ADS)

    Bradley, Lena R.; Carton, Ann-Katherine; Maidment, Andrew D. A.

    2010-04-01

    Digital Breast Tomosynthesis (DBT) is an emerging imaging modality that combines tomography with conventional digital mammography. In developing DBT dosimetry, a direct application of mammographic dosimetry has appeal. However, DBT introduces rotation of the x-ray tube relative to the dosimeter, thus raising questions about the angular dependence of mammographic dosimeters. To measure this dependence, two ionization chambers, two solid-stated detectors, and one photodiode were rotated relative to an incident Mo/Mo x-ray beam. In this isocentric DBT simulation, the signal of each dosimeter was studied over an angular range of 180° for tube voltages of 26 to 34 kV. One ionization chamber was then modeled numerically to study the response to various monoenergetic beams. The results show that all dosimeters underestimate dose to varying degrees; solid-state detectors show the greatest angular dependence while ionization chambers show the least. Correction factors were computed from the data for isocentric DBT images using projection angles up to +/-25° these factors ranged from 1.0014 to 1.1380. The magnitude of the angular dependence generally decreased with increasing energy, as shown with both the measured and modeled data. As a result, the error arising in measuring DBT dose with a mammographic dosimeter varies significantly; it cannot always be disregarded. The use of correction factors may be possible but is largely impractical, as they are specific to the dosimeter, x-ray beam, and DBT geometry. Instead, an angle-independent dosimeter may be more suitable for DBT.

  18. 21 CFR 892.1710 - Mammographic x-ray system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mammographic x-ray system. 892.1710 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1710 Mammographic x-ray system. (a) Identification. A mammographic x-ray system is a device intended to be used to produce radiographs of the...

  19. 21 CFR 892.1710 - Mammographic x-ray system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Mammographic x-ray system. 892.1710 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1710 Mammographic x-ray system. (a) Identification. A mammographic x-ray system is a device intended to be used to produce radiographs of the...

  20. 21 CFR 892.1710 - Mammographic x-ray system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Mammographic x-ray system. 892.1710 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1710 Mammographic x-ray system. (a) Identification. A mammographic x-ray system is a device intended to be used to produce radiographs of the...

  1. 21 CFR 892.1710 - Mammographic x-ray system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Mammographic x-ray system. 892.1710 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1710 Mammographic x-ray system. (a) Identification. A mammographic x-ray system is a device intended to be used to produce radiographs of the...

  2. 21 CFR 892.1710 - Mammographic x-ray system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Mammographic x-ray system. 892.1710 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1710 Mammographic x-ray system. (a) Identification. A mammographic x-ray system is a device intended to be used to produce radiographs of the...

  3. Screening CEST contrast agents using ultrafast CEST imaging.

    PubMed

    Xu, Xiang; Yadav, Nirbhay N; Song, Xiaolei; McMahon, Michael T; Jerschow, Alexej; van Zijl, Peter C M; Xu, Jiadi

    2016-04-01

    A chemical exchange saturation transfer (CEST) experiment can be performed in an ultrafast fashion if a gradient field is applied simultaneously with the saturation pulse. This approach has been demonstrated for studying dia- and para-magnetic CEST agents, hyperpolarized Xe gas and in vivo spectroscopy. In this study we present a simple method for the simultaneous screening of multiple samples. Furthermore, by interleaving a number of saturation and readout periods within the TR, a series of images with different saturation times can be acquired, allowing for the quantification of exchange rates using the variable saturation time (QUEST) approach in a much accelerated fashion, thus enabling high throughput screening of CEST contrast agents. PMID:26969814

  4. Cloud screening Coastal Zone Color Scanner images using channel 5

    NASA Technical Reports Server (NTRS)

    Eckstein, B. A.; Simpson, J. J.

    1991-01-01

    Clouds are removed from Coastal Zone Color Scanner (CZCS) data using channel 5. Instrumentation problems require pre-processing of channel 5 before an intelligent cloud-screening algorithm can be used. For example, at intervals of about 16 lines, the sensor records anomalously low radiances. Moreover, the calibration equation yields negative radiances when the sensor records zero counts, and pixels corrupted by electronic overshoot must also be excluded. The remaining pixels may then be used in conjunction with the procedure of Simpson and Humphrey to determine the CZCS cloud mask. These results plus in situ observations of phytoplankton pigment concentration show that pre-processing and proper cloud-screening of CZCS data are necessary for accurate satellite-derived pigment concentrations. This is especially true in the coastal margins, where pigment content is high and image distortion associated with electronic overshoot is also present. The pre-processing algorithm is critical to obtaining accurate global estimates of pigment from spacecraft data.

  5. Vision 20/20: Mammographic breast density and its clinical applications

    SciTech Connect

    Ng, Kwan-Hoong Lau, Susie

    2015-12-15

    Breast density is a strong predictor of the failure of mammography screening to detect breast cancer and is a strong predictor of the risk of developing breast cancer. The many imaging options that are now available for imaging dense breasts show great promise, but there is still the question of determining which women are “dense” and what imaging modality is suitable for individual women. To date, mammographic breast density has been classified according to the Breast Imaging-Reporting and Data System (BI-RADS) categories from visual assessment, but this is known to be very subjective. Despite many research reports, the authors believe there has been a lack of physics-led and evidence-based arguments about what breast density actually is, how it should be measured, and how it should be used. In this paper, the authors attempt to start correcting this situation by reviewing the history of breast density research and the debates generated by the advocacy movement. The authors review the development of breast density estimation from pattern analysis to area-based analysis, and the current automated volumetric breast density (VBD) analysis. This is followed by a discussion on seeking the ground truth of VBD and mapping volumetric methods to BI-RADS density categories. The authors expect great improvement in VBD measurements that will satisfy the needs of radiologists, epidemiologists, surgeons, and physicists. The authors believe that they are now witnessing a paradigm shift toward personalized breast screening, which is going to see many more cancers being detected early, with the use of automated density measurement tools as an important component.

  6. Vision 20/20: Mammographic breast density and its clinical applications.

    PubMed

    Ng, Kwan-Hoong; Lau, Susie

    2015-12-01

    Breast density is a strong predictor of the failure of mammography screening to detect breast cancer and is a strong predictor of the risk of developing breast cancer. The many imaging options that are now available for imaging dense breasts show great promise, but there is still the question of determining which women are "dense" and what imaging modality is suitable for individual women. To date, mammographic breast density has been classified according to the Breast Imaging-Reporting and Data System (BI-RADS) categories from visual assessment, but this is known to be very subjective. Despite many research reports, the authors believe there has been a lack of physics-led and evidence-based arguments about what breast density actually is, how it should be measured, and how it should be used. In this paper, the authors attempt to start correcting this situation by reviewing the history of breast density research and the debates generated by the advocacy movement. The authors review the development of breast density estimation from pattern analysis to area-based analysis, and the current automated volumetric breast density (VBD) analysis. This is followed by a discussion on seeking the ground truth of VBD and mapping volumetric methods to BI-RADS density categories. The authors expect great improvement in VBD measurements that will satisfy the needs of radiologists, epidemiologists, surgeons, and physicists. The authors believe that they are now witnessing a paradigm shift toward personalized breast screening, which is going to see many more cancers being detected early, with the use of automated density measurement tools as an important component. PMID:26632060

  7. High mammographic density in women of Ashkenazi Jewish descent

    PubMed Central

    2013-01-01

    Introduction Percent mammographic density (PMD) adjusted for age and body mass index is one of the strongest risk factors for breast cancer and is known to be approximately 60% heritable. Here we report a finding of an association between genetic ancestry and adjusted PMD. Methods We selected self-identified Caucasian women in the California Pacific Medical Center Research Institute Cohort whose screening mammograms placed them in the top or bottom quintiles of age-adjusted and body mass index-adjusted PMD. Our final dataset included 474 women with the highest adjusted PMD and 469 with the lowest genotyped on the Illumina 1 M platform. Principal component analysis (PCA) and identity-by-descent analyses allowed us to infer the women's genetic ancestry and correlate it with adjusted PMD. Results Women of Ashkenazi Jewish ancestry, as defined by the first principal component of PCA and identity-by-descent analyses, represented approximately 15% of the sample. Ashkenazi Jewish ancestry, defined by the first principal component of PCA, was associated with higher adjusted PMD (P = 0.004). Using multivariate regression to adjust for epidemiologic factors associated with PMD, including age at parity and use of postmenopausal hormone therapy, did not attenuate the association. Conclusions Women of Ashkenazi Jewish ancestry, based on genetic analysis, are more likely to have high age-adjusted and body mass index-adjusted PMD. Ashkenazi Jews may have a unique set of genetic variants or environmental risk factors that increase mammographic density. PMID:23668689

  8. Mammographic density is the main correlate of tumors detected on ultrasound but not on mammography.

    PubMed

    Häberle, Lothar; Fasching, Peter A; Brehm, Barbara; Heusinger, Katharina; Jud, Sebastian M; Loehberg, Christian R; Hack, Carolin C; Preuss, Caroline; Lux, Michael P; Hartmann, Arndt; Vachon, Celine M; Meier-Meitinger, Martina; Uder, Michael; Beckmann, Matthias W; Schulz-Wendtland, Rüdiger

    2016-11-01

    Although mammography screening programs do not include ultrasound examinations, some diagnostic units do provide women with both mammography and ultrasonography. This article is concerned with estimating the risk of a breast cancer patient diagnosed in a hospital-based mammography unit having a tumor that is visible on ultrasound but not on mammography. A total of 1,399 women with invasive breast cancer from a hospital-based diagnostic mammography unit were included in this retrospective study. For inclusion, mammograms from the time of the primary diagnosis had to be available for computer-assisted assessment of percentage mammographic density (PMD), as well as Breast Imaging Reporting and Data System (BIRADS) assessment of mammography. In addition, ultrasound findings were available for the complete cohort as part of routine diagnostic procedures, regardless of any patient or imaging characteristics. Logistic regression analyses were conducted to identify predictors of mammography failure, defined as BIRADS assessment 1 or 2. The probability that the visibility of a tumor might be masked at diagnosis was estimated using a regression model with the identified predictors. Tumors were only visible on ultrasound in 107 cases (7.6%). PMD was the strongest predictor for mammography failure, but age, body mass index and previous breast surgery also influenced the risk, independently of the PMD. Risk probabilities ranged from 1% for a defined low-risk group up to 40% for a high-risk group. These findings might help identify women who should be offered ultrasound examinations in addition to mammography. PMID:27389655

  9. Classification of mammographic lesion based in Completed Local Binary Pattern and using multiresolution representation

    NASA Astrophysics Data System (ADS)

    Duarte, Y. A. S.; Nascimento, M. Z.; Oliveira, D. L. L.

    2014-03-01

    This paper presents a comparison of two methods for features extraction of mammograms based in completed local binary pattern (CLBP) and wavelet transform. In first part, CLBP was applied in digitized mammograms. In second part, we applied CLBP in the sub-bands obtained from the wavelet multi-resolution representation of the mammographies. In this study, we evaluated the CLBP in the image in the spatial domain and in the sub-bands obtained with wavelet transform. Then, the statistical technique of variance analysis (ANOVA) was used to reduce the number of features. Finally, the classifier Support Vector Machine (SVM) was applied in the samples. The proposed methods were tested on 720 mammographies which 240 was diagnosed as normal samples, 240 as benign lesion and 240 as malign lesion. The images were obtained randomly of the Digital Database for Screening Mammography (DDSM). The system effectiveness was evaluated using the area under the ROC curve (AUC). The experiments demonstrate that the textural feature extraction of the multi-resolution representation was more relevant with value of AUC=1.0. In our experiments, CLBP in the spatial domain resulted in value of AUC=0.89. The proposed method demonstrated promising results in the classification of different classes of mammographic lesions.

  10. Improving CAD performance by fusion of the bilateral mammographic tissue asymmetry information

    NASA Astrophysics Data System (ADS)

    Wang, Xingwei; Li, Lihua; Liu, Wei; Xu, Weidong; Lederman, Dror; Zheng, Bin

    2012-03-01

    Bilateral mammographic tissue density asymmetry could be an important factor in assessing risk of developing breast cancer and improving the detection of the suspicious lesions. This study aims to assess whether fusion of the bilateral mammographic density asymmetrical information into a computer-aided detection (CAD) scheme could improve CAD performance in detecting mass-like breast cancers. A testing dataset involving 1352 full-field digital mammograms (FFDM) acquired from 338 cases was used. In this dataset, half (169) cases are positive containing malignant masses and half are negative. Two computerized schemes were first independently applied to process FFDM images of each case. The first single-image based CAD scheme detected suspicious mass regions on each image. The second scheme detected and computed the bilateral mammographic tissue density asymmetry for each case. A fusion method was then applied to combine the output scores of the two schemes. The CAD performance levels using the original CAD-generated detection scores and the new fusion scores were evaluated and compared using a free-response receiver operating characteristic (FROC) type data analysis method. By fusion with the bilateral mammographic density asymmetrical scores, the case-based CAD sensitivity was increased from 79.2% to 84.6% at a false-positive rate of 0.3 per image. CAD also cued more "difficult" masses with lower CAD-generated detection scores while discarded some "easy" cases. The study indicated that fusion between the scores generated by a single-image based CAD scheme and the computed bilateral mammographic density asymmetry scores enabled to increase mass detection sensitivity in particular to detect more subtle masses.

  11. Portable, low-priced retinal imager for eye disease screening

    NASA Astrophysics Data System (ADS)

    Soliz, Peter; Nemeth, Sheila; VanNess, Richard; Barriga, E. S.; Zamora, Gilberto

    2014-02-01

    The objective of this project was to develop and demonstrate a portable, low-priced, easy to use non-mydriatic retinal camera for eye disease screening in underserved urban and rural locations. Existing portable retinal imagers do not meet the requirements of a low-cost camera with sufficient technical capabilities (field of view, image quality, portability, battery power, and ease-of-use) to be distributed widely to low volume clinics, such as the offices of single primary care physicians serving rural communities or other economically stressed healthcare facilities. Our approach for Smart i-Rx is based primarily on a significant departure from current generations of desktop and hand-held commercial retinal cameras as well as those under development. Our techniques include: 1) Exclusive use of off-the-shelf components; 2) Integration of retinal imaging device into low-cost, high utility camera mount and chin rest; 3) Unique optical and illumination designed for small form factor; and 4) Exploitation of autofocus technology built into present digital SLR recreational cameras; and 5) Integration of a polarization technique to avoid the corneal reflex. In a prospective study, 41 out of 44 diabetics were imaged successfully. No imaging was attempted on three of the subjects due to noticeably small pupils (less than 2mm). The images were of sufficient quality to detect abnormalities related to diabetic retinopathy, such as microaneurysms and exudates. These images were compared with ones taken non-mydriatically with a Canon CR-1 Mark II camera. No cases identified as having DR by expert retinal graders were missed in the Smart i-Rx images.

  12. Vitamin D and Mammographic Findings

    PubMed Central

    Riedel, J.; Straub, L.; Wissing, J.; Artmann, A.; Schmidmayr, M.; Kiechle, M.; Seifert-Klauss, V. R.

    2016-01-01

    Introduction: Pleiotropic immune-modulatory and anti-proliferative effects of vitamin D and hopes to stop cancerogenesis have led to an increased interest in possible reduction of breast cancer with higher vitamin D levels. Mammographic density is an established risk factor for breast cancer risk, and its association with serum vitamin D is complex, as recent studies have shown. Patients and Methods: In this cross-sectional study, 1103 participants were recruited in the breast diagnostic unit of the Klinikum rechts der Isar, TU Munich. A standardised questionnaire and blood samples for 25-OH-vitamin D were taken on the day of mammography. Histologic results of biopsies in suspicious mammographies were documented. Results: In the 1090 data-sets analysed, vitamin D-deficiency was common among women under 40. Highest vitamin D values were observed in participants aged 60–69 years, but average values for all age cohorts were below 20 ng/ml of vitamin D. 15.6 % of all participants had very low vitamin D values (< 10 ng/ml), 51.3 % were vitamin D-deficient (10–19 ng/ml) and only 5.7 % were above 30 ng/ml, i.e. showed sufficient vitamin D. Patients with malignant results had vitamin D < 10 ng/ml more often (16.9 %; p = 0.61), and only 3.4 % in this group had sufficient vitamin D supply (> 30 ng/ml). There were no significant differences in vitamin D-levels between density groups according to the American College of Radiology (ACR) criteria. Conclusion: Vitamin D values were lower than in comparable US women. Up to now, there is no direct clinical evidence for a relationship between the risk for breast cancer and a specific vitamin D value. PMID:27239067

  13. Hyperspectral fluorescence imaging coupled with multivariate image analysis techniques for contaminant screening of leafy greens

    NASA Astrophysics Data System (ADS)

    Everard, Colm D.; Kim, Moon S.; Lee, Hoyoung

    2014-05-01

    The production of contaminant free fresh fruit and vegetables is needed to reduce foodborne illnesses and related costs. Leafy greens grown in the field can be susceptible to fecal matter contamination from uncontrolled livestock and wild animals entering the field. Pathogenic bacteria can be transferred via fecal matter and several outbreaks of E.coli O157:H7 have been associated with the consumption of leafy greens. This study examines the use of hyperspectral fluorescence imaging coupled with multivariate image analysis to detect fecal contamination on Spinach leaves (Spinacia oleracea). Hyperspectral fluorescence images from 464 to 800 nm were captured; ultraviolet excitation was supplied by two LED-based line light sources at 370 nm. Key wavelengths and algorithms useful for a contaminant screening optical imaging device were identified and developed, respectively. A non-invasive screening device has the potential to reduce the harmful consequences of foodborne illnesses.

  14. Microfluidics-enabled phenotyping, imaging, and screening of multicellular organisms.

    PubMed

    Crane, Matthew M; Chung, Kwanghun; Stirman, Jeffrey; Lu, Hang

    2010-06-21

    This paper reviews the technologies that have been invented in the last few years on high-throughput phenotyping, imaging, screening, and related techniques using microfluidics. The review focuses on the technical challenges and how microfluidics can help to solve these existing problems, specifically discussing the applications of microfluidics to multicellular model organisms. The challenges facing this field include handling multicellular organisms in an efficient manner, controlling the microenvironment and precise manipulation of the local conditions to allow the phenotyping, screening, and imaging of the small animals. Not only does microfluidics have the proper length scale for manipulating these biological entities, but automation has also been demonstrated with these systems, and more importantly the ability to deliver stimuli or alter biophysical/biochemical conditions to the biological entities with good spatial and temporal controls. In addition, integration with and interfacing to other hardware/software allows quantitative approaches. We include several successful examples of microfluidics solving these high-throughput problems. The paper also highlights other applications that can be developed in the future. PMID:20383347

  15. The imaging performance of compact Lu{sub 2}O{sub 3}:Eu powdered phosphor screens: Monte Carlo simulation for applications in mammography

    SciTech Connect

    Liaparinos, P. F.; Kandarakis, I. S.

    2009-06-15

    In medical mammographic imaging systems, one type of detector configuration, often referred to as indirect detectors, is based on a scintillator layer (phosphor screen) that converts the x-ray radiation into optical signal. The indirect detector performance may be optimized either by improving the structural parameters of the screen or by employing new phosphor materials with improved physical characteristics (e.g., x-ray absorption efficiency, intrinsic conversion efficiency, emitted light spectrum). Lu{sub 2}O{sub 3}:Eu is a relatively new phosphor material that exhibits improved scintillating properties indicating a promising material for mammographic applications. In this article, a custom validated Monte Carlo program was used in order to examine the performance of compact Lu{sub 2}O{sub 3}:Eu powdered phosphor screens under diagnostic mammography conditions (x-ray spectra: 28 kV Mo, 0.030 mm Mo and 32 kV W, 0.050 mm Rh). Lu{sub 2}O{sub 3}:Eu screens of coating weight in the range between 20 and 40 mg/cm{sup 2} were examined. The Monte Carlo code was based on a model using Mie-scattering theory for the description of light propagation within the phosphor. The overall performance of Lu{sub 2}O{sub 3}:Eu powdered phosphor screens was investigated in terms of the (i) quantum detection efficiency, (ii) luminescence efficiency, (iii) compatibility with optical sensors, (iv) modulation transfer function, (v) the Swank factor, and (vi) zero-frequency detective quantum efficiency. Results were compared to the traditional rare-earth Gd{sub 2}O{sub 2}S:Tb phosphor material. The increased packing density and therefore the light extinction properties of Lu{sub 2}O{sub 3}:Eu phosphor were found to improve the x-ray absorption (approximately up to 21% and 16% at 40 mg/cm{sup 2} for Mo and W x-ray spectra, respectively), the spatial resolution (approximately 2.6 and 2.4 cycles/mm at 40 mg/cm{sup 2} for Mo and W x-ray spectra, respectively), as well as the zero

  16. Fluorescent screens and image processing for the APS linac test stand

    SciTech Connect

    Berg, W.; Ko, K.

    1992-12-01

    A fluorescent screen was used to monitor relative beam position and spot size of a 56-MeV electron beam in the linac test stand. A chromium doped alumina ceramic screen inserted into the beam was monitored by a video camera. The resulting image was captured using a frame grabber and stored into memory. Reconstruction and analysis of the stored image was performed using PV-WAVE. This paper will discuss the hardware and software implementation of the fluorescent screen and imaging system. Proposed improvements for the APS linac fluorescent screens and image processing will also be discussed.

  17. An infrared image based methodology for breast lesions screening

    NASA Astrophysics Data System (ADS)

    Morais, K. C. C.; Vargas, J. V. C.; Reisemberger, G. G.; Freitas, F. N. P.; Oliari, S. H.; Brioschi, M. L.; Louveira, M. H.; Spautz, C.; Dias, F. G.; Gasperin, P.; Budel, V. M.; Cordeiro, R. A. G.; Schittini, A. P. P.; Neto, C. D.

    2016-05-01

    The objective of this paper is to evaluate the potential of utilizing a structured methodology for breast lesions screening, based on infrared imaging temperature measurements of a healthy control group to establish expected normality ranges, and of breast cancer patients, previously diagnosed through biopsies of the affected regions. An analysis of the systematic error of the infrared camera skin temperature measurements was conducted in several different regions of the body, by direct comparison to high precision thermistor temperature measurements, showing that infrared camera temperatures are consistently around 2 °C above the thermistor temperatures. Therefore, a method of conjugated gradients is proposed to eliminate the infrared camera direct temperature measurement imprecision, by calculating the temperature difference between two points to cancel out the error. The method takes into account the human body approximate bilateral symmetry, and compares measured dimensionless temperature difference values (Δ θ bar) between two symmetric regions of the patient's breast, that takes into account the breast region, the surrounding ambient and the individual core temperatures, and doing so, the results interpretation for different individuals become simple and non subjective. The range of normal whole breast average dimensionless temperature differences for 101 healthy individuals was determined, and admitting that the breasts temperatures exhibit a unimodal normal distribution, the healthy normal range for each region was considered to be the dimensionless temperature difference plus/minus twice the standard deviation of the measurements, Δ θ bar ‾ + 2σ Δ θ bar ‾ , in order to represent 95% of the population. Forty-seven patients with previously diagnosed breast cancer through biopsies were examined with the method, which was capable of detecting breast abnormalities in 45 cases (96%). Therefore, the conjugated gradients method was considered effective

  18. Stereotactic (Mammographically Guided) Breast Biopsy

    MedlinePlus

    ... Z Stereotactic Breast Biopsy Stereotactic breast biopsy uses mammography – a specific type of breast imaging that uses ... the breast are often detected by physical examination, mammography, or other imaging studies. However, it is not ...

  19. Image quality assurance in the prostate, lung, colorectal, and ovarian cancer screening trial network of the National Lung Screening Trial.

    PubMed

    Moore, Stephen M; Gierada, David S; Clark, Kenneth W; Blaine, G James

    2005-09-01

    The National Lung Screening Trial is evaluating the effectiveness of low-dose spiral CT and conventional chest X-ray as screening tests for persons who are at high risk for developing lung cancer. This multicenter trial requires quality assurance (QA) for the image quality and technical parameters of the scans. The electronic system described here helps manage the QA process. The system includes a workstation at each screening center that de-identifies the data, a DICOM storage service at the QA Coordinating Center, and Web-based systems for presenting images and QA evaluation forms to the QA radiologists. Quality assurance data are collated and analyzed by an independent statistical organization. We describe the design and implementation of this electronic QA system, emphasizing issues relating to data security and privacy, the various obstacles encountered in the installation of a common system at different participating screening centers, and the functional success of the system deployed. PMID:15924251

  20. The future of imaging screening: proceedings of the Fourth Annual ACR FORUM.

    PubMed

    Hillman, Bruce J; Amis, E Stephen; Weinreb, Jeffrey C; Neiman, Harvey L

    2005-01-01

    The FORUM is an ACR planning activity focused on a specific topic deemed to be of long-range importance to the college. A select panel of multidisciplinary experts met in 2004 to consider the ramifications of imaging screening from diverse perspectives. Considerations included the nature of screening for disease, its technological issues, and biases associated with the perceived success of screening; potential technologies and target diseases; business and economics; insurance coverage; ethics and the law; how imaging screening could be paired with nonimaging screening; and how the lay public perceives screening. The FORUM participants considered how imaging screening might develop over the next 5 to 10 years and made recommendations to the ACR on actions it might take to benefit both the specialty and patients. PMID:17411759

  1. Creation of a CT Image Library for the Lung Screening Study of the National Lung Screening Trial.

    PubMed

    Clark, K W; Gierada, D S; Moore, S M; Maffitt, D R; Koppel, P; Phillips, S R; Prior, F W

    2007-03-01

    The CT Image Library (CTIL) of the Lung Screening Study (LSS) network of the National Lung Screening Trial (NLST) consists of up to three annual screens using CT imaging from each of 17,308 participants with a significant history of smoking but no evidence of cancer at trial enrollment (Fall 2002-Spring 2004). Screens performed at numerous medical centers associated with 10 LSS-NLST screening centers are deidentified of protected health information and delivered to the CTIL via DVD, external hard disk, or Internet/Virtual Private Network transmission. The collection will be completed in late 2006. The CTIL is of potential interest to clinical researchers and software developers of nodule detection algorithms. Its attractiveness lies in its very specific, well-defined patient population, scanned via a common CT protocol, and in its collection of evenly spaced serial screens. In this work, we describe the technical details of the CTIL collection process from screening center retrieval through library storage. PMID:16783598

  2. Mammographic density and its interaction with other breast cancer risk factors in an Asian population

    PubMed Central

    Wong, C S; Lim, G H; Gao, F; Jakes, R W; Offman, J; Chia, K S; Duffy, S W

    2011-01-01

    Background: Joint effects of mammographic density and other risk factors on breast cancer risk remain unclear. Methods: From The Singapore Breast Screening Project, we selected 491 cases and 982 controls. Mammographic density was measured quantitatively. Data analysis was by conditional logistic regression. Results: Density was a significant risk factor, adjusting for other factors. Density of 76–100% had an odds ratio of 5.54 (95% CI 2.38–12.90) compared with 0–10%. Density had significant interactions with body mass index and oral contraceptive use (P=0.02). Conclusions: Percent density increases breast cancer risk in addition to effects of other risk factors, and modifies the effects of BMI and OCs. PMID:21245860

  3. Robust estimation of mammographic breast density: a patient-based approach

    NASA Astrophysics Data System (ADS)

    Heese, Harald S.; Erhard, Klaus; Gooßen, Andre; Bulow, Thomas

    2012-02-01

    Breast density has become an established risk indicator for developing breast cancer. Current clinical practice reflects this by grading mammograms patient-wise as entirely fat, scattered fibroglandular, heterogeneously dense, or extremely dense based on visual perception. Existing (semi-) automated methods work on a per-image basis and mimic clinical practice by calculating an area fraction of fibroglandular tissue (mammographic percent density). We suggest a method that follows clinical practice more strictly by segmenting the fibroglandular tissue portion directly from the joint data of all four available mammographic views (cranio-caudal and medio-lateral oblique, left and right), and by subsequently calculating a consistently patient-based mammographic percent density estimate. In particular, each mammographic view is first processed separately to determine a region of interest (ROI) for segmentation into fibroglandular and adipose tissue. ROI determination includes breast outline detection via edge-based methods, peripheral tissue suppression via geometric breast height modeling, and - for medio-lateral oblique views only - pectoral muscle outline detection based on optimizing a three-parameter analytic curve with respect to local appearance. Intensity harmonization based on separately acquired calibration data is performed with respect to compression height and tube voltage to facilitate joint segmentation of available mammographic views. A Gaussian mixture model (GMM) on the joint histogram data with a posteriori calibration guided plausibility correction is finally employed for tissue separation. The proposed method was tested on patient data from 82 subjects. Results show excellent correlation (r = 0.86) to radiologist's grading with deviations ranging between -28%, (q = 0.025) and +16%, (q = 0.975).

  4. Individualized grid-enabled mammographic training system

    NASA Astrophysics Data System (ADS)

    Yap, M. H.; Gale, A. G.

    2009-02-01

    The PERFORMS self-assessment scheme measures individuals skills in identifying key mammographic features on sets of known cases. One aspect of this is that it allows radiologists' skills to be trained, based on their data from this scheme. Consequently, a new strategy is introduced to provide revision training based on mammographic features that the radiologist has had difficulty with in these sets. To do this requires a lot of random cases to provide dynamic, unique, and up-to-date training modules for each individual. We propose GIMI (Generic Infrastructure in Medical Informatics) middleware as the solution to harvest cases from distributed grid servers. The GIMI middleware enables existing and legacy data to support healthcare delivery, research, and training. It is technology-agnostic, data-agnostic, and has a security policy. The trainee examines each case, indicating the location of regions of interest, and completes an evaluation form, to determine mammographic feature labelling, diagnosis, and decisions. For feedback, the trainee can choose to have immediate feedback after examining each case or batch feedback after examining a number of cases. All the trainees' result are recorded in a database which also contains their trainee profile. A full report can be prepared for the trainee after they have completed their training. This project demonstrates the practicality of a grid-based individualised training strategy and the efficacy in generating dynamic training modules within the coverage/outreach of the GIMI middleware. The advantages and limitations of the approach are discussed together with future plans.

  5. Simultaneous image reproduction on CRT screen: Moves ultrasonic sectional view and electrocardiogram curves

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A method for simultaneous reproduction of images, requiring different amounts of time to reproduce, on a cathode ray tube (CRT) screen is disclosed. Ultrasonic sectional views and electrocardiogram curves are simultaneously reproduced on the CRT screen by producing the images on different areas of a screen with two phosphors having different persistence times and luminous colors, within the times required for the appearance of the images. In front of the area on which is produced the image requiring the shorter time is a color filter which is permeable to the color of the phosphor with the shorter persistence time by which absorbs the color of the other phosphor.

  6. Characteristics and prognosis of interval cancers after biennial screen-film or full-field digital screening mammography.

    PubMed

    Weber, Roy J P; van Bommel, Rob M G; Louwman, Marieke W; Nederend, Joost; Voogd, Adri C; Jansen, Frits H; Tjan-Heijnen, Vivianne C G; Duijm, Lucien E M

    2016-08-01

    We determined the characteristics and prognosis of interval breast cancers (IC) at screen-film (SFM) and full-field digital (FFDM) screening mammography. The study population consisted of 417,746 consecutive screening mammograms (302,699 SFM screens and 115,047 FFDM screens), obtained between 2000 and 2011. During 2-year follow-up, we collected breast imaging reports, surgical reports, and pathology results. A total of 800 ICs had been diagnosed in the screened population, of which 288 detected in the first year (early ICs) and 512 in the second year (late ICs) after a negative screen. 31.3 % of early IC's and 19.1 % of late IC's, respectively, were visible in retrospect on the latest previous screens, but had been missed during screening (P < 0.001). Missed invasive ICs were larger (28.5 mm vs. 23.9 mm, P = 0.003) and showed a higher fraction of T3+cancers (16.9 vs. 8.5 %, P = 0.02) than true ICs (i.e., not visible at the latest screen). A higher portion of missed than true ICs underwent mastectomy (44.7 vs. 30.8 %, P = 0.002). We found no differences in mammographic and tumor characteristics for early ICs, detected either after SFM or FFDM. Late ICs following FFDM were more often true ICs than missed ICs (69.0 vs. 57.6 %, P = 0.03) and more often receptor triple negative (P = 0.02), compared to late ICs at SFM. Interval cancer subgroups showed comparable overall survival. Interval cancer subgroups show distinctive mammographic and tumor characteristics but a comparable overall survival. PMID:27393617

  7. Just Noticeable Difference Estimation for Screen Content Images.

    PubMed

    Wang, Shiqi; Ma, Lin; Fang, Yuming; Lin, Weisi; Ma, Siwei; Gao, Wen

    2016-08-01

    We propose a novel just noticeable difference (JND) model for a screen content image (SCI). The distinct properties of the SCI result in different behaviors of the human visual system when viewing the textual content, which motivate us to employ a local parametric edge model with an adaptive representation of the edge profile in JND modeling. In particular, we decompose each edge profile into its luminance, contrast, and structure, and then evaluate the visibility threshold in different ways. The edge luminance adaptation, contrast masking, and structural distortion sensitivity are studied in subjective experiments, and the final JND model is established based on the edge profile reconstruction with tolerable variations. Extensive experiments are conducted to verify the proposed JND model, which confirm that it is accurate in predicting the JND profile, and outperforms the state-of-the-art schemes in terms of the distortion masking ability. Furthermore, we explore the applicability of the proposed JND model in the scenario of perceptually lossless SCI compression, and experimental results show that the proposed scheme can outperform the conventional JND guided compression schemes by providing better visual quality at the same coding bits. PMID:27249834

  8. Status of the fluorescent screens and image processing for the APS linac

    SciTech Connect

    Berg, W.; Ko, K.

    1993-11-01

    Ten fluorescent screens and cameras determine the relative position and image profile of the beam in both the electron and positron linacs at the Advanced Photon Source (APS). The timing techniques used to capture the beam image allow direct synchronization to the electron gun trigger to minimize timing uncertainties. This paper discusses the design and status of the APS linac fluorescent screen assemblies and imaging system.

  9. Quality Imaging - Comparison of CR Mammography with Screen-Film Mammography

    SciTech Connect

    Gaona, E.; Azorin Nieto, J.; Iran Diaz Gongora, J. A.; Arreola, M.; Casian Castellanos, G.; Perdigon Castaneda, G. M.; Franco Enriquez, J. G.

    2006-09-08

    The aim of this work is a quality imaging comparison of CR mammography images printed to film by a laser printer with screen-film mammography. A Giotto and Elscintec dedicated mammography units with fully automatic exposure and a nominal large focal spot size of 0.3 mm were used for the image acquisition of phantoms in screen-film mammography. Four CR mammography units from two different manufacturers and three dedicated x-ray mammography units with fully automatic exposure and a nominal large focal spot size of 0.3 mm were used for the image acquisition of phantoms in CR mammography. The tests quality image included an assessment of system resolution, scoring phantom images, Artifacts, mean optical density and density difference (contrast). In this study, screen-film mammography with a quality control program offers a significantly greater level of quality image relative to CR mammography images printed on film.

  10. The use of breast imaging to screen women at high risk for cancer.

    PubMed

    Sickles, Edward A

    2010-09-01

    Although there currently is no evidence of reduced breast cancer mortality for screening women at high risk with mammography, magnetic resonance (MR) imaging, or ultrasonography (US), the presumptive evidence of early cancer detection provided by numerous observational studies has led to the publication of guidelines and recommendations for the selective use of these imaging modalities. In general, annual screening mammography is recommended for women of appropriately high risk beginning at age 30 years, supplemental screening with MR imaging is recommended for a subset of women at very high risk, and screening US is suggested for women for whom MR imaging is appropriate but unavailable, impractical, or poorly tolerated. The use of screening US remains controversial among women who have no substantial risk factors other than dense breasts. PMID:20868890

  11. Vertically dispersive holographic screens and autostereoscopic displays in 3D medical imaging

    NASA Astrophysics Data System (ADS)

    Magalhães, Daniel S. F.; Serra, Rolando L.; Vannucci, André L.; Moreno, Alfredo B.; Magalhães, Lucas V. B.; Llovera, Juan J.; Li, Li M.

    2011-05-01

    In this work we describe a setup employed for the recording of vertical dispersive holographic screens that can be used for medical applications. We show how to obtain holographic screens with areas up to 1200 cm2, focal length of 25+/-2 cm and diffraction efficiency of 7.2%. We analyze the technique employed and the holographic screens obtained. Using this screen we describe a setup for the projection of Magnetic Resonance or Tomographic Images. We also describe and present the first results of an autostereoscopic system for 3D medical imaging.

  12. Risk of Breast Cancer in Women with False-Positive Results according to Mammographic Features.

    PubMed

    Castells, Xavier; Torá-Rocamora, Isabel; Posso, Margarita; Román, Marta; Vernet-Tomas, Maria; Rodríguez-Arana, Ana; Domingo, Laia; Vidal, Carmen; Baré, Marisa; Ferrer, Joana; Quintana, María Jesús; Sánchez, Mar; Natal, Carmen; Espinàs, Josep A; Saladié, Francina; Sala, María

    2016-08-01

    Purpose To assess the risk of breast cancer in women with false-positive screening results according to radiologic classification of mammographic features. Materials and Methods Review board approval was obtained, with waiver of informed consent. This retrospective cohort study included 521 200 women aged 50-69 years who underwent screening as part of the Spanish Breast Cancer Screening Program between 1994 and 2010 and who were observed until December 2012. Cox proportional hazards regression analysis was used to estimate the age-adjusted hazard ratio (HR) of breast cancer and the 95% confidence interval (CI) in women with false-positive mammograms as compared with women with negative mammograms. Separate models were adjusted for screen-detected and interval cancers and for screen-film and digital mammography. Time without a breast cancer diagnosis was plotted by using Kaplan-Meier curves. Results When compared with women with negative mammograms, the age-adjusted HR of cancer in women with false-positive results was 1.84 (95% CI: 1.73, 1.95; P < .001). The risk was higher in women who had calcifications, whether they were (HR, 2.73; 95% CI: 2.28, 3.28; P < .001) or were not (HR, 2.24; 95% CI: 2.02, 2.48; P < .001) associated with masses. Women in whom mammographic features showed changes in subsequent false-positive results were those who had the highest risk (HR, 9.13; 95% CI: 8.28, 10.07; P < .001). Conclusion Women with false-positive results had an increased risk of breast cancer, particularly women who had calcifications at mammography. Women who had more than one examination with false-positive findings and in whom the mammographic features changed over time had a highly increased risk of breast cancer. Previous mammographic features might yield useful information for further risk-prediction models and personalized follow-up screening protocols. (©) RSNA, 2016 Online supplemental material is available for this article. PMID:26878225

  13. Evaluating thin compression paddles for mammographically compatible ultrasound.

    PubMed

    Booi, Rebecca C; Krücker, Jochen F; Goodsitt, Mitchell M; O'Donnell, Matthew; Kapur, Ajay; LeCarpentier, Gerald L; Roubidoux, Marilyn A; Fowlkes, J Brian; Carson, Paul L

    2007-03-01

    We are developing a combined digital mammography/3D ultrasound system to improve detection and/or characterization of breast lesions. Ultrasound scanning through a mammographic paddle could significantly reduce signal level, degrade beam focusing and create reverberations. Thus, appropriate paddle choice is essential for accurate sonographic lesion detection and assessment with this system. In this study, we characterized ultrasound image quality through paddles of varying materials (lexan, polyurethane, TPX, mylar) and thicknesses (0.25 to 2.5 mm). Analytical experiments focused on lexan and TPX, which preliminary results demonstrated were most competitive. Spatial and contrast resolution, side-lobe and range lobe levels, contrast and signal strength were compared with no-paddle images. When the beamforming of the system was corrected to account for imaging through the paddle, the TPX 2.5 mm paddle performed the best. Test objects imaged through this paddle demonstrated < or = 15% reduction in spatial resolution, < or = 7.5 dB signal loss, < or = 3 dB contrast loss and range lobe levels > or = 35 dB below signal maximum over 4 cm. TPX paddles <2.5 mm could also be used with this system, depending on imaging goals. In 10 human subjects with cysts, small CNR losses were observed but were determined to be statistically insignificant. Radiologists concluded that 75% of cysts in through-paddle scans were at least as detectable as in their corresponding direct-contact scans. PMID:17280765

  14. Ethnic Differences in Mammographic Densities: An Asian Cross-Sectional Study

    PubMed Central

    Mariapun, Shivaani; Li, Jingmei; Yip, Cheng Har; Taib, Nur Aishah Mohd; Teo, Soo-Hwang

    2015-01-01

    Background Mammographic density is a strong risk factor for breast cancer and is highly variable, but, to date, few studies have examined density in Asian women, particularly those in low and middle-income Asian countries where genetic and lifestyle determinants may be significantly different. Methods A total of 1,240 women who attended an opportunistic mammogram screening programme were eligible for analysis. Mammographic density was estimated using a fully-automated thresholding method and differences across ethnic groups were examined using linear regression in 205 randomly selected Chinese women, 138 Malay and 199 Indian women. Results Percent density was significantly higher in Chinese women (28.5%; 95% CI 27.0%, 30.0%) compared to Malay (24.2%; 95% CI 22.5%, 26.0%) and Indian (24.3%; 95% CI 22.8%, 25.7%) women (p<0.001), after adjustment for age, BMI, menopausal status, parity and age at first full term pregnancy. Correspondingly, adjusted nondense area was significantly lower in Chinese (72.2cm2; 95% CI 67.9cm2, 76.5cm2) women compared to Malay (92.1cm2; 95% CI 86.9cm2, 97.2cm2) and Indian (97.7cm2; 95% CI 93.4cm2, 101.9cm2) women (p<0.001), but dense area did not differ across the three ethnic groups. Conclusions Our study shows that higher percent density and lower nondense area reflect the higher incidence of breast cancer in Chinese compared to Malay and Indian women in Malaysia. Known lifestyle determinants of mammographic density do not fully account for the ethnic variations observed in mammographic density in this Asian cohort. PMID:25659139

  15. Compound image compression for real-time computer screen image transmission.

    PubMed

    Lin, Tony; Hao, Pengwei

    2005-08-01

    We present a compound image compression algorithm for real-time applications of computer screen image transmission. It is called shape primitive extraction and coding (SPEC). Real-time image transmission requires that the compression algorithm should not only achieve high compression ratio, but also have low complexity and provide excellent visual quality. SPEC first segments a compound image into text/graphics pixels and pictorial pixels, and then compresses the text/graphics pixels with a new lossless coding algorithm and the pictorial pixels with the standard lossy JPEG, respectively. The segmentation first classifies image blocks into picture and text/graphics blocks by thresholding the number of colors of each block, then extracts shape primitives of text/graphics from picture blocks. Dynamic color palette that tracks recent text/graphics colors is used to separate small shape primitives of text/graphics from pictorial pixels. Shape primitives are also extracted from text/graphics blocks. All shape primitives from both block types are losslessly compressed by using a combined shape-based and palette-based coding algorithm. Then, the losslessly coded bitstream is fed into a LZW coder. Experimental results show that the SPEC has very low complexity and provides visually lossless quality while keeping competitive compression ratios. PMID:16121449

  16. Transmission-type holographic screen for displaying projected three-dimensional images with large viewing angle

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangsu; Liu, Shou; Ren, Xuechang

    2008-03-01

    A new type of holographic screen used to display projected 3-dimensional (3D) images with large viewing angle and relatively high brightness is presented. The screen is 2-dimensional hexagonal lattice relief in micron-scale lattice period, fabricated in plastic sheet using holographic technique and pattern replication method so that the fabrication of the screen is fast and cost effective and large-size screen can be obtained. Theoretical analysis and experimental results demonstrate that larger lattice period generates more diffracted rays thus provides larger viewing anlge and brighter image. 45° horizontal and 30° vertical viewing anlges have been achieved and the images with parallax have been observed. The screen has the potential of being applied for 3D holographic movie display and 3D art exhibition.

  17. Development of a multi-channel time-domain fluorescence mammograph

    NASA Astrophysics Data System (ADS)

    Hagen, A.; Steinkellner, O.; Grosenick, D.; Möller, M.; Ziegler, R.; Nielsen, T.; Lauritsen, K.; Macdonald, R.; Rinneberg, H.

    2007-02-01

    We developed an eight-channel scanning time-domain fluorescence mammograph capable of imaging the distribution of a non-specific fluorescent contrast agent in the female breast, besides imaging intrinsic absorption and scattering properties of healthy breast tissue and tumors. The apparatus is based on the PTB multi-channel laser pulse mammograph, originally designed for measurements of absorption and scattering coefficients at four selected wavelengths (λ = 652 nm, 684 nm, 797nm, and 830 nm). It was upgraded for time-resolved detection of fluorescence, excited at 735 nm by a ps diode laser with 10 mW output power and detected at wavelengths λ >= 780 nm. Cooled PMTs with GaAs photocathodes are used to detect laser and fluorescence photons at five positions in transmission and three positions in reflection. Measurements are performed with the breast being slightly compressed between two parallel glass plates. The transmitting and receiving fiber bundles are scanned synchronously over the breast in steps of typically 2.5 mm. At each scan position, distributions of times of flight of laser photons are measured by time-correlated single photon counting at eight detector positions, followed by measurements of distributions of times of arrival of fluorescence photons. The performance of the fluorescence mammograph was investigated by using breast-like phantoms with a fluorescent inhomogeneity with dye enrichment varying between 2:1 and 10:1 over background values.

  18. Advantages and Disadvantages of Mammography Screening

    PubMed Central

    Heywang-Köbrunner, Sylvia H.; Hacker, Astrid; Sedlacek, Stefan

    2011-01-01

    Summary Mammography screening is the only method presently considered appropriate for mass screening of asymptomatic women. Its frequent use, however, warrants diligent analysis of potential side effects. Radiation risk is far below the natural yearly risk of breast cancer and should not be used as an argument against screening. False-positive calls lead to additional imaging or histopathological assessment, mainly percutaneous breast biopsy. These measures are tolerated and accepted fairly well. Their number is limited by strict quality assurance and constant training. Interval cancers represent a limitation of breast screening that should prompt further research for optimization. Evaluation of overdiagnosis is a highly debated topic in the literature. According to the probably most realistic available calculations, overdiagnosis is acceptable as it is compensated by the potential mortality reduction. Nonetheless, this potential side effect warrants optimal adjustment of therapy to the patient's individual risk. The mortality reduction seen in randomized studies was confirmed by results from national screening programs. A recent case referent study indicated that improvements in mortality reduction run parallel to improved mammographic techniques. Use of less aggressive therapies is another valuable effect of screening. Awareness of potential problems, strict quality assurance, and further research should help to further develop screening programs. PMID:21779225

  19. Comparison of fully and semi-automated area-based methods for measuring mammographic density and predicting breast cancer risk

    PubMed Central

    Sovio, U; Li, J; Aitken, Z; Humphreys, K; Czene, K; Moss, S; Hall, P; McCormack, V; dos-Santos-Silva, I

    2014-01-01

    Background: Mammographic density is a strong risk factor for breast cancer but the lack of valid fully automated methods for quantifying it has precluded its use in clinical and screening settings. We compared the performance of a recently developed automated approach, based on the public domain ImageJ programme, to the well-established semi-automated Cumulus method. Methods: We undertook a case-control study within the intervention arm of the Age Trial, in which ∼54 000 British women were offered annual mammography at ages 40–49 years. A total of 299 breast cancer cases diagnosed during follow-up and 422 matched (on screening centre, date of birth and dates of screenings) controls were included. Medio-lateral oblique (MLO) images taken closest to age 41 and at least one year before the index case's diagnosis were digitised for each participant. Cumulus readings were performed in the left MLO and ImageJ-based readings in both left and right MLOs. Conditional logistic regression was used to examine density–breast cancer associations. Results: The association between density readings taken from one single MLO and breast cancer risk was weaker for the ImageJ-based method than for Cumulus (age–body mass index-adjusted odds ratio (OR) per one s.d. increase in percent density (95% CI): 1.52 (1.24–1.86) and 1.61 (1.33–1.94), respectively). The ImageJ-based density–cancer association strengthened when the mean of left–right MLO readings was used: OR=1.61 (1.31–1.98). Conclusions: The mean of left–right MLO readings yielded by the ImageJ-based method was as strong a predictor of risk as Cumulus readings from a single MLO image. The ImageJ-based method, using the mean of two measurements, is a valid automated alternative to Cumulus for measuring density in analogue films. PMID:24556624

  20. Maintaining quality in the UK breast screening program

    NASA Astrophysics Data System (ADS)

    Gale, Alastair

    2010-02-01

    Breast screening in the UK has been implemented for over 20 years and annually nearly two million women are now screened with an estimated 1,400 lives saved. Nationally, some 700 individuals interpret screening mammograms in almost 110 screening centres. Currently, women aged 50 to 70 are invited for screening every three years and by 2012 this age range will increase to 47 - 73 years. There is a rapid ongoing transition from using film mammograms to full field digital mammography such that in 2010 every screening centre will be partly digital. An early, and long running, concern has been how to ensure the highest quality of imaging interpretation across the UK, an issue enhanced by the use of a three year screening interval. To partly address this question a self assessment scheme was developed in 1988 and subsequently implemented nationally in the UK as a virtually mandatory activity. The scheme is detailed from its beginnings, through its various developments to current incarnation and future plans. This encompasses both radiological (single view screening, two view screening, mammographic film and full field digital mammography) as well as design changes (cases reported by means of: form filling; PDA; tablet PC; iPhone, and the internet). The scheme provides a rich data source which is regularly studied to examine different aspects of radiological performance. Overall it aids screening radiologists by giving them regular access to a range of difficult exemplar cases together with feedback on their performance as compared to their peers.

  1. Application of computer-extracted breast tissue texture features in predicting false-positive recalls from screening mammography

    NASA Astrophysics Data System (ADS)

    Ray, Shonket; Choi, Jae Y.; Keller, Brad M.; Chen, Jinbo; Conant, Emily F.; Kontos, Despina

    2014-03-01

    Mammographic texture features have been shown to have value in breast cancer risk assessment. Previous models have also been developed that use computer-extracted mammographic features of breast tissue complexity to predict the risk of false-positive (FP) recall from breast cancer screening with digital mammography. This work details a novel locallyadaptive parenchymal texture analysis algorithm that identifies and extracts mammographic features of local parenchymal tissue complexity potentially relevant for false-positive biopsy prediction. This algorithm has two important aspects: (1) the adaptive nature of automatically determining an optimal number of region-of-interests (ROIs) in the image and each ROI's corresponding size based on the parenchymal tissue distribution over the whole breast region and (2) characterizing both the local and global mammographic appearances of the parenchymal tissue that could provide more discriminative information for FP biopsy risk prediction. Preliminary results show that this locallyadaptive texture analysis algorithm, in conjunction with logistic regression, can predict the likelihood of false-positive biopsy with an ROC performance value of AUC=0.92 (p<0.001) with a 95% confidence interval [0.77, 0.94]. Significant texture feature predictors (p<0.05) included contrast, sum variance and difference average. Sensitivity for false-positives was 51% at the 100% cancer detection operating point. Although preliminary, clinical implications of using prediction models incorporating these texture features may include the future development of better tools and guidelines regarding personalized breast cancer screening recommendations. Further studies are warranted to prospectively validate our findings in larger screening populations and evaluate their clinical utility.

  2. Personnel screening with terahertz opto-mechanical scanning imaging

    NASA Astrophysics Data System (ADS)

    Guo, Lan-tao; Liu, Xin; Deng, Chao; Zhao, Yuan-meng; Zhang, Cun-lin

    2014-11-01

    We presented a passive THz opto-mechnical scanning imaging method using a single detector and a trihedral scanning mirror. The system improved the imaging speed through employing two flapping mirrors. Also the trihedral scanning mirror and an ellipsoidal mirror were adopted. The parameters were set as follows: the best imaging distance was 2.2m with the image range of 1.6m (W) ×1.6m (H), the imaging time was 2s, and the resolution was 3cm. We imaged human body with different objects concealed under their clothes, such as buckle, ceramic chip, etc.

  3. Mammography workstation design: effect on mammographer behaviour and the risk of musculoskeletal disorders

    NASA Astrophysics Data System (ADS)

    Taylor-Phillips, S.; Wallis, M. G.; Gale, A. G.

    2008-03-01

    In the UK Breast Screening Programme there is a growing transition from film to digital mammography, and consequently a change in mammography workstation ergonomics. This paper investigates the effect of the change for radiologists including their comfort, likelihood of developing musculoskeletal disorders (MSD's), and work practices. Three workstations types were investigated: one with all film mammograms; one with digital mammograms alongside film mammograms from the previous screening round, and one with digital mammograms alongside digitised film mammograms from the previous screening round. Mammographers were video-taped whilst conducting work sessions at each of the workstations. Event based Rapid Upper Limb Assessment (RULA) postural analysis showed no overall increase in MSD risk level in the switch from the film to digital workstation. Average number of visual glances at the prior mammograms per case measured by analysis of recorded video footage showed an increase if the prior mammograms were digitised, rather than displayed on a multi-viewer (p<.05). This finding has potential implications for mammographer performance in the transition to digital mammography in the UK.

  4. Clinical comparison of CR and screen film for imaging the critically ill neonate

    NASA Astrophysics Data System (ADS)

    Andriole, Katherine P.; Brasch, Robert C.; Gooding, Charles A.; Gould, Robert G.; Cohen, Pierre A.; Rencken, Ingo R.; Huang, H. K.

    1996-05-01

    A clinical comparison of computed radiography (CR) versus screen-film for imaging the critically-ill neonate is performed, utilizing a modified (hybrid) film cassette containing a CR (standard ST-V) imaging plate, a conventional screen and film, allowing simultaneous acquisition of perfectly matched CR and plain film images. For 100 portable neonatal chest and abdominal projection radiographs, plain film was subjectively compared to CR hardcopy. Three pediatric radiologists graded overall image quality on a scale of one (poor) to five (excellent), as well as visualization of various anatomic structures (i.e., lung parenchyma, pulmonary vasculature, tubes/lines) and pathological findings (i.e., pulmonary interstitial emphysema, pleural effusion, pneumothorax). Results analyzed using a combined kappa statistic of the differences between scores from each matched set, combined over the three readers showed no statistically significant difference in overall image quality between screen- film and CR (p equals 0.19). Similarly, no statistically significant difference was seen between screen-film and CR for anatomic structure visualization and for visualization of pathological findings. These results indicate that the image quality of CR is comparable to plain film, and that CR may be a suitable alternative to screen-film imaging for portable neonatal chest and abdominal examinations.

  5. International Consortium on Mammographic Density: Methodology and population diversity captured across 22 countries.

    PubMed

    McCormack, Valerie A; Burton, Anya; dos-Santos-Silva, Isabel; Hipwell, John H; Dickens, Caroline; Salem, Dorria; Kamal, Rasha; Hartman, Mikael; Lee, Charmaine Pei Ling; Chia, Kee-Seng; Ozmen, Vahit; Aribal, Mustafa Erkin; Flugelman, Anath Arzee; Lajous, Martín; Lopez-Riduara, Ruy; Rice, Megan; Romieu, Isabelle; Ursin, Giske; Qureshi, Samera; Ma, Huiyan; Lee, Eunjung; van Gils, Carla H; Wanders, Johanna O P; Vinayak, Sudhir; Ndumia, Rose; Allen, Steve; Vinnicombe, Sarah; Moss, Sue; Won Lee, Jong; Kim, Jisun; Pereira, Ana; Garmendia, Maria Luisa; Sirous, Reza; Sirous, Mehri; Peplonska, Beata; Bukowska, Agnieszka; Tamimi, Rulla M; Bertrand, Kimberly; Nagata, Chisato; Kwong, Ava; Vachon, Celine; Scott, Christopher; Perez-Gomez, Beatriz; Pollan, Marina; Maskarinec, Gertraud; Giles, Graham; Hopper, John; Stone, Jennifer; Rajaram, Nadia; Teo, Soo-Hwang; Mariapun, Shivaani; Yaffe, Martin J; Schüz, Joachim; Chiarelli, Anna M; Linton, Linda; Boyd, Norman F

    2016-02-01

    Mammographic density (MD) is a quantitative trait, measurable in all women, and is among the strongest markers of breast cancer risk. The population-based epidemiology of MD has revealed genetic, lifestyle and societal/environmental determinants, but studies have largely been conducted in women with similar westernized lifestyles living in countries with high breast cancer incidence rates. To benefit from the heterogeneity in risk factors and their combinations worldwide, we created an International Consortium on Mammographic Density (ICMD) to pool individual-level epidemiological and MD data from general population studies worldwide. ICMD aims to characterize determinants of MD more precisely, and to evaluate whether they are consistent across populations worldwide. We included 11755 women, from 27 studies in 22 countries, on whom individual-level risk factor data were pooled and original mammographic images were re-read for ICMD to obtain standardized comparable MD data. In the present article, we present (i) the rationale for this consortium; (ii) characteristics of the studies and women included; and (iii) study methodology to obtain comparable MD data from original re-read films. We also highlight the risk factor heterogeneity captured by such an effort and, thus, the unique insight the pooled study promises to offer through wider exposure ranges, different confounding structures and enhanced power for sub-group analyses. PMID:26724463

  6. Fractal analysis of radiologists' visual scanning pattern in screening mammography

    NASA Astrophysics Data System (ADS)

    Alamudun, Folami T.; Yoon, Hong-Jun; Hudson, Kathy; Morin-Ducote, Garnetta; Tourassi, Georgia

    2015-03-01

    Several researchers have investigated radiologists' visual scanning patterns with respect to features such as total time examining a case, time to initially hit true lesions, number of hits, etc. The purpose of this study was to examine the complexity of the radiologists' visual scanning pattern when viewing 4-view mammographic cases, as they typically do in clinical practice. Gaze data were collected from 10 readers (3 breast imaging experts and 7 radiology residents) while reviewing 100 screening mammograms (24 normal, 26 benign, 50 malignant). The radiologists' scanpaths across the 4 mammographic views were mapped to a single 2-D image plane. Then, fractal analysis was applied on the composite 4- view scanpaths. For each case, the complexity of each radiologist's scanpath was measured using fractal dimension estimated with the box counting method. The association between the fractal dimension of the radiologists' visual scanpath, case pathology, case density, and radiologist experience was evaluated using fixed effects ANOVA. ANOVA showed that the complexity of the radiologists' visual search pattern in screening mammography is dependent on case specific attributes (breast parenchyma density and case pathology) as well as on reader attributes, namely experience level. Visual scanning patterns are significantly different for benign and malignant cases than for normal cases. There is also substantial inter-observer variability which cannot be explained only by experience level.

  7. Prognosis for Mammographically Occult, Early-Stage Breast Cancer Patients Treated With Breast-Conservation Therapy

    SciTech Connect

    Yang, Tzu-I. J.; Yang Qifeng; Haffty, Bruce G.; Moran, Meena S.

    2010-01-15

    Purpose: To compare mammographically occult (MamOcc) and mammographically positive (MamPos) early-stage breast cancer patients treated with breast-conservation therapy (BCT), to analyze differences between the two cohorts. Methods and Materials: Our two cohorts consisted of 214 MamOcc and 2168 MamPos patients treated with BCT. Chart reviews were conducted to assess mammogram reports and method of detection. All clinical-pathologic and outcome parameters were analyzed to detect differences between the two cohorts. Results: Median follow-up was 7 years. There were no differences in final margins, T stage, nodal status, estrogen/progesterone receptor status, or 'triple-negative' status. Significant differences included younger age at diagnosis (p < 0.0001), more positive family history (p = 0.0033), less HER-2+ disease (p = 0.0294), and 1{sup o} histology (p < 0.0001). At 10 years, the differences in overall survival, cause-specific survival, and distant relapse between the two groups did not differ significantly. The MamOcc cohort had more breast relapses (15% vs. 8%; p = 0.0357), but on multivariate analysis this difference was not significant (hazard ratio 1.0, 95% confidence interval 0.993-1.007, p = 0.9296). Breast relapses were mammographically occult in 32% of the MamOcc and 12% of the MamPos cohorts (p = 0.0136). Conclusions: Although our study suggests that there are clinical-pathologic variations for the MamOcc cohort vs. MamPos patients that may ultimately affect management, breast relapse after BCT was not significantly different. Breast recurrences were more often mammographically occult in the MamOcc cohort; consideration should be given to closer follow-up and alternative imaging strategies (ultrasound, breast MRI) for routine posttreatment examination. To our knowledge, this represents the largest series addressing the prognostic significance of MamOcc cancers treated with BCT.

  8. Screening Outcomes Following Implementation of Digital Breast Tomosynthesis in a General-Population Screening Program

    PubMed Central

    McCarthy, Anne Marie; Kontos, Despina; Synnestvedt, Marie; Tan, Kay See; Heitjan, Daniel F.; Schnall, Mitchell

    2014-01-01

    Background Early data on breast cancer screening utilizing digital breast tomosynthesis (DBT) combined with digital mammography (DM) have shown improvements in false-positive and false-negative screening rates compared with DM alone. However, these trials were performed at sites where conventional mammographic screening was concurrently performed, possibly leading to selection biases or with complex, multireader algorithms not reflecting general clinical practice. Our study reports the impact on screening outcomes for DBT screening implemented in an entire clinic population. Methods Recall rates, cancer detection, and positive predictive values of screening were compared for 15571 women screened with DBT and 10728 screened with DM alone prior to DBT implementation at a single breast imaging center. Generalized linear mixed-effects models were used to estimate the odds ratio (OR) for recall rate adjusted for age, race, presence of prior mammograms, breast density and reader. All statistical tests were two-sided. Results DBT screening showed a statistically significant reduction in recalls compared to DM alone. For the entire population, there were 16 fewer recalls (8.8% vs 10.4%, P <.001, adjusted OR = 0.80, 95% confidence interval [CI] = 0.74 to 0.88, P < .001) and 0.9 additional cancers detected per 1000 screened with DBT compared to DM alone. There was a statistically significant increase in PPV1 (6.2% vs 4.4%, P = .047). In women younger than age 50 years screened with DBT, there were 17 fewer recalls (12.3% vs 14.0%, P = .02) and 3.6 additional cancer detected per 1000 screened (5.7 vs 2.2 per 1000, P = .02). Conclusions Our data support the clinical implementation of DBT in breast cancer screening; however, larger prospective trials are needed to validate our findings in specific patient subgroups. PMID:25313245

  9. Black Images in the American Theatre: NAACP Protest Campaigns--Stage, Screen, Radio & Television.

    ERIC Educational Resources Information Center

    Archer, Leonard C.

    Black America's struggle to create a new image of Negro Americans on the stage and screen, in literature, and in the news media is the focus of this book. Chapters review the history of the black image and the early and persistent efforts of the National Association for the Advancement of Colored People (NAACP) to achieve realistic and unbiased…

  10. CellProfiler Analyst: data exploration and analysis software for complex image-based screens

    PubMed Central

    Jones, Thouis R; Kang, In Han; Wheeler, Douglas B; Lindquist, Robert A; Papallo, Adam; Sabatini, David M; Golland, Polina; Carpenter, Anne E

    2008-01-01

    Background Image-based screens can produce hundreds of measured features for each of hundreds of millions of individual cells in a single experiment. Results Here, we describe CellProfiler Analyst, open-source software for the interactive exploration and analysis of multidimensional data, particularly data from high-throughput, image-based experiments. Conclusion The system enables interactive data exploration for image-based screens and automated scoring of complex phenotypes that require combinations of multiple measured features per cell. PMID:19014601

  11. Exploratory survey of image quality on CR digital mammography imaging systems in Mexico.

    PubMed

    Gaona, E; Rivera, T; Arreola, M; Franco, J; Molina, N; Alvarez, B; Azorín, C G; Casian, G

    2014-01-01

    The purpose of this study was to assess the current status of image quality and dose in computed radiographic digital mammography (CRDM) systems. Studies included CRDM systems of various models and manufacturers which dose and image quality comparisons were performed. Due to the recent rise in the use of digital radiographic systems in Mexico, CRDM systems are rapidly replacing conventional film-screen systems without any regard to quality control or image quality standards. Study was conducted in 65 mammography facilities which use CRDM systems in the Mexico City and surrounding States. The systems were tested as used clinically. This means that the dose and beam qualities were selected using the automatic beam selection and photo-timed features. All systems surveyed generate laser film hardcopies for the radiologist to read on a scope or mammographic high luminance light box. It was found that 51 of CRDM systems presented a variety of image artefacts and non-uniformities arising from inadequate acquisition and processing, as well as from the laser printer itself. Undisciplined alteration of image processing settings by the technologist was found to be a serious prevalent problem in 42 facilities. Only four of them showed an image QC program which is periodically monitored by a medical physicist. The Average Glandular Dose (AGD) in the surveyed systems was estimated to have a mean value of 2.4 mGy. To improve image quality in mammography and make more efficient screening mammographic in early detection of breast cancer is required new legislation. PMID:23938078

  12. Numerical simulation of the displayed image on the entire screen of autostereoscopic displays.

    PubMed

    Jung, Sung-Min; Kang, Hoon; Lee, Bu-Yeol; Kang, In-Byeong

    2015-03-23

    A three-dimensional simulation model calculating the optical intensity distribution for the entire screen of an autostereoscopic display at a given eye position was developed in this study. A parallax barrier array was used for the optical model and reverse ray tracing of light from the observer's eye to the subpixels through the slits of the barrier was performed based on reverse geometrical optics. By investigating the optical behavior of the displayed image for the nine-view design condition for various viewing distances, we found the inhomogeneous crosstalk from the unwanted views and predicted segmented images which were comprised of multiple images from different views on the entire display screen. From the results, our simulation model shows good potentiality for predicting the displayed image on the entire display screen of autostereoscopic displays for various positions of the observer's eye with sufficient calculation speed. PMID:25837123

  13. Fundus autofluorescence and colour fundus imaging compared during telemedicine screening in patients with diabetes.

    PubMed

    Kolomeyer, Anton M; Baumrind, Benjamin R; Szirth, Bernard C; Shahid, Khadija; Khouri, Albert S

    2013-06-01

    We investigated the use of fundus autofluorescence (FAF) imaging in screening the eyes of patients with diabetes. Images were obtained from 50 patients with type 2 diabetes undergoing telemedicine screening with colour fundus imaging. The colour and FAF images were obtained with a 15.1 megapixel non-mydriatic retinal camera. Colour and FAF images were compared for pathology seen in nonproliferative and proliferative diabetic retinopathy (NPDR and PDR, respectively). A qualitative assessment was made of the ease of detecting early retinopathy changes and the extent of existing retinopathy. The mean age of the patients was 47 years, most were male (82%) and most were African American (68%). Their mean visual acuity was 20/45 and their mean intraocular pressure was 14.3 mm Hg. Thirty-eight eyes (76%) did not show any diabetic retinopathy changes on colour or FAF imaging. Seven patients (14%) met the criteria for NPDR and five (10%) for severe NPDR or PDR. The most common findings were microaneurysms, hard exudates and intra-retinal haemorrhages (IRH) (n = 6 for each). IRH, microaneurysms and chorioretinal scars were more easily visible on FAF images. Hard exudates, pre-retinal haemorrhage and fibrosis, macular oedema and Hollenhorst plaque were easier to identify on colour photographs. The value of FAF imaging as a complementary technique to colour fundus imaging in detecting diabetic retinopathy during ocular screening warrants further investigation. PMID:24163061

  14. Reduction of radiation dose and imaging costs in scoliosis radiography. Application of large-screen image intensifier photofluorography

    SciTech Connect

    Manninen, H.; Kiekara, O.; Soimakallio, S.; Vainio, J.

    1988-04-01

    Photofluorography using a large-field image intensifier (Siemens Optilux 57) was applied to scoliosis radiography and compared with a full-size rare-earth screen/film technique. When scoliosis radiography (PA-projection) was performed on 25 adolescent patients, the photofluorographs were found to be of comparable diagnostic quality with full-size films. A close correspondence between the imaging techniques was found in the Cobb angle measurements as well as in the grading of rotation with the pedicle method. The use of photofluorography results in a radiation dose reduction of about one-half and considerable savings in direct imaging costs and archive space. In our opinion the method is particularly well-suited for follow-up and screening evaluation of scoliosis, but in tall patients the image field size of 40 x 40 cm restricts its usefulness as initial examination.

  15. Light emission efficiency and imaging properties of YAP:Ce granular phosphor screens

    NASA Astrophysics Data System (ADS)

    Kalivas, N.; Valais, I.; Nikolopoulos, D.; Konstantinidis, A.; Gaitanis, A.; Cavouras, D.; Nomicos, C. D.; Panayiotakis, G.; Kandarakis, I.

    2007-11-01

    Phosphor materials are used in medical imaging combined with radiographic film or other photodetectors. Cerium (Ce3+) -doped scintillators are of particular interest for medical imaging, because of their very fast response. YAP:Ce scintillator-based image detectors have already been evaluated in single-crystal form and under conditions of positron emission tomography and synchrotron or γ-ray irradiation. Furthermore, YAP:Ce phosphor has been evaluated in conjunction with radiographic films. The present work reports experimental and theoretical data concerning the light output absolute luminescence efficiency (AE) of the YAP:Ce screens under irradiation conditions employed in medical X-ray projection imaging (i.e., in diagnostic radiology). projection imaging (i.e., in diagnostic radiology). YAP:Ce phosphor screens with surface densities ranging between 53 and 110 mg/cm2 were prepared by sedimentation on fused silica substates in our laboratory. The resulted surface density of the screens was determined by dividing the phosphor mass deposited on the screen surface with the area of the surface. Additionally this work addresses the imaging performance of YAP:Ce by estimation of the detective quantum efficiency (DQE), i.e., the square of the signal to noise ratio transfer. Absolute efficiency was found to decrease with X-ray tube voltage for for YAP:Ce phosphor. The highest experimental efficiency was obtained for the 53.7 mg/cm2 and 88.0 mg/cm2 YAP:Ce screens. The highest DQE value was found for the 88.0 mg/cm2 screen irradiated at 60 kVp.

  16. Controversies in Screening Mammography.

    PubMed

    Swain, Monique; Jeudy, Myrlene; Pearlman, Mark D

    2016-06-01

    The utility and effectiveness of screening mammography in diagnosing breast cancer at earlier stages and reducing disease-specific mortality remain controversial especially as to when to start and stop routine mammographic screening, and whether mammograms should be performed annually or biennially in average-risk women. This manuscript will analyze the available moderate and high-quality data to analyze both the benefits (lives saved and life-years saved) and inconveniences/harms (additional views, extra biopsies/overdiagnosis, and overtreatment of ductal carcinoma in situ) of different mammography screening guidelines to assist the practitioner in counseling their patients in clinical practice. PMID:27101240

  17. Illumination strategies to achieve effective indoor millimeter wave imaging for personnel screening applications

    NASA Astrophysics Data System (ADS)

    Doyle, Rory; Lyons, Brendan; Lettington, Alan; McEnroe, Tony; Walshe, John; McNaboe, John; Curtin, Peter

    2005-05-01

    The ability of millimetre-waves (mm-wave) to penetrate obscurants, be they clothing, fog etc., enables unique imaging applications in areas such as security screening of personnel and landing aids for aircraft. When used in an outdoor application, the natural thermal contrast provided by cold sky reflections off of objects allow for direct imaging of a scene. Imaging at mm-wave frequencies in an indoor situation requires that a thermal contrast be generated in order to illuminate and detect objects of interest. In the case of a portal screening application the illumination needs to be provided over the imaged area in a uniform, omni-directional manner and at a sufficient level of contrast to achieve the desired signal to noise ratio at the sensor. The primary options are to generate this contrast by using active noise sources or to develop a passive thermally induced source of mm-wave energy. This paper describes the approaches taken to developing and implementing an indoor imaging configuration for a mm-wave camera that is to be used in people screening applications. The camera uses a patented mechanical scanning method to directly generate a raster frame image of portal dimensions. Imaging has been conducted at a range of frequencies with the main focus being on 94GHz operation. Experiences with both active and passive illumination schemes are described with conclusions on the merits or otherwise of each. The results of imaging trials demonstrate the potential for using mm-wave imaging in an indoor situation and example images illustrate the capability of the camera and the illumination methods when used for personnel screening.

  18. Design for a coherent-scatter imaging system compatible with screening mammography.

    PubMed

    Kern, Katie; Peerzada, Lubna; Hassan, Laila; MacDonald, Carolyn

    2016-07-01

    A system using a wide-slot beam and simple antiscatter grids or slots has been designed to provide a localized map of tissue type that could be overlaid on the simultaneous conventional transmission image to provide an inexpensive, low dose adjunct to conventional screening mammography. Depth information is obtainable from the stereoscopic viewing angles. The system was demonstrated to produce observable contrast between adipose tissue and a phantom chosen to mimic carcinoma at an exposure comparable with screening mammography. Imaging data was collected over a range of system parameters to optimize contrast and to allow verification of simulation modeling. PMID:27610395

  19. Targets detection in smoke-screen image sequences using fractal and rough set theory

    NASA Astrophysics Data System (ADS)

    Yan, Xiaoke

    2015-08-01

    In this paper, a new algorithm for the detection of moving targets in smoke-screen image sequences is presented, which can combine three properties of pixel: grey, fractal dimensions and correlation between pixels by Rough Set. The first step is to locate and extract regions that may contain objects in an image by locally grey threshold technique. Secondly, the fractal dimensions of pixels are calculated, Smoke-Screen is done at different fractal dimensions. Finally, according to temporal and spatial correlations between different frames, the singular points can be filtered. The experimental results show that the algorithm can effectively increase detection probability and has robustness.

  20. A Picture You Can Handle: Infants Treat Touch-Screen Images More Like Photographs than Objects

    PubMed Central

    Ziemer, Christine J.; Snyder, Makenna

    2016-01-01

    Infants actively explore their world in order to determine the different ways in which they can interact with various objects. Although research on infant perception has focused on how infants understand the differences between 2- and 3-dimensional objects, today’s infants increasingly encounter 2D images with interactive qualities on smart-phone screens, tablets, and laptops. The purpose of this experiment was to examine the types of manual behaviors infants direct toward tablet images and to compare these actions to those evoked by 2D photographs or 3D when tactile feedback is controlled. Infants between the ages of 7–10 months sat on their parent’s lap in front of a table with a built-in well covered by a clear, plastic sheet while the three types of displays (photographs, objects, and screen images on a tablet) were presented for 30 s each. Infants saw three examples of each type of display presented in the built-in well so that tactile feedback information from the different displays was controlled. Coders noted the proportion of trials in which infants grasped, scratched, rubbed, or patted the display. Results indicate that infants direct significantly more grasps, scratches, and rubs toward 3D objects than 2D photographs. Infants also direct more grasps to objects compared to screen images. Our data suggests that infants are treating screen images more similarly to 2D photographs than 3D objects. PMID:27597837

  1. A Picture You Can Handle: Infants Treat Touch-Screen Images More Like Photographs than Objects.

    PubMed

    Ziemer, Christine J; Snyder, Makenna

    2016-01-01

    Infants actively explore their world in order to determine the different ways in which they can interact with various objects. Although research on infant perception has focused on how infants understand the differences between 2- and 3-dimensional objects, today's infants increasingly encounter 2D images with interactive qualities on smart-phone screens, tablets, and laptops. The purpose of this experiment was to examine the types of manual behaviors infants direct toward tablet images and to compare these actions to those evoked by 2D photographs or 3D when tactile feedback is controlled. Infants between the ages of 7-10 months sat on their parent's lap in front of a table with a built-in well covered by a clear, plastic sheet while the three types of displays (photographs, objects, and screen images on a tablet) were presented for 30 s each. Infants saw three examples of each type of display presented in the built-in well so that tactile feedback information from the different displays was controlled. Coders noted the proportion of trials in which infants grasped, scratched, rubbed, or patted the display. Results indicate that infants direct significantly more grasps, scratches, and rubs toward 3D objects than 2D photographs. Infants also direct more grasps to objects compared to screen images. Our data suggests that infants are treating screen images more similarly to 2D photographs than 3D objects. PMID:27597837

  2. Influence of Lifestyle Factors on Mammographic Density in Postmenopausal Women

    PubMed Central

    Brand, Judith S.; Czene, Kamila; Eriksson, Louise; Trinh, Thang; Bhoo-Pathy, Nirmala; Hall, Per; Celebioglu, Fuat

    2013-01-01

    Background Mammographic density is a strong risk factor for breast cancer. Apart from hormone replacement therapy (HRT), little is known about lifestyle factors that influence breast density. Methods We examined the effect of smoking, alcohol and physical activity on mammographic density in a population-based sample of postmenopausal women without breast cancer. Lifestyle factors were assessed by a questionnaire and percentage and area measures of mammographic density were measured using computer-assisted software. General linear models were used to assess the association between lifestyle factors and mammographic density and effect modification by body mass index (BMI) and HRT was studied. Results Overall, alcohol intake was positively associated with percent mammographic density (P trend  = 0.07). This association was modified by HRT use (P interaction  = 0.06): increasing alcohol intake was associated with increasing percent density in current HRT users (P trend  = 0.01) but not in non-current users (P trend  = 0.82). A similar interaction between alcohol and HRT was found for the absolute dense area, with a positive association being present in current HRT users only (P interaction  = 0.04). No differences in mammographic density were observed across categories of smoking and physical activity, neither overall nor in stratified analyses by BMI and HRT use. Conclusions Increasing alcohol intake is associated with an increase in mammography density, whereas smoking and physical activity do not seem to influence density. The observed interaction between alcohol and HRT may pose an opportunity for HRT users to lower their mammographic density and breast cancer risk. PMID:24349146

  3. Metabolic syndrome, insulin resistance, and mammographic density in pre- and postmenopausal women.

    PubMed

    Kim, Bo-Kyoung; Chang, Yoosoo; Ahn, Jiin; Jung, Hyun-Suk; Kim, Chan-Won; Yun, Kyung Eun; Kwon, Min-Jung; Suh, Byung-Seong; Chung, Eun Chul; Shin, Hocheol; Ryu, Seungho

    2015-09-01

    Little is known about the association of metabolic syndrome (MetS) or insulin resistance (IR) with mammographic density, a strong risk factor for breast cancer. The goal of this study was to evaluate these associations in pre- and postmenopausal women. A cross-sectional study was performed in 73,974 adult women who underwent a comprehensive health screening examination that included a mammogram between 2011 and 2013 (mean age 42.6 years). MetS was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III. IR was assessed with the homeostasis model assessment-insulin resistance (HOMA-IR). Adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for dense breast were estimated using logistic regression models after adjustment for potential confounders. In premenopausal women, MetS and all its components except waist circumference were associated with dense breast. After adjustment for potential confounders, the OR (95% CI) for dense breast in women with MetS compared with those without MetS was 1.22 (1.06-1.39). In postmenopausal women, however, there was positive but non-significant association between MetS and dense breast. In both pre- and postmenopausal women, high blood glucose and IR were positively associated with dense breast. The OR (95% CI) for dense breast between the highest and lowest quartiles of HOMA-IR was 1.29 (1.20-1.39) for premenopausal women and 1.44 (1.05-1.97) for postmenopausal women. In a large sample of Korean women, MetS and IR were associated with mammographic dense breast, demonstrating that IR, a potentially modifiable risk factor, may increase breast cancer risk, possibly through high mammographic density. PMID:26277917

  4. Screening for Drugs Against the Plasmodium falciparum Digestive Vacuole by Imaging Flow Cytometry.

    PubMed

    Lee, Yan Quan; Hall, Brian E; Tan, Kevin S W

    2016-01-01

    Phenotypic assays are increasingly employed to provide clues about drug mechanisms. In antimalarial drug screening, however, the majority of assays are designed to only measure parasite-killing activity. We describe here a high-content assay to detect drug-mediated perturbation of the digestive vacuole integrity in the trophozoite stage of Plasmodium falciparum, using the ImageStream imaging flow cytometer. PMID:27460247

  5. Application of Imaging-Based Assays in Microplate Formats for High-Content Screening.

    PubMed

    Fogel, Adam I; Martin, Scott E; Hasson, Samuel A

    2016-01-01

    The use of multiparametric microscopy-based screens with automated analysis has enabled the large-scale study of biological phenomena that are currently not measurable by any other method. Collectively referred to as high-content screening (HCS), or high-content analysis (HCA), these methods rely on an expanding array of imaging hardware and software automation. Coupled with an ever-growing amount of diverse chemical matter and functional genomic tools, HCS has helped open the door to a new frontier of understanding cell biology through phenotype-driven screening. With the ability to interrogate biology on a cell-by-cell basis in highly parallel microplate-based platforms, the utility of HCS continues to grow as advancements are made in acquisition speed, model system complexity, data management, and analysis systems. This chapter uses an example of screening for genetic factors regulating mitochondrial quality control to exemplify the practical considerations in developing and executing high-content campaigns. PMID:27317002

  6. Combined use of backscattered and transmitted images in x-ray personnel screening systems

    NASA Astrophysics Data System (ADS)

    Tracey, B.; Schiefele, Markus; Alvino, Christopher; Miller, Eric; Al-Kofani, Omar

    2012-06-01

    Current aviation security relies heavily on personnel screening using X-ray backscatter systems or other advanced imaging technologies. Passenger privacy concerns and screening times can be reduced through the use of low-dose twosided X-ray backscatter (Bx) systems, which also have the ability to collect transmission (Tx) X-ray. Bx images reveal objects placed on the body, such as contraband and security threats, as well as anatomical features at or close to the surface, such as lungs cavities and bones. While the quality of the transmission images is lower than medical imagery due to the low X-ray dose, Tx images can be of significant value in interpreting features in the Bx images, such as lung cavities, which can cause false alarms in automated threat detection (ATD) algorithms. Here we demonstrate an ATD processing chain fusing both Tx and BX images. The approach employs automatically extracted fiducial points on the body and localized active contour methods to segments lungs in acquired Tx and Bx images. Additionally, we derive metrics from the Tx image can be related to the probability of observing internal body structure in the Bx image. The combined use of Tx and Bx data can enable improved overall system performance.

  7. Agreement between objective and subjective assessment of image quality in ultrasound abdominal aortic aneurism screening

    PubMed Central

    Wolstenhulme, S; Keeble, C; Moore, S; Evans, J A

    2015-01-01

    Objective: To investigate agreement between objective and subjective assessment of image quality of ultrasound scanners used for abdominal aortic aneurysm (AAA) screening. Methods: Nine ultrasound scanners were used to acquire longitudinal and transverse images of the abdominal aorta. 100 images were acquired per scanner from which 5 longitudinal and 5 transverse images were randomly selected. 33 practitioners scored 90 images blinded to the scanner type and subject characteristics and were required to state whether or not the images were of adequate diagnostic quality. Odds ratios were used to rank the subjective image quality of the scanners. For objective testing, three standard test objects were used to assess penetration and resolution and used to rank the scanners. Results: The subjective diagnostic image quality was ten times greater for the highest ranked scanner than for the lowest ranked scanner. It was greater at depths of <5.0 cm (odds ratio, 6.69; 95% confidence interval, 3.56, 12.57) than at depths of 15.1–20.0 cm. There was a larger range of odds ratios for transverse images than for longitudinal images. No relationship was seen between subjective scanner rankings and test object scores. Conclusion: Large variation was seen in the image quality when evaluated both subjectively and objectively. Objective scores did not predict subjective scanner rankings. Further work is needed to investigate the utility of both subjective and objective image quality measurements. Advances in knowledge: Ratings of clinical image quality and image quality measured using test objects did not agree, even in the limited scenario of AAA screening. PMID:25494526

  8. Retinal Image Classification for the Screening of Age-Related Macular Degeneration

    NASA Astrophysics Data System (ADS)

    Hijazi, Mohd Hanafi Ahmad; Coenen, Frans; Zheng, Yalin

    Age-related Macular Degeneration (AMD) is the most common cause of blindness in old-age. Early identification of AMD can allow for mitigation (but not cure). One of the fist symptoms of AMD is the presence of fatty deposits, called drusen, on the retina. The presence of drusen may be identified through inspection of retina images. Given the aging global population, the prevalence of AMD is increasing. Many health authorities therefore run screening programmes. The automation, or at least partial automation, of retina image screening is therefore seen as beneficial. This paper describes a Case Based Reasoning (CBR) approach to retina image classification to provide support for AMD screening programmes. In the proposed approach images are represented in the form of spatial-histograms that store both colour and spatial image information. Each retina image is represented using a series of histograms each encapsulated as a time series curve. The Case Base (CB) is populated with a labelled set of such curves. New cases are classified by finding the most similar case (curve) in the CB. Similarity checking is achieved using the Dynamic Time warping (DTW).

  9. Performance assessment of CsI(Tl) screens on various substrates for X-ray imaging

    NASA Astrophysics Data System (ADS)

    Feng, Zhao-Dong; Jiang, Peng; Zhang, Hong-Kai; Zhao, Bo-Zhen; Qin, Xiu-Bo; Wei, Cun-Feng; Liu, Yu; Wei, Long

    2015-07-01

    Thallium-doped cesium iodide (CsI(Tl)) screens are widely used in X-ray imaging devices because of the columnar structure of the CsI(Tl) layer, but few reports focus on the optical role of the substrate in the screen system. In this paper, four substrates including fused silica (SiO2), silver-film coated SiO2, graphite (C) and fiber optic plate (FOP) are used to fabricate CsI(Tl) screens by thermal evaporation. Their imaging performance is evaluated by relative light output (RLO), modulation transfer function (MTF), normalized noise power spectrum (NNPS) and noise equivalent quanta (NEQ). The results reveal that although CsI(Tl) film on graphite plate yields images with the lowest light output, it presents relatively higher spatial resolution and better signal-to-noise characteristics. However, films on SiO2 plate obtain low MTF but high NNPS curves, whether they are coated with silver film or not. Furthermore, scintillation screens on FOP have bright images with low NNPS and high NEQ, but have the lowest MTF. By controlling the substrate optical features, CsI(Tl) films can be tailored to suit a given application. Supported by National Key Scientific Instrument and Equipment Development Project (2011YQ03011205, 2013YQ03062902) and Key Program of the National Natural Science Foundation of China (U1332202)

  10. Imaging carbon and nitrogen concentrations for narcotics and explosives screening

    SciTech Connect

    Trower, W.P.

    1993-12-31

    The author describes a nuclear technique for imaging carbon and nitrogen concentrations with surface densities characteristics of bulk narcotics and concealed explosives, the Carbon and the Nitrogen Camera. The physics is rooted in the tightly bound carbon-12 nucleus to which its neighboring isobars, nitrogen-12 and boron-12, decay rapidly (11 and 20 ms), mostly to its ground state, by emitting energetic beta particles (E{sub {beta}}{sup max} {approximately} 13 and 17 MeV) all of which produce bremsstrahlung and some yield annihilate radiation. The signal, photons detected in the multiscalar mode, results from the reactions {sup 13}C({gamma},p){sup 12}{Beta} for the bulk narcotics application and {sup 14}N({gamma},2n){sup 12}N and 14N({gamma},2p){sup 12}{Beta} for explosives detection and are initiated by a stepped pulsed electron beam with energy of {approximately} 30 and {approximately} 50 MeV, respectively. Images of 180 {approximately} 5 cm{sup 2} pixels taken in {approximately} 7 seconds will be presented of the carbon in a kilo of cocaine and the nitrogen in 125 grams of SEMTEX.

  11. Accuracy of Primary Care Clinicians in Screening for Diabetic Retinopathy Using Single-Image Retinal Photography

    PubMed Central

    Farley, Tillman F.; Mandava, Naresh; Prall, F. Ryan; Carsky, Cece

    2008-01-01

    PURPOSE Diabetic patients with limited access to ophthalmologists have low screening rates for diabetic retinopathy. We evaluated a diabetic retinopathy screening program in a community health center using single images taken with a nonmydriatic retinal camera and primary care clinicians trained to read retinal images. METHODS This study was conducted from 2001 to 2004 in a multisite community health center staffed by family physicians, advanced practice nurses, and physician’s assistants. The clinic serves a primarily low-income, Hispanic population. Clinic clinicians were trained to read the retinal photographs. All images were overread by an ophthalmologist. Patients were referred to eye care specialists for severe diabetic retinopathy, unknown or other abnormality, or inadequate photographs. We analyzed agreement between the clinicians and the ophthalmologist in recognizing diabetic retinopathy and in determining which patients needed referral. We also analyzed overall screening rates based on clinic access to the camera. RESULTS One thousand forty diabetic patients were screened for diabetic retinopathy at the health center. One hundred thirteen (10.9%) were found to have diabetic retinopathy, 46 severe enough to warrant referral to an ophthalmologist. The clinicians failed to refer 35 (10.2%) of the 344 patients the ophthalmologist believed needed referral. Most cases of missed referral were due to failure to recognize an inadequate photograph or for abnormalities other than diabetic retinopathy. Screening rates were better in the clinic with a permanent camera. CONCLUSIONS Primary care clinicians trained to read single images from a retinal camera have acceptable accuracy in screening for diabetic retinopathy. Further training may be necessary to recognize other common abnormalities. PMID:18779547

  12. Screen-imaging guidance using a modified portable video macroscope for middle cerebral artery occlusion.

    PubMed

    Zhu, Xingbao; Luo, Junli; Liu, Yun; Chen, Guolong; Liu, Song; Ruan, Qiangjin; Deng, Xunding; Wang, Dianchun; Fan, Quanshui; Pan, Xinghua

    2012-04-25

    The use of operating microscopes is limited by the focal length. Surgeons using these instruments cannot simultaneously view and access the surgical field and must choose one or the other. The longer focal length (more than 1 000 mm) of an operating telescope permits a position away from the operating field, above the surgeon and out of the field of view. This gives the telescope an advantage over an operating microscope. We developed a telescopic system using screen-imaging guidance and a modified portable video macroscope constructed from a Computar MLH-10 × macro lens, a DFK-21AU04 USB CCD Camera and a Dell laptop computer as monitor screen. This system was used to establish a middle cerebral artery occlusion model in rats. Results showed that magnification of the modified portable video macroscope was appropriate (5-20 ×) even though the Computar MLH-10 × macro lens was placed 800 mm away from the operating field rather than at the specified working distance of 152.4 mm with a zoom of 1-40 ×. The screen-imaging telescopic technique was clear, life-like, stereoscopic and matched the actual operation. Screen-imaging guidance led to an accurate, smooth, minimally invasive and comparatively easy surgical procedure. Success rate of the model establishment evaluated by neurological function using the modified neurological score system was 74.07%. There was no significant difference in model establishment time, sensorimotor deficit and infarct volume percentage. Our findings indicate that the telescopic lens is effective in the screen surgical operation mode referred to as "long distance observation and short distance operation" and that screen-imaging guidance using an modified portable video macroscope can be utilized for the establishment of a middle cerebral artery occlusion model and micro-neurosurgery. PMID:25722675

  13. Fractal Analysis of Radiologists Visual Scanning Pattern in Screening Mammography

    SciTech Connect

    Alamudun, Folami T; Yoon, Hong-Jun; Hudson, Kathy; Morin-Ducote, Garnetta; Tourassi, Georgia

    2015-01-01

    Several investigators have investigated radiologists visual scanning patterns with respect to features such as total time examining a case, time to initially hit true lesions, number of hits, etc. The purpose of this study was to examine the complexity of the radiologists visual scanning pattern when viewing 4-view mammographic cases, as they typically do in clinical practice. Gaze data were collected from 10 readers (3 breast imaging experts and 7 radiology residents) while reviewing 100 screening mammograms (24 normal, 26 benign, 50 malignant). The radiologists scanpaths across the 4 mammographic views were mapped to a single 2-D image plane. Then, fractal analysis was applied on the derived scanpaths using the box counting method. For each case, the complexity of each radiologist s scanpath was estimated using fractal dimension. The association between gaze complexity, case pathology, case density, and radiologist experience was evaluated using 3 factor fixed effects ANOVA. ANOVA showed that case pathology, breast density, and experience level are all independent predictors of the visual scanning pattern complexity. Visual scanning patterns are significantly different for benign and malignant cases than for normal cases as well as when breast parenchyma density changes.

  14. A knowledge-based approach to the CADx of mammographic masses

    NASA Astrophysics Data System (ADS)

    Elter, Matthias; Haßlmeyer, Erik

    2008-03-01

    Today, mammography is recognized as the most effective technique for breast cancer screening. Unfortunately, the low positive predictive value of breast biopsy examinations resulting from mammogram interpretation leads to many unnecessary biopsies performed on benign lesions. In the last years, several computer assisted diagnosis (CADx) systems have been proposed with the goal to assist the radiologist in the discrimination of benign and malignant breast lesions and thus to reduce the high number of unnecessary biopsies. In this paper we present a novel, knowledge-based approach to the computer aided discrimination of mammographic mass lesions that uses computer-extracted attributes of mammographic masses and clinical data as input attributes to a case-based reasoning system. Our approach emphasizes a transparent reasoning process which is important for the acceptance of a CADx system in clinical practice. We evaluate the performance of the proposed system on a large publicly available mammography database using receiver operating characteristic curve analysis. Our results indicate that the proposed CADx system has the potential to significantly reduce the number of unnecessary breast biopsies in clinical practice.

  15. Use of a Fluorometric Imaging Plate Reader in high-throughput screening

    NASA Astrophysics Data System (ADS)

    Groebe, Duncan R.; Gopalakrishnan, Sujatha; Hahn, Holly; Warrior, Usha; Traphagen, Linda; Burns, David J.

    1999-04-01

    High-throughput screening (HTS) efforts at Abbott Laboratories have been greatly facilitated by the use of a Fluorometric Imaging Plate Reader. The FLIPR consists of an incubated cabinet with integrated 96-channel pipettor and fluorometer. An argon laser is used to excite fluorophores in a 96-well microtiter plate and the emitted fluorometer. An argon laser is used to excite fluorophores in a 96-well microtiter plate and the emitted fluorescence is imaged by a cooled CCD camera. The image data is downloaded from the camera and processed to average the signal form each well of the microtiter pate for each time point. The data is presented in real time on the computer screen, facilitating interpretation and trouble-shooting. In addition to fluorescence, the camera can also detect luminescence form firefly luciferase.

  16. Image-based high-throughput screening for inhibitors of angiogenesis.

    PubMed

    Evensen, Lasse; Link, Wolfgang; Lorens, James B

    2013-01-01

    Automated multicolor fluorescence microscopy facilitates high-throughput quantitation of cellular parameters of complex, organotypic systems. In vitro co-cultured vascular cells form capillary-like networks that model facets of angiogenesis, making it an attractive alternative for anti-angiogenic drug discovery. We have adapted this angiogenesis assay system to a high-throughput format to enable automated image-based high-throughput screening of live primary human vascular cell co-cultures with chemical libraries for anti-angiogenic drug discovery. Protocols are described for setup of a fluorescence-based co-culture assay, live cell image acquisition, image analysis of morphological parameters, and screening data handling. PMID:23027002

  17. Evaluation of the Accuracy of Grading Indirect Ophthalmoscopy Video Images for Retinopathy of Prematurity Screening

    PubMed Central

    Prakalapakorn, Sasapin G.; Wallace, David K.; Dolland, Riana S.; Freedman, Sharon F.

    2015-01-01

    Purpose To determine whether digital retinal images obtained using a video indirect ophthalmoscopy system (Keeler) can be accurately graded for zone, stage, and plus or pre-plus disease and used to screen for type 1 retinopathy of prematurity (ROP). Methods We retrospectively reviewed the charts of 114 infants who had retinal video images acquired using the Keeler system during routine ROP examinations. Two masked ophthalmologists (1 expert and 1 non-expert in ROP screening) graded these videos for image quality, zone, stage, and pre-plus or plus disease. We compared the ophthalmologists’ grades of the videos against the clinical examination results, which served as the reference standard. We then determined the sensitivity/specificity of 2 predefined criteria for referral in detecting disease requiring treatment (i.e. type 1 ROP). Results Of images the expert considered fair or good quality (n=68), the expert and non-expert correctly identified zone (75% vs. 74%, respectively), stage (75% vs. 40%, respectively), and the presence of pre-plus or plus disease in 79% of images. Expert and non-expert judgment of prethreshold disease, pre-plus or plus disease had 100% sensitivity and 75% vs. 79% specificity, respectively, for detecting type 1 ROP. Expert and non-expert judgment of pre-plus or plus disease had 92% vs. 100% sensitivity and 77% vs. 82% specificity, respectively, for detecting type 1 ROP. Conclusions High-quality retinal video images can be read with high sensitivity and acceptable specificity to screen for type 1 ROP. Grading for pre-plus or plus disease alone may be sufficient for the purpose of ROP screening. PMID:25608280

  18. Breast cancer detection among young survivors of pediatric Hodgkin lymphoma with screening magnetic resonance imaging

    PubMed Central

    Tieu, Minh Thi; Cigsar, Candemir; Ahmed, Sameera; Ng, Andrea; Diller, Lisa; Millar, B-A; Crystal, Pavel; Hodgson, David C

    2014-01-01

    BACKGROUND Female survivors of pediatric Hodgkin lymphoma (HL) who have received chest radiotherapy are at increased risk of breast cancer. Guidelines for early breast cancer screening among these survivors are based on little data regarding clinical outcomes. This study reports outcomes of breast cancer screening with MRI and mammography (MMG) after childhood HL. METHODS We evaluated the results of breast MRI and MMG screening among 96 female survivors of childhood HL treated with chest radiotherapy. Outcomes measured included imaging sensitivity and specificity, breast cancer characteristics, and incidence of additional imaging and breast biopsy. RESULTS Median age at first screening was 30 years, and the median number of MRI screening rounds was 3. Ten breast cancers were detected in 9 women at a median age of 39 years (range, 24-43 years). Half were invasive and half were preinvasive. The median size of invasive tumors was 8 mm (range, 3-15 mm), and none had lymph node involvement. Sensitivity and specificity of the screening modalities were as follows: for MRI alone, 80% and 93.5%, respectively; MMG alone, 70% and 95%, respectively; both modalities combined, 100% and 88.6%, respectively. All invasive tumors were detected by MRI. Additional investigations were required in 52 patients, (54%), and 26 patients (27%) required breast biopsy, with 10 patients requiring more than 1 biopsy. CONCLUSIONS Screening including breast MRI with MMG has high sensitivity and specificity in pediatric HL survivors, with breast cancers detected at an early stage, although it is associated with a substantial rate of additional investigations. Cancer 2014;120:2507–2513. © 2014 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. Screening female survivors of pediatric Hodgkin Lymphoma for breast cancer with MRI and mammography detected tumors at an earlier stage than prior studies of mammography alone, although a substantial proportion of

  19. Images of single X-ray photons from X-ray phosphor screens

    NASA Technical Reports Server (NTRS)

    Fishman, G. J.

    1981-01-01

    Photographs show the efficiency and resolution characteristics of single X-ray photons converted to optical photons in a variety of commercial X-ray phosphor screens. The recording system uses a cooled, two-stage image intensifier system with fiber optics coupling to the phosphor screen. High efficiencies in the energy range 20-100 keV with position resolution of the order 200 microns are readily achievable, although the sensitive area is presently limited. Potential applications include X-ray astronomy, high-speed X-ray diffractometry, and extremely low dose radiography.

  20. A review of the cost-effectiveness of Tc-99m sestamibi scintimammography in diagnosis of breast cancer in Taiwanese women with indeterminate mammographically dense breast.

    PubMed

    Chen, Yi-Shan; Wang, Wei-Hua; Chan, Tam; Sun, Shung-Shung; Kao, Albert

    2002-11-01

    In general, biopsy is the preferred management method for women with indeterminate mammographically dense breasts. In this review, we describe a decision analysis model comparing technetium-99m methoxyisobutylisonitrile (Tc-99m sestamibi) scintimammography and excisional biopsy as breast cancer evaluation strategies for hypothetical cohorts of estimated 16,000-40,000 women with indeterminate mammographic probability of malignancy because of mammographically dense breasts. In cost-effectiveness analysis, quantitative decision tree sensitivity analysis was used to compare the conventional excision biopsy alone strategy (strategy A) with decision strategy for screening with Tc-99m sestamibi scintimammography before excision biopsy (strategy B) after an indeterminate mammogram. Strategy B showed a cost saving of US dollars 649,600-1,624,000 in reducing the cost of unnecessary biopsies. The total cost of strategy B showed a cost saving of US dollars 123,075-307,776 compared to strategy A. The analysis data indicate that Tc-99m sestamibi scintimammography can save the cost of unnecessary biopsies in Taiwanese women with non-diagnostic mammogram because of mammographically dense breasts. PMID:12356511

  1. Enhanced Images for Checked and Carry-on Baggage and Cargo Screening

    NASA Technical Reports Server (NTRS)

    Woodell, Glenn; Rahman, Zia-ur; Jobson, Daniel J.; Hines, Glenn

    2004-01-01

    The current X-ray systems used by airport security personnel for the detection of contraband, and objects such as knives and guns that can impact the security of a flight, have limited effect because of the limited display quality of the X-ray images. Since the displayed images do not possess optimal contrast and sharpness, it is possible for the security personnel to miss potentially hazardous objects. This problem is also common to other disciplines such as medical Xrays, and can be mitigated, to a large extent, by the use of state-of-the-art image processing techniques to enhance the contrast and sharpness of the displayed image. The NASA Langley Research Center's Visual Information Processing Group has developed an image enhancement technology that has direct applications to this problem of inadequate display quality. Airport security X-ray imaging systems would benefit considerably by using this novel technology, making the task of the personnel who have to interpret the X-ray images considerably easier, faster, and more reliable. This improvement would translate into more accurate screening as well as minimizing the screening time delays to airline passengers. This technology, Retinex, has been optimized for consumer applications but has been applied to medical X-rays on a very preliminary basis. The resultant technology could be incorporated into a new breed of commercial x-ray imaging systems which would be transparent to the screener yet allow them to see subtle detail much more easily, reducing the amount of time needed for screening while greatly increasing the effectiveness of contraband detection and thus public safety.

  2. Enhanced Images for Checked and Carry-on Baggage and Cargo Screening

    NASA Technical Reports Server (NTRS)

    Woodell, Glen; Rahman, Zia-ur; Jobson, Daniel J.; Hines, Glenn

    2004-01-01

    The current X-ray systems used by airport security personnel for the detection of contraband, and objects such as knives and guns that can impact the security of a flight, have limited effect because of the limited display quality of the X-ray images. Since the displayed images do not possess optimal contrast and sharpness, it is possible for the security personnel to miss potentially hazardous objects. This problem is also common to other disciplines such as medical X-rays, and can be mitigated, to a large extent, by the use of state-of-the-art image processing techniques to enhance the contrast and sharpness of the displayed image. The NASA Langley Research Centers Visual Information Processing Group has developed an image enhancement technology that has direct applications to this problem of inadequate display quality. Airport security X-ray imaging systems would benefit considerably by using this novel technology, making the task of the personnel who have to interpret the X-ray images considerably easier, faster, and more reliable. This improvement would translate into more accurate screening as well as minimizing the screening time delays to airline passengers. This technology, Retinex, has been optimized for consumer applications but has been applied to medical X-rays on a very preliminary basis. The resultant technology could be incorporated into a new breed of commercial x-ray imaging systems which would be transparent to the screener yet allow them to see subtle detail much more easily, reducing the amount of time needed for screening while greatly increasing the effectiveness of contraband detection and thus public safety.

  3. Varying performance in mammographic interpretation across two countries: Do results indicate reader or population variances?

    NASA Astrophysics Data System (ADS)

    Soh, BaoLin P.; Lee, Warwick B.; Wong, Jill; Sim, Llewellyn; Hillis, Stephen L.; Tapia, Kriscia A.; Brennan, Patrick C.

    2016-03-01

    Aim: To compare the performance of Australian and Singapore breast readers interpreting a single test-set that consisted of mammographic examinations collected from the Australian population. Background: In the teleradiology era, breast readers are interpreting mammographic examinations from different populations. The question arises whether two groups of readers with similar training backgrounds, demonstrate the same level of performance when presented with a population familiar only to one of the groups. Methods: Fifty-three Australian and 15 Singaporean breast radiologists participated in this study. All radiologists were trained in mammogram interpretation and had a median of 9 and 15 years of experience in reading mammograms respectively. Each reader interpreted the same BREAST test-set consisting of sixty de-identified mammographic examinations arising from an Australian population. Performance parameters including JAFROC, ROC, case sensitivity as well as specificity were compared between Australian and Singaporean readers using a Mann Whitney U test. Results: A significant difference (P=0.036) was demonstrated between the JAFROC scores of the Australian and Singaporean breast radiologists. No other significant differences were observed. Conclusion: JAFROC scores for Australian radiologists were higher than those obtained by the Singaporean counterparts. Whilst it is tempting to suggest this is down to reader expertise, this may be a simplistic explanation considering the very similar training and audit backgrounds of the two populations of radiologists. The influence of reading images that are different from those that radiologists normally encounter cannot be ruled out and requires further investigation, particularly in the light of increasing international outsourcing of radiologic reporting.

  4. A multichannel time-domain scanning fluorescence mammograph: performance assessment and first in vivo results.

    PubMed

    Grosenick, Dirk; Hagen, Axel; Steinkellner, Oliver; Poellinger, Alexander; Burock, Susen; Schlag, Peter M; Rinneberg, Herbert; Macdonald, Rainer

    2011-02-01

    We present a scanning time-domain fluorescence mammograph capable to image the distribution of a fluorescent contrast agent within a female breast, slightly compressed between two parallel glass plates, with high sensitivity. Fluorescence of the contrast agent is excited using a near infrared picosecond diode laser module. Four additional picosecond diode lasers with emission wavelengths between 660 and 1066 nm allow to measure the intrinsic optical properties of the breast tissue. By synchronously moving a source fiber and seven detection fiber bundles across the breast, distributions of times of flight of photons are recorded simultaneously for selected source-detector combinations in transmission and reflection geometry either at the fluorescence wavelength or at the selected laser wavelengths. To evaluate the performance of the mammograph, we used breastlike rectangular phantoms comprising fluorescent and absorbing objects using the fluorescent dye Omocyanine as contrast agent excited at 735 nm. We compare two-dimensional imaging of the phantom based on transmission and reflection data. Furthermore, we developed an improved tomosynthesis algorithm which permits three-dimensional reconstruction of fluorescence and absorption properties of lesions with good spatial resolution. For illustration, we present fluorescence mammograms of one patient recorded 30 min after administration of the contrast agent indocyanine green showing the carcinoma at high contrast originating from fluorescence of the extravasated dye, excited at 780 nm. PMID:21361617

  5. A multichannel time-domain scanning fluorescence mammograph: Performance assessment and first in vivo results

    NASA Astrophysics Data System (ADS)

    Grosenick, Dirk; Hagen, Axel; Steinkellner, Oliver; Poellinger, Alexander; Burock, Susen; Schlag, Peter M.; Rinneberg, Herbert; Macdonald, Rainer

    2011-02-01

    We present a scanning time-domain fluorescence mammograph capable to image the distribution of a fluorescent contrast agent within a female breast, slightly compressed between two parallel glass plates, with high sensitivity. Fluorescence of the contrast agent is excited using a near infrared picosecond diode laser module. Four additional picosecond diode lasers with emission wavelengths between 660 and 1066 nm allow to measure the intrinsic optical properties of the breast tissue. By synchronously moving a source fiber and seven detection fiber bundles across the breast, distributions of times of flight of photons are recorded simultaneously for selected source-detector combinations in transmission and reflection geometry either at the fluorescence wavelength or at the selected laser wavelengths. To evaluate the performance of the mammograph, we used breastlike rectangular phantoms comprising fluorescent and absorbing objects using the fluorescent dye Omocyanine as contrast agent excited at 735 nm. We compare two-dimensional imaging of the phantom based on transmission and reflection data. Furthermore, we developed an improved tomosynthesis algorithm which permits three-dimensional reconstruction of fluorescence and absorption properties of lesions with good spatial resolution. For illustration, we present fluorescence mammograms of one patient recorded 30 min after administration of the contrast agent indocyanine green showing the carcinoma at high contrast originating from fluorescence of the extravasated dye, excited at 780 nm.

  6. The relationship between real life breast screening and an annual self assessment scheme

    NASA Astrophysics Data System (ADS)

    Scott, Hazel J.; Evans, Andrew; Gale, Alastair G.; Murphy, Alison; Reed, Jacquie

    2009-02-01

    Incidence of cancer in the UK NHS Breast Screening Programme (NHSBSP) is relatively low (approximately 7% per 1,000 cases screened). As such, feedback from cancers missed or interval cancers can be a relatively lengthy process (whereby a woman will not present for corroborating imaging for a further three years). Therefore in order to monitor their radiological skill, all breast screening radiologists and technologists read a self-assessed, standard set of challenging mammographic images bi-yearly. This scheme, 'PERFORMS' (Personal Performance in Mammographic Screening) has been running since near the inception of the NHSBSP in 1991. Although PERFORMS has functioned as an educational tool for film-readers on the UKBSP for decades, its relation to real life screening in past years has proven to be somewhat equivocal (Cowley & Gale, 1999). The present study investigated the relationship between performance measures in real life and their equivalent on the PERFORMS self assessment scheme namely: Miss Rate (FN), Cases Arbitrated and Returned to Routine screening and Incorrect recall (FP), Specificity (TN) and Cancer Detection (TP). Over 40 individuals from one NHS region in the UK submitted their real life data for comparison with PERFORMS results from the same time frame. Data from this initial study were taken from the year 2005-2006 and compared with the relevant PERFORMS set of cases. Results indicated a significant positive correlation between PERFORMS performance measures and performance measures for real life. These results are discussed in the light of the legitimacy of self-assessment comparative to film-reading skill (during real life clinical practice).

  7. Evaluation of radiographers’ mammography screen-reading accuracy in Australia

    SciTech Connect

    Debono, Josephine C; Poulos, Ann E; Houssami, Nehmat; Turner, Robin M; Boyages, John

    2015-03-15

    This study aimed to evaluate the accuracy of radiographers’ screen-reading mammograms. Currently, radiologist workforce shortages may be compromising the BreastScreen Australia screening program goal to detect early breast cancer. The solution to a similar problem in the United Kingdom has successfully encouraged radiographers to take on the role as one of two screen-readers. Prior to consideration of this strategy in Australia, educational and experiential differences between radiographers in the United Kingdom and Australia emphasise the need for an investigation of Australian radiographers’ screen-reading accuracy. Ten radiographers employed by the Westmead Breast Cancer Institute with a range of radiographic (median = 28 years), mammographic (median = 13 years) and BreastScreen (median = 8 years) experience were recruited to blindly and independently screen-read an image test set of 500 mammograms, without formal training. The radiographers indicated the presence of an abnormality using BI-RADS®. Accuracy was determined by comparison with the gold standard of known outcomes of pathology results, interval matching and client 6-year follow-up. Individual sensitivity and specificity levels ranged between 76.0% and 92.0%, and 74.8% and 96.2% respectively. Pooled screen-reader accuracy across the radiographers estimated sensitivity as 82.2% and specificity as 89.5%. Areas under the reading operating characteristic curve ranged between 0.842 and 0.923. This sample of radiographers in an Australian setting have adequate accuracy levels when screen-reading mammograms. It is expected that with formal screen-reading training, accuracy levels will improve, and with support, radiographers have the potential to be one of the two screen-readers in the BreastScreen Australia program, contributing to timeliness and improved program outcomes.

  8. A review of automated image understanding within 3D baggage computed tomography security screening.

    PubMed

    Mouton, Andre; Breckon, Toby P

    2015-01-01

    Baggage inspection is the principal safeguard against the transportation of prohibited and potentially dangerous materials at airport security checkpoints. Although traditionally performed by 2D X-ray based scanning, increasingly stringent security regulations have led to a growing demand for more advanced imaging technologies. The role of X-ray Computed Tomography is thus rapidly expanding beyond the traditional materials-based detection of explosives. The development of computer vision and image processing techniques for the automated understanding of 3D baggage-CT imagery is however, complicated by poor image resolutions, image clutter and high levels of noise and artefacts. We discuss the recent and most pertinent advancements and identify topics for future research within the challenging domain of automated image understanding for baggage security screening CT. PMID:26409422

  9. Measurements and simulations of scatter imaging as a simultaneous adjunct for screening mammography

    NASA Astrophysics Data System (ADS)

    Kern, Katie; Hassan, Laila; Peerzada, Lubna; Ur-Rehman, Mahboob; MacDonald, C. A.

    2015-03-01

    X-ray coherent scatter is dependent upon the molecular structure of the scattering material and hence allows differentiation between tissue types with potentially much higher contrast than conventional absorption-based radiography. Coherent-scatter computed tomography has been used to produce images based on the x-ray scattering properties of the tissue. However, the geometry for CT imaging requires a thin fan beam and multiple projections and is incommensurate with screening mammography. In this work we demonstrate progress in a developing a system using a wide slot beam and simple anti-scatter grid which is adequate to differentiate between scatter peaks to remove the fat background from the coherent scatter image. Adequate intensity in the coherent scatter image can be achieved at the dose commonly used for screening mammography to detect carcinoma surrogates as small as 2 mm in diameter. This technique would provide an inexpensive, low dose, simultaneous adjunct to conventional screening mammography to provide a localized map of tissue type that could be overlaid on the conventional transmission mammogram. Comparisons between phantom measurements and Monte Carlo simulations show good agreement, which allowed for detailed examination of the visibility of carcinoma under realistic conditions.

  10. Technologist-performed handheld screening breast US imaging: how is it performed and what are the outcomes to date?

    PubMed

    Berg, Wendie A; Mendelson, Ellen B

    2014-07-01

    Breast density-inform legislation is increasing the need for data on outcomes of tailored screening. Dense parenchyma can mask cancers, and denser tissue is also more likely to develop breast cancer than fatty tissue. Digital mammography is standard for women with dense breasts. Supplemental screening magnetic resonance imaging should be offered to women who meet high-risk criteria. Supplemental screening ultrasonographic (US) imaging may be appropriate in the much larger group of women with dense breasts. Both physician- and technologist-performed screening US imaging increases detection of node-negative invasive breast cancer. To meet anticipated demand in the United States, screening US images will most likely be acquired by trained technologists rather than physicians. While automated US offers standard documentation, there are few data on outcomes. US has been used diagnostically for decades to characterize masses seen by using mammography, but training specific to screening has been lacking. Standard approaches to training and documentation of technologist-performed handheld screening US imaging are needed. This article reviews the current status of technologist-performed handheld screening breast US imaging. PMID:24956046

  11. HER2 Targeting Peptides Screening and Applications in Tumor Imaging and Drug Delivery

    PubMed Central

    Geng, Lingling; Wang, Zihua; Jia, Xiangqian; Han, Qiuju; Xiang, Zhichu; Li, Dan; Yang, Xiaoliang; Zhang, Di; Bu, Xiangli; Wang, Weizhi; Hu, Zhiyuan; Fang, Qiaojun

    2016-01-01

    Herein, computational-aided one-bead-one-compound (OBOC) peptide library design combined with in situ single-bead sequencing microarray methods were successfully applied in screening peptides targeting at human epidermal growth factor receptor-2 (HER2), a biomarker of human breast cancer. As a result, 72 novel peptides clustered into three sequence motifs which are PYL***NP, YYL***NP and PPL***NP were acquired. Particularly one of the peptides, P51, has nanomolar affinity and high specificity for HER2 in ex vivo and in vivo tests. Moreover, doxorubicin (DOX)-loaded liposome nanoparticles were modified with peptide P51 or P25 and demonstrated to improve the targeted delivery against HER2 positive cells. Our study provides an efficient peptide screening method with a combination of techniques and the novel screened peptides with a clear binding site on HER2 can be used as probes for tumor imaging and targeted drug delivery. PMID:27279916

  12. A completely automated CAD system for mass detection in a large mammographic database

    SciTech Connect

    Bellotti, R.; De Carlo, F.; Tangaro, S.

    2006-08-15

    Mass localization plays a crucial role in computer-aided detection (CAD) systems for the classification of suspicious regions in mammograms. In this article we present a completely automated classification system for the detection of masses in digitized mammographic images. The tool system we discuss consists in three processing levels: (a) Image segmentation for the localization of regions of interest (ROIs). This step relies on an iterative dynamical threshold algorithm able to select iso-intensity closed contours around gray level maxima of the mammogram. (b) ROI characterization by means of textural features computed from the gray tone spatial dependence matrix (GTSDM), containing second-order spatial statistics information on the pixel gray level intensity. As the images under study were recorded in different centers and with different machine settings, eight GTSDM features were selected so as to be invariant under monotonic transformation. In this way, the images do not need to be normalized, as the adopted features depend on the texture only, rather than on the gray tone levels, too. (c) ROI classification by means of a neural network, with supervision provided by the radiologist's diagnosis. The CAD system was evaluated on a large database of 3369 mammographic images [2307 negative, 1062 pathological (or positive), containing at least one confirmed mass, as diagnosed by an expert radiologist]. To assess the performance of the system, receiver operating characteristic (ROC) and free-response ROC analysis were employed. The area under the ROC curve was found to be A{sub z}=0.783{+-}0.008 for the ROI-based classification. When evaluating the accuracy of the CAD against the radiologist-drawn boundaries, 4.23 false positives per image are found at 80% of mass sensitivity.

  13. Simulations of three-dimensional radiometric imaging of extended sources in a security screening portal

    NASA Astrophysics Data System (ADS)

    Salmon, Neil A.; Bowring, Nick

    2015-10-01

    This paper investigates by simulation the use of the three-dimensional aperture synthesis imaging technique to image three-dimensional extended sources. Software was written to access the three-dimensional information from computer graphics models in the formats of *.dxf and *.3ds and use these to generate synthetic cross-correlations, as if they would have been generated by an aperture synthesis antenna/receiver array measuring the radiometric emission from the three-dimensional object. A three-dimensional (near-field) aperture synthesis imaging algorithm generates [1] a voxel image of the three-dimensional object. Images created from a sphere indicate faithful reproduction about a single phase centre when the radius of the sphere is less than the Fresnel scale. However, for larger spheres, definition in the threedimensional imagery suffers and a phenomenon, referred to in this paper as Fresnel noise, appears in the image. Images of objects larger than the Fresnel scale can be created by having multiple smaller images, each having a size approximately of the Fresnel scale and centred on separate phase centres. Using the software to generate threedimensional imagery of a person, to demonstrate capabilities for portal security screening, indicates the technique works to first order. Improvements are needed in the software to improve the spatial sampling of the radiometric fields from the three-dimensional objects and implement a volumetric image mosaicking technique to remove the Fresnel noise.

  14. Potential use of a large-screen display for interpreting radiographic images

    NASA Astrophysics Data System (ADS)

    Krupinski, Elizabeth; Roehrig, Hans; Berger, William; Dalal, Sandeep; Stanton, Douglas

    2006-03-01

    Radiology has readily made the transition to the digital reading room. One commodity left behind when moving to digital displays however is display real estate. Even with multiple monitors radiologists cannot display numerous images as they did on a film alternator. We evaluated a large-screen rear-projection display (Philips Electronics) for potential use in radiology. Resolution was 1920 x 1080 with a 44-inch diagonal size and it was a color display. For comparison we used the IBM 9 Mpixel color display (22-inch diagonal) set to a comparable resolution and maximum luminance. Diagnostic accuracy with a series of bone images with subtle fractures and six observers was comparable (F = 0.3170, p = 0.5743) to traditional computer monitor. Viewing time, however, was significantly shorter (t = 6.723, p < 0.0001) with the large display for both normal and fracture images. On average, readers sat significantly closer (t = 5.578, p = 0.0026) to the small display than the large display. Four of the 6 radiologists preferred the smaller display, judging it to yield a sharper image. Half of the readers thought the black level was better with the large display and half with the small display. Most of the radiologists thought the large-screen display has potential for use in conferencing situations or those in which multiple viewers need to see images simultaneously.

  15. Development of x-ray imaging technique for liquid screening at airport

    NASA Astrophysics Data System (ADS)

    Sulaiman, Nurhani binti; Srisatit, Somyot

    2016-01-01

    X-ray imaging technology is a viable option to recognize flammable liquids for the purposes of aviation security. In this study, an X-ray imaging technology was developed whereby, the image viewing system was built with the use of a digital camera coupled with a gadolinium oxysulfide (GOS) fluorescent screen. The camera was equipped with a software for remote control setting of the camera via a USB cable which allows the images to be captured. The image was analysed to determine the average grey level using a software designed by Microsoft Visual Basic 6.0. The data was obtained for various densities of liquid thickness of 4.5 cm, 6.0 cm and 7.5 cm respectively for X-ray energies ranging from 70 to 200 kVp. In order to verify the reliability of the constructed calibration data, the system was tested with a few types of unknown liquids. The developed system could be conveniently employed for security screening in order to discriminate between a threat and an innocuous liquid.

  16. Resonant waveguide grating imagers for single cell analysis and high throughput screening

    NASA Astrophysics Data System (ADS)

    Fang, Ye

    2015-08-01

    Resonant waveguide grating (RWG) systems illuminate an array of diffractive nanograting waveguide structures in microtiter plate to establish evanescent wave for measuring tiny changes in local refractive index arising from the dynamic mass redistribution of living cells upon stimulation. Whole-plate RWG imager enables high-throughput profiling and screening of drugs. Microfluidics RWG imager not only manifests distinct receptor signaling waves, but also differentiates long-acting agonism and antagonism. Spatially resolved RWG imager allows for single cell analysis including receptor signaling heterogeneity and the invasion of cancer cells in a spheroidal structure through 3-dimensional extracellular matrix. High frequency RWG imager permits real-time detection of drug-induced cardiotoxicity. The wide coverage in target, pathway, assay, and cell phenotype has made RWG systems powerful tool in both basic research and early drug discovery process.

  17. Thermographic image analysis as a pre-screening tool for the detection of canine bone cancer

    NASA Astrophysics Data System (ADS)

    Subedi, Samrat; Umbaugh, Scott E.; Fu, Jiyuan; Marino, Dominic J.; Loughin, Catherine A.; Sackman, Joseph

    2014-09-01

    Canine bone cancer is a common type of cancer that grows fast and may be fatal. It usually appears in the limbs which is called "appendicular bone cancer." Diagnostic imaging methods such as X-rays, computed tomography (CT scan), and magnetic resonance imaging (MRI) are more common methods in bone cancer detection than invasive physical examination such as biopsy. These imaging methods have some disadvantages; including high expense, high dose of radiation, and keeping the patient (canine) motionless during the imaging procedures. This project study identifies the possibility of using thermographic images as a pre-screening tool for diagnosis of bone cancer in dogs. Experiments were performed with thermographic images from 40 dogs exhibiting the disease bone cancer. Experiments were performed with color normalization using temperature data provided by the Long Island Veterinary Specialists. The images were first divided into four groups according to body parts (Elbow/Knee, Full Limb, Shoulder/Hip and Wrist). Each of the groups was then further divided into three sub-groups according to views (Anterior, Lateral and Posterior). Thermographic pattern of normal and abnormal dogs were analyzed using feature extraction and pattern classification tools. Texture features, spectral feature and histogram features were extracted from the thermograms and were used for pattern classification. The best classification success rate in canine bone cancer detection is 90% with sensitivity of 100% and specificity of 80% produced by anterior view of full-limb region with nearest neighbor classification method and normRGB-lum color normalization method. Our results show that it is possible to use thermographic imaging as a pre-screening tool for detection of canine bone cancer.

  18. A multi-step system for screening and localization of hard exudates in retinal images

    NASA Astrophysics Data System (ADS)

    Bopardikar, Ajit S.; Bhola, Vishal; Raghavendra, B. S.; Narayanan, Rangavittal

    2012-03-01

    The number of people being affected by Diabetes mellitus worldwide is increasing at an alarming rate. Monitoring of the diabetic condition and its effects on the human body are therefore of great importance. Of particular interest is diabetic retinopathy (DR) which is a result of prolonged, unchecked diabetes and affects the visual system. DR is a leading cause of blindness throughout the world. At any point of time 25 - 44% of people with diabetes are afflicted by DR. Automation of the screening and monitoring process for DR is therefore essential for efficient utilization of healthcare resources and optimizing treatment of the affected individuals. Such automation would use retinal images and detect the presence of specific artifacts such as hard exudates, hemorrhages and soft exudates (that may appear in the image) to gauge the severity of DR. In this paper, we focus on the detection of hard exudates. We propose a two step system that consists of a screening step that classifies retinal images as normal or abnormal based on the presence of hard exudates and a detection stage that localizes these artifacts in an abnormal retinal image. The proposed screening step automatically detects the presence of hard exudates with a high sensitivity and positive predictive value (PPV ). The detection/localization step uses a k-means based clustering approach to localize hard exudates in the retinal image. Suitable feature vectors are chosen based on their ability to isolate hard exudates while minimizing false detections. The algorithm was tested on a benchmark dataset (DIARETDB1) and was seen to provide a superior performance compared to existing methods. The two-step process described in this paper can be embedded in a tele-ophthalmology system to aid with speedy detection and diagnosis of the severity of DR.

  19. BAXSTER: an image quality tester for x-ray baggage screening systems

    NASA Astrophysics Data System (ADS)

    Bijl, Piet; Hogervorst, Maarten A.; Valeton, J. Mathieu; de Ruiter, C. Jaap

    2003-09-01

    TNO Human Factors in the Netherlands developed a prototype apparatus for testing the image quality of X-ray Baggage Screening Systems: BAXSTER. BAXSTER stands for BAggage X-ray Screening TesteR. The test has a variety of applications, e.g. support by the choice of optimal screening systems for airport security, comparison of competing X-ray systems, delivery tests and routine tests. Advantages over existing tests are (1) a strong relationship with real object recognition, (2) accurate and objective test results, and (3) ease of use: performing a test is almost as easy as doing an eye test at the optometrist. BAXSTER is based on the patented TOD (Triangle Orientation Discrimination) test method, which is well-suited for standardization, and development of the test apparatus was funded by the US FAA/TSA (Transportation Security Administration). The apparatus consists of two parts. The first part is a set of test charts containing triangular test patterns of various metals of different sizes and thicknesses. These charts are placed in a frame that is scanned by the X-ray system like a regular baggage item. The operator has to judge the orientation of these patterns on the X-ray image. The second part is a laptop with peripherals and software that controls and analyses the test. The result of a test is a set of performance indicators (relating to detection, resolution, penetration, wire detection and wire penetration) for the entire system, including the display, the operator and the effect of environmental conditions. No (electronic) connection with the X-ray system is required. The effectiveness of automatic object detection and material discrimination through dual-energy X-ray analysis cannot be tested with BAXSTER. In conclusion: with BAXSTER the image quality of X-ray Baggage Screening Systems can be tested easily and objectively.

  20. An evaluation of a fluorescent screen-isocon camera system for x-ray imaging in radiology.

    PubMed

    Nelson, R S; Barbaric, Z L; Gomes, A S; Moler, C L; Deckard, M E

    1982-01-01

    A large field format imaging system which utilizes a flat fluorescent screen rather than the traditional image intensifier as the primary x-ray detector is discussed in this paper. A low light level image isocon camera is optically coupled to a rare-earth screen. An overview of the isocon camera and its return beam mode of operation is included. Theoretical limitations to this approach to real time radiographic imaging are discussed in terms of system efficiency and signal-to-noise ratio (SNR) requirements. The viability of this concept for radiographic imaging is considered with respect to the image intensifier-camera unit. The merits of employing a CsI:Na screen as the primary detector and an isocon tube with an improved SNR are presented as potential areas for further investigation. PMID:7155082

  1. Exudate detection in color retinal images for mass screening of diabetic retinopathy.

    PubMed

    Zhang, Xiwei; Thibault, Guillaume; Decencière, Etienne; Marcotegui, Beatriz; Laÿ, Bruno; Danno, Ronan; Cazuguel, Guy; Quellec, Gwénolé; Lamard, Mathieu; Massin, Pascale; Chabouis, Agnès; Victor, Zeynep; Erginay, Ali

    2014-10-01

    The automatic detection of exudates in color eye fundus images is an important task in applications such as diabetic retinopathy screening. The presented work has been undertaken in the framework of the TeleOphta project, whose main objective is to automatically detect normal exams in a tele-ophthalmology network, thus reducing the burden on the readers. A new clinical database, e-ophtha EX, containing precisely manually contoured exudates, is introduced. As opposed to previously available databases, e-ophtha EX is very heterogeneous. It contains images gathered within the OPHDIAT telemedicine network for diabetic retinopathy screening. Image definition, quality, as well as patients condition or the retinograph used for the acquisition, for example, are subject to important changes between different examinations. The proposed exudate detection method has been designed for this complex situation. We propose new preprocessing methods, which perform not only normalization and denoising tasks, but also detect reflections and artifacts in the image. A new candidates segmentation method, based on mathematical morphology, is proposed. These candidates are characterized using classical features, but also novel contextual features. Finally, a random forest algorithm is used to detect the exudates among the candidates. The method has been validated on the e-ophtha EX database, obtaining an AUC of 0.95. It has been also validated on other databases, obtaining an AUC between 0.93 and 0.95, outperforming state-of-the-art methods. PMID:24972380

  2. A Population-Wide Screening and Tailored Intervention Platform for Eating Disorders on College Campuses: The Healthy Body Image Program

    PubMed Central

    Jones, Megan; Kass, Andrea E.; Trockel, Mickey; Glass, Alan I.; Wilfley, Denise E.; Taylor, C. Barr

    2014-01-01

    Objectives This paper presents a new approach to intervention for eating disorders and body image concerns on college campuses, using a model of integrated eating disorder screening and intervention. Formative data on implementation feasibility are presented. Participants College students enrolled at two universities between 2011–2012. Methods The Healthy Body Image program is an evidence-based screening and intervention platform, enacted via community and online resources. An online screen was used to identify students at varying levels of risk or eating disorder symptom status; responses were used to direct students to universal or targeted online interventions or further evaluation. Universal prevention programs to improve healthy weight regulation and body image culture were offered to all students. Results Formative data from 1,551 students illustrates the application of this model. Conclusions The Healthy Body Image program is feasible to deliver and provides a comprehensive system of screening, evidence-based intervention, and community culture change. PMID:24621000

  3. DetecTiff: a novel image analysis routine for high-content screening microscopy.

    PubMed

    Gilbert, Daniel F; Meinhof, Till; Pepperkok, Rainer; Runz, Heiko

    2009-09-01

    In this article, the authors describe the image analysis software DetecTiff, which allows fully automated object recognition and quantification from digital images. The core module of the LabView-based routine is an algorithm for structure recognition that employs intensity thresholding and size-dependent particle filtering from microscopic images in an iterative manner. Detected structures are converted into templates, which are used for quantitative image analysis. DetecTiff enables processing of multiple detection channels and provides functions for template organization and fast interpretation of acquired data. The authors demonstrate the applicability of DetecTiff for automated analysis of cellular uptake of fluorescence-labeled low-density lipoproteins as well as diverse other image data sets from a variety of biomedical applications. Moreover, the performance of DetecTiff is compared with preexisting image analysis tools. The results show that DetecTiff can be applied with high consistency for automated quantitative analysis of image data (e.g., from large-scale functional RNAi screening projects). PMID:19641223

  4. Geant4 simulation of the response of phosphor screens for X-ray imaging

    NASA Astrophysics Data System (ADS)

    Pistrui-Maximean, S. A.; Freud, N.; Létang, J. M.; Koch, A.; Munier, B.; Walenta, A. H.; Montarou, G.; Babot, D.

    2006-07-01

    In order to predict and optimize the response of phosphor screens, it is important to understand the role played by the different physical processes inside the scintillator layer. A simulation model based on the Monte Carlo code Geant4 was developed to determine the Modulation Transfer Function (MTF) of phosphor screens for energies used in X-ray medical imaging and nondestructive testing applications. The visualization of the dose distribution inside the phosphor layer gives an insight into how the MTF is progressively degraded by X-ray and electron transport. The simulation model allows to study the influence of physical and technological parameters on the detector performances, as well as to design and optimize new detector configurations. Preliminary MTF measurements have been carried out and agreement with experimental data has been found in the case of a commercial screen (Kodak Lanex Fine) at an X-ray tube potential of 100 kV. Further validation with other screens (transparent or granular) at different energies is under way.

  5. Mammographic density measurement: a comparison of automated volumetric density measurement to BIRADS

    NASA Astrophysics Data System (ADS)

    McEntee, Mark F.; Damases, Christine N.

    2014-03-01

    The aim of this study is to compare mammographic breast density assessment with automated volumetric software with Breast Imaging Reporting and Data System (BIRADS) categorization by radiologists on two imaging systems. A data set of 120 mammograms was classified by twenty American Board of Radiology (ABR) Examiners. The mammograms were of 20 women (mean age, 60 years; range, 42-89 years). These women were image twice once with GE system and the following year with Hologic system. These images also had their volumetric density classified by using Volpara Density Grade (VDG). The radiologists were asked to estimate the mammographic density according to BIRADS categories (1- 4). There was a moderate agreement between VDG classification and radiologist BIRADS density shown with Cohen's Kappa (K=0.45; p<0.001). Radiologists estimated percentage density to be lower by an average of 0.37, the radiologist's BIRADS having a mean of 2.13 and the mean VDG higher at 2.50 (t = -11.99; p<0.001). VDG and radiologist's BIRADS showed a positive strong correlation (r=0.84; p<0.001). Radiologist BIRADS and VDG AvBD% also showed a strong positive correlation (r=0.86; p<0.001). There was a large spread of radiologist's BIRADS categories for each of the VDG AvBD% classifications. Using Volpara, the Hologic system showed a higher meanAvBD% (10.02 vs. 9.97). However using BIRADS the Hologic systems showed a lower mean (2.05 vs. 2.21). Automated systems demonstrated higher internal validity. The results demonstrated a moderate agreement and a strong correlation between VDG classification and radiologist BIRADS density assessment.

  6. Portable retinal imaging for eye disease screening using a consumer-grade digital camera

    NASA Astrophysics Data System (ADS)

    Barriga, Simon; Larichev, Andrey; Zamora, Gilberto; Soliz, Peter

    2012-03-01

    The development of affordable means to image the retina is an important step toward the implementation of eye disease screening programs. In this paper we present the i-RxCam, a low-cost, hand-held, retinal camera for widespread applications such as tele-retinal screening for eye diseases like diabetic retinopathy (DR), glaucoma, and age-related ocular diseases. Existing portable retinal imagers do not meet the requirements of a low-cost camera with sufficient technical capabilities (field of view, image quality, portability, battery power, and ease-of-use) to be distributed widely to low volume clinics, such as the offices of single primary care physicians serving rural communities. The i-RxCam uses a Nikon D3100 digital camera body. The camera has a CMOS sensor with 14.8 million pixels. We use a 50mm focal lens that gives a retinal field of view of 45 degrees. The internal autofocus can compensate for about 2D (diopters) of focusing error. The light source is an LED produced by Philips with a linear emitting area that is transformed using a light pipe to the optimal shape at the eye pupil, an annulus. To eliminate corneal reflex we use a polarization technique in which the light passes through a nano-wire polarizer plate. This is a novel type of polarizer featuring high polarization separation (contrast ratio of more than 1000) and very large acceptance angle (>45 degrees). The i-RxCam approach will yield a significantly more economical retinal imaging device that would allow mass screening of the at-risk population.

  7. Can laptops be left inside passenger bags if motion imaging is used in X-ray security screening?

    PubMed Central

    Mendes, Marcia; Schwaninger, Adrian; Michel, Stefan

    2013-01-01

    This paper describes a study where a new X-ray machine for security screening featuring motion imaging (i.e., 5 views of a bag are shown as an image sequence) was evaluated and compared to single view imaging available on conventional X-ray screening systems. More specifically, it was investigated whether with this new technology X-ray screening of passenger bags could be enhanced to such an extent that laptops could be left inside passenger bags, without causing a significant impairment in threat detection performance. An X-ray image interpretation test was created in four different versions, manipulating the factors packing condition (laptop and bag separate vs. laptop in bag) and display condition (single vs. motion imaging). There was a highly significant and large main effect of packing condition. When laptops and bags were screened separately, threat item detection was substantially higher. For display condition, a medium effect was observed. Detection could be slightly enhanced through the application of motion imaging. There was no interaction between display and packing condition, implying that the high negative effect of leaving laptops in passenger bags could not be fully compensated by motion imaging. Additional analyses were carried out to examine effects depending on different threat categories (guns, improvised explosive devices, knives, others), the placement of the threat items (in bag vs. in laptop) and viewpoint (easy vs. difficult view). In summary, although motion imaging provides an enhancement, it is not strong enough to allow leaving laptops in bags for security screening. PMID:24151457

  8. High-accuracy x-ray imaging: screen, lens, and CCD

    NASA Astrophysics Data System (ADS)

    Zeman, Herbert D.; DiBianca, Frank A.; Thomason, Donald B.; Sebes, Jeno I.; Lovhoiden, Gunnar; Liao, D.-Z.; Kambeyanda, Dona

    1993-09-01

    A liquid nitrogen cooled CCD TV camera from Astromed, Ltd. has been used for quantitative X-ray medical imaging. The CCD camera is coupled to a Kodak Lanex Regular X-ray intensifying screen with a 5:1 macro lens for bone mineral densitometry of the femur of a rat for a study of the development of osteoporosis. As a feasibility study of the use of the CCD for mammography, a 2:1 macro lens has been used to couple the CCD to a clear CsI(Tl) crystal, 100 mm in diameter and 3 mm thick. The spatial resolution and quantum efficiency of the system is significantly improved by replacing the Lanex Regular screen with the CsI(Tl) crystal.

  9. Sensitometric analyses of screen-film systems for mammography exams in Brazil

    NASA Astrophysics Data System (ADS)

    Magalhães, L. A. G.; Drexler, G. G.; de Almeida, C. E.; Medeiros, L. L.; Ferreira, N. M. P. D.; Estrada, J. J. S.

    2015-12-01

    A determination of the sensitometric parameters of screen-film systems to evaluate their qualities was performed. The quality control of the automatic film processor was carried out to ensure a high level of efficiency. Based on ISO 9236-3, the following potentials were applied on the X-ray tubes: 25 kV, 28 kV, 30 kV and 35 kV. Four different mammography films from different manufacturers with and without screens were tested for curve shape, speed and average gradient. The results indicated that film 1 exhibited better contrast, film 3 demonstrated the highest energy dependence, and film 4 presented the largest base+fog density. None of the four mammographic films tested achieved satisfactory results in all parameters analyzed. Improvements in the manufacturing process for these films must be completed to avoid losses in the image quality.

  10. A cell-based quantitative high-throughput image screening identified novel autophagy modulators.

    PubMed

    Li, Yuan; McGreal, Steven; Zhao, Jean; Huang, Ruili; Zhou, Yan; Zhong, Hua; Xia, Menghang; Ding, Wen-Xing

    2016-08-01

    Macroautophagy is a major cellular degradation pathway for long-lived proteins and cellular organelles to maintain cellular homeostasis. Reduced autophagy has been implicated in neurodegenerative diseases, metabolic syndrome, and tumorigenesis. In contrast, increased autophagy has been shown to protect against tissue injury and aging. Here we employed a cell-based quantitative high-throughput image screening (qHTS) for autophagy modulators using mouse embryonic fibroblasts (MEFs) that are stably expressing GFP-LC3. The library of pharmacologically active compounds (LOPAC) was used to screen for the autophagy modulators in compounds alone or in combination with the lysosome inhibitor chloroquine (CQ). The GFP-LC3 puncta were then quantified to measure autophagic flux. The primary screening revealed 173 compounds with efficacy more than 40%. These compounds were cherry-picked and re-tested at multiple different concentrations using the same assay. A number of novel autophagy inducers, inhibitors, and modulators with dual-effects on autophagy were identified from the cherry-pick screening. Interestingly, we found a group of compounds that induce autophagy are related to dopamine receptors and are commonly used as clinical psychiatric drugs. Among them, indatraline hydrochloride (IND), a dopamine inhibitor, and chlorpromazine hydrochloride (CPZ) and fluphenazine dihydrochloride (FPZ), two dopamine receptor antagonists, were further evaluated. We found that FPZ-induced autophagy through mTOR inhibition but IND and CPZ induced autophagy in an mTOR-independent manner. Our data suggest that image-based autophagic flux qHTS can efficiently identify autophagy inducers and inhibitors. PMID:27168224

  11. The myImageAnalysis Project: A Web-Based Application for High-Content Screening

    PubMed Central

    Szafran, Adam T.

    2014-01-01

    Abstract A major challenge faced by screening centers developing image-based assays is the wide range of assays needed compared to the limited resources that are available to effectively analyze and manage them. To overcome this limitation, we have developed the web-based myImageAnalysis (mIA) application, integrated with an open database connectivity compliant database and powered by Pipeline Pilot (PLP) that incorporates dataset tracking, scheduling and archiving, image analysis, and data reporting. For system administrators, mIA provides automated methods for managing and archiving data. For the biologist, this application allows those without any programming or image analysis experience to quickly develop, validate, and share results of complex image-based assays. Further, the structure of the application within PLP allows those with experience in PLP programming to easily add additional analysis tools as required. The tools within mIA allow users to assess basic (cell count, protein per cell, protein subcellular localization) and more advanced (engineered cell lines analysis, cell toxicity) biological image-based assays that employ advanced statistics and provides key assay performance metrics. PMID:24547743

  12. Fast localization of optic disc and fovea in retinal images for eye disease screening

    NASA Astrophysics Data System (ADS)

    Yu, H.; Barriga, S.; Agurto, C.; Echegaray, S.; Pattichis, M.; Zamora, G.; Bauman, W.; Soliz, P.

    2011-03-01

    Optic disc (OD) and fovea locations are two important anatomical landmarks in automated analysis of retinal disease in color fundus photographs. This paper presents a new, fast, fully automatic optic disc and fovea localization algorithm developed for diabetic retinopathy (DR) screening. The optic disc localization methodology comprises of two steps. First, the OD location is identified using template matching and directional matched filter. To reduce false positives due to bright areas of pathology, we exploit vessel characteristics inside the optic disc. The location of the fovea is estimated as the point of lowest matched filter response within a search area determined by the optic disc location. Second, optic disc segmentation is performed. Based on the detected optic disc location, a fast hybrid level-set algorithm which combines the region information and edge gradient to drive the curve evolution is used to segment the optic disc boundary. Extensive evaluation was performed on 1200 images (Messidor) composed of 540 images of healthy retinas, 431 images with DR but no risk of macular edema (ME), and 229 images with DR and risk of ME. The OD location methodology obtained 98.3% success rate, while fovea location achieved 95% success rate. The average mean absolute distance (MAD) between the OD segmentation algorithm and "gold standard" is 10.5% of estimated OD radius. Qualitatively, 97% of the images achieved Excellent to Fair performance for OD segmentation. The segmentation algorithm performs well even on blurred images.

  13. The myImageAnalysis project: a web-based application for high-content screening.

    PubMed

    Szafran, Adam T; Mancini, Michael A

    2014-01-01

    A major challenge faced by screening centers developing image-based assays is the wide range of assays needed compared to the limited resources that are available to effectively analyze and manage them. To overcome this limitation, we have developed the web-based myImageAnalysis (mIA) application, integrated with an open database connectivity compliant database and powered by Pipeline Pilot (PLP) that incorporates dataset tracking, scheduling and archiving, image analysis, and data reporting. For system administrators, mIA provides automated methods for managing and archiving data. For the biologist, this application allows those without any programming or image analysis experience to quickly develop, validate, and share results of complex image-based assays. Further, the structure of the application within PLP allows those with experience in PLP programming to easily add additional analysis tools as required. The tools within mIA allow users to assess basic (cell count, protein per cell, protein subcellular localization) and more advanced (engineered cell lines analysis, cell toxicity) biological image-based assays that employ advanced statistics and provides key assay performance metrics. PMID:24547743

  14. Rapid, Noninvasive Screening for Perturbations of Metabolism and Plant Growth Using Chlorophyll Fluorescence Imaging1

    PubMed Central

    Barbagallo, Romina P.; Oxborough, Kevin; Pallett, Kenneth E.; Baker, Neil R.

    2003-01-01

    A rapid, noninvasive technique involving imaging of chlorophyll fluorescence parameters for detecting perturbations of leaf metabolism and growth in seedlings is described. Arabidopsis seedlings were grown in 96-well microtitre plates for 4 d and then treated with eight herbicides with differing modes of action to induce perturbations in a range of different metabolic processes. Imaging of chlorophyll fluorescence emissions from 96 seedlings growing on a microtitre plate enabled images of a number of fluorescence parameters to be rapidly and simultaneously produced for the plants in each well. Herbicideinduced perturbations in metabolism, even in metabolic reactions not directly associated with photosynthetic metabolism, were detected from the changes in the images of fluorescence parameters considerably before any visual effects on seedling growth were observed. Evaluations of seedling growth were made from measurements of the area of chlorophyll fluorescence emission in images of plants growing in the 96-well plates. Decreased seedling growth related directly to herbicideinduced changes in the imaged chlorophyll fluorescence parameters. The applicability of this rapid-screening technique for metabolic perturbations in monocotyledonous species was demonstrated by treating Agrostis tenuis seedlings with Imazapyr, an inhibitor of branched-chain amino acid synthesis. PMID:12805581

  15. Characterization of a mammographic system based on single photon counting pixel arrays coupled to GaAs x-ray detectors.

    PubMed

    Amendolia, S R; Bisogni, M G; Delogu, P; Fantacci, M E; Paternoster, G; Rosso, V; Stefanini, A

    2009-04-01

    The authors report on the imaging capabilities of a mammographic system demonstrator based on GaAs pixel detectors operating in single photon counting (SPC) mode. The system imaging performances have been assessed by means of the transfer functions: The modulation transfer function (MTF), the normalized noise power spectrum, and the detective quantum efficiency (DQE) have been measured following the guidelines of the IEC 62220-1-2 protocol. The transfer function analysis has shown the high spatial resolution capabilities of the GaAs detectors. The MTF calculated at the Nyquist frequency (2.94 cycles/mm) is indeed 60%. The DQE, measured with a standard mammographic beam setup (Mo/Mo, 28 kVp, with 4 mm Al added filter) and calculated at zero frequency, is 46%. Aiming to further improve the system's image quality, the authors investigate the DQE limiting factors and show that they are mainly related to system engineering. For example, the authors show that optimization of the image equalization procedure increases the DQE(0) up to 74%, which is better than the DQE(0) of most clinical mammographic systems. The authors show how the high detection efficiency of GaAs detectors and the noise discrimination associated with the SPC technology allow optimizing the image quality in mammography. In conclusion, the authors propose technological solutions to exploit to the utmost the potentiality of GaAs detectors coupled to SPC electronics. PMID:19472640

  16. Characterization of a mammographic system based on single photon counting pixel arrays coupled to GaAs x-ray detectors

    SciTech Connect

    Amendolia, S. R.; Bisogni, M. G.; Delogu, P.; Fantacci, M. E.; Paternoster, G.; Rosso, V.; Stefanini, A.

    2009-04-15

    The authors report on the imaging capabilities of a mammographic system demonstrator based on GaAs pixel detectors operating in single photon counting (SPC) mode. The system imaging performances have been assessed by means of the transfer functions: The modulation transfer function (MTF), the normalized noise power spectrum, and the detective quantum efficiency (DQE) have been measured following the guidelines of the IEC 62220-1-2 protocol. The transfer function analysis has shown the high spatial resolution capabilities of the GaAs detectors. The MTF calculated at the Nyquist frequency (2.94 cycles/mm) is indeed 60%. The DQE, measured with a standard mammographic beam setup (Mo/Mo, 28 kVp, with 4 mm Al added filter) and calculated at zero frequency, is 46%. Aiming to further improve the system's image quality, the authors investigate the DQE limiting factors and show that they are mainly related to system engineering. For example, the authors show that optimization of the image equalization procedure increases the DQE(0) up to 74%, which is better than the DQE(0) of most clinical mammographic systems. The authors show how the high detection efficiency of GaAs detectors and the noise discrimination associated with the SPC technology allow optimizing the image quality in mammography. In conclusion, the authors propose technological solutions to exploit to the utmost the potentiality of GaAs detectors coupled to SPC electronics.

  17. Virtual display: mirror image of dual-views display and interface system for extension of screen region

    NASA Astrophysics Data System (ADS)

    Sakamoto, Kunio; Morimoto, Hiroyuki; Tanaka, Akihiro

    2007-09-01

    A liquid crystal display (LCD) recently comes into common use. It is possible for this display unit to provide the same size of displaying area as the image screen on the panel. Thus the conventional display can show only one screen, but it is impossible to enlarge the size of a screen, for example twice. To solve this problem, we presented an enlarging method of display area using a mirror. Our extension method enables the observers to show the virtual image plane and to enlarge a screen area twice. Although the displaying region is doubled, the user cannot touch and point the extended screen in the mirror. In this paper, the authors propose a pointing interface for this virtual display, which realizes to point on a virtual area in the mirror.

  18. Effects of image compression and degradation on an automatic diabetic retinopathy screening algorithm

    NASA Astrophysics Data System (ADS)

    Agurto, C.; Barriga, S.; Murray, V.; Pattichis, M.; Soliz, P.

    2010-03-01

    Diabetic retinopathy (DR) is one of the leading causes of blindness among adult Americans. Automatic methods for detection of the disease have been developed in recent years, most of them addressing the segmentation of bright and red lesions. In this paper we present an automatic DR screening system that does approach the problem through the segmentation of features. The algorithm determines non-diseased retinal images from those with pathology based on textural features obtained using multiscale Amplitude Modulation-Frequency Modulation (AM-FM) decompositions. The decomposition is represented as features that are the inputs to a classifier. The algorithm achieves 0.88 area under the ROC curve (AROC) for a set of 280 images from the MESSIDOR database. The algorithm is then used to analyze the effects of image compression and degradation, which will be present in most actual clinical or screening environments. Results show that the algorithm is insensitive to illumination variations, but high rates of compression and large blurring effects degrade its performance.

  19. Constraint factor graph cut–based active contour method for automated cellular image segmentation in RNAi screening

    PubMed Central

    CHEN, C.; LI, H.; ZHOU, X.; WONG, S. T. C.

    2010-01-01

    Summary Image-based, high throughput genome-wide RNA interference (RNAi) experiments are increasingly carried out to facilitate the understanding of gene functions in intricate biological processes. Automated screening of such experiments generates a large number of images with great variations in image quality, which makes manual analysis unreasonably time-consuming. Therefore, effective techniques for automatic image analysis are urgently needed, in which segmentation is one of the most important steps. This paper proposes a fully automatic method for cells segmentation in genome-wide RNAi screening images. The method consists of two steps: nuclei and cytoplasm segmentation. Nuclei are extracted and labelled to initialize cytoplasm segmentation. Since the quality of RNAi image is rather poor, a novel scale-adaptive steerable filter is designed to enhance the image in order to extract long and thin protrusions on the spiky cells. Then, constraint factor GCBAC method and morphological algorithms are combined to be an integrated method to segment tight clustered cells. Compared with the results obtained by using seeded watershed and the ground truth, that is, manual labelling results by experts in RNAi screening data, our method achieves higher accuracy. Compared with active contour methods, our method consumes much less time. The positive results indicate that the proposed method can be applied in automatic image analysis of multi-channel image screening data. PMID:18445146

  20. Advances in Tumor Screening, Imaging, and Avatar Technologies for High-Grade Serous Ovarian Cancer

    PubMed Central

    Ohman, Anders W.; Hasan, Noor; Dinulescu, Daniela M.

    2014-01-01

    The majority of high-grade serous ovarian carcinoma cases are detected in advanced stages when treatment options are limited. Surgery is less effective at eradicating the disease when it is widespread, resulting in high rates of disease relapse and chemoresistance. Current screening techniques are ineffective for early tumor detection and consequently, BRCA mutations carriers, with an increased risk for developing high-grade serous ovarian cancer, elect to undergo risk-reducing surgery. While prophylactic surgery is associated with a significant reduction in the risk of cancer development, it also results in surgical menopause and significant adverse side effects. The development of efficient early-stage screening protocols and imaging technologies is critical to improving the outcome and quality of life for current patients and women at increased risk. In addition, more accurate animal models are necessary in order to provide relevant in vivo testing systems and advance our understanding of the disease origin and progression. Moreover, both genetically engineered and tumor xenograft animal models enable the preclinical testing of novel imaging techniques and molecularly targeted therapies as they become available. Recent advances in xenograft technologies have made possible the creation of avatar mice, personalized tumorgrafts, which can be used as therapy testing surrogates for individual patients prior to or during treatment. High-grade serous ovarian cancer may be an ideal candidate for use with avatar models based on key characteristics of the tumorgraft platform. This review explores multiple strategies, including novel imaging and screening technologies in both patients and animal models, aimed at detecting cancer in the early-stages and improving the disease prognosis. PMID:25478323

  1. Sensitivity and specificity of nonmydriatic digital imaging in screening diabetic retinopathy in Indian eyes

    PubMed Central

    Gupta, Vishali; Bansal, Reema; Gupta, Amod; Bhansali, Anil

    2014-01-01

    Background: Nonmydriatic digital imaging (NMDI) is ideal for screening diabetic retinopathy (DR), but its use in Indian eyes has not been evaluated. Aim: The aim was to evaluate the sensitivity and specificity of NMDI as a screening tool in detecting DR in Indian eyes. Design: A prospective, nonrandomized, noncomparative, noninterventional study. Materials and Methods: A total of 500 diabetic patients visiting the endocrinology clinic (September 2008-June 2010) underwent NMDI (Zeiss Procam), followed by routine dilated fundus photography (FP; Zeiss Visupac 450+) of 345° retinal fields (1) optic disc and macula, (2) superotemporal, and (3) nasal to optic disc. Two-masked retina specialists graded the images for quality and severity of DR, and compared between NMDI and dilated FP. Statistical Analysis: SPSS Windows 17 for version. Results: Mean age was 52.97 ± 13.46 years (306 males: 194 females). The rate of ungradable images was 30.6% and 31% by the two observers. By observer 1, the sensitivity and specificity of detecting any DR was 58.8% and 69.1%, respectively, (κ = 0.608) and sight-threatening DR (STDR) was 63.1% and 68.9%, respectively, (κ = 0.641). By observer 2, the sensitivity and specificity was 57.3% and 68.3%, respectively, for any DR (κ = 0.593) and 62.8% and 68.3%, respectively, for STDR (κ = 0.637). The level of agreement between two observers was high (κ = 0.96). Conclusion: A high rate of poor quality photographs and low sensitivity limited the use of NMDI as a perfect screening system, particularly in dark iris population with diabetes as seen in Indian eyes. PMID:25230960

  2. Evaluation of an Automated Information Extraction Tool for Imaging Data Elements to Populate a Breast Cancer Screening Registry.

    PubMed

    Lacson, Ronilda; Harris, Kimberly; Brawarsky, Phyllis; Tosteson, Tor D; Onega, Tracy; Tosteson, Anna N A; Kaye, Abby; Gonzalez, Irina; Birdwell, Robyn; Haas, Jennifer S

    2015-10-01

    Breast cancer screening is central to early breast cancer detection. Identifying and monitoring process measures for screening is a focus of the National Cancer Institute's Population-based Research Optimizing Screening through Personalized Regimens (PROSPR) initiative, which requires participating centers to report structured data across the cancer screening continuum. We evaluate the accuracy of automated information extraction of imaging findings from radiology reports, which are available as unstructured text. We present prevalence estimates of imaging findings for breast imaging received by women who obtained care in a primary care network participating in PROSPR (n = 139,953 radiology reports) and compared automatically extracted data elements to a "gold standard" based on manual review for a validation sample of 941 randomly selected radiology reports, including mammograms, digital breast tomosynthesis, ultrasound, and magnetic resonance imaging (MRI). The prevalence of imaging findings vary by data element and modality (e.g., suspicious calcification noted in 2.6% of screening mammograms, 12.1% of diagnostic mammograms, and 9.4% of tomosynthesis exams). In the validation sample, the accuracy of identifying imaging findings, including suspicious calcifications, masses, and architectural distortion (on mammogram and tomosynthesis); masses, cysts, non-mass enhancement, and enhancing foci (on MRI); and masses and cysts (on ultrasound), range from 0.8 to1.0 for recall, precision, and F-measure. Information extraction tools can be used for accurate documentation of imaging findings as structured data elements from text reports for a variety of breast imaging modalities. These data can be used to populate screening registries to help elucidate more effective breast cancer screening processes. PMID:25561069

  3. Systematic Review of Digital Imaging Screening Strategies for Retinopathy of Prematurity

    PubMed Central

    Kemper, Alex R.; Wallace, David K.; Quinn, Graham E.

    2008-01-01

    BACKGROUND Retinal imaging with remote interpretation could decrease the number of diagnostic eye examinations that premature infants need for the detection of retinopathy of prematurity and thus decrease the time demand on the relatively small pool of ophthalmologists who perform retinopathy of prematurity examinations. OBJECTIVE Our goal was to review systematically the evidence regarding the reliability, validity, safety, costs, and benefits of retinal imaging to screen infants who are at risk for retinopathy of prematurity. METHODS We searched Medline, the Cochrane library, CINAHL, and the bibliographies of all relevant articles. All English-language studies regardless of design with primary data about our study questions were included. We excluded (1) studies that only included subjects with retinopathy of prematurity, (2) hypothetical models other than cost-effectiveness studies, and (3) validity studies without sufficient data to determine prevalence, sensitivity, and specificity or that only evaluated subjects for 1 component of retinopathy of prematurity (eg, plus disease only). RESULTS Studies of only 1 retinal imaging device (RetCam [Clarity Medical Systems, Inc, Pleasanton, CA]) met the inclusion criteria. There was a wide range in reported sensitivity, but specificity was high. There were several important limitations noted, including the eye as the unit of analysis instead of the individual or variations in the criteria for determining a true-positive or true-negative screening result. The risk of retinal hemorrhage resulting from imaging is low, and systemic effects (eg, bradycardia, hypertension, decreased oxygen saturation) are mild. No generalizable cost-effectiveness data were found. CONCLUSIONS The evidence base is not sufficient to recommend that retinal imaging be routinely adopted by NICUs to identify infants who have serious retinopathy of prematurity. PMID:18829807

  4. Surface impedance based microwave imaging method for breast cancer screening: contrast-enhanced scenario

    NASA Astrophysics Data System (ADS)

    Güren, Onan; Çayören, Mehmet; Tükenmez Ergene, Lale; Akduman, Ibrahim

    2014-10-01

    A new microwave imaging method that uses microwave contrast agents is presented for the detection and localization of breast tumours. The method is based on the reconstruction of breast surface impedance through a measured scattered field. The surface impedance modelling allows for representing the electrical properties of the breasts in terms of impedance boundary conditions, which enable us to map the inner structure of the breasts into surface impedance functions. Later a simple quantitative method is proposed to screen breasts against malignant tumours where the detection procedure is based on weighted cross correlations among impedance functions. Numerical results demonstrate that the method is capable of detecting small malignancies and provides reasonable localization.

  5. [Suture foreign body reaction as a mammographic pitfall].

    PubMed

    Plagborg, G J; Andersen, H K

    2000-02-14

    A mammographic pitfall is presented. After lumpectomy owing to cancer in the breast a woman developed an immediate allergic reaction presumably caused by the subcutaneous sutures (vicryl). After adjuvant irradiation the breast became swollen and mammography gave suspicion of a recurrent breast cancer. Surgical excision was performed and examination of the biopsy specimen showed a foreign body reaction to the suture material with fibrosis and eosinophilia. PMID:10740437

  6. Toxicology screen

    MedlinePlus

    Barbiturates - screen; Benzodiazepines - screen; Amphetamines - screen; Analgesics - screen; Antidepressants - screen; Narcotics - screen; Phenothiazines - screen; Drug abuse screen; Blood alcohol test

  7. Population-based study of DNA image cytometry as screening method for esophageal cancer

    PubMed Central

    Zhao, Lin; Wei, Wen-Qiang; Zhao, De-Li; Hao, Chang-Qing; Lin, Dong-Mei; Pan, Qin-Jing; Li, Xin-Qing; Lei, Fu-Hua; Wang, Jin-Wu; Wang, Guo-Qing; Shang, Qi; Qiao, You-Lin

    2012-01-01

    AIM: To explore the DNA image cytometry (DNA-ICM) technique as a primary screening method for esophageal squamous precancerous lesions. METHODS: This study was designed as a population-based screening study. A total of 582 local residents aged 40 years-69 years were recruited from Linzhou in Henan and Feicheng in Shandong. However, only 452 subjects had results of liquid-based cytology, DNA-ICM and pathology. The sensitivity and specificity of DNA-ICM were calculated and compared with liquid-based cytology in moderate dysplasia or worse. RESULTS: Sensitivities of DNA-ICM ranging from at least 1 to 4 aneuploid cells were 90.91%, 86.36%, 79.55% and 77.27%, respectively, which were better than that of liquid-based cytology (75%). Specificities of DNA-ICM were 70.83%, 84.07%, 92.65% and 96.81%, but the specificity of liquid-based cytology was 91.91%. The sensitivity and specificity of a combination of liquid-based cytology and DNA-ICM were 84.09% and 85.78%, respectively. CONCLUSION: It is possible to use DNA-ICM technique as a primary screening method for esophageal squamous precancerous lesions. PMID:22294844

  8. Live imaging RNAi screen reveals genes essential for meiosis in mammalian oocytes

    PubMed Central

    Tischer, Thomas; Santhanam, Balaji; Schuh, Melina

    2015-01-01

    During fertilization, an egg and a sperm fuse to form a new embryo. Eggs develop from oocytes in a process called meiosis. Meiosis in human oocytes is highly error-prone1,2, and defective eggs are the leading cause of pregnancy loss and several genetic disorders such as Down’s syndrome3-5. Which genes safeguard accurate progression through meiosis is largely unclear. Here, we developed high-content phenotypic screening methods for the systematic identification of mammalian meiotic genes. We targeted 774 genes by RNAi within follicle-enclosed mouse oocytes to block protein expression from an early stage of oocyte development onwards. We then analysed the function of several genes simultaneously by high-resolution imaging of chromosomes and microtubules in live oocytes and scored each oocyte quantitatively for 50 phenotypes, generating a comprehensive resource of meiotic gene function. The screen generated an unprecedented annotated dataset of meiotic progression in 2,241 mammalian oocytes, which allowed us to analyse systematically which defects are linked to abnormal chromosome segregation during meiosis, identifying progression into anaphase with misaligned chromosomes as well as defects in spindle organization as risk factors. This study demonstrates how high-content screens can be performed in oocytes, and now allows systematic studies of meiosis in mammals. PMID:26147080

  9. Reconstruction of burst activity from calcium imaging of neuronal population via Lq minimization and interval screening

    PubMed Central

    Quan, Tingwei; Lv, Xiaohua; Liu, Xiuli; Zeng, Shaoqun

    2016-01-01

    Calcium imaging is becoming an increasingly popular technology to indirectly measure activity patterns in local neuronal networks. Based on the dependence of calcium fluorescence on neuronal spiking, two-photon calcium imaging affords single-cell resolution of neuronal population activity. However, it is still difficult to reconstruct neuronal activity from complex calcium fluorescence traces, particularly for traces contaminated by noise. Here, we describe a robust and efficient neuronal-activity reconstruction method that utilizes Lq minimization and interval screening (IS), which we refer to as LqIS. The simulation results show that LqIS performs satisfactorily in terms of both accuracy and speed of reconstruction. Reconstruction of simulation and experimental data also shows that LqIS has advantages in terms of the recall rate, precision rate, and timing error. Finally, LqIS is demonstrated to effectively reconstruct neuronal burst activity from calcium fluorescence traces recorded from large-size neuronal population. PMID:27375930

  10. An assessment of reference exposure in analogic and digital mammographic units

    NASA Astrophysics Data System (ADS)

    Tilly, J. G.; Miguel, C.; Schelin, H. R.; Porto, L. E.; Paschuk, S.; Denyak, V.; Kmiecik, C.

    2014-11-01

    In this study, the incident air kerma (Ki,a), half-value layer (HVL), output and voltage accuracy for 28 mammography services were evaluated. All mammographs had high frequency rectification, a focus-film distance greater than 60 cm, automatic exposure control, a Mo-Mo anode-filter combination, and compression system. Twenty-three evaluations were made of analogic imaging systems and 21 of digital imaging systems, two of which were full field digital mammography units. The Ki,a was measured in the beam radiation with a 6 cm3 ionization chamber, calibrated for a mammography range of energy. A standard American College of Radiology mammographic phantom simulated a skull caudal incidence. The average, minimum, and maximum Ki,a values were 10.13 mGy, 3.92 mGy, and 30.41 mGy, respectively. However, when the analogic and digital systems are analyzed separately in two subsets, the values were 8.13 mGy, 3.92 mGy, and 11.78 mGy for the analogic systems and 12.33 mGy, 5.21 mGy, and 30.41 mGy for the digital systems, respectively. The results show that the Ki,a values found in digital systems were higher than those in analogic systems, highlighting the differences between these acquisition systems. All HVL values, measured in the primary beam at 28 kV were found between 0.33 mm Al and 0.43 mm Al. Although the manufacture time of the equipment was approximately 146 months (~12 years) prior, the variation in output was between 0.071 mGy/mAs and 0.164 mGy/mAs for the entire sample.

  11. A Versatile Cell Death Screening Assay Using Dye-Stained Cells and Multivariate Image Analysis

    PubMed Central

    Collins, Tony J.; Ylanko, Jarkko; Geng, Fei

    2015-01-01

    Abstract A novel dye-based method for measuring cell death in image-based screens is presented. Unlike conventional high- and medium-throughput cell death assays that measure only one form of cell death accurately, using multivariate analysis of micrographs of cells stained with the inexpensive mix, red dye nonyl acridine orange, and a nuclear stain, it was possible to quantify cell death induced by a variety of different agonists even without a positive control. Surprisingly, using a single known cytotoxic agent as a positive control for training a multivariate classifier allowed accurate quantification of cytotoxicity for mechanistically unrelated compounds enabling generation of dose–response curves. Comparison with low throughput biochemical methods suggested that cell death was accurately distinguished from cell stress induced by low concentrations of the bioactive compounds Tunicamycin and Brefeldin A. High-throughput image-based format analyses of more than 300 kinase inhibitors correctly identified 11 as cytotoxic with only 1 false positive. The simplicity and robustness of this dye-based assay makes it particularly suited to live cell screening for toxic compounds. PMID:26422066

  12. A Versatile Cell Death Screening Assay Using Dye-Stained Cells and Multivariate Image Analysis.

    PubMed

    Collins, Tony J; Ylanko, Jarkko; Geng, Fei; Andrews, David W

    2015-11-01

    A novel dye-based method for measuring cell death in image-based screens is presented. Unlike conventional high- and medium-throughput cell death assays that measure only one form of cell death accurately, using multivariate analysis of micrographs of cells stained with the inexpensive mix, red dye nonyl acridine orange, and a nuclear stain, it was possible to quantify cell death induced by a variety of different agonists even without a positive control. Surprisingly, using a single known cytotoxic agent as a positive control for training a multivariate classifier allowed accurate quantification of cytotoxicity for mechanistically unrelated compounds enabling generation of dose-response curves. Comparison with low throughput biochemical methods suggested that cell death was accurately distinguished from cell stress induced by low concentrations of the bioactive compounds Tunicamycin and Brefeldin A. High-throughput image-based format analyses of more than 300 kinase inhibitors correctly identified 11 as cytotoxic with only 1 false positive. The simplicity and robustness of this dye-based assay makes it particularly suited to live cell screening for toxic compounds. PMID:26422066

  13. An integrated microfluidic biosensor for the rapid screening of foodborne pathogens by surface plasmon resonance imaging

    NASA Astrophysics Data System (ADS)

    Zordan, Michael D.; Grafton, Meggie M. G.; Leary, James F.

    2011-03-01

    The rapid detection of foodborne pathogens is of vital importance to keep the food supply rid of contamination. Previously we have demonstrated the design of a hybrid optical device that performs real-time surface plasmon resonance (SPR) and epi-fluorescence imaging. Additionally we have developed a biosensor array chip that is able to specifically detect the presence of two known pathogens. This biosensor detects the presence of the pathogen strains by the selective capture of whole pathogens by peptide ligands functionalized to the spots of the array. We have incorporated this biosensor array into a self contained PDMS microfluidic chip. The enclosure of the biosensor array by a PDMS microfluidic chip allows for a sample to be screened for many strains of pathogens simultaneously in a safe one time use biochip. This disposable optical biochip is inserted into with the hybrid SPR/epi-fluorescence imaging device to form an integrated system for the detection of foodborne pathogens. Using this integrated system, we can selectively detect the presence of E. coli 0157:H7 or S. enterica in a simultaneously in real-time. Additionally, we have modeled the mechanical properties of the microfluidic biochip in order to manipulate the flow conditions to achieve optimal pathogen capture by the biosensor array. We have developed an integrated system that is able to screen a sample for multiple foodborne pathogens simultaneously in a safe, rapid and label-free manner.

  14. Expanding the Diversity of Imaging-Based RNAi Screen Applications Using Cell Spot Microarrays

    PubMed Central

    Rantala, Juha K.; Kwon, Sunjong; Korkola, James; Gray, Joe W.

    2013-01-01

    Over the past decade, great strides have been made in identifying gene aberrations and deregulated pathways that are associated with specific disease states. These association studies guide experimental studies aimed at identifying the aberrant genes and networks that cause the disease states. This requires functional manipulation of these genes and networks in laboratory models of normal and diseased cells. One approach is to assess molecular and biological responses to high-throughput RNA interference (RNAi)-induced gene knockdown. These responses can be revealed by immunofluorescent staining for a molecular or cellular process of interest and quantified using fluorescence image analysis. These applications are typically performed in multiwell format, but are limited by high reagent costs and long plate processing times. These limitations can be mitigated by analyzing cells grown in cell spot microarray (CSMA) format. CSMAs are produced by growing cells on small (~200 μm diameter) spots with each spot carrying an siRNA with transfection reagent. The spacing between spots is only a few hundred micrometers, thus thousands of cell spots can be arranged on a single cell culture surface. These high-density cell cultures can be immunofluorescently stained with minimal reagent consumption and analyzed quickly using automated fluorescence microscopy platforms. This review covers basic aspects of imaging-based CSMA technology, describes a wide range of immunofluorescence assays that have already been implemented successfully for CSMA screening and suggests future directions for advanced RNAi screening experiments.

  15. An image-based software tool for screening retinal fundus images using vascular morphology and network transport analysis

    NASA Astrophysics Data System (ADS)

    Clark, Richard D.; Dickrell, Daniel J.; Meadows, David L.

    2014-03-01

    As the number of digital retinal fundus images taken each year grows at an increasing rate, there exists a similarly increasing need for automatic eye disease detection through image-based analysis. A new method has been developed for classifying standard color fundus photographs into both healthy and diseased categories. This classification was based on the calculated network fluid conductance, a function of the geometry and connectivity of the vascular segments. To evaluate the network resistance, the retinal vasculature was first manually separated from the background to ensure an accurate representation of the geometry and connectivity. The arterial and venous networks were then semi-automatically separated into two separate binary images. The connectivity of the arterial network was then determined through a series of morphological image operations. The network comprised of segments of vasculature and points of bifurcation, with each segment having a characteristic geometric and fluid properties. Based on the connectivity and fluid resistance of each vascular segment, an arterial network flow conductance was calculated, which described the ease with which blood can pass through a vascular system. In this work, 27 eyes (13 healthy and 14 diabetic) from patients roughly 65 years in age were evaluated using this methodology. Healthy arterial networks exhibited an average fluid conductance of 419 ± 89 μm3/mPa-s while the average network fluid conductance of the diabetic set was 165 ± 87 μm3/mPa-s (p < 0.001). The results of this new image-based software demonstrated an ability to automatically, quantitatively and efficiently screen diseased eyes from color fundus imagery.

  16. Automatic Screening and Grading of Age-Related Macular Degeneration from Texture Analysis of Fundus Images.

    PubMed

    Phan, Thanh Vân; Seoud, Lama; Chakor, Hadi; Cheriet, Farida

    2016-01-01

    Age-related macular degeneration (AMD) is a disease which causes visual deficiency and irreversible blindness to the elderly. In this paper, an automatic classification method for AMD is proposed to perform robust and reproducible assessments in a telemedicine context. First, a study was carried out to highlight the most relevant features for AMD characterization based on texture, color, and visual context in fundus images. A support vector machine and a random forest were used to classify images according to the different AMD stages following the AREDS protocol and to evaluate the features' relevance. Experiments were conducted on a database of 279 fundus images coming from a telemedicine platform. The results demonstrate that local binary patterns in multiresolution are the most relevant for AMD classification, regardless of the classifier used. Depending on the classification task, our method achieves promising performances with areas under the ROC curve between 0.739 and 0.874 for screening and between 0.469 and 0.685 for grading. Moreover, the proposed automatic AMD classification system is robust with respect to image quality. PMID:27190636

  17. Automatic Screening and Grading of Age-Related Macular Degeneration from Texture Analysis of Fundus Images

    PubMed Central

    Phan, Thanh Vân; Seoud, Lama; Chakor, Hadi; Cheriet, Farida

    2016-01-01

    Age-related macular degeneration (AMD) is a disease which causes visual deficiency and irreversible blindness to the elderly. In this paper, an automatic classification method for AMD is proposed to perform robust and reproducible assessments in a telemedicine context. First, a study was carried out to highlight the most relevant features for AMD characterization based on texture, color, and visual context in fundus images. A support vector machine and a random forest were used to classify images according to the different AMD stages following the AREDS protocol and to evaluate the features' relevance. Experiments were conducted on a database of 279 fundus images coming from a telemedicine platform. The results demonstrate that local binary patterns in multiresolution are the most relevant for AMD classification, regardless of the classifier used. Depending on the classification task, our method achieves promising performances with areas under the ROC curve between 0.739 and 0.874 for screening and between 0.469 and 0.685 for grading. Moreover, the proposed automatic AMD classification system is robust with respect to image quality. PMID:27190636

  18. Development of a screening tool for staging of diabetic retinopathy in fundus images

    NASA Astrophysics Data System (ADS)

    Dhara, Ashis Kumar; Mukhopadhyay, Sudipta; Bency, Mayur Joseph; Rangayyan, Rangaraj M.; Bansal, Reema; Gupta, Amod

    2015-03-01

    Diabetic retinopathy is a condition of the eye of diabetic patients where the retina is damaged because of long-term diabetes. The condition deteriorates towards irreversible blindness in extreme cases of diabetic retinopathy. Hence, early detection of diabetic retinopathy is important to prevent blindness. Regular screening of fundus images of diabetic patients could be helpful in preventing blindness caused by diabetic retinopathy. In this paper, we propose techniques for staging of diabetic retinopathy in fundus images using several shape and texture features computed from detected microaneurysms, exudates, and hemorrhages. The classification accuracy is reported in terms of the area (Az) under the receiver operating characteristic curve using 200 fundus images from the MESSIDOR database. The value of Az for classifying normal images versus mild, moderate, and severe nonproliferative diabetic retinopathy (NPDR) is 0:9106. The value of Az for classification of mild NPDR versus moderate and severe NPDR is 0:8372. The Az value for classification of moderate NPDR and severe NPDR is 0:9750.

  19. Museum as an integrated imaging device: visualization of ancient Kyoto cityscape from folding screen artifact

    NASA Astrophysics Data System (ADS)

    Miyata, Kimiyoshi; Oyabu, Umi; Kojima, Michihiro

    2012-03-01

    Museums hold cultural resources such as artworks, historical artifacts, and folklore materials. The National Museum of Japanese History holds over 200,000 of the cultural resources. A role of museum is to exhibit the cultural resources, therefore a museum could be referred to as a visualization device for the information society. In this research, visualization of a history image from cultural resources with interactive user interface will be mentioned. The material focused on is the oldest extant version of a genre of folding screen paintings that depict the thriving city of Kyoto in the four seasons, named Rekihaku's "Scenes In and Around Kyoto" designated as a nationally important cultural property in Japan. Over 1,400 people and a lot of residences, temples, and houses are drawn, and those are also information resource telling us about city scenes and people's life in Kyoto at that time. Historical researches were done by using a high resolution digital image obtained by a large scaled scanner, and scanned images are used for computer programs to visualize a history image of ancient Kyoto. Combinations between real materials and information provided by using the computer programs are also described in this research.

  20. Split-screen display system and standardized methods for ultrasound image acquisition and multi-frame data processing

    NASA Technical Reports Server (NTRS)

    Selzer, Robert H. (Inventor); Hodis, Howard N. (Inventor)

    2011-01-01

    A standardized acquisition methodology assists operators to accurately replicate high resolution B-mode ultrasound images obtained over several spaced-apart examinations utilizing a split-screen display in which the arterial ultrasound image from an earlier examination is displayed on one side of the screen while a real-time "live" ultrasound image from a current examination is displayed next to the earlier image on the opposite side of the screen. By viewing both images, whether simultaneously or alternately, while manually adjusting the ultrasound transducer, an operator is able to bring into view the real-time image that best matches a selected image from the earlier ultrasound examination. Utilizing this methodology, dynamic material properties of arterial structures, such as IMT and diameter, are measured in a standard region over successive image frames. Each frame of the sequence has its echo edge boundaries automatically determined by using the immediately prior frame's true echo edge coordinates as initial boundary conditions. Computerized echo edge recognition and tracking over multiple successive image frames enhances measurement of arterial diameter and IMT and allows for improved vascular dimension measurements, including vascular stiffness and IMT determinations.

  1. Detection of mammographic masses using sector features with a multiple-circular-path neural network

    NASA Astrophysics Data System (ADS)

    Lo, Shih-Chung B.; Li, Huai; Hasegawa, Akira; Wang, Yue J.; Freedman, Matthew T.; Mun, Seong K.

    1998-06-01

    In the clinical course of detecting masses, mammographers usually evaluate the surrounding background of a radiodense when breast cancer is suspected. In this study, we adapted this fundamental concept and computed features of the suspicious region in radial sections. These features were then arranged by circular convolution processes within a neural network, which led to an improvement in detecting mammographic masses.

  2. Mammographic film-processor temperature, development time, and chemistry: effect on dose, contrast, and noise

    SciTech Connect

    Kimme-Smith, C.; Rothschild, P.A.; Bassett, L.W.; Gold, R.H.; Moler, C.

    1989-01-01

    Six different combinations of film-processor temperature (33.3 degrees C, 35 degrees C), development time (22 sec, 44 sec), and chemistry (Du Pont medium contrast developer (MCD) and Kodak rapid process (RP) developer) were each evaluated by separate analyses with Hurter and Driffield curves, test images of plastic step wedges, noise variance analysis, and phantom images; each combination also was evaluated clinically. Du Pont MCD chemistry produced greater contrast than did Kodak RP chemistry. A change in temperature from 33.3 degrees C (92 degrees F) to 35 degrees C (95 degrees F) had the least effect on dose and image contrast. Temperatures of 36.7 degrees C (98 degrees F) and 38.3 degrees C (101 degrees F) also were tested with extended processing. The speed increased for 36.7 degrees C but decreased at 38.3 degrees C. Base plus fog increased, but contrast decreased for these higher temperatures. Increasing development time had the greatest effect on decreasing the dose required for equivalent film darkening when imaging BR12 breast equivalent test objects; ion chamber measurements showed a 32% reduction in dose when the development time was increased from 22 to 44 sec. Although noise variance doubled in images processed with the extended development time, diagnostic capability was not compromised. Extending the processing time for mammographic films was an effective method of dose reduction, whereas varying the processing temperature and chemicals had less effect on contrast and dose.

  3. Inter-observer variability within BI-RADS and RANZCR mammographic density assessment schemes

    NASA Astrophysics Data System (ADS)

    Damases, Christine N.; Mello-Thoms, Claudia; McEntee, Mark F.

    2016-03-01

    This study compares variability associated with two visual mammographic density (MD) assessment methods using two separate samples of radiologists. The image test-set comprised of images obtained from 20 women (age 42-89 years). The images were assessed for their MD by twenty American Board of Radiology (ABR) examiners and twenty-six radiologists registered with the Royal Australian and New Zealand College of Radiologists (RANZCR). Images were assessed using the same technology and conditions, however the ABR radiologists used the BI-RADS and the RANZCR radiologists used the RANZCR breast density synoptic. Both scales use a 4-point assessment. The images were then grouped as low- and high-density; low including BIRADS 1 and 2 or RANZCR 1 and 2 and high including BI-RADS 3 and 4 or RANZCR 3 and 4. Four-point BI-RADS and RANZCR showed no or negligible correlation (ρ=-0.029 p<0.859). The average inter-observer agreement on the BI-RADS scale had a Kappa of 0.565; [95% CI = 0.519 - 0.610], and ranged between 0.328-0.669 while the inter-observer agreement using the RANZCR scale had a Kappa of 0.360; [95% CI = 0.308 - 0.412] and a range of 0.078-0.499. Our findings show a wider range of inter-observer variability among RANZCR registered radiologists than the ABR examiners.

  4. Digital mammographic tumor classification using transfer learning from deep convolutional neural networks.

    PubMed

    Huynh, Benjamin Q; Li, Hui; Giger, Maryellen L

    2016-07-01

    Convolutional neural networks (CNNs) show potential for computer-aided diagnosis (CADx) by learning features directly from the image data instead of using analytically extracted features. However, CNNs are difficult to train from scratch for medical images due to small sample sizes and variations in tumor presentations. Instead, transfer learning can be used to extract tumor information from medical images via CNNs originally pretrained for nonmedical tasks, alleviating the need for large datasets. Our database includes 219 breast lesions (607 full-field digital mammographic images). We compared support vector machine classifiers based on the CNN-extracted image features and our prior computer-extracted tumor features in the task of distinguishing between benign and malignant breast lesions. Five-fold cross validation (by lesion) was conducted with the area under the receiver operating characteristic (ROC) curve as the performance metric. Results show that classifiers based on CNN-extracted features (with transfer learning) perform comparably to those using analytically extracted features [area under the ROC curve [Formula: see text

  5. Variation in Inflammatory Cytokine/Growth-Factor Genes and Mammographic Density in Premenopausal Women Aged 50–55

    PubMed Central

    Ozhand, Ali; Lee, Eunjung; Wu, Anna H.; Ellingjord-Dale, Merete; Akslen, Lars A.; McKean-Cowdin, Roberta; Ursin, Giske

    2013-01-01

    Background Mammographic density (MD) has been found to be an independent risk factor for breast cancer. Although data from twin studies suggest that MD has a strong genetic component, the exact genes involved remain to be identified. Alterations in stromal composition and the number of epithelial cells are the most predominant histopathological determinants of mammographic density. Interactions between the breast stroma and epithelium are critically important in the maturation and development of the mammary gland and the cross-talk between these cells are mediated by paracrine growth factors and cytokines. The potential impact of genetic variation in growth factors and cytokines on MD is largely unknown. Methods We investigated the association between 89 single nucleotide polymorphisms (SNPs) in 7 cytokine/growth-factor genes (FGFR2, IGFBP1, IGFBP3, TGFB1, TNF, VEGF, IL6) and percent MD in 301 premenopausal women (aged 50 to 55 years) participating in the Norwegian Breast Cancer Screening Program. We evaluated the suggestive associations in 216 premenopausal Singapore Chinese Women of the same age. Results We found statistically significant associations between 9 tagging SNPs in the IL6 gene and MD in Norwegian women; the effect ranged from 3–5% in MD per variant allele (p-values = 0.02 to 0.0002). One SNP in the IL6 (rs10242595) significantly influenced MD in Singapore Chinese women. Conclusion Genetic variations in IL6 may be associated with MD and therefore may be an indicator of breast cancer risk in premenopausal women. PMID:23762340

  6. A new study on mammographic image denoising using multiresolution techniques

    NASA Astrophysics Data System (ADS)

    Dong, Min; Guo, Ya-Nan; Ma, Yi-De; Ma, Yu-run; Lu, Xiang-yu; Wang, Ke-ju

    2015-12-01

    Mammography is the most simple and effective technology for early detection of breast cancer. However, the lesion areas of breast are difficult to detect which due to mammograms are mixed with noise. This work focuses on discussing various multiresolution denoising techniques which include the classical methods based on wavelet and contourlet; moreover the emerging multiresolution methods are also researched. In this work, a new denoising method based on dual tree contourlet transform (DCT) is proposed, the DCT possess the advantage of approximate shift invariant, directionality and anisotropy. The proposed denoising method is implemented on the mammogram, the experimental results show that the emerging multiresolution method succeeded in maintaining the edges and texture details; and it can obtain better performance than the other methods both on visual effects and in terms of the Mean Square Error (MSE), Peak Signal to Noise Ratio (PSNR) and Structure Similarity (SSIM) values.

  7. RELATIONSHIP OF MAMMOGRAPHIC DENSITY AND GENE EXPRESSION: ANALYSIS OF NORMAL BREAST TISSUE SURROUNDING BREAST CANCER

    PubMed Central

    Sandhu, Rupninder; Williams, Tyisha; Midkiff, Bentley R.; Lissowska, Jolanta; Wesolowska, Ewa; Boyd, Norman F.; Johnson, Nicole B.; Figueroa, Jonine D.; Sherman, Mark E.; Troester, Melissa A.

    2014-01-01

    Purpose Previous studies of breast tissue gene expression have demonstrated that the extratumoral microenvironment has substantial variability across individuals, some of which can be attributed to epidemiologic factors. To evaluate how mammographic density (MD) and breast tissue composition relate to extratumoral microenvironment gene expression, we used data on 121 breast cancer patients from the population-based Polish Women's Breast Cancer Study. Design Breast cancer cases were classified based on a previously reported, biologically-defined extratumoral gene expression signature with two subtypes: an Active subtype, which is associated with high expression of genes related to fibrosis and wound response, and an Inactive subtype, which has high expression of cellular adhesion genes. MD of the contralateral breast was assessed using pre-treatment mammograms and a quantitative, reliable computer-assisted thresholding method. Breast tissue composition was evaluated based on digital image analysis of tissue sections. Results The Inactive extratumoral subtype was associated with significantly higher percentage mammographic density (PD) and dense area (DA) in univariate analysis (PD: p=0.001; DA: p=0.049) and in multivariable analyses adjusted for age and body mass index (PD: p=0.004; DA: p=0.049). Inactive/higher MD tissue was characterized by a significantly higher percentage of stroma and a significantly lower percentage of adipose tissue, with no significant change in epithelial content. Analysis of published gene expression signatures suggested that Inactive/higher MD tissue expressed increased estrogen response and decreased TGF-β signaling. Conclusions By linking novel molecular phenotypes with MD, our results indicate that MD reflects broad transcriptional changes, including changes in both epithelia- and stroma-derived signaling. PMID:23918601

  8. Combined effects of endogenous sex hormone levels and mammographic density on postmenopausal breast cancer risk: results from the Breakthrough Generations Study

    PubMed Central

    Schoemaker, M J; Folkerd, E J; Jones, M E; Rae, M; Allen, S; Ashworth, A; Dowsett, M; Swerdlow, A J

    2014-01-01

    Background: Mammographic density and sex hormone levels are strong risk factors for breast cancer, but it is unclear whether they represent the same aetiological entity or are independent risk factors. Methods: Within the Breakthrough Generations Study cohort, we conducted a case–control study of 265 postmenopausal breast cancer cases and 343 controls with prediagnostic mammograms and blood samples. Plasma was assayed for oestradiol, testosterone and sex hormone-binding globulin (SHBG) concentrations and mammographic density assessed by Cumulus. Results: Oestradiol and testosterone were negatively and SHBG positively associated with percentage density and absolute dense area, but after adjusting for body mass index the associations remained significant only for SHBG. Breast cancer risk was independently and significantly positively associated with percentage density (P=0.002), oestradiol (P=0.002) and testosterone (P=0.007) levels. Women in the highest tertile of both density and sex hormone level were at greatest risk, with an odds ratio of 7.81 (95% confidence interval (CI): 2.89–21.1) for oestradiol and 4.57 (95% CI: 1.75–11.9) for testosterone and high density compared with those who were in the lowest tertiles. The cumulative risk of breast cancer in the highest oestradiol and density tertiles, representing 8% of controls, was estimated as 12.8% at ages 50–69 years and 19.4% at ages 20–79 years, and in the lowest tertiles was 1.7% and 4.3%, respectively. Associations of breast cancer risk with tertiles of mammographic dense area were less strong than for percentage density. Conclusions: Endogenous sex hormone levels and mammographic density are independent risk factors for postmenopausal breast cancer, which in combination can identify women who might benefit from increased frequency of screening and chemoprophylaxis. PMID:24518596

  9. Brain magnetic resonance imaging screening is not useful for HIV-1-infected patients without neurological symptoms.

    PubMed

    Nishijima, Takeshi; Gatanaga, Hiroyuki; Teruya, Katsuji; Tajima, Tsuyoshi; Kikuchi, Yoshimi; Hasuo, Kanehiro; Oka, Shinichi

    2014-10-01

    We investigated the diagnostic usefulness of brain magnetic resonance imaging (MRI) screening in HIV-1-infected patients without neurological symptoms in detecting intracranial diseases at early stages. In this retrospective analysis, the study patients were HIV-1-infected patients who underwent brain MRI scan in clinical practice between 2001 and 2013. We excluded patients with MRI for (1) follow-up examination for prediagnosed intracranial diseases, (2) cancer staging, (3) screening mycobacterium/bacteria/fungi disease proliferation in the brain, and (4) evaluation for meningitis/encephalitis. The study patients (n=485) were classified into two groups: those who underwent brain MRI scan without any neurological symptoms/signs (asymptomatic patients, n=158) and those who underwent MRI due to such symptoms (symptomatic patients, n=327). Asymptomatic patients had lower CD4 counts than symptomatic patients (median 78 versus 241/μl). Intracranial diseases were detected in three (2%) of the asymptomatic patients [two toxoplasmosis and one progressive multifocal leukoencephalopathy (PML)] compared to 58 (19%) of the symptomatic patients (the χ(2) test, p<0.01). The latter included toxoplasmosis (n=10), PML (n=7), cytomegalovirus encephalitis (n=3), primary central nervous system lymphoma (n=3), cryptococcoma/meningitis (n=3), and HIV-associated dementia (n=17). Among symptomatic patients, intracranial diseases were common in those with slurred speech (3/6, 50%), seizure (4/10, 40%), eyesight/vision abnormality (5/16, 31%), altered mental status (8/31, 26%), and hemiplegia/numbness (13/50, 26%). For patients with CD4 count <200/μl, intracranial diseases were detected in only 3 (3%) of 144 asymptomatic patients, compared with 46 (32%) of 113 symptomatic patients (p<0.01). Brain MRI screening for HIV-1-infected patients without neurological symptoms is of little value. PMID:25084148

  10. Screening for Body Image Dissatisfaction in Patients with Advanced Cancer: A Pilot Study

    PubMed Central

    Rhondali, Wadih; Chisholm, Gary B.; Filbet, Marilene; Kang, Duck-Hee; Hui, David; Cororve Fingeret, Michelle

    2015-01-01

    Abstract Background Cancer and its treatment can significantly affect appearance and body integrity. A number of studies have explored the impact of cancer and its treatment on body image, primarily in head and neck and breast cancer. The aim of this pilot study was to examine the construct of body image dissatisfaction and its measurement using a single question in patients with advanced cancer. Methods Outpatients with advanced cancer were recruited (n=81). Assessments included Body Image Scale (BIS), Appearance Schema Inventory (ASI-R), Edmonton Symptom Assessment System (ESAS) with a total symptom distress score (TSDS) and two subscales scores (physical distress [PHS] and psychological distress [PSS]), Hospital Anxiety Depression Scale (HADS), and one question assessing the overall appearance satisfaction from the Multidimensional Body-Self Relations Questionnaire (MBSRQ). We also asked patients to rate the body image changes importance compared with five symptoms (pain, fatigue, depression, insomnia, lack of appetite). Results Forty-seven (58%) patients had a BIS score >10 (body image dissatisfaction) with a median of 11 (first–third quartiles, Q1–Q3; 5–16) and a median ASI-R of 3.1 (Q1–Q3; 2.8–3.5). Sensitivity and specificity of ≤3 for body image dissatisfaction in the single overall appearance question using the BIS as a standard was 0.70 and 0.71, respectively. BIS score was significantly correlated with ASI-R (r=0.248; p=0.025), age (r=−0.225; p=0.043), HADS-A (r=0.522, p<0.001), HADS-D (r=0.422, p<0.001), PSS score (r=0.371, p=0.001), PHS score (r=0.356, p=0.001), TSDS score (r=0.416, p<0.001), and the overall appearance question (MBSRQ; r=−0.449, p<0.001). Conclusion Body image dissatisfaction was frequent and associated with symptom burden. A single item ≤3 has a sensitivity of 70% for body image satisfaction screening. PMID:25188590

  11. Proteome-wide drug screening using mass spectrometric imaging of bead-arrays

    PubMed Central

    Zhou, Ying; Liu, Ziying; Rothschild, Kenneth J.; Lim, Mark J.

    2016-01-01

    A fundamental challenge in the drug discovery process is to develop compounds with high efficacy and minimal side-effects. We describe a new approach to proteome-wide drug screening for detection of on- and off-target binding which combines the advantages of mass spectrometry with microarray technology. The method involves matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) of agarose micro-beads randomly arrayed at high-density in custom micro-well plates. Each bead carries a unique protein target and a corresponding photocleavable mass-tag for coding (PC-Mass-Tag). Compounds bound to specific protein beads and a photo-released coding PC-Mass-Tag are detected simultaneously using MALDI-MSI. As an initial demonstration of this approach, two kinase-targeted drugs, Dasatinib and Brigatinib (AP26113), were simultaneously screened against a model 50-member kinase-bead library. A MALDI-MSI scan performed at the equivalent density of 495,000 beads in the footprint of a microscope slide yielded 100% sensitivity for detecting known strong interactions with no false positives. PMID:27194112

  12. Small molecule regulators of autophagy identified by an image-based high-throughput screen

    PubMed Central

    Zhang, Lihong; Yu, Jia; Pan, Heling; Hu, Ping; Hao, Yan; Cai, Wenqing; Zhu, Hong; Yu, Albert D.; Xie, Xin; Ma, Dawei; Yuan, Junying

    2007-01-01

    Autophagy is a lysosome-dependent cellular catabolic mechanism mediating the turnover of intracellular organelles and long-lived proteins. Reduction of autophagy activity has been shown to lead to the accumulation of misfolded proteins in neurons and may be involved in chronic neurodegenerative diseases such as Huntington's disease and Alzheimer's disease. To explore the mechanism of autophagy and identify small molecules that can activate it, we developed a series of high-throughput image-based screens for small-molecule regulators of autophagy. This series of screens allowed us to distinguish compounds that can truly induce autophagic degradation from those that induce the accumulation of autophagosomes as a result of causing cellular damage or blocking downstream lysosomal functions. Our analyses led to the identification of eight compounds that can induce autophagy and promote long-lived protein degradation. Interestingly, seven of eight compounds are FDA-approved drugs for treatment of human diseases. Furthermore, we show that these compounds can reduce the levels of expanded polyglutamine repeats in cultured cells. Our studies suggest the possibility that some of these drugs may be useful for the treatment of Huntington's and other human diseases associated with the accumulation of misfolded proteins. PMID:18024584

  13. Automatic screening of polycystic kidney disease in x-ray CT images of laboratory mice

    NASA Astrophysics Data System (ADS)

    Gleason, Shaun S.; Sari-Sarraf, Hamed; Paulus, Michael J.; Johnson, Dabney K.; Abidi, Mongi A.

    2000-06-01

    This paper describes the application of a statistical-based deformable model algorithm to the segmentation of kidneys in x-ray computed tomography (CT) images of laboratory mice. This segmentation algorithm has been developed as the crucial first step in a process to automatically screen mice for genetically-induced polycystic kidney disease (PKD). The algorithm is based on active shape models (ASMs) initially developed by Cootes, et al. Once the segmentation is complete, texture measurements are applied within kidney boundaries to detect the presence of PKD. The challenges associated with the segmentation of mouse kidneys (non-rigid organs) are presented, and the motivation for using ASMs in this application is discussed. Also, improvements were made to published ASM methods that may be generally helpful in other segmentation applications. In 15 of the 18 cases tested, the mouse kidneys and spine were detected with only minor errors in boundary position. In the remaining three cases, small parts of the kidneys were missed and/or some extra abdominal tissue was inadvertently included by the boundary. In all 18 cases, however, the kidneys were successfully detected at a level where PKD could be automatically screened for using mean-of-local-variance (MOLV) texture measurements.

  14. A High-Content Imaging Screen for Cellular Regulators of β-Catenin Protein Abundance.

    PubMed

    Zeng, Xin; Montoute, Monica; Bee, Tiger W; Lin, Hong; Kallal, Lorena A; Liu, Yan; Agarwal, Pankaj; Wang, Dayuan; Lu, Quinn; Morrow, Dwight; Pope, Andrew J; Wu, Zining

    2016-03-01

    Abnormal accumulation of β-catenin protein, a key transcriptional activator required for Wnt signaling, is the hallmark of many tumor types, including colon cancer. In normal cells, β-catenin protein level is tightly controlled by a multiprotein complex through the proteosome pathway. Mutations in the components of the β-catenin degradation complex, such as adenomatous polyposis coli (APC) and Axin, lead to β-catenin stabilization and the constitutive activation of target genes. Since the signal transduction of Wnt/β-catenin is mainly mediated by protein-protein interactions, this pathway has been particularly refractory to conventional target-based small-molecule screening. Here we designed a cellular high-content imaging assay to detect β-catenin protein through immunofluorescent staining in the SW480 colon cancer cell line, which has elevated β-catenin endogenously. We demonstrate that the assay is robust and specific to screen a focused biologically diverse chemical library set against known targets that play diverse cellular functions. We identified a number of hits that reduce β-catenin levels without causing cell death. These hits may serve as tools to understand the dynamics of β-catenin degradation. This study demonstrates that detecting cell-based β-catenin protein stability is a viable approach to identifying novel mechanisms of β-catenin regulation as well as small molecules of therapeutic potential. PMID:26656867

  15. Proteome-wide drug screening using mass spectrometric imaging of bead-arrays.

    PubMed

    Zhou, Ying; Liu, Ziying; Rothschild, Kenneth J; Lim, Mark J

    2016-01-01

    A fundamental challenge in the drug discovery process is to develop compounds with high efficacy and minimal side-effects. We describe a new approach to proteome-wide drug screening for detection of on- and off-target binding which combines the advantages of mass spectrometry with microarray technology. The method involves matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) of agarose micro-beads randomly arrayed at high-density in custom micro-well plates. Each bead carries a unique protein target and a corresponding photocleavable mass-tag for coding (PC-Mass-Tag). Compounds bound to specific protein beads and a photo-released coding PC-Mass-Tag are detected simultaneously using MALDI-MSI. As an initial demonstration of this approach, two kinase-targeted drugs, Dasatinib and Brigatinib (AP26113), were simultaneously screened against a model 50-member kinase-bead library. A MALDI-MSI scan performed at the equivalent density of 495,000 beads in the footprint of a microscope slide yielded 100% sensitivity for detecting known strong interactions with no false positives. PMID:27194112

  16. Breast screening: understanding case difficulty and the nature of errors

    NASA Astrophysics Data System (ADS)

    Dong, Leng; Chen, Yan; Gale, Alastair G.

    2013-03-01

    In the UK all screeners undertake the PERFORMS scheme where they read annual sets of challenging cases. During this assessment, they give each case a confidence rating on whether it should be recalled. If they decide to recall a case, they also indicate the center of any key mammographic features on a display of the relevant mammographic case view. Expert radiological opinion defines what the key abnormalities (targets) are in any case. Data can then be analyzed using ROC and JAFROC approaches, and particularly for the latter, assessing whether a user has correctly located a feature or not is important. Using image pixel information alone it is possible to delineate correct localization of an abnormality from an incorrect location by defining an area of interest. To explore such location information in more detail, data from the last year of the PERFORMS scheme were reanalyzed and the location responses for each of the 675 participants on 120 screening cases examined. Additionally, expert radiological opinions had been garnered for various reasons, including accurately delineating any abnormalities. An algorithmic approach is developed which assesses whether users' indications should be included as correct abnormality identification or not, based on the feedback location information of all participants' indicated locations and the relative position of an indicated location to the abnormality. This approach is proposed to be superior to simple pixel distance approaches which measure a fixed distance from the centre of a target to the user's indicated location. The approach adds to the experimenter's repertoire of tools when examining user errors and case difficulty in medical imaging research.

  17. PopulationProfiler: A Tool for Population Analysis and Visualization of Image-Based Cell Screening Data

    PubMed Central

    Matuszewski, Damian J.; Wählby, Carolina

    2016-01-01

    Image-based screening typically produces quantitative measurements of cell appearance. Large-scale screens involving tens of thousands of images, each containing hundreds of cells described by hundreds of measurements, result in overwhelming amounts of data. Reducing per-cell measurements to the averages across the image(s) for each treatment leads to loss of potentially valuable information on population variability. We present PopulationProfiler—a new software tool that reduces per-cell measurements to population statistics. The software imports measurements from a simple text file, visualizes population distributions in a compact and comprehensive way, and can create gates for subpopulation classes based on control samples. We validate the tool by showing how PopulationProfiler can be used to analyze the effect of drugs that disturb the cell cycle, and compare the results to those obtained with flow cytometry. PMID:26987120

  18. Affinity imaging mass spectrometry (AIMS): high-throughput screening for specific small molecule interactions with frozen tissue sections.

    PubMed

    Yoshimi, T; Kawabata, S; Taira, S; Okuno, A; Mikawa, R; Murayama, S; Tanaka, K; Takikawa, O

    2015-11-01

    A novel screening system, using affinity imaging mass spectrometry (AIMS), has been developed to identify protein aggregates or organ structures in unfixed human tissue. Frozen tissue sections are positioned on small (millimetre-scale) stainless steel chips and incubated with an extensive library of small molecules. Candidate molecules showing specific affinity for the tissue section are identified by imaging mass spectrometry (IMS). As an example application, we screened over a thousand compounds against Alzheimer's disease (AD) brain tissue and identified several compounds with high affinity for AD brain sections containing tau deposits compared to age-matched controls. It should also be possible to use AIMS to isolate chemical compounds with affinity for tissue structures or components that have been extensively modified by events such as oxidation, phosphorylation, acetylation, aggregation, racemization or truncation, for example, due to aging. It may also be applicable to biomarker screening programs. PMID:26365298

  19. An Intermittent Live Cell Imaging Screen for siRNA Enhancers and Suppressors of a Kinesin-5 Inhibitor

    PubMed Central

    Tsui, Melody; Xie, Tiao; Orth, James D.; Carpenter, Anne E.; Rudnicki, Stewart; Kim, Suejong; Shamu, Caroline E.; Mitchison, Timothy J.

    2009-01-01

    Kinesin-5 (also known as Eg5, KSP and Kif11) is required for assembly of a bipolar mitotic spindle. Small molecule inhibitors of Kinesin-5, developed as potential anti-cancer drugs, arrest cell in mitosis and promote apoptosis of cancer cells. We performed a genome-wide siRNA screen for enhancers and suppressors of a Kinesin-5 inhibitor in human cells to elucidate cellular responses, and thus identify factors that might predict drug sensitivity in cancers. Because the drug's actions play out over several days, we developed an intermittent imaging screen. Live HeLa cells expressing GFP-tagged histone H2B were imaged at 0, 24 and 48 hours after drug addition, and images were analyzed using open-source software that incorporates machine learning. This screen effectively identified siRNAs that caused increased mitotic arrest at low drug concentrations (enhancers), and vice versa (suppressors), and we report siRNAs that caused both effects. We then classified the effect of siRNAs for 15 genes where 3 or 4 out of 4 siRNA oligos tested were suppressors as assessed by time lapse imaging, and by testing for suppression of mitotic arrest in taxol and nocodazole. This identified 4 phenotypic classes of drug suppressors, which included known and novel genes. Our methodology should be applicable to other screens, and the suppressor and enhancer genes we identified may open new lines of research into mitosis and checkpoint biology. PMID:19802393

  20. Associations between soy, diet, reproductive factors, and mammographic density in Singapore Chinese women.

    PubMed

    Ursin, Giske; Sun, Can-Lan; Koh, Woon-Puay; Khoo, Kei-Siong; Gao, Fei; Wu, Anna H; Yu, Mimi C

    2006-01-01

    Although the evidence is not completely consistent, soy intake has been inversely associated with breast cancer risk, and the strongest results have been observed in certain Asian populations. To address this issue and to examine the association between mammographic density and reproductive factors in this population, we conducted a cross-sectional analysis of mammograms and validated food-frequency questionnaires from 380 Chinese women living in Singapore. Percent mammographic density, a biomarker for breast cancer risk, was assessed using a validated computer-assisted method. We used generalized linear models to estimate mean mammographic density by quartiles of soy intake and intake of other dietary factors while adjusting for potential confounders. Percent mammographic density was inversely associated with age, body mass index, parity, breastfeeding, and soy intake. The difference in mammographic density between the highest and lowest quartiles of soy intake was 4-5%; this difference was statistically significant for soy protein and soy isoflavone intake and is similar in magnitude to what has been reported in Western populations when women undergo menopause or commence hormone therapy. We found no evidence that high fiber, fruit, or vegetable intake has protective effects on mammographic density. Our results suggest that the effect of soy intake on percent mammographic density is moderate but possibly of clinical relevance. PMID:17474857

  1. CADx of mammographic masses and clustered microcalcifications: A review

    SciTech Connect

    Elter, Matthias; Horsch, Alexander

    2009-06-15

    Breast cancer is the most common type of cancer among women in the western world. While mammography is regarded as the most effective tool for the detection and diagnosis of breast cancer, the interpretation of mammograms is a difficult and error-prone task. Hence, computer aids have been developed that assist the radiologist in the interpretation of mammograms. Computer-aided detection (CADe) systems address the problem that radiologists often miss signs of cancers that are retrospectively visible in mammograms. Furthermore, computer-aided diagnosis (CADx) systems have been proposed that assist the radiologist in the classification of mammographic lesions as benign or malignant. While a broad variety of approaches to both CADe and CADx systems have been published in the past two decades, an extensive survey of the state of the art is only available for CADe approaches. Therefore, a comprehensive review of the state of the art of CADx approaches is presented in this work. Besides providing a summary, the goals for this article are to identify relations, contradictions, and gaps in literature, and to suggest directions for future research. Because of the vast amount of publications on the topic, this survey is restricted to the two most important types of mammographic lesions: masses and clustered microcalcifications. Furthermore, it focuses on articles published in international journals.

  2. Evaluation of four mammographic density measures on HRT data

    NASA Astrophysics Data System (ADS)

    Raundahl, Jakob; Loog, Marco; Pettersen, Paola; Nielsen, Mads

    2007-03-01

    Numerous studies have investigated the relation between mammographic density and breast cancer risk. These studies indicate that women with dense breasts have a four to six fold risk increase. There is currently no gold standard for automatic assessment of mammographic density. In previous work two different automated methods for measuring the effect of HRT w.r.t. changes in breast density have been presented. One is a percentage density based on an adaptive global threshold, and the other is an intensity invariant measure, which provides structural information orthogonal to intensity-based methods. In this article we investigate the ability to detect density changes induced by HRT for these measures and compare to a radiologist's BI-RADS rating and interactive threshold percentage density. In the experiments, two sets of mammograms of 80 patients from a double blind, placebo controlled HRT experiment are used. The p-values for the statistical significance of the separation of density means, for the HRT group and the placebo group at end of study, are 0.2, 0.1, 0.02 and 0.02 for the automatic threshold, BI-RADS, the stripyness and the interactive threshold respectively.

  3. Increases in Serum Estrone Sulfate Level Are Associated with Increased Mammographic Density during Menopausal Hormone Therapy

    PubMed Central

    Crandall, Carolyn J.; Guan, Min; Laughlin, Gail A.; Ursin, Giske A.; Stanczyk, Frank Z.; Ingles, Sue A.; Barrett-Connor, Elizabeth; Greendale, Gail A.

    2009-01-01

    Background Menopausal hormone therapy increases mammographic density. We determined whether increases in serum estrone sulfate (E1S) levels during menopausal hormone therapy predict increased mammographic density. Methods We measured percent mammographic density and serum E1S levels in 428 participants of the Postmenopausal Estrogen/Progestin Interventions study who were randomly assigned to daily conjugated equine estrogen (CEE) 0.625 mg alone, CEE + daily medroxyprogesterone acetate (MPA) 2.5 mg, CEE + cyclical MPA (10 mg days 1-12 per 28-day cycle), or CEE + cyclical micronized progesterone (10 mg days 1-12). Serum E1S levels were determined by RIA. Information about covariates was determined by annual questionnaire. Using linear regression, we determined the association between change in E1S level from baseline to 12 months and change in percent mammographic density (by semiquantitative interactive threshold method). Results After controlling for baseline mammographic density, age, body mass index, alcohol intake, parity, smoking, ethnicity, physical activity, and age at first pregnancy, mammographic density increased by 1.3% for every 1 ng/mL increase in E1S level (P < 0.0001). The association between change in E1S level and change in mammographic density differed by treatment group (greater effect in CEE + cyclical MPA group versus CEE group; P = 0.05). After controlling for treatment group, change in the ratio of E1S to E1 was also positively associated with change in mammographic density. Conclusions Increases in serum E1S levels during menopausal hormone therapy are associated with increases in mammographic density. The relative contribution of E1S and E1 to stimulation of breast tissue awaits further elucidation. PMID:18628419

  4. Cyclic endogenous estrogen and progesterone vary by mammographic density phenotypes in premenopausal women

    PubMed Central

    Iversen, Anita; Furberg, Anne-Sofie; Flote, Vidar G.; Finstad, Sissi Espetvedt; McTiernan, Anne; Ursin, Giske; Wilsgaard, Tom; Ellison, Peter T.; Jasienska, Grazyna; Thune, Inger

    2016-01-01

    Estrogen and progesterone are key factors in the development of breast cancer, but it remains unclear whether these hormones are associated with mammographic density phenotypes in premenopausal women. We measured percent mammographic density, nondense area, and absolute mammographic density using computer-assisted breast density readings (Madena) from digitized mammograms taken on a scheduled day of the menstrual cycle (day 7–12) among 202 healthy, premenopausal women (Energy Balance and Breast cancer Aspects Study-I). Daily salivary concentrations of 17β-estradiol and progesterone throughout an entire menstrual cycle and fasting morning serum concentrations of hormones on 3 specific days of the menstrual cycle were assessed. Salivary and serum 17β-estradiol and progesterone were positively associated with percent mammographic density, we observed by 1 SD increase in overall salivary estradiol (β-value equal to 2.07, P=0.044), luteal salivary progesterone (β-value equal to 2.40, P=0.020). Women with above-median percent mammographic density had a 20% higher mean salivary 17β-estradiol level throughout the menstrual cycle. The odds ratio for having above-median percent mammographic density (>28.5%) per 1 SD increase in overall salivary 17β-estradiol was 1.66 (95% confidence interval 1.13–2.45). Women in the top tertile of the overall average daily 17β-estradiol concentrations had an odds ratio of 2.54 (confidence interval 1.05–6.16) of above-median percent mammographic density compared with women in the bottom tertile. Our finding of a relationship between estrogen, progesterone, and percent mammographic density and not with other mammographic density phenotypes in premenopausal women is biologically plausible, but needs to be replicated in larger studies. PMID:25714648

  5. How much is enough? Factors affecting the optimal interpretation of breast screening mammograms

    NASA Astrophysics Data System (ADS)

    Scott, Hazel J.; Gale, Alastair G.

    2007-03-01

    PERFORMS (Personal Performance in Mammographic Screening), a self-assessment scheme for film-readers is undertaken as an educational tool by mammographers reading breast-screening films in the UK. The scheme has been running as a bi-annual exercise since its inception in 1991. In addition to completing the scheme each year the majority of film-readers also choose to complete a questionnaire, administered as part of the scheme, indicating key aspects of their every-day reading practice. These key aspects include, volume of cases read per week, time-on-task reading screening films, incidence and time of break periods as well as typical number of film-reading sessions per week. Previous recommendations on best screening practice (significantly the optimum time on task) were considered in the light of these film-readers' self-reports on a current PERFORMS case set. In addition we looked at performance accuracy of over 450 film-readers reading PERFORMS cases (60 difficult mammographic cases). Performance on measures akin to True Positive (Correct Recall Percentages) and True Negative (Correct Return to Screen Percentages) decisions were investigated. Data presented demonstrate that individual behaviours in real life screening, for the interpretation of mammographic cases, affect film-reading accuracy on a test set of mammograms for specificity and sensitivity (namely volume of cases read per week and film-reading experience). The consequences for best screening practice, in real life, are considered.

  6. Classification of mammographic microcalcifications using wavelets

    NASA Astrophysics Data System (ADS)

    Chitre, Yateen S.; Dhawan, Atam P.; Moskowitz, Myron; Sarwal, Alok; Bonasso, Christine; Narayan, Suresh B.

    1995-05-01

    Breast cancer is the leading cause of death among women. Breast cancer can be detected earlier by mammography than any other non-invasive examination. About 30% to 50% of breast cancers demonstrate tiny granulelike deposits of calcium called microcalcifications. It is difficult to distinguish between benign and malignant cases based on an examination of calcification regions, especially in hard-to-diagnose cases. We investigate the potential of using energy and entropy features computed from wavelet packets for their correlation with malignancy. Two types of Daubechies discrete filters were used as prototype wavelets. The energy and entropy features were computed for 128 benign and 63 malignant cases and analyzed using a multivariate cluster analysis and a univariate statistical analysis to reduce the feature set to a `five best set of features.' The efficacy of the reduced feature set to discriminate between the malignant and benign categories was evaluated using different multilayer perceptron architectures. The multilayer perceptron was trained using the backpropagation algorithm for various training and test set sizes. For each case 40 partitions of the data set were used to set up the training and test sets. The performance of the features was evaluated by computing the best area under the relative operating characteristic (ROC) curve and the average area under the ROC curve. The performance of the features computed from the wavelet packets was compared to a second set of features consisting of the wavelet packet features, image structure features and cluster features. The classification results are encouraging and indicate the potential of using features derived from wavelet packets in discriminating microcalcification regions into benign and malignant categories.

  7. Bioreactor System Using Noninvasive Imaging and Mechanical Stretch for Biomaterial Screening

    PubMed Central

    Kluge, Jonathan A.; Leisk, Gary G.; Cardwell, Robyn S.; Fernandes, Alexander P.; House, Michael; Ward, Andrew; Dorfmann, A. Luis; Kaplan, David L.

    2012-01-01

    Screening biomaterial and tissue systems in vitro, for guidance of performance in vivo, remains a major requirement in the field of tissue engineering. It is critical to understand how culture stimulation affects both tissue construct maturation and function, with the goal of eliminating resource-intensive trial-and-error screening and better matching specifications for various in vivo needs. We present a multifunctional and robust bioreactor design that addresses this need. The design enables a range of mechanical inputs, durations, and frequencies to be applied in coordination with noninvasive optical assessments. A variety of biomaterial systems, including micro- and nano-fiber and porous sponge biomaterials, as well as cell-laden tissue engineering constructs were used in validation studies in order to demonstrate the versatility and utility of this new bioreactor design. The silk-based biomaterials highlighted in these studies offered several unique optical signatures for use in label-free nondestructive imaging that allowed for sequential profiling. Both short- and long-term culture studies were conducted to evaluate several practical scenarios of usage: on a short-term basis, we demonstrate that construct cellularity can be monitored by usage of nonpermanent dyes; on a more long-term basis, we show that cell ingrowth can be monitored by GFP-labeling and construct integrity probed with concurrent load/displacement data. The ability to nondestructively track cells, biomaterials, and new matrix formation without harvesting designated samples at each time point will lead to less resource-intensive studies and should enhance our understanding and the discovery of biomaterial designs related to functional tissue engineering. PMID:21298345

  8. Mammographic density and risk of breast cancer according to tumor characteristics and mode of detection: a Spanish population-based case-control study

    PubMed Central

    2013-01-01

    Introduction It is not clear whether high mammographic density (MD) is equally associated with all subtypes of breast cancer (BC). We investigated the association between MD and subsequent BC, considering invasiveness, means of detection, pathologic subtype, and the time elapsed since mammographic exploration and BC diagnosis. Methods BC cases occurring in the population of women who attended screening from 1997 through 2004 in Navarre, a Spanish region with a fully consolidated screening program, were identified via record linkage with the Navarre Cancer Registry (n = 1,172). Information was extracted from the records of their first attendance at screening in that period. For each case, we randomly selected four controls, matched by screening round, year of birth, and place of residence. Cases were classified according to invasiveness (ductal carcinoma in situ (DCIS) versus invasive tumors), pathologic subtype (considering hormonal receptors and HER2), and type of diagnosis (screen-detected versus interval cases). MD was evaluated by a single, experienced radiologist by using a semiquantitative scale. Data on BC risk factors were obtained by the screening program in the corresponding round. The association between MD and tumor subtype was assessed by using conditional logistic regression. Results MD was clearly associated with subsequent BC. The odds ratio (OR) for the highest MD category (MD >75%) compared with the reference category (MD <10%) was similar for DCIS (OR = 3.47; 95% CI = 1.46 to 8.27) and invasive tumors (OR = 2.95; 95% CI = 2.01 to 4.35). The excess risk was particularly high for interval cases (OR = 7.72; 95% CI = 4.02 to 14.81) in comparison with screened detected tumors (OR = 2.17; 95% CI = 1.40 to 3.36). Sensitivity analyses excluding interval cases diagnosed in the first year after MD assessment or immediately after an early recall to screening yielded similar results. No differences were seen regarding pathologic subtypes. The excess risk

  9. Mammographically Occult Asymptomatic Radial Scars/Complex Sclerosing Lesions at Ultrasonography-Guided Core Needle Biopsy: Follow-Up Can Be Recommended.

    PubMed

    Park, Vivian Youngjean; Kim, Eun-Kyung; Kim, Min Jung; Yoon, Jung Hyun; Moon, Hee Jung

    2016-10-01

    An increasing number of radial scars are detected by ultrasound (US), but their management is controversial. This study investigated the upgrade rate in mammographically occult radial scars/complex sclerosing lesions without epithelial atypia at US-guided 14-gauge core needle biopsy in asymptomatic patients. Nineteen mammographically occult benign radial scars/complex sclerosing lesions (median size, 7 mm; range, 3-23 mm) were included. Patients underwent surgical excision (n = 10) or vacuum-assisted excision, with follow-up US at least 6 mo after benign vacuum-assisted excision results (n = 8), or underwent US follow-up for 2 y after core needle biopsy (n = 1). Any cases with change in diagnosis to high-risk lesions or malignancy at excision were considered upgrades. The upgrade rate was 0.0%. Based on US findings, 15.8% (3/19) were Breast Imaging Reporting and Data System (BI-RADS) category 3, 68.4% (13/19) were BI-RADS category 4a and 15.8% (3/19) were BI-RADS category 4b. Follow-up with US can be considered for mammographically occult benign radial scar/complex sclerosing lesions diagnosed by US core needle biopsy in asymptomatic patients. PMID:27444865

  10. Mammographic mass detection based on extended concentric morphology model

    NASA Astrophysics Data System (ADS)

    Li, Yanfeng; Chen, Houjin

    2014-01-01

    Breast cancer occurs with high frequency among women. In most cases, the main early signs appear as mass and calcification. Distinguishing masses from normal tissues is still a challenging work as mass varies with shapes, margins and sizes. In this paper, a novel method for mass detection in mammograms was presented. First, morphology operators are employed to locate mass candidates. Then anisotropic diffusion was applied to make mass region display better multiple concentric layers (MCL). Finally an extended concentric morphology model (ECMM) criterion combining MCL criterion and template matching was proposed to detect masses. This method was examined on 170 images from Digital Database for Screening Mammography (DDSM) database. The detection rate is 93.92% at 1.88 false positives per image (FPs/I), demonstrating the effectiveness of the proposed method.

  11. Screening mammography intervals among postmenopausal hormone therapy users and nonusers

    PubMed Central

    Onega, Tracy; MacKenzie, Todd; Weiss, Julia; Goodrich, Martha; Titus-Ernstoff, Linda

    2013-01-01

    Background The recent decline in US breast cancer incidence rates has been attributed to the marked reduction in use of postmenopausal hormone therapy (HT). An alternative explanation is that women who are not routinely seeking medical care to renew HT prescriptions may be less adherent to recommendations for mammographic screening. To investigate the latter possibility, we compared mammographic intervals according to HT use. Methods Using data (1995–2007) from the New Hampshire Mammography Network (NHMN), a state-based mammography registry, we assessed mammographic intervals corresponding to HT use or nonuse among postmenopausal women. We used linear mixed effects models to assess whether the length of screening mammogram intervals differed according to HT use. Results A total of 310,185 mammograms, representing 76,192 postmenopausal women and 319,353 person-years of screening, were included in the analysis. The median screening interval corresponding to HT use overall was 13.0 months (interquartile range: 12.4–15.1) and for nonuse was 13.1 (interquartile range: 12.4–15.8). Virtually, all screening mammograms occurred within a 2-year interval regardless of HT use or nonuse (98.5 and 98.1%, respectively). Conclusions Our findings indicate that screening mammography intervals are similar whether or not women are using HT. Thus, reduced utilization of screening mammography is unlikely to account for the decrease in breast cancer incidence seen soon after the WHI report. PMID:19844798

  12. Increased vitamin D and calcium intake associated with reduced mammographic breast density among premenopausal women.

    PubMed

    Fair, Alecia Malin; Lewis, Toni J; Sanderson, Maureen; Dupont, William D; Fletcher, Sarah; Egan, Kathleen M; Disher, Anthony C

    2015-10-01

    Vitamin D has been identified as a weak protective factor for postmenopausal breast cancer (relative risk, ~0.9), whereas high breast density has been identified as a strong risk factor (relative risk, ~4-6). To test the hypothesis that there is an association between vitamin D intake, but not circulating vitamin D levels, and mammographic breast density among women in our study, we conducted a cross-sectional study of 165 screening mammography patients at Nashville General Hospital's Breast Health Center, a public facility serving medically indigent and underserved women. Dietary and total (dietary plus supplements) vitamin D and calcium intakes were estimated by the Harvard African American Food Frequency Questionnaire, and blood samples were analyzed for 25-hydroxyvitamin D. Average percent breast density for the left and right breasts combined was estimated from digitized films using an interactive thresholding method available through Cumulus software. After statistical adjustment for age, race, and body mass index, the results revealed that there were significant trends of decreasing breast density with increasing vitamin D and calcium intake among premenopausal but not among postmenopausal women. There was no association between serum vitamin D and breast density in premenopausal or postmenopausal women. Confirmation of our findings in larger studies may assist in clarifying the role of vitamin D in breast density. PMID:26321093

  13. Image filtering as an alternative to the application of a different reconstruction kernel in CT imaging: Feasibility study in lung cancer screening

    SciTech Connect

    Ohkubo, Masaki; Wada, Shinichi; Kayugawa, Akihiro; Matsumoto, Toru; Murao, Kohei

    2011-07-15

    Purpose: While the acquisition of projection data in a computed tomography (CT) scanner is generally carried out once, the projection data is often removed from the system, making further reconstruction with a different reconstruction filter impossible. The reconstruction kernel is one of the most important parameters. To have access to all the reconstructions, either prior reconstructions with multiple kernels must be performed or the projection data must be stored. Each of these requirements would increase the burden on data archiving. This study aimed to design an effective method to achieve similar image quality using an image filtering technique in the image space, instead of a reconstruction filter in the projection space for CT imaging. The authors evaluated the clinical feasibility of the proposed method in lung cancer screening. Methods: The proposed technique is essentially the same as common image filtering, which performs processing in the spatial-frequency domain with a filter function. However, the filter function was determined based on the quantitative analysis of the point spread functions (PSFs) measured in the system. The modulation transfer functions (MTFs) were derived from the PSFs, and the ratio of the MTFs was used as the filter function. Therefore, using an image reconstructed with a kernel, an image reconstructed with a different kernel was obtained by filtering, which used the ratio of the MTFs obtained for the two kernels. The performance of the method was evaluated by using routine clinical images obtained from CT screening for lung cancer in five subjects. Results: Filtered images for all combinations of three types of reconstruction kernels (''smooth,''''standard,'' and ''sharp'' kernels) showed good agreement with original reconstructed images regarded as the gold standard. On the filtered images, abnormal shadows suspected as being lung cancers were identical to those on the reconstructed images. The standard deviations (SDs) for

  14. Design and image-quality performance of high resolution CMOS-based X-ray imaging detectors for digital mammography

    NASA Astrophysics Data System (ADS)

    Cha, B. K.; Kim, J. Y.; Kim, Y. J.; Yun, S.; Cho, G.; Kim, H. K.; Seo, C.-W.; Jeon, S.; Huh, Y.

    2012-04-01

    In digital X-ray imaging systems, X-ray imaging detectors based on scintillating screens with electronic devices such as charge-coupled devices (CCDs), thin-film transistors (TFT), complementary metal oxide semiconductor (CMOS) flat panel imagers have been introduced for general radiography, dental, mammography and non-destructive testing (NDT) applications. Recently, a large-area CMOS active-pixel sensor (APS) in combination with scintillation films has been widely used in a variety of digital X-ray imaging applications. We employed a scintillator-based CMOS APS image sensor for high-resolution mammography. In this work, both powder-type Gd2O2S:Tb and a columnar structured CsI:Tl scintillation screens with various thicknesses were fabricated and used as materials to convert X-ray into visible light. These scintillating screens were directly coupled to a CMOS flat panel imager with a 25 × 50 mm2 active area and a 48 μm pixel pitch for high spatial resolution acquisition. We used a W/Al mammographic X-ray source with a 30 kVp energy condition. The imaging characterization of the X-ray detector was measured and analyzed in terms of linearity in incident X-ray dose, modulation transfer function (MTF), noise-power spectrum (NPS) and detective quantum efficiency (DQE).

  15. Fluorescence imaging technology (FI) for high-throughput screening of selenide-modified nano-TiO2 catalysts.

    PubMed

    Wang, Liping; Lee, Jianchao; Zhang, Meijuan; Duan, Qiannan; Zhang, Jiarui; Qi, Hailang

    2016-02-18

    A high-throughput screening (HTS) method based on fluorescence imaging (FI) was implemented to evaluate the catalytic performance of selenide-modified nano-TiO2. Chemical ink-jet printing (IJP) technology was reformed to fabricate a catalyst library comprising 1405 (Ni(a)Cu(b)Cd(c)Ce(d)In(e)Y(f))Se(x)/TiO2 (M6Se/Ti) composite photocatalysts. Nineteen M6Se/Tis were screened out from the 1405 candidates efficiently. PMID:26777131

  16. Research into the usage of integrated jamming of IR weakening and smoke-screen resisting the IR imaging guided missiles

    NASA Astrophysics Data System (ADS)

    Wang, Long-tao; Jiang, Ning; Lv, Ming-shan

    2015-10-01

    With the emergence of the anti-ship missle with the capability of infrared imaging guidance, the traditional single jamming measures, because of the jamming mechanism and technical flaws or unsuitable use, greatly reduced the survival probability of the war-ship in the future naval battle. Intergrated jamming of IR weakening + smoke-screen Can not only make jamming to the search and tracking of IR imaging guidance system , but also has feasibility in conjunction, besides , which also make the best jamming effect. The research conclusion has important realistic meaning for raising the antimissile ability of surface ships. With the development of guidance technology, infrared guidance system has expanded by ir point-source homing guidance to infrared imaging guidance, Infrared imaging guidance has made breakthrough progress, Infrared imaging guidance system can use two-dimensional infrared image information of the target, achieve the precise tracking. Which has Higher guidance precision, better concealment, stronger anti-interference ability and could Target the key parts. The traditional single infrared smoke screen jamming or infrared decoy flare interference cannot be imposed effective interference. So, Research how to effectively fight against infrared imaging guided weapons threat measures and means, improving the surface ship antimissile ability is an urgent need to solve.

  17. Potential of near-infrared hyperspectral reflectance imaging for screening of farm feed contamination

    NASA Astrophysics Data System (ADS)

    Wang, Wenbo; Paliwal, Jitendra

    2005-09-01

    With the outbreak of Bovine Spongiform Encephalopathy (BSE) (commonly known as mad cow disease) in 1987 in the United Kingdom and a recent case discovered in Alberta, more and more emphasis is placed on food and farm feed quality and safety issues internationally. The disease is believed to be spread through farm feed contamination by animal byproducts in the form of meat-and-bone-meal (MBM). The paper reviewed the available techniques necessary to the enforcement of legislation concerning the feed safety issues. The standard microscopy method, although highly sensitive, is laborious and costly. A method to routinely screen farm feed contamination certainly helps to reduce the complexity of safety inspection. A hyperspectral imaging system working in the near-infrared wavelength region of 1100-1600 nm was used to study the possibility of detection of ground broiler feed contamination by ground pork. Hyperspectral images of raw broiler feed, ground broiler feed, ground pork, and contaminated feed samples were acquired. Raw broiler feed samples were found to possess comparatively large spectral variations due to light scattering effect. Ground feed adulterated with 1%, 3%, 5%, and 10% of ground pork was tested to identify feed contamination. Discriminant analysis using Mahalanobis distance showed that the model trained using pure ground feed samples and pure ground pork samples resulted in 100% false negative errors for all test replicates of contaminated samples. A discriminant model trained with pure ground feed samples and 10% contamination level samples resulted in 12.5% false positive error and 0% false negative error.

  18. Myocardial perfusion imaging is an effective screening test for coronary artery disease in liver transplant candidates.

    PubMed

    Baker, Sally; Chambers, Charles; McQuillan, Patrick; Janicki, Piotr; Kadry, Zakiyah; Bowen, Daniel; Bezinover, Dmitri

    2015-04-01

    A reliable screening test for coronary artery disease (CAD) in liver transplant (LT) candidates with end-stage liver disease is essential because a high percentage of perioperative mortality and morbidity is CAD-related. In this study, the effectiveness of myocardial perfusion imaging (MPI) for identification of significant CAD in LT candidates was evaluated. Records of 244 patients meeting criteria for MPI were evaluated: 74 met inclusion criteria; 40 had a positive MPI and cardiology follow-up; 27 had a negative MPI and underwent LT; and seven had a negative MPI and then had coronary angiography or a significant cardiac event. A selective MPI interpretation strategy was established where MPI-positive patients were divided into high, intermediate, and low CAD risk groups. The overall incidence of CAD in this study population was 5.1% and our strategy resulted in PPV 20%, NPV 94%, sensitivity 80%, and specificity 50% for categorizing CAD risk. When applied only to the subset of patients categorized as high CAD risk, the strategy was more effective, with PPV 67%, NPV 97%, sensitivity 80%, and specificity 94%. We determined that renal dysfunction was an independent predictive factor for CAD (p < 0.0001, odds ratio = 8.1), and grades of coronary occlusion correlated significantly with chronic renal dysfunction (p = 0.0079). PMID:25604507

  19. Early developability screen of therapeutic antibody candidates using Taylor dispersion analysis and UV area imaging detection.

    PubMed

    Lavoisier, Alexandra; Schlaeppi, Jean-Marc

    2015-01-01

    Therapeutic antibodies represent one of the fastest growing segments in the pharmaceutical market. They are used in a broad range of disease fields, such as autoimmune diseases, cancer, inflammation and infectious diseases. The growth of the segment has necessitated development of new analytical platforms for faster and better antibody selection and characterization. Early quality control and risk assessment of biophysical parameters help prevent failure in later stages of antibody development, and thus can reduce costs and save time. Critical parameters such as aggregation, conformational stability, colloidal stability and hydrophilicity, are measured during the early phase of antibody generation and guide the selection process of the best lead candidates in terms of technical developability. We report on the use of a novel instrument (ActiPix/Viscosizer) for measuring both the hydrodynamic radius and the absolute viscosity of antibodies based on Taylor dispersion analysis and UV area imaging. The looped microcapillary-based method combines low sample consumption, fast throughput and high precision compared to other conventional methods. From a random panel of 130 antibodies in the early selection process, we identified some with large hydrodynamic radius outside the normal distribution and others with non-Gaussian Taylor dispersion profiles. The antibodies with such abnormal properties were confirmed later in the selection process to show poor developability profiles. Moreover, combining these results with those of the viscosity measurements at high antibody concentrations allows screening, with limited amounts of materials, candidates with potential issues in pre-formulation development. PMID:25514497

  20. Evaluation of an Image Analysis Device (APAS) for Screening Urine Cultures.

    PubMed

    Glasson, John; Hill, Rhys; Summerford, Michael; Giglio, Steven

    2016-02-01

    While advancements have been made in some areas of pathology with diagnostic materials being screened using image analysis technologies, the reporting of cultures from agar plates remains a manual process. We compared the results for 2,163 urine cultures read by a reference panel of microbiologists, by the routine laboratory process, and by an automated plate reading system, APAS (LBT Innovations Ltd., South Australia). APAS detected colonies with a sensitivity of 99.1% and a specificity of 99.3% on blood agar, while on MacConkey agar, the colony detection sensitivity was 99.4% with a specificity of 99.3%. The device's ability to enumerate growth had an accuracy of 89.2%, and the morphological identification of colonies showed a high level of performance for the colony types typical of Escherichia coli and other enteric bacilli. On blood agar, lactose-fermenting colonies were morphologically identified with a sensitivity of 98.9%, while on MacConkey agar they were identified with a sensitivity of 99.2%. In this first clinical evaluation, APAS demonstrated high performance in the detection, enumeration, and colony classification of isolates compared with that for conventional plate-reading methods. The device found all cases reported by the laboratory and detected the most commonly encountered organisms found in urinary tract infections. PMID:26582838

  1. Bilateral Image Subtraction and Multivariate Models for the Automated Triaging of Screening Mammograms

    PubMed Central

    Celaya-Padilla, José; Martinez-Torteya, Antonio; Rodriguez-Rojas, Juan; Galvan-Tejada, Jorge; Treviño, Victor; Tamez-Peña, José

    2015-01-01

    Mammography is the most common and effective breast cancer screening test. However, the rate of positive findings is very low, making the radiologic interpretation monotonous and biased toward errors. This work presents a computer-aided diagnosis (CADx) method aimed to automatically triage mammogram sets. The method coregisters the left and right mammograms, extracts image features, and classifies the subjects into risk of having malignant calcifications (CS), malignant masses (MS), and healthy subject (HS). In this study, 449 subjects (197 CS, 207 MS, and 45 HS) from a public database were used to train and evaluate the CADx. Percentile-rank (p-rank) and z-normalizations were used. For the p-rank, the CS versus HS model achieved a cross-validation accuracy of 0.797 with an area under the receiver operating characteristic curve (AUC) of 0.882; the MS versus HS model obtained an accuracy of 0.772 and an AUC of 0.842. For the z-normalization, the CS versus HS model achieved an accuracy of 0.825 with an AUC of 0.882 and the MS versus HS model obtained an accuracy of 0.698 and an AUC of 0.807. The proposed method has the potential to rank cases with high probability of malignant findings aiding in the prioritization of radiologists work list. PMID:26240818

  2. Evaluation of an Image Analysis Device (APAS) for Screening Urine Cultures

    PubMed Central

    Hill, Rhys; Summerford, Michael; Giglio, Steven

    2015-01-01

    While advancements have been made in some areas of pathology with diagnostic materials being screened using image analysis technologies, the reporting of cultures from agar plates remains a manual process. We compared the results for 2,163 urine cultures read by a reference panel of microbiologists, by the routine laboratory process, and by an automated plate reading system, APAS (LBT Innovations Ltd., South Australia). APAS detected colonies with a sensitivity of 99.1% and a specificity of 99.3% on blood agar, while on MacConkey agar, the colony detection sensitivity was 99.4% with a specificity of 99.3%. The device's ability to enumerate growth had an accuracy of 89.2%, and the morphological identification of colonies showed a high level of performance for the colony types typical of Escherichia coli and other enteric bacilli. On blood agar, lactose-fermenting colonies were morphologically identified with a sensitivity of 98.9%, while on MacConkey agar they were identified with a sensitivity of 99.2%. In this first clinical evaluation, APAS demonstrated high performance in the detection, enumeration, and colony classification of isolates compared with that for conventional plate-reading methods. The device found all cases reported by the laboratory and detected the most commonly encountered organisms found in urinary tract infections. PMID:26582838

  3. Predictive Modeling of Human Perception Subjectivity: Feasibility Study of Mammographic Lesion Similarity

    SciTech Connect

    Xu, Songhua; Tourassi, Georgia

    2012-01-01

    The majority of clinical content-based image retrieval (CBIR) studies disregard human perception subjectivity, aiming to duplicate the consensus expert assessment of the visual similarity on example cases. The purpose of our study is twofold: (i) discern better the extent of human perception subjectivity when assessing the visual similarity of two images with similar semantic content, and (ii) explore the feasibility of personalized predictive modeling of visual similarity. We conducted a human observer study in which five observers of various expertise were shown ninety-nine triplets of mammographic masses with similar BI-RADS descriptors and were asked to select the two masses with the highest visual relevance. Pairwise agreement ranged between poor and fair among the five observers, as assessed by the kappa statistic. The observers' self-consistency rate was remarkably low, based on repeated questions where either the orientation or the presentation order of a mass was changed. Various machine learning algorithms were explored to determine whether they can predict each observer's personalized selection using textural features. Many algorithms performed with accuracy that exceeded each observer's self-consistency rate, as determined using a cross-validation scheme. This accuracy was statistically significantly higher than would be expected by chance alone (two-tailed p-value ranged between 0.001 and 0.01 for all five personalized models). The study confirmed that human perception subjectivity should be taken into account when developing CBIR-based medical applications.

  4. Pixelated CdTe detectors to overcome intrinsic limitations of crystal based positron emission mammographs

    NASA Astrophysics Data System (ADS)

    De Lorenzo, G.; Chmeissani, M.; Uzun, D.; Kolstein, M.; Ozsahin, I.; Mikhaylova, E.; Arce, P.; Cañadas, M.; Ariño, G.; Calderón, Y.

    2013-01-01

    A positron emission mammograph (PEM) is an organ dedicated positron emission tomography (PET) scanner for breast cancer detection. State-of-the-art PEMs employing scintillating crystals as detection medium can provide metabolic images of the breast with significantly higher sensitivity and specificity with respect to standard whole body PET scanners. Over the past few years, crystal PEMs have dramatically increased their importance in the diagnosis and treatment of early stage breast cancer. Nevertheless, designs based on scintillators are characterized by an intrinsic deficiency of the depth of interaction (DOI) information from relatively thick crystals constraining the size of the smallest detectable tumor. This work shows how to overcome such intrinsic limitation by substituting scintillating crystals with pixelated CdTe detectors. The proposed novel design is developed within the Voxel Imaging PET (VIP) Pathfinder project and evaluated via Monte Carlo simulation. The volumetric spatial resolution of the VIP-PEM is expected to be up to 6 times better than standard commercial devices with a point spread function of 1 mm full width at half maximum (FWHM) in all directions. Pixelated CdTe detectors can also provide an energy resolution as low as 1.5% FWHM at 511 keV for a virtually pure signal with negligible contribution from scattered events.

  5. Erythrocyte Omega-6 and Omega-3 Fatty Acids and Mammographic Breast Density

    PubMed Central

    Hudson, Alana G.; Reeves, Katherine W.; Modugno, Francesmary; Wilson, John W.; Evans, Rhobert W.; Vogel, Victor G.; Gierach, Gretchen L.; Simpson, Jennifer; Weissfeld, Joel L.

    2013-01-01

    Diets low in omega-6 (n-6) polyunsaturated fatty acids (PUFAs) and high in omega-3 (n-3) PUFAs may protect against breast cancer development. Associations of PUFA intake with mammographic density, an intermediate marker of breast cancer risk, have been inconsistent; however, prior studies have relied on self-reported dietary PUFA intake. We examined the association between circulating erythrocyte n-6 and n-3 PUFAs with mammographic density in 248 postmenopausal women who were not taking exogenous hormones. PUFAs in erythrocytes were measured by gas-liquid chromatography, and mammographic density was assessed quantitatively by planimetry. Spearman’s correlation coefficients and generalized linear models were used to evaluate the relationships between PUFA measures and mammographic density. None of the erythrocyte n-6 or n-3 PUFA measures were associated with percent density or dense breast area. PMID:23530640

  6. Current and Future Clinical Applications for Optical Imaging of Cancer: From Intraoperative Surgical Guidance to Cancer Screening

    PubMed Central

    Hadjipanayis, Costas G.; Jiang, Huabei; Roberts, David W.; Yang, Lily

    2011-01-01

    Optical imaging is an inexpensive, fast, and sensitive imaging approach for the non-invasive detection of human cancers in locations that are accessible by an optical imaging device. Light is used to probe cellular and molecular function in the context of cancer in the living body. Recent advances in the development of optical instrumentation make it possible to detect optical signals produced at a tissue depth of several centimeters. The optical signals can be endogenous contrasts that capture the heterogeneity and biological status of different tissues including tumors, or extrinsic optical contrasts that selectively accumulate in tumors to be imaged after local or systemic delivery. The use of optical imaging is now being applied in the clinic and operating room for the localization and resection of malignant tumors in addition to screening for cancer. PMID:21362519

  7. Classification of mammographic masses: use and influence of a bilateral-filter-based flat-texture approach

    NASA Astrophysics Data System (ADS)

    Wagner, Florian; Elter, Matthias; Schulz-Wendtland, Rüdiger; Wittenberg, Thomas

    2011-03-01

    Computer-assisted diagnosis (CADx) for the interactive characterization of mammographic masses as benign or malignant has a high potential to help radiologists during the critical process of diagnostic decision making. By default, the characterization of mammographic masses is performed by extracting features from a region of interest (ROI) depicting the mass. To investigate the influence of a so-called bilateral filter based emph{flat texture} (FT) preprocessing step on the classification performance, textural as well as frequency-based features are calculated in the ROI, in the core of the mass and in the mass margin for preprocessed and unprocessed images. Furthermore. the influence of the parameterization of the bilateral filter on the classification performance is investigated. Additionally, as reference Median and Gaussian filters have been used to compute the FT image and the resulting classification performances of the feature extractors are compared to those obtained with the bilateral filters. Classification is done using a k-NN classifier. The classification performance was evaluated using the area Az under the receiver operating characteristic (ROC) curve. A publicly available mammography database was used as reference image data set. The results show that the proposed FT preprocessing step has a positive influence on the texture-based feature extractors while most of the frequency-based feature extractors perform better on the unprocessed images. For some of the features the original Az could be improved up to 10%. The comparison of the bilateral filter approach with the Median and Gaussian filter approaches showed the superiority of the bilateral filter.

  8. A spatial shape constrained clustering method for mammographic mass segmentation.

    PubMed

    Lou, Jian-Yong; Yang, Xu-Lei; Cao, Ai-Ze

    2015-01-01

    A novel clustering method is proposed for mammographic mass segmentation on extracted regions of interest (ROIs) by using deterministic annealing incorporating circular shape function (DACF). The objective function reported in this study uses both intensity and spatial shape information, and the dominant dissimilarity measure is controlled by two weighting parameters. As a result, pixels having similar intensity information but located in different regions can be differentiated. Experimental results shows that, by using DACF, the mass segmentation results in digitized mammograms are improved with optimal mass boundaries, less number of noisy patches, and computational efficiency. An average probability of segmentation error of 7.18% for well-defined masses (or 8.06% for ill-defined masses) was obtained by using DACF on MiniMIAS database, with 5.86% (or 5.55%) and 6.14% (or 5.27%) improvements as compared to the standard DA and fuzzy c-means methods. PMID:25737739

  9. [Mammographic evaluation of dense breasts: techniques and limits].

    PubMed

    Chérel, P; Hagay, C; Benaim, B; De Maulmont, C; Engerand, S; Langer, A; Talma, V

    2008-09-01

    Breast density is a radiological concept based on the proportion of radiopaque glandular tissue relative to radiolucent fatty tissue. Mammographic evaluation of dense breasts is more difficult, related to technical difficulties, with decreased rates for detection and characterization of breast lesions, resulting in reduced sensitivity with increased number of interval cancers at routine follow-up when compared to radiolucent breasts. We will review the definition of dense breasts and their frequency, especially their relationship with the age of patients. We will discuss the current technical problems and the impact of breast density on the efficacy of conventional mammography. We will discuss the value of digital mammography, the role of computer assisted diagnosis (CAD) systems and tomosynthesis in the evaluation of dense breasts. PMID:18772800

  10. Computerized analysis of mammographic parenchymal patterns using fractal analysis

    NASA Astrophysics Data System (ADS)

    Li, Hui; Giger, Maryellen L.; Huo, Zhimin; Olopade, Olufunmilayo I.; Chinander, Michael R.; Lan, Li; Bonta, Ioana R.

    2003-05-01

    Mammographic parenchymal patterns have been shown to be associated with breast cancer risk. Fractal-based texture analyses, including box-counting methods and Minkowski dimension, were performed within parenchymal regions of normal mammograms of BRCA1/BRCA2 gene mutation carriers and within those of women at low risk for developing breast cancer. Receiver Operating Characteristic (ROC) analysis was used to assess the performance of the computerized radiographic markers in the task of distinguishing between high and low-risk subjects. A multifractal phenomenon was observed with the fractal analyses. The high frequency component of fractal dimension from the conventional box-counting technique yielded an Az value of 0.84 in differentiating between two groups, while using the LDA to estimate the fractal dimension yielded an Az value of 0.91 for the high frequency component. An Az value of 0.82 was obtained with fractal dimensions extracted using the Minkowski algorithm.

  11. Premenopausal plasma 25-hydroxyvitamin D, mammographic density, and risk of breast cancer.

    PubMed

    Bertrand, Kimberly A; Rosner, Bernard; Eliassen, A Heather; Hankinson, Susan E; Rexrode, Kathryn M; Willett, Walter; Tamimi, Rulla M

    2015-01-01

    Epidemiologic evidence for an association between plasma 25-hydroxyvitamin D [25(OH)D] and breast cancer is inconsistent. Data are especially limited for premenopausal women and for associations with mammographic density. To test the hypothesis that plasma concentration of 25(OH)D is associated with mammographic density, we conducted a cross-sectional study among 835 premenopausal women in the Nurses' Health Studies. We measured 25(OH)D in blood samples and used multivariable linear regression to quantify the association of average percent density by quartile of plasma 25(OH)D. In a nested case-control analysis including 493 breast cancer cases, we evaluated risk of breast cancer associated with vitamin D status within tertiles of mammographic density. Women in the top quartile of plasma 25(OH)D levels had an average percent breast density 5.2 percentage points higher than women in the bottom quartile (95 % confidence interval: 1.8, 8.7; P trend <0.01), after adjusting for predictors of 25(OH)D and established breast cancer risk factors. Plasma 25(OH)D concentration was significantly inversely associated with breast cancer risk among women with high mammographic density (P trend < 0.01) but not among women in lower tertiles of mammographic density (P-interaction < 0.01). These results do not support the hypothesis that vitamin D is inversely associated with percent mammographic density in premenopausal women. There was evidence that the association between premenopausal 25(OH)D and breast cancer risk varies by mammographic density, with an inverse association apparent only among women with high mammographic density. PMID:25543181

  12. Premenopausal plasma 25-hydroxyvitamin D, mammographic density, and risk of breast cancer

    PubMed Central

    Bertrand, Kimberly A.; Rosner, Bernard; Eliassen, A. Heather; Hankinson, Susan E.; Rexrode, Kathryn M.; Willett, Walter; Tamimi, Rulla M.

    2015-01-01

    Purpose Epidemiologic evidence for an association between plasma 25-hydroxyvitamin D [25(OH)D] and breast cancer is inconsistent. Data are especially limited for premenopausal women and for associations with mammographic density. Methods To test the hypothesis that plasma concentration of 25(OH)D is associated with mammographic density, we conducted a cross-sectional study among 835 premenopausal women in the Nurses’ Health Studies. We measured 25(OH)D in blood samples and used multivariable linear regression to quantify the association of average percent density by quartile of plasma 25(OH)D. In a nested case-control analysis including 493 breast cancer cases, we evaluated risk of breast cancer associated with vitamin D status within tertiles of mammographic density. Results Women in the top quartile of plasma 25(OH)D levels had an average percent breast density 5.2 percentage points higher than women in the bottom quartile (95% confidence interval: 1.8, 8.7; P-trend <0.01), after adjusting for predictors of 25(OH)D and established breast cancer risk factors. Plasma 25(OH)D concentration was significantly inversely associated with breast cancer risk among women with high mammographic density (odds ratio comparing top to bottom tertile of 25(OH)D = 0.50; 95% confidence interval= 0.30, 0.83; P-trend <0.01) but not among women in lower tertiles of mammographic density (P-interaction <0.01). Conclusions These results do not support the hypothesis that vitamin D is inversely associated with percent mammographic density in premenopausal women. There was evidence that the association between premenopausal 25(OH)D and breast cancer risk varies by mammographic density, with an inverse association apparent only among women with high mammographic density. PMID:25543181

  13. Metabolic syndrome and mammographic density in Mexican women

    PubMed Central

    Rice, Megan; Biessy, Carine; Lajous, Martin; Bertrand, Kimberly A.; Tamimi, Rulla M.; Torres-Mejía, Gabriela; López-Ridaura, Ruy; Romieu, Isabelle

    2014-01-01

    Background Metabolic syndrome has been associated with an increased risk of breast cancer; however little is known about the association between metabolic syndrome and percent mammographic density, a strong predictor of breast cancer. Methods We analyzed cross-sectional data from 789 premenopausal and 322 postmenopausal women in the Mexican Teacher's Cohort (ESMaestras). Metabolic syndrome was defined according to the harmonized definition. We measured percent density on mammograms using a computer-assisted thresholding method. Multivariable linear regression was used to estimate the association between density and metabolic syndrome, as well as its components by state (Jalisco, Veracruz) and menopausal status (premenopausal, postmenopausal). Results Among premenopausal women in Jalisco, women with metabolic syndrome had higher percent density compared to those without after adjusting for potential confounders including BMI (difference = 4.76, 95%CI: 1.72, 7.81). Among the metabolic syndrome components, only low high-density lipoprotein levels (<50mg/dl) were associated with significantly higher percent density among premenopausal women in Jalisco (difference=4.62, 95%CI: 1.73, 7.52). Metabolic syndrome was not associated with percent density among premenopausal women in Veracruz (difference=-2.91, 95% CI: -7.19, 1.38), nor among postmenopausal women in either state. Conclusion Metabolic syndrome was associated with higher percent density among premenopausal women in Jalisco, Mexico, but was not associated with percent density among premenopausal women in Veracruz, Mexico or among postmenopausal women in either Jalisco or Veracruz. These findings provide some support for a possible role of metabolic syndrome in mammographic density among premenopausal women; however results were inconsistent across states and require further confirmation in larger studies. PMID:23682074

  14. Green Tea, Soy, and Mammographic Density in Singapore Chinese Women

    PubMed Central

    Wu, Anna H.; Ursin, Giske; Koh, Woon-Puay; Wang, Renwei; Yuan, Jian-Min; Khoo, Kei-Siong; Yu, Mimi C.

    2009-01-01

    There is increasing evidence from observational studies that breast cancer risk is inversely associated with soy and green tea consumption. We investigated the effects of these two dietary agents on mammographic density, a well-established biomarker for breast cancer risk, in a cross-sectional analysis of mammograms and validated food frequency questionnaires from 3,315 Chinese women in Singapore. Percent mammographic density (PMD) was assessed using a reproducible computer-assisted method. We used generalized linear models to estimate PMD by intake of soy, green tea, and black tea while adjusting for potential confounders. Daily green tea drinkers showed statistically significantly lower PMD (19.5%) than non-tea drinkers (21.7%; P = 0.002) after adjusting for relevant covariates. This difference in PMD between daily green tea drinkers and non-tea drinkers remained statistically significant after adjustment for soy (P = 0.002); the effect was more apparent among lower soy consumers (Q1–Q3; 21.9% versus 19.4%; P = 0.002) than in higher (Q4) consumers (20.9% versus 19.5%; P = 0.32). Black tea intake was unrelated to PMD. Only among postmenopausal women who reported very high soy intake (Q4) compared with those with less soy intake was there any association noted between PMD and soy intake (18.9% versus 20.5%; P = 0.035). Following adjustment for green tea intake, the association between soy and PMD was no longer statistically significant (P = 0.52). Our findings suggest that both regular green tea and high soy intake may have beneficial effects on the breast; the effect of green tea on PMD may be stronger than the effect of soy. PMID:19064551

  15. Observer study to evaluate the simulation of mammographic calcification clusters

    NASA Astrophysics Data System (ADS)

    Sousa, Maria A. Z.; Marcomini, Karem D.; Bakic, Predrag R.; Maidment, Andrew D. A.; Schiabel, Homero

    2016-03-01

    Numerous breast phantoms have been developed to be as realistic as possible to ensure the accuracy of image quality analysis, covering a greater range of applications. In this study, we simulated three different densities of the breast parenchyma using paraffin gel, acrylic plates and PVC films. Hydroxyapatite was used to simulate calcification clusters. From the images acquired with a GE Senographe DR 2000D mammography system, we selected 68 regions of interest (ROIs) with and 68 without a simulated calcification cluster. To validate the phantom simulation, we selected 136 ROIs from the University of South Florida's Digital Database for Screening Mammography (DDSM). Seven trained observers performed two observer experiments by using a high-resolution monitor Barco mod. E-3620. In the first experiment, the observers had to distinguish between real or phantom ROIs (with and without calcification). In the second one, the observers had to indicate the ROI with calcifications between a pair of ROIs. Results from our study show that the hydroxyapatite calcifications had poor contrast in the simulated breast parenchyma, thus observers had more difficulty in identifying the presence of calcification clusters in phantom images. Preliminary analysis of the power spectrum was conducted to investigate the radiographic density and the contrast thresholds for calcification detection. The values obtained for the power spectrum exponent (β) were comparable with those found in the literature.

  16. Development and Optimization of a Novel 384-Well Anti-Malarial Imaging Assay Validated for High-Throughput Screening

    PubMed Central

    Duffy, Sandra; Avery, Vicky M.

    2012-01-01

    With the increasing occurrence of drug resistance in the malaria parasite, Plasmodium falciparum, there is a great need for new and novel anti-malarial drugs. We have developed a 384-well, high-throughput imaging assay for the detection of new anti-malarial compounds, which was initially validated by screening a marine natural product library, and subsequently used to screen more than 3 million data points from a variety of compound sources. Founded on another fluorescence-based P. falciparum growth inhibition assay, the DNA-intercalating dye 4′,6-diamidino-2-phenylindole, was used to monitor changes in parasite number. Fluorescent images were acquired on the PerkinElmer Opera High Throughput confocal imaging system and analyzed with a spot detection algorithm using the Acapella data processing software. Further optimization of this assay sought to increase throughput, assay stability, and compatibility with our high-throughput screening equipment platforms. The assay typically yielded Z'-factor values of 0.5–0.6, with signal-to-noise ratios of 12. PMID:22232455

  17. Factors Associated with Mammographic Decisions of Chinese-Australian Women

    ERIC Educational Resources Information Center

    Kwok, Cannas; Cant, Rosemary; Sullivan, Gerard

    2005-01-01

    BreastScreen (a free breast cancer screening service) has been implemented in Australia since 1991. Surveys conducted overseas consistently report that women of Chinese ancestry have low participation rates in breast cancer screening. Although Chinese women's use of breast cancer screening services has been investigated abroad, to date there are…

  18. Rapid contrast evaluation method based on affinity beads and backscattered electron imaging for the screening of electron stains.

    PubMed

    Kaku, Hiroki; Inoue, Kanako; Muranaka, Yoshinori; Park, Pyoyun; Ikeda, Kenichi

    2015-10-01

    Uranyl salts are toxic and radioactive; therefore, several studies have been conducted to screen for substitutes of electron stains. In this regard, the contrast evaluation process is time consuming and the results obtained are inconsistent. In this study, we developed a novel contrast evaluation method using affinity beads and a backscattered electron image (BSEI), obtained using scanning electron microscopy. The contrast ratios of BSEI in each electron stain treatment were correlated with those of transmission electron microscopic images. The affinity beads bound to cell components independently. Protein and DNA samples were enhanced by image contrast treated with electron stains; however, this was not observed for sugars. Protein-conjugated beads showed an additive effect of image contrast when double-stained with lead. However, additive effect of double staining was not observed in DNA-conjugated beads. The varying chemical properties of oligopeptides showed differences in image contrast when treated with each electron stain. This BSEI-based evaluation method not only enables screening for alternate electron stains, but also helps analyze the underlying mechanisms of electron staining of cellular structures. PMID:26199255

  19. A volumetric method for estimation of breast density on digitized screen-film mammograms.

    PubMed

    Pawluczyk, Olga; Augustine, Bindu J; Yaffe, Martin J; Rico, Dan; Yang, Jiwei; Mawdsley, Gordon E; Boyd, Norman F

    2003-03-01

    A method is described for the quantitative volumetric analysis of the mammographic density (VBD) from digitized screen-film mammograms. The method is based on initial calibration of the imaging system with a tissue-equivalent plastic device and the subsequent correction for variations in exposure factors and film processing characteristics through images of an aluminum step wedge placed adjacent to the breast during imaging. From information about the compressed breast thickness and technique factors used for taking the mammogram as well as the information from the calibration device, VBD is calculated. First, optical sensitometry is used to convert images to Log relative exposure. Second, the images are corrected for x-ray field inhomogeneity using a spherical section PMMA phantom image. The effectiveness of using the aluminum step wedge in tracking down the variations in exposure factors and film processing was tested by taking test images of the calibration device, aluminum step wedge and known density phantoms at various exposure conditions and also at different times over one year. Results obtained on known density phantoms show that VBD can be estimated to within 5% accuracy from the actual value. A first order thickness correction is employed to correct for inaccuracy in the compression thickness indicator of the mammography units. Clinical studies are ongoing to evaluate whether VBD can be a better indicator for breast cancer risk. PMID:12674236

  20. Fabrication and characterization of pixelated Gd2O2S:Tb scintillator screens for digital X-ray imaging applications

    NASA Astrophysics Data System (ADS)

    Kim, Jongyul; Kyoung Cha, Bo; Hyung Bae, Jun; Lee, Chae-Hun; Kim, Hyungtaek; Chang, Sungho; Cho, Gyuseong; Sim, Cheulmuu; Kim, Taejoo

    2011-05-01

    X-ray imaging detectors in combination with scintillator screens have been widely used in digital X-ray imaging applications. Gd2O2S:Tb was used as scintillation material for pixelated scintillator screens based on silicon substrates (wafer) with a micropore array of various dimensions fabricated using the photolithography and deep reactive ion etching (DRIE) process. The relative light output and the modulation transfer function (MTF) of each fabricated scintillator screen were measured by a cooled CCD and compared with those of Lanex screens. The spatial resolution of our scintillator screens was higher but their light outputs were lower than those of Lanex screen probably due to the loss of light at the wall surfaces. Therefore further treatment of the wall surface, such as reflective coating, seems necessary to compensate the light loss.

  1. Does sensitivity measured from screening test-sets predict clinical performance?

    NASA Astrophysics Data System (ADS)

    Soh, BaoLin P.; Lee, Warwick B.; Mello-Thoms, Claudia R.; Tapia, Kriscia A.; Ryan, John; Hung, Wai Tak; Thompson, Graham J.; Heard, Rob; Brennan, Patrick C.

    2014-03-01

    Aim: To examine the relationship between sensitivity measured from the BREAST test-set and clinical performance. Background: Although the UK and Australia national breast screening programs have regarded PERFORMS and BREAST test-set strategies as possible methods of estimating readers' clinical efficacy, the relationship between test-set and real life performance results has never been satisfactorily understood. Methods: Forty-one radiologists from BreastScreen New South Wales participated in this study. Each reader interpreted a BREAST test-set which comprised sixty de-identified mammographic examinations sourced from the BreastScreen Digital Imaging Library. Spearman's rank correlation coefficient was used to compare the sensitivity measured from the BREAST test-set with screen readers' clinical audit data. Results: Results shown statistically significant positive moderate correlations between test-set sensitivity and each of the following metrics: rate of invasive cancer per 10 000 reads (r=0.495; p < 0.01); rate of small invasive cancer per 10 000 reads (r=0.546; p < 0.001); detection rate of all invasive cancers and DCIS per 10 000 reads (r=0.444; p < 0.01). Conclusion: Comparison between sensitivity measured from the BREAST test-set and real life detection rate demonstrated statistically significant positive moderate correlations which validated that such test-set strategies can reflect readers' clinical performance and be used as a quality assurance tool. The strength of correlation demonstrated in this study was higher than previously found by others.

  2. The effect of skin thickness determined using breast CT on mammographic dosimetry

    SciTech Connect

    Huang Shihying; Boone, John M.; Yang, Kai; Kwan, Alexander L. C.; Packard, Nathan J.

    2008-04-15

    The effect of breast skin thickness on dosimetry in mammography was investigated. Breast computed tomography (CT) acquisition techniques, combined with algorithms designed for determining specific breast metrics, were useful for estimating skin thickness. A radial-geometry edge detection scheme was implemented on coronal reconstructed breast CT (bCT) images to measure the breast skin thickness. Skin thickness of bilateral bCT volume data from 49 women and unilateral bCT volume data from 2 women (10 healthy women and 41 women with BIRADS 4 and 5 diagnoses) was robustly measured with the edge detection scheme. The mean breast skin thickness ({+-}inter-breast standard deviation) was found to be 1.45{+-}0.30 mm. Since most current published normalized glandular dose (D{sub gN}) coefficients are based on the assumption of a 4-mm breast skin thickness, the D{sub gN} values computed with Monte Carlo techniques will increase up to 18% due to the thinner skin layers (e.g., 6-cm 50% glandular breast, 28 kVp Mo-Mo spectrum). The thinner skin dimensions found in this study suggest that the current D{sub gN} values used for mammographic dosimetry lead to a slight underestimate in glandular dose.

  3. Screening for breast cancer in England: past and future.

    PubMed

    2006-01-01

    The NHS Breast Screening Programme (NHSBSP) began in 1988. It aims to invite all women aged 50-70 years for mammographic screening once every three years. The programme now screens 1.3 million women each year, about 75% of those invited, and diagnoses about 10,000 breast cancers annually. Although some have questioned the value of screening for breast cancer, the scientific evidence demonstrates clearly that regular mammographic screening between the ages of 50 and 70 years reduces mortality from the malignancy. Screened women are slightly more likely than unscreened women to be diagnosed with breast cancer. The cancers in screened women are smaller and are less likely to be treated with mastectomy than they would have been if diagnosed without screening. For every 400 women screened regularly by the NHSBSP over a 10-year period, one woman fewer will die from breast cancer than would have died without screening. The current NHSBSP saves an estimated 1400 lives each year in England. The screening programme spends about pound sterling 3000 for every year of life saved. PMID:16792825

  4. Computer simulation technique to preview the influence of the recording system on the image sharpness in mammography

    NASA Astrophysics Data System (ADS)

    Schiabel, Homero; Silva, Marcia A.; de Oliveira, Henrique J. Q.; Azevedo Marques, Paulo M.; Frere, Annie F.

    1998-07-01

    Following procedures used to simulate the image sharpness along the radiation field based on X-rays geometric exposure developed in previous work, here we describe another computer simulation procedure intended to evaluate the influence of any recording system as radiographic film or screen-film combinations, on the image sharpness in mammography. In this current work we take into account the parameters from the recording system besides the radiation projection from the focal spot in order to yield a simulated image on the computer screen relative to the expected image to be obtained in actual conditions with a singular recording system for a singular mammography equipment. The focal spot sizes in all field locations, as well as the respectives intensity distributions, the sensitometric curve for a radiographic film or for a screen-film combination, and also the screen intensifying factor, conversion efficiency, absorption factor and emission spectrum were used as input parameters for the simulation. Simulated images were compared to those obtained with actual mammographic equipment, by using a resolution phantom, and both types of images were in good agreement. The main advantage of this procedure will be the possibility of predicting the image sharpness characteristics for any mammography equipment with any type of recording system without exposure tests.

  5. Breast cancer screening: controversy of impact.

    PubMed

    Berry, Donald A

    2013-08-01

    Few medical issues have been as controversial--or as political, at least in the United States-as the role of mammographic screening for breast cancer. The advantages of finding a cancer early seem obvious. Indeed, randomized trials evaluating screening mammography demonstrate a reduction in breast cancer mortality, but the benefits are less than one would hope. Moreover, the randomized trials are themselves subject to criticism, including that they are irrelevant in the modern era because most were conducted before chemotherapy and hormonal therapy became widely used. In this article I chronicle the evidence and controversies regarding mammographic screening, including attempts to assess the relative contributions of screening and therapy in the substantial decreases in breast cancer mortality that have been observed in many countries over the last 20-25 years. I emphasize the trade-off between harms and benefits depending on the woman's age and other risk factors. I also discuss ways for communicating the associated risks to women who have to decide whether screening (and what screening strategy) is right for them. PMID:24074796

  6. A new CAD approach for improving efficacy of cancer screening

    NASA Astrophysics Data System (ADS)

    Zheng, Bin; Qian, Wei; Li, Lihua; Pu, Jiantao; Kang, Yan; Lure, Fleming; Tan, Maxine; Qiu, Yuchen

    2015-03-01

    Since performance and clinical utility of current computer-aided detection (CAD) schemes of detecting and classifying soft tissue lesions (e.g., breast masses and lung nodules) is not satisfactory, many researchers in CAD field call for new CAD research ideas and approaches. The purpose of presenting this opinion paper is to share our vision and stimulate more discussions of how to overcome or compensate the limitation of current lesion-detection based CAD schemes in the CAD research community. Since based on our observation that analyzing global image information plays an important role in radiologists' decision making, we hypothesized that using the targeted quantitative image features computed from global images could also provide highly discriminatory power, which are supplementary to the lesion-based information. To test our hypothesis, we recently performed a number of independent studies. Based on our published preliminary study results, we demonstrated that global mammographic image features and background parenchymal enhancement of breast MR images carried useful information to (1) predict near-term breast cancer risk based on negative screening mammograms, (2) distinguish between true- and false-positive recalls in mammography screening examinations, and (3) classify between malignant and benign breast MR examinations. The global case-based CAD scheme only warns a risk level of the cases without cueing a large number of false-positive lesions. It can also be applied to guide lesion-based CAD cueing to reduce false-positives but enhance clinically relevant true-positive cueing. However, before such a new CAD approach is clinically acceptable, more work is needed to optimize not only the scheme performance but also how to integrate with lesion-based CAD schemes in the clinical practice.

  7. Mammographic density in relation to daidzein-metabolizing phenotypes in overweight, postmenopausal women.

    PubMed

    Frankenfeld, Cara L; McTiernan, Anne; Aiello, Erin J; Thomas, Wendy K; LaCroix, Kristin; Schramm, Judy; Schwartz, Stephen M; Holt, Victoria L; Lampe, Johanna W

    2004-07-01

    Circulating hormones are associated with mammographic density, an intermediate marker of breast cancer risk. Differences in circulating hormones, including estrone and testosterone, have been observed in premenopausal women based on their capacity to metabolize daidzein, an isoflavone found predominantly in soybeans. Equol and O-desmethylangolensin (O-DMA) are products of intestinal bacterial metabolism of daidzein. There is interindividual variability in the capacity to produce daidzein metabolites; individuals can be equol producers or non-producers and O-DMA producers or non-producers. We tested the hypothesis that daidzein-metabolizing phenotypes are associated with mammographic density. Participants were recruited from among 92 sedentary, postmenopausal women, ages 50 to 75 years, who participated in a 1-year physical activity intervention. Pre-intervention mammographic density was determined using a computer-assisted, gray-scale thresholding technique. Fifty-five of these women consumed supplemental soy protein (>10 mg daidzein/d) for 3 days and collected a first-void urine sample on the fourth day to determine daidzein-metabolizing phenotypes. Equol and O-DMA concentrations were measured using gas chromatography-mass spectrometry. Associations between daidzein-metabolizing phenotypes and percent mammographic density were adjusted for age, maximum adult weight, gravidity, family history of breast cancer, and serum follicle-stimulating hormone and free testosterone concentrations. Mammographic density was 39% lower in equol producers compared with non-producers (P = 0.04). O-DMA producers had mammographic density 69% greater than non-producers (P = 0.05). These results suggest that particular intestinal bacterial profiles are associated with postmenopausal mammographic density, and these associations are not entirely explained by differences in reproductive or anthropometric characteristics or circulating hormones. PMID:15247126

  8. A feasibility study into the screening and imaging of hand luggage for threat items at 35 GHz using an active large aperture (1.6 m) security screening imager

    NASA Astrophysics Data System (ADS)

    Bowring, Nicholas J.; O'Reilly, Dean; Salmon, Neil A.; Andrews, David A.; Rezgui, Nacer-Ddine; Harmer, Stuart W.

    2013-10-01

    The feasibility of screening hand luggage for concealed threat items such as Person-Borne Improvised Explosive Devices (PBIED's) both metallic and non-metallic, together with handguns and at millimetre wavelengths is investigated. Previous studies by the authors and others indicate that hand baggage material and fabric is much more transmissive and has less scattering at lower millimetre wave frequencies and the ability to use K-band active imaging with high spatial resolution presents an opportunity to image and hence recognise concealed threats. For this feasibility study, a 1.6 m aperture, 35 GHz security screening imaging system with a spatial resolution of 2.5 cm and a depth of field of around 5 cm is employed, using spatially incoherent illuminating panels to enhance image contrast. In this study, realistic scenarios using backpacks containing a realistic range of threat and non-threat items are scanned, both carried and standalone. This range of items contains large vessels suitable for containing simulated home-made PBIED's and handguns. The comprehensive list of non-threat items includes laptops, bottles, clothing and power supplies. For this study, the range at which imaging data at standoff distances can be acquired is confined to that of the particular system in use, although parameters such as illumination and integration time are optimised. However, techniques for extrapolating towards effective standoff distances using aperture synthesis imagers are discussed. The transmission loss through fabrics and clothing that may form, or be contained in baggage, are reported over range of frequencies ranging from 26 to 110 GHz.

  9. XRIndex: a brief screening tool for individual differences in security threat detection in x-ray images.

    PubMed

    Rusconi, Elena; Ferri, Francesca; Viding, Essi; Mitchener-Nissen, Timothy

    2015-01-01

    X-ray imaging is a cost-effective technique at security checkpoints that typically require the presence of human operators. We have previously shown that self-reported attention to detail can predict threat detection performance with small-vehicle x-ray images (Rusconi et al., 2012). Here, we provide evidence for the generality of such a link by having a large sample of naïve participants screen more typical dual-energy x-ray images of hand luggage. The results show that the Attention to Detail score from the autism-spectrum quotient (AQ) questionnaire (Baron-Cohen et al., 2001) is a linear predictor of threat detection accuracy. We then develop and fine-tune a novel self-report scale for security screening: the XRIndex, which improves on the Attention to Detail scale for predictive power and opacity to interpretation. The XRIndex is not redundant with any of the Big Five personality traits. We validate the XRIndex against security x-ray images with an independent sample of untrained participants and suggest that the XRIndex may be a useful aid for the identification of suitable candidates for professional security training with a focus on x-ray threat detection. Further studies are needed to determine whether this can also apply to trained professionals. PMID:26321935

  10. XRIndex: a brief screening tool for individual differences in security threat detection in x-ray images

    PubMed Central

    Rusconi, Elena; Ferri, Francesca; Viding, Essi; Mitchener-Nissen, Timothy

    2015-01-01

    X-ray imaging is a cost-effective technique at security checkpoints that typically require the presence of human operators. We have previously shown that self-reported attention to detail can predict threat detection performance with small-vehicle x-ray images (Rusconi et al., 2012). Here, we provide evidence for the generality of such a link by having a large sample of naïve participants screen more typical dual-energy x-ray images of hand luggage. The results show that the Attention to Detail score from the autism-spectrum quotient (AQ) questionnaire (Baron-Cohen et al., 2001) is a linear predictor of threat detection accuracy. We then develop and fine-tune a novel self-report scale for security screening: the XRIndex, which improves on the Attention to Detail scale for predictive power and opacity to interpretation. The XRIndex is not redundant with any of the Big Five personality traits. We validate the XRIndex against security x-ray images with an independent sample of untrained participants and suggest that the XRIndex may be a useful aid for the identification of suitable candidates for professional security training with a focus on x-ray threat detection. Further studies are needed to determine whether this can also apply to trained professionals. PMID:26321935

  11. Gold silver alloy nanoparticles (GSAN): an imaging probe for breast cancer screening with dual-energy mammography or computed tomography.

    PubMed

    Naha, Pratap C; Lau, Kristen C; Hsu, Jessica C; Hajfathalian, Maryam; Mian, Shaameen; Chhour, Peter; Uppuluri, Lahari; McDonald, Elizabeth S; Maidment, Andrew D A; Cormode, David P

    2016-07-14

    Earlier detection of breast cancer reduces mortality from this disease. As a result, the development of better screening techniques is a topic of intense interest. Contrast-enhanced dual-energy mammography (DEM) is a novel technique that has improved sensitivity for cancer detection. However, the development of contrast agents for this technique is in its infancy. We herein report gold-silver alloy nanoparticles (GSAN) that have potent DEM contrast properties and improved biocompatibility. GSAN formulations containing a range of gold : silver ratios and capped with m-PEG were synthesized and characterized using various analytical methods. DEM and computed tomography (CT) phantom imaging showed that GSAN produced robust contrast that was comparable to silver alone. Cell viability, reactive oxygen species generation and DNA damage results revealed that the formulations with 30% or higher gold content are cytocompatible to Hep G2 and J774A.1 cells. In vivo imaging was performed in mice with and without breast tumors. The results showed that GSAN produce strong DEM and CT contrast and accumulated in tumors. Furthermore, both in vivo imaging and ex vivo analysis indicated the excretion of GSAN via both urine and feces. In summary, GSAN produce strong DEM and CT contrast, and has potential for both blood pool imaging and for breast cancer screening. PMID:27412458

  12. The link between women's body image disturbances and body-focused cancer screening behaviors: a critical review of the literature and a new integrated model for women.

    PubMed

    Ridolfi, Danielle R; Crowther, Janis H

    2013-03-01

    A large body of literature demonstrates the association between body image disturbances and health compromising behaviors among women (e.g., pathological eating, substance use, inappropriate exercise). However, given that disturbed body image is a pervasive problem, it is likely inversely related to health maintenance behaviors. Cancer screenings for breast, skin, and cervical cancer represent an important type of health maintenance behavior, yet adherence rates are low. Given the body-focused nature of these screenings, body image may be a salient predictor. This paper reviews the literature on the relationship between body image disturbances and cancer screening behaviors among women culminating in the proposal of a theoretical model. This model posits that body shame and body avoidance predict performance of cancer screenings and that variables drawn from the cancer literature, including risk perception, health anxiety, subjective norms, and self-efficacy, may moderate this relationship. Clinical implications and suggestions for research are discussed. PMID:23265838

  13. Towards a nanoscale mammographic contrast agent: development of a modular pre-clinical dual optical/x-ray agent

    NASA Astrophysics Data System (ADS)

    Hill, Melissa L.; Gorelikov, Ivan; Niroui, Farnaz; Levitin, Ronald B.; Mainprize, James G.; Yaffe, Martin J.; Rowlands, J. A.; Matsuura, Naomi

    2013-08-01

    Contrast-enhanced digital mammography (CEDM) can provide improved breast cancer detection and characterization compared to conventional mammography by imaging the effects of tumour angiogenesis. Current small-molecule contrast agents used for CEDM are limited by a short plasma half-life and rapid extravasation into tissue interstitial space. To address these limitations, nanoscale agents that can remain intravascular except at sites of tumour angiogenesis can be used. For CEDM, this agent must be both biocompatible and strongly attenuate mammographic energy x-rays. Nanoscale perfluorooctylbromide (PFOB) droplets have good x-ray attenuation and have been used in patients for other applications. However, the macroscopic scale of x-ray imaging (50-100 µm) is inadequate for direct verification that PFOB droplets localize at sites of breast tumour angiogenesis. For efficient pre-clinical optimization for CEDM, we integrated an optical marker into PFOB droplets for microscopic assessment (≪50 µm). To develop PFOB droplets as a new nanoscale mammographic contrast agent, PFOB droplets were labelled with fluorescent quantum dots (QDs). The droplets had mean diameters of 160 nm, fluoresced at 635 nm and attenuated x-ray spectra at 30.5 keV mean energy with a relative attenuation of 5.6 ± 0.3 Hounsfield units (HU) mg-1 mL-1 QD-PFOB. With the agent loaded into tissue phantoms, good correlation between x-ray attenuation and optical fluorescence was found (R2 = 0.96), confirming co-localization of the QDs with PFOB for quantitative assessment using x-ray or optical methods. Furthermore, the QDs can be removed from the PFOB agent without affecting its x-ray attenuation or structural properties for expedited translation of optimized PFOB droplet formulations into patients.

  14. Screening of a virtual mirror-image library of natural products.

    PubMed

    Noguchi, Taro; Oishi, Shinya; Honda, Kaori; Kondoh, Yasumitsu; Saito, Tamio; Ohno, Hiroaki; Osada, Hiroyuki; Fujii, Nobutaka

    2016-06-01

    We established a facile access to an unexplored mirror-image library of chiral natural product derivatives using d-protein technology. In this process, two chemical syntheses of mirror-image substances including a target protein and hit compound(s) allow the lead discovery from a virtual mirror-image library without the synthesis of numerous mirror-image compounds. PMID:27198617

  15. Radiation-Induced Breast Cancer Incidence and Mortality from Digital Mammography Screening: A Modeling Study

    PubMed Central

    Miglioretti, Diana L.; Lange, Jane; van den Broek, Jeroen J.; Lee, Christoph I.; van Ravesteyn, Nicolien T.; Ritley, Dominique; Kerlikowske, Karla; Fenton, Joshua J.; Melnikow, Joy; de Koning, Harry J.; Hubbard, Rebecca A.

    2016-01-01

    Background Estimates of radiation-induced breast cancer risk from mammography screening have not previously considered dose exposure variation or diagnostic work-up after abnormal screening. Objective To estimate distributions of radiation-induced breast cancer incidence and mortality from digital mammography screening, considering exposure from screening and diagnostic mammography and dose variation across women. Design Two simulation-modeling approaches using common data on screening mammography from the Breast Cancer Surveillance Consortium and radiation dose from mammography from the Digital Mammographic Imaging Screening Trial. Setting U.S. population. Patients Women aged 40–74 years. Interventions Annual or biennial digital mammography screening from age 40, 45, or 50 until 74. Measurements Lifetime breast cancer deaths averted (benefits) and radiation-induced breast cancer incidence and mortality per 100,000 women screened (harms). Results On average, annual screening of 100,000 women aged 40 to 74 years was projected to induce 125 breast cancers (95% confidence interval [CI]=88–178) leading to 16 deaths (95% CI=11–23) relative to 968 breast cancer deaths averted by early detection from screening. Women exposed at the 95th percentile were projected to develop 246 radiation-induced breast cancers leading to 32 deaths per 100,000 women. Women with large breasts requiring extra views for complete breast examination (8% of population) were projected to have higher radiation-induced breast cancer incidence and mortality (266 cancers, 35 deaths per 100,000 women), compared to women with small or average breasts (113 cancers, 15 deaths per 100,000 women). Biennial screening starting at age 50 reduced risk of radiation-induced cancers 5-fold. Limitations We were unable to estimate years of life lost from radiation-induced breast cancer. Conclusions Radiation-induced breast cancer incidence and mortality from digital mammography screening are impacted by dose

  16. Consequences of False-Positive Screening Mammograms

    PubMed Central

    Tosteson, Anna N. A.; Fryback, Dennis G.; Hammond, Cristina S.; Hanna, Lucy G.; Grove, Margaret R.; Brown, Mary; Wang, Qianfei; Lindfors, Karen; Pisano, Etta D.

    2014-01-01

    Importance False-positive mammograms, a common occurrence in breast cancer screening programs, represent a potential screening harm that is currently being evaluated by the United States Preventive Services Task Force. Objective To measure the impact of false-positive mammograms on quality of life by measuring personal anxiety, health utility and future screening attitudes. Design Longitudinal Digital Mammographic Imaging Screening Trial (DMIST) quality-of-life sub-study telephone survey shortly after screening and one year later. Setting Twenty-two DMIST sites Participants Randomly-selected DMIST participants with positive and negative mammograms. Exposure(s) for observational studies Mammogram requiring follow-up testing or referral without a cancer diagnosis. Main Outcome(s) and Measure(s) The Spielberger State-Trait Anxiety Index short-form (STAI-6) and the EuroQol EQ-5D with United States scoring. Attitudes toward future screening measured by women’s self-report of future intention to undergo mammography screening and willingness to travel and stay overnight to receive a hypothetical new mammogram that would detect as many cancers with half the false-positives. Results Among 1,450 eligible women invited to participate, 1,226 women (85%) were enrolled with follow-up interviews obtained for 1,028 (84%). Anxiety was significantly higher for women with false-positive mammograms (STAI-6:35.2 vs. 32.7), but health utility did not differ and there were no significant differences between groups at one year. Future screening intentions differed by group (26% vs. 14% more likely in false-positive vs. negative); willingness to travel and stay overnight did not (11% vs. 10% in false-positive vs. negative). Future screening intention was significantly increased among women with false-positive mammograms (OR: 2.12; 95%CI:1.54, 2.93), younger age (OR:2.78; 95%CI:1.5,5.0) and poorer health (OR: 1.63; 95%CI:1.09, 2.43). Women’s anticipated high-level anxiety regarding

  17. Features of Undiagnosed Breast Cancers at Screening Breast MR Imaging and Potential Utility of Computer-Aided Evaluation

    PubMed Central

    Seo, Mirinae; Bae, Min Sun; Koo, Hye Ryoung; Kim, Won Hwa; Lee, Su Hyun; Chu, Ajung

    2016-01-01

    Objective To retrospectively evaluate the features of undiagnosed breast cancers on prior screening breast magnetic resonance (MR) images in patients who were subsequently diagnosed with breast cancer, as well as the potential utility of MR-computer-aided evaluation (CAE). Materials and Methods Between March 2004 and May 2013, of the 72 consecutive pairs of prior negative MR images and subsequent MR images with diagnosed cancers (median interval, 32.8 months; range, 5.4-104.6 months), 36 (50%) had visible findings (mean size, 1.0 cm; range, 0.3-5.2 cm). The visible findings were divided into either actionable or underthreshold groups by the blinded review by 5 radiologists. MR imaging features, reasons for missed cancer, and MR-CAE features according to actionability were evaluated. Results Of the 36 visible findings on prior MR images, 33.3% (12 of 36) of the lesions were determined to be actionable and 66.7% (24 of 36) were underthreshold; 85.7% (6 of 7) of masses and 31.6% (6 of 19) of non-mass enhancements were classified as actionable lesions. Mimicking physiologic enhancements (27.8%, 10 of 36) and small lesion size (27.8%, 10 of 36) were the most common reasons for missed cancer. Actionable findings tended to show more washout or plateau kinetic patterns on MR-CAE than underthreshold findings, as the 100% of actionable findings and 46.7% of underthreshold findings showed washout or plateau (p = 0.008). Conclusion MR-CAE has the potential for reducing the number of undiagnosed breast cancers on screening breast MR images, the majority of which are caused by mimicking physiologic enhancements or small lesion size. PMID:26798217

  18. Perception in screening mammography: Can insertion of obvious cases enhance detection?

    NASA Astrophysics Data System (ADS)

    Lewis, Sarah J.; Pietrzyk, Mariusz W.; Nurthen, Robert C. K.; McEntee, Mark F.; Evanoff, Michael; Lee, Warwick; Brennan, Patrick C.; Reed, Warren M.

    2013-03-01

    Purpose : To determine whether a strategy of inserting obvious cancers can improve the detection of subsequent abnormal cases in screening mammography sets. Method : Eight experienced breast imaging radiologists (mammographers) were asked to interpret 40 mammography cases in two sittings and localise any malignancies present. Two differing conditions were presented to participants. In Condition 1, there were 36 normal images interspersed with 4 abnormal cases determined to be of medium to high difficulty. Condition 2 differed in that two normal cases were replaced with two obvious malignant cases. These two obvious cases were placed shortly before two subtle malignancies. In both sittings, participants were told they were viewing a screening mammography set. Results: There was no statistical difference in the location sensitivity between the 2 conditions. There was decreased overall specificity in Condition 2 (p = 0.43). Conclusion: Preliminary findings suggest that the insertion of more easily observed abnormal cases into image sets does not improve performance and may in fact result in lower specificity. Further analysis of participants' eye-positions, and search strategies may offer some explanation of our findings

  19. Sensitivity of F-106B Leading-Edge-Vortex Images to Flight and Vapor-Screen Parameters

    NASA Technical Reports Server (NTRS)

    Lamar, John E.; Johnson, Thomas D., Jr.

    1988-01-01

    A flight test was undertaken at NASA Langley Research Center with vapor-screen and image-enhancement techniques to obtain qualitative and quantitative information about near-field vortex flows above the wings of fighter aircraft. In particular, the effects of Reynolds and Mach numbers on the vortex system over an angle-of-attack range were sought. The relevance of these flows stems from their present and future use at many points in the flight envelope, especially during transonic maneuvers. The aircraft used in this flight program was the F-106B because it was available and had sufficient wing sweep (60 deg) to generate a significant leading-edge vortex system. The sensitivity of the visual results to vapor screen hardware and to onset flow changes is discussed.

  20. A high-content imaging-based screening pipeline for the systematic identification of anti-progeroid compounds.

    PubMed

    Kubben, Nard; Brimacombe, Kyle R; Donegan, Megan; Li, Zhuyin; Misteli, Tom

    2016-03-01

    Hutchinson-Gilford Progeria Syndrome (HGPS) is an early onset lethal premature aging disorder caused by constitutive production of progerin, a mutant form of the nuclear architectural protein lamin A. The presence of progerin causes extensive morphological, epigenetic and DNA damage related nuclear defects that ultimately disrupt tissue and organismal functions. Hypothesis-driven approaches focused on HGPS affected pathways have been used in attempts to identify druggable targets with anti-progeroid effects. Here, we report an unbiased discovery approach to HGPS by implementation of a high-throughput, high-content imaging based screening method that enables systematic identification of small molecules that prevent the formation of multiple progerin-induced aging defects. Screening a library of 2816 FDA approved drugs, we identified retinoids as a novel class of compounds that reverses aging defects in HGPS patient skin fibroblasts. These findings establish a novel approach to anti-progeroid drug discovery. PMID:26341717

  1. Stress Signaling from Human Mammary Epithelial Cells Contributes to Phenotypes of Mammographic Density

    PubMed Central

    Patten, Kelley; Chang, Hang; Zhao, Jianxin; Fontenay, Gerald V.; Kerlikowske, Karla; Parvin, Bahram; Tlsty, Thea D.

    2014-01-01

    Telomere malfunction and other types of DNA damage induce an activin A-dependent stress response in mortal non-tumorigenic human mammary epithelial cells that subsequently induces desmoplastic-like phenotypes in neighboring fibroblasts. Some characteristics of this fibroblast/stromal response, such as reduced adipocytes and increased extracellular matrix content, are observed not only in tumor tissues but also in disease-free breast tissues at high risk for developing cancer, especially high mammographic density tissues. We found that these phenotypes are induced by repression of the fatty acid translocase CD36, which is seen in desmoplastic and disease-free high mammographic density tissues. In this study, we show that epithelial cells from high mammographic density tissues have more DNA damage signaling, shorter telomeres, increased activin A secretion and an altered DNA damage response compared to epithelial cells from low mammographic density tissues. Strikingly, both telomere malfunction and activin A expression in epithelial cells can repress CD36 expression in adjacent fibroblasts. These results provide new insights into how high mammographic density arises and why it is associated with breast cancer risk, with implications for the definition of novel invention targets (e.g. activin A, CD36) to prevent breast cancer. PMID:25172842

  2. Novel Associations between Common Breast Cancer Susceptibility Variants and Risk-Predicting Mammographic Density Measures.

    PubMed

    Stone, Jennifer; Thompson, Deborah J; Dos Santos Silva, Isabel; Scott, Christopher; Tamimi, Rulla M; Lindstrom, Sara; Kraft, Peter; Hazra, Aditi; Li, Jingmei; Eriksson, Louise; Czene, Kamila; Hall, Per; Jensen, Matt; Cunningham, Julie; Olson, Janet E; Purrington, Kristen; Couch, Fergus J; Brown, Judith; Leyland, Jean; Warren, Ruth M L; Luben, Robert N; Khaw, Kay-Tee; Smith, Paula; Wareham, Nicholas J; Jud, Sebastian M; Heusinger, Katharina; Beckmann, Matthias W; Douglas, Julie A; Shah, Kaanan P; Chan, Heang-Ping; Helvie, Mark A; Le Marchand, Loic; Kolonel, Laurence N; Woolcott, Christy; Maskarinec, Gertraud; Haiman, Christopher; Giles, Graham G; Baglietto, Laura; Krishnan, Kavitha; Southey, Melissa C; Apicella, Carmel; Andrulis, Irene L; Knight, Julia A; Ursin, Giske; Alnaes, Grethe I Grenaker; Kristensen, Vessela N; Borresen-Dale, Anne-Lise; Gram, Inger Torhild; Bolla, Manjeet K; Wang, Qin; Michailidou, Kyriaki; Dennis, Joe; Simard, Jacques; Pharoah, Paul; Dunning, Alison M; Easton, Douglas F; Fasching, Peter A; Pankratz, V Shane; Hopper, John L; Vachon, Celine M

    2015-06-15

    Mammographic density measures adjusted for age and body mass index (BMI) are heritable predictors of breast cancer risk, but few mammographic density-associated genetic variants have been identified. Using data for 10,727 women from two international consortia, we estimated associations between 77 common breast cancer susceptibility variants and absolute dense area, percent dense area and absolute nondense area adjusted for study, age, and BMI using mixed linear modeling. We found strong support for established associations between rs10995190 (in the region of ZNF365), rs2046210 (ESR1), and rs3817198 (LSP1) and adjusted absolute and percent dense areas (all P < 10(-5)). Of 41 recently discovered breast cancer susceptibility variants, associations were found between rs1432679 (EBF1), rs17817449 (MIR1972-2: FTO), rs12710696 (2p24.1), and rs3757318 (ESR1) and adjusted absolute and percent dense areas, respectively. There were associations between rs6001930 (MKL1) and both adjusted absolute dense and nondense areas, and between rs17356907 (NTN4) and adjusted absolute nondense area. Trends in all but two associations were consistent with those for breast cancer risk. Results suggested that 18% of breast cancer susceptibility variants were associated with at least one mammographic density measure. Genetic variants at multiple loci were associated with both breast cancer risk and the mammographic density measures. Further understanding of the underlying mechanisms at these loci could help identify etiologic pathways implicated in how mammographic density predicts breast cancer risk. PMID:25862352

  3. Identification of modulators of autophagic flux in an image-based high content siRNA screen.

    PubMed

    Hale, Christopher M; Cheng, Qingwen; Ortuno, Danny; Huang, Ming; Nojima, Dana; Kassner, Paul D; Wang, Songli; Ollmann, Michael M; Carlisle, Holly J

    2016-04-01

    Autophagy is the primary process for recycling cellular constituents through lysosomal degradation. In addition to nonselective autophagic engulfment of cytoplasm, autophagosomes can recognize specific cargo by interacting with ubiquitin-binding autophagy receptors such as SQSTM1/p62 (sequestosome 1). This selective form of autophagy is important for degrading aggregation-prone proteins prominent in many neurodegenerative diseases. We carried out a high content image-based siRNA screen (4 to 8 siRNA per gene) for modulators of autophagic flux by monitoring fluorescence of GFP-SQSTM1 as well as colocalization of GFP-SQSTM1 with LAMP2 (lysosomal-associated membrane protein 2)-positive lysosomal vesicles. GFP-SQSTM1 and LAMP2 phenotypes of primary screen hits were confirmed in 2 cell types and profiled with image-based viability and MTOR signaling assays. Common seed analysis guided siRNA selection for these assays to reduce bias toward off-target effects. Confirmed hits were further validated in a live-cell assay to monitor fusion of autophagosomes with lysosomes. Knockdown of 10 targets resulted in phenotypic profiles across multiple assays that were consistent with upregulation of autophagic flux. These hits include modulators of transcription, lysine acetylation, and ubiquitination. Two targets, KAT8 (K[lysine] acetyltransferase 8) and CSNK1A1 (casein kinase 1, α 1), have been implicated in autophagic regulatory feedback loops. We confirmed that CSNK1A1 knockout (KO) cell lines have accelerated turnover of long-lived proteins labeled with (14)C-leucine in a pulse-chase assay as additional validation of our screening assays. Data from this comprehensive autophagy screen point toward novel regulatory pathways that might yield new therapeutic targets for neurodegeneration. PMID:27050463

  4. Role of computer-assisted visual search in mammographic interpretation

    NASA Astrophysics Data System (ADS)

    Nodine, Calvin F.; Kundel, Harold L.; Mello-Thoms, Claudia; Weinstein, Susan P.

    2001-06-01

    We used eye-position data to develop Computer-Assisted Visual Search (CAVS) as an aid to mammographic interpretation. CAVS feeds back regions of interest that receive prolonged visual dwell (greater than or equal to 1000 ms) by highlighting them on the mammogram. These regions are then reevaluated for possible missed breast cancers. Six radiology residents and fellows interpreted a test set of 40 mammograms twice, once with CAVS feedback (FB), and once without CAVS FB in a crossover, repeated- measures design. Eye position was monitored. LROC performance (area) was compared with and without CAVS FB. Detection and localization of malignant lesions improved 12% with CAVS FB. This was not significant. The test set contained subtle malignant lesions. 65% (176/272) of true lesions were fixated. Of those fixated, 49% (87/176) received prolonged attention resulting in CAVS FB, and 54% (47/87) of FBs resulted in TPs. Test-set difficulty and the lack of reading experience of the readers may have contributed to the relatively low overall performance, and may have also limited the effectiveness of CAVS FB which could only play a role in localizing potential lesions if the reader fixated and dwelled on them.

  5. Hormone metabolism genes and mammographic density in Singapore Chinese women

    PubMed Central

    Lee, Eunjung; Su, Yu-Chen; Lewinger, Juan Pablo; Hsu, Chris; Van den Berg, David; Ursin, Giske; Koh, Woon-Puay; Yuan, Jian-Min; Stram, Daniel O.; Yu, Mimi C.; Wu, Anna H.

    2014-01-01

    Background Female steroid hormone levels and exogenous hormone use influence breast cancer risk. We investigated the association between genetic variation in the hormone metabolism and signaling pathway and mammographic density (MD), a strong predictor of breast cancer risk. Methods We genotyped 161 SNPs in 15 hormone metabolism pathway gene regions and evaluated MD in 2,038 Singapore Chinese women. Linear regression analysis was used to investigate SNP-MD association. An overall pathway summary was obtained using the adaptive ranked truncated product test. Results We did not find any of the individually tested SNPs to be associated with MD after a multiple testing correction. There was no evidence of an overall effect on MD of genetic variation in the hormone metabolism pathway. Conclusions In this cross-sectional study, genetic variation in hormone metabolism pathway was not associated with MD in Singapore Chinese women. Impact Consistent with existing data from Caucasian populations, polymorphisms in hormone pathway genes are not likely to be strong predictors of MD in Asian women. PMID:23429186

  6. Mammographic Breast Density Patterns in Asymptomatic Mexican Women

    PubMed Central

    Calderón-Garcidueñas, Ana Laura; Sanabria-Mondragón, Mónica; Hernández-Beltrán, Lourdes; López-Amador, Noé; Cerda-Flores, Ricardo M.

    2012-01-01

    Breast density (BD) is a risk factor for breast cancer. Aims. To describe BD patterns in asymptomatic Mexican women and the pathological mammographic findings. Methods and Material. Prospective, descriptive, and comparative study. Women answered a questionnaire and their mammograms were analyzed according to BI-RADS. Univariate (χ2) and conditional logistic regression analyses were performed. Results. In 300 women studied the BD patterns were fat 56.7% (170), fibroglandular 29% (87), heterogeneously dense 5.7% (17), and dense pattern 8.6% (26). Prevalence of fat pattern was significantly different in women under 50 years (37.6%, 44/117) and older than 50 (68.8%, 126/183). Patterns of high breast density (BD) (dense + heterogeneously dense) were observed in 25.6% (30/117) of women ≤50 years and 7.1% (13/183) of women >50. Asymmetry in BD was observed in 22% (66/300). Compression cone ruled out underlying disease in 56 cases. In the remaining 10, biopsy revealed one fibroadenoma, one complex cyst, and 6 invasive and 2 intraductal carcinomas. 2.6% (8/300) of patients had non-palpable carcinomas. Benign lesions were observed in 63.3% (190/300) of cases, vascular calcification in 150 cases (78.9%), and fat necrosis in 38 cases (20%). Conclusions. Mexican women have a low percentage of high-density patterns. PMID:23346398

  7. Bilateral image subtraction features for multivariate automated classification of breast cancer risk

    NASA Astrophysics Data System (ADS)

    Celaya-Padilla, Jose M.; Rodriguez-Rojas, Juan; Galván-Tejada, Jorge I.; Martínez-Torteya, Antonio; Treviño, Victor; Tamez-Peña, José G.

    2014-03-01

    Early tumor detection is key in reducing breast cancer deaths and screening mammography is the most widely available method for early detection. However, mammogram interpretation is based on human radiologist, whose radiological skills, experience and workload makes radiological interpretation inconsistent. In an attempt to make mammographic interpretation more consistent, computer aided diagnosis (CADx) systems has been introduced. This paper presents an CADx system aimed to automatically triage normal mammograms form suspicious mammograms. The CADx system co-reregister the left and breast images, then extracts image features from the co-registered mammographic bilateral sets. Finally, an optimal logistic multivariate model is generated by means of an evolutionary search engine. In this study, 440 subjects form the DDSM public data sets were used: 44 normal mammograms, 201 malignant mass mammograms, and 195 mammograms with malignant calci cations. The results showed a cross validation accuracy of 0.88 and an area under receiver operating characteristic (AUC) of 0.89 for the calci cations vs. normal mammograms. The optimal mass vs. normal mammograms model obtained an accuracy of 0.85 and an AUC of 0.88.

  8. Gold silver alloy nanoparticles (GSAN): an imaging probe for breast cancer screening with dual-energy mammography or computed tomography

    NASA Astrophysics Data System (ADS)

    Naha, Pratap C.; Lau, Kristen C.; Hsu, Jessica C.; Hajfathalian, Maryam; Mian, Shaameen; Chhour, Peter; Uppuluri, Lahari; McDonald, Elizabeth S.; Maidment, Andrew D. A.; Cormode, David P.

    2016-07-01

    Earlier detection of breast cancer reduces mortality from this disease. As a result, the development of better screening techniques is a topic of intense interest. Contrast-enhanced dual-energy mammography (DEM) is a novel technique that has improved sensitivity for cancer detection. However, the development of contrast agents for this technique is in its infancy. We herein report gold-silver alloy nanoparticles (GSAN) that have potent DEM contrast properties and improved biocompatibility. GSAN formulations containing a range of gold : silver ratios and capped with m-PEG were synthesized and characterized using various analytical methods. DEM and computed tomography (CT) phantom imaging showed that GSAN produced robust contrast that was comparable to silver alone. Cell viability, reactive oxygen species generation and DNA damage results revealed that the formulations with 30% or higher gold content are cytocompatible to Hep G2 and J774A.1 cells. In vivo imaging was performed in mice with and without breast tumors. The results showed that GSAN produce strong DEM and CT contrast and accumulated in tumors. Furthermore, both in vivo imaging and ex vivo analysis indicated the excretion of GSAN via both urine and feces. In summary, GSAN produce strong DEM and CT contrast, and has potential for both blood pool imaging and for breast cancer screening.Earlier detection of breast cancer reduces mortality from this disease. As a result, the development of better screening techniques is a topic of intense interest. Contrast-enhanced dual-energy mammography (DEM) is a novel technique that has improved sensitivity for cancer detection. However, the development of contrast agents for this technique is in its infancy. We herein report gold-silver alloy nanoparticles (GSAN) that have potent DEM contrast properties and improved biocompatibility. GSAN formulations containing a range of gold : silver ratios and capped with m-PEG were synthesized and characterized using various

  9. Novel method for screening of enteric film coatings properties with magnetic resonance imaging.

    PubMed

    Dorożyński, Przemysław; Jamróz, Witold; Niwiński, Krzysztof; Kurek, Mateusz; Węglarz, Władysław P; Jachowicz, Renata; Kulinowski, Piotr

    2013-11-18

    The aim of the study is to present the concept of novel method for fast screening of enteric coating compositions properties without the need of preparation of tablets batches for fluid bed coating. Proposed method involves evaluation of enteric coated model tablets in specially designed testing cell with application of MRI technique. The results obtained in the testing cell were compared with results of dissolution studies of mini-tablets coated in fluid bed apparatus. The method could be useful in early stage of formulation development for screening of film coating properties that will shorten and simplify the development works. PMID:23994758

  10. Optimal x-ray spectra for screen-film mammography.

    PubMed

    Jennings, R J; Eastgate, R J; Siedband, M P; Ergun, D L

    1981-01-01

    Theoretical and experimental techniques have been used to study optimal x-ray for screen-film mammography. A simple model of mammographic imaging predicts optimum x-ray energies which are significantly higher than the K-characteristic energies of Mo. A subjective comparison of x-ray spectra from Mo-anode and W-anode tubes indicates that spectra produced by a W-anode tube filtered with materials of atomic number just above that of Mo are more suitable for screen-film mammography than spectra produced by the Mo-anode/Mo-filter system. The imaging performance of K-edge filtered, W-anode tube spectra was compared to the performance of Mo-anode spectra using phantom measurements and mastectomy specimen radiography. It was shown that optimal W-anode spectra can produce equal contrast with an exposure reduction of a factor of two to three, a dose reduction of a factor of two, and equal or reducing tube loading, compared to Mo-anode spectra. A computer simulation was carried out to extend the initial, monoenergetic theory to the case of real, polychromatic sources. The effects of varying filter material and thickness, tube operating potential, and breast thickness were all studied. Since W-anode x-ray tubes are considered to be better for Xerox mammography than Mo-anode tubes, this study has shown that both Xerox and screen-film techniques can be performed optimally with a single, properly designed, W-anode x-ray tube. PMID:7290015

  11. High-content screening of drug-induced cardiotoxicity using quantitative single cell imaging cytometry on microfluidic device.

    PubMed

    Kim, Min Jung; Lee, Su Chul; Pal, Sukdeb; Han, Eunyoung; Song, Joon Myong

    2011-01-01

    Drug-induced cardiotoxicity or cytotoxicity followed by cell death in cardiac muscle is one of the major concerns in drug development. Herein, we report a high-content quantitative multicolor single cell imaging tool for automatic screening of drug-induced cardiotoxicity in an intact cell. A tunable multicolor imaging system coupled with a miniaturized sample platform was destined to elucidate drug-induced cardiotoxicity via simultaneous quantitative monitoring of intracellular sodium ion concentration, potassium ion channel permeability and apoptosis/necrosis in H9c2(2-1) cell line. Cells were treated with cisapride (a human ether-à-go-go-related gene (hERG) channel blocker), digoxin (Na(+)/K(+)-pump blocker), camptothecin (anticancer agent) and a newly synthesized anti-cancer drug candidate (SH-03). Decrease in potassium channel permeability in cisapride-treated cells indicated that it can also inhibit the trafficking of the hERG channel. Digoxin treatment resulted in an increase of intracellular [Na(+)]. However, it did not affect potassium channel permeability. Camptothecin and SH-03 did not show any cytotoxic effect at normal use (≤300 nM and 10 μM, respectively). This result clearly indicates the potential of SH-03 as a new anticancer drug candidate. The developed method was also used to correlate the cell death pathway with alterations in intracellular [Na(+)]. The developed protocol can directly depict and quantitate targeted cellular responses, subsequently enabling an automated, easy to operate tool that is applicable to drug-induced cytotoxicity monitoring with special reference to next generation drug discovery screening. This multicolor imaging based system has great potential as a complementary system to the conventional patch clamp technique and flow cytometric measurement for the screening of drug cardiotoxicity. PMID:21060932

  12. High-throughput screening of large volumes of whole blood using structured illumination and fluorescent on-chip imaging

    PubMed Central

    Arpali, Serap Altay; Arpali, Caglar; Coskun, Ahmet F.; Chiang, Hsin-Hao; Ozcan, Aydogan

    2012-01-01

    Undiluted blood samples are difficult to image in large volumes since blood constitutes a highly absorbing and scattering medium. As a result of this limitation, optical imaging of rare cells (e.g., circulating tumour cells) within unprocessed whole blood remains a challenge, demanding the use of special micro-fluidic technologies. Here we demonstrate a new fluorescent on-chip imaging modality that can rapidly screen large volumes of absorbing and scattering media such as undiluted whole blood samples for detection of fluorescent micro-objects at low concentrations (for example ≤ 50–100 particles/mL). In this high-throughput imaging modality, a large area micro-fluidic device (e.g., 7–18 cm2), which contains for example ~0.3–0.7 mL of undiluted whole blood sample, is directly positioned onto a wide-field opto-electronic sensor-array such that the fluorescent emission within the micro-channel can be detected without the use of any imaging lenses. This micro-fluidic device is then illuminated and laterally scanned with an array of Gaussian excitation spots, which is generated through a spatial light modulator. For each scanning position of this excitation array, a lensfree fluorescent image of the blood sample is captured using the opto-electronic sensor-array, resulting in a sequence of images (e.g., 144 lensfree frames captured in ~36 seconds) for the same sample chip. Digitally merging these lensfree fluorescent images based on a Maximum Intensity Projection (MIP) algorithm enabled us to significantly boost the signal-to-noise ratio (SNR) and contrast of the fluorescent micro-objects within whole blood, which normally remain undetected (i.e., hidden) using conventional uniform excitation schemes, involving plane wave illumination. This high-throughput on-chip imaging platform based on structured excitation could be useful for rare cell research by enabling rapid screening of large volume micro-fluidic devices that process whole blood and other optically

  13. Subscale Ship Airwake Studies Using Novel Vortex Flow Devices with Smoke, Laser-Vapor-Screen and Particle Image Velocimetry

    NASA Technical Reports Server (NTRS)

    Lamar, John E.; Landman, Drew; Swift, Russell S.; Parikh, Paresh C.

    2007-01-01

    Ships produce vortices and air-wakes while either underway or stationary in a wind. These flow fields can be detrimental to the conduction of air operations in that they can adversely impact the air vehicles and flight crews. There are potential solutions to these problems for both frigates/destroyers and carriers through the use of novel vortex flow or flow control devices. This appendix highlights several devices which may have application and points out that traditional wind-tunnel testing using smoke, laser-vapor screen, and Particle Image Velocimetry can be useful in sorting out the effectiveness of different devices.

  14. Live Cell Bioluminescence Imaging in Temporal Reaction of G Protein-Coupled Receptor for High-Throughput Screening and Analysis.

    PubMed

    Hattori, Mitsuru; Ozawa, Takeaki

    2016-01-01

    G protein-coupled receptors (GPCRs) are notable targets of basic therapeutics. Many screening methods have been established to identify novel agents for GPCR signaling in a high-throughput manner. However, information related to the temporal reaction of GPCR with specific ligands remains poor. We recently developed a bioluminescence method for the quantitative detection of the interaction between GPCR and β-arrestin using split luciferase complementation. To monitor time-course variation of the interactions, a new imaging system contributes to the accurate evaluation of drugs for GPCRs in a high-throughput manner. PMID:27424906

  15. [The development of the skin-optical perception of color and images in blind schoolchildren on an "internal visual screen"].

    PubMed

    Mizrakhi, V M; Protsiuk, R G

    2000-03-01

    In profound impairement of vision the function of colour and seen objects perception is absent, with the person being unable to orient himself in space. The uncovered sensory sensations of colour allowed their use in training the blind in recognizing the colour of paper, fabric, etc. Further study in those having become blind will, we believe, help in finding eligible people and relevant approaches toward educating the blind, which will make for development of the trainee's ability to recognize images on the "inner visual screen". PMID:10862485

  16. The Effect of Raloxifene on Mammographic Density and Breast MRI in Premenopausal Women at Increased Risk for Breast Cancer

    PubMed Central

    Eng-Wong, Jennifer; Orzano-Birgani, Jennifer; Chow, Catherine K.; Venzon, David; Yao, Jianhua; Galbo, Claudia E.; Zujewski, Jo Anne; Prindiville, Sheila

    2008-01-01

    Background Mammographic density (MD) is a risk factor for breast cancer. MD and breast MRI volume (MRIV) assess the amount of fibroglandular tissue in the breast. MD and MRIV can be modulated with hormonal interventions, suggesting that these imaging modalities may be useful as surrogate endpoint biomarkers for breast cancer chemoprevention trials. We evaluated the effect of raloxifene on MD and MRIV in premenopausal women at increased risk for breast cancer. Materials and Methods Mammograms and MRIs were obtained at baseline and after one and two years of raloxifene 60 mg by mouth daily for 27 premenopausal women. Mammographic percent dense area was calculated using a semi-quantitative thresholding technique. T1 weighted spoiled gradient-echo MRI with fat suppression was used to determine breast MRIV using a semiautomatic method. Mean change in MD and median change in MRIV were assessed by the Wilcoxon signed-rank test. Results No significant change in MD was seen after treatment with raloxifene. Mean change after one year was 1% (95% CI -3 to +5) and after two years was 1% (95% CI -2 to +5). MRIV decreased on raloxifene. Median relative change in MRIV after one year was -17% (95% CI % -28 to -9; p=0.0017) and after two years was -16% (95% CI -31 to -4; p=0.0004). Conclusions In high risk premenopausal women MD did not change on raloxifene, while MRIV significantly declined. Our findings suggest that MRIV is a promising surrogate biomarker in premenopausal women at increased risk for breast cancer and should be investigated further in breast cancer prevention trials. PMID:18583470

  17. Does Mammographic Density Distribution Correlate with Location of Breast Cancer Tumors?

    NASA Astrophysics Data System (ADS)

    Yu, Clare; Mitchell, James

    2013-03-01

    The risk of breast cancer is higher in women with denser, stiffer breasts. In mammograms, one measure of breast density is mammographic density. Mammograms involve x-rays, and radiodense material is characterized by white areas on a mammogram. The more white areas there are, the higher the mammographic density and the higher the risk of breast cancer. It is also known that most breast tumors occur in the upper half of the breast. Actually, about half of breast tumors occur in the upper outer quadrant of the breast near the armpit. We have analyzed mammograms and find that the mammographic density (white stuff) is higher in the upper half of the breast where there is more tissue. This work is supported by the National Cancer Institute through the Princeton Physical Sciences Oncology Center.

  18. High-throughput screening of zebrafish embryos using automated heart detection and imaging.

    PubMed

    Spomer, Waldemar; Pfriem, Alexander; Alshut, Rüdiger; Just, Steffen; Pylatiuk, Christian

    2012-12-01

    Over the past decade, the zebrafish has become a key model organism in genetic screenings and drug discovery. A number of genes have been identified to affect the development of the shape and functioning of the heart, leading to zebrafish mutants with heart defects. The development of semiautomated microscopy systems has allowed for the investigation of drugs that reverse a disease phenotype on a larger scale. However, there is a lack of automated feature detection, and commercially available computer-aided microscopes are expensive. Screening of the zebrafish heart for drug discovery typically includes the identification of heart parameters, such as the frequency or fractional shortening. Until now, screening processes have been characterized by manual handling of the larvae and manual microscopy. Here, an intelligent robotic microscope is presented, which automatically identifies the orientation of a zebrafish in a micro well. A predefined region of interest, such as the heart, is detected automatically, and a video with higher magnification is recorded. Screening of a 96-well plate takes 35 to 55 min, depending on the length of the videos. Of the zebrafish hearts, 75% are recorded accurately without any user interaction. A description of the system, including the graphical user interface, is given. PMID:23053930

  19. Imaging Ferroelectric Domains and Domain Walls Using Charge Gradient Microscopy: Role of Screening Charges.

    PubMed

    Tong, Sheng; Jung, Il Woong; Choi, Yoon-Young; Hong, Seungbum; Roelofs, Andreas

    2016-02-23

    Advanced scanning probe microscopies (SPMs) open up the possibilities of the next-generation ferroic devices that utilize both domains and domain walls as active elements. However, current SPMs lack the capability of dynamically monitoring the motion of domains and domain walls in conjunction with the transport of the screening charges that lower the total electrostatic energy of both domains and domain walls. Charge gradient microscopy (CGM) is a strong candidate to overcome these shortcomings because it can map domains and domain walls at high speed and mechanically remove the screening charges. Yet the underlying mechanism of the CGM signals is not fully understood due to the complexity of the electrostatic interactions. Here, we designed a semiconductor-metal CGM tip, which can separate and quantify the ferroelectric domain and domain wall signals by simply changing its scanning direction. Our investigation reveals that the domain wall signals are due to the spatial change of polarization charges, while the domain signals are due to continuous removal and supply of screening charges at the CGM tip. In addition, we observed asymmetric CGM domain currents from the up and down domains, which are originated from the different debonding energies and the amount of the screening charges on positive and negative bound charges. We believe that our findings can help design CGM with high spatial resolution and lead to breakthroughs in information storage and energy-harvesting devices. PMID:26751281

  20. Investigation of radio astronomy image processing techniques for use in the passive millimetre-wave security screening environment

    NASA Astrophysics Data System (ADS)

    Taylor, Christopher T.; Hutchinson, Simon; Salmon, Neil A.; Wilkinson, Peter N.; Cameron, Colin D.

    2014-06-01

    Image processing techniques can be used to improve the cost-effectiveness of future interferometric Passive MilliMetre Wave (PMMW) imagers. The implementation of such techniques will allow for a reduction in the number of collecting elements whilst ensuring adequate image fidelity is maintained. Various techniques have been developed by the radio astronomy community to enhance the imaging capability of sparse interferometric arrays. The most prominent are Multi- Frequency Synthesis (MFS) and non-linear deconvolution algorithms, such as the Maximum Entropy Method (MEM) and variations of the CLEAN algorithm. This investigation focuses on the implementation of these methods in the defacto standard for radio astronomy image processing, the Common Astronomy Software Applications (CASA) package, building upon the discussion presented in Taylor et al., SPIE 8362-0F. We describe the image conversion process into a CASA suitable format, followed by a series of simulations that exploit the highlighted deconvolution and MFS algorithms assuming far-field imagery. The primary target application used for this investigation is an outdoor security scanner for soft-sided Heavy Goods Vehicles. A quantitative analysis of the effectiveness of the aforementioned image processing techniques is presented, with thoughts on the potential cost-savings such an approach could yield. Consideration is also given to how the implementation of these techniques in CASA might be adapted to operate in a near-field target environment. This may enable a much wider usability by the imaging community outside of radio astronomy and thus would be directly relevant to portal screening security systems in the microwave and millimetre wave bands.

  1. Stereoscopic uncooled thermal imaging with autostereoscopic 3D flat-screen display in military driving enhancement systems

    NASA Astrophysics Data System (ADS)

    Haan, H.; Münzberg, M.; Schwarzkopf, U.; de la Barré, R.; Jurk, S.; Duckstein, B.

    2012-06-01

    Thermal cameras are widely used in driver vision enhancement systems. However, in pathless terrain, driving becomes challenging without having a stereoscopic perception. Stereoscopic imaging is a well-known technique already for a long time with understood physical and physiological parameters. Recently, a commercial hype has been observed, especially in display techniques. The commercial market is already flooded with systems based on goggle-aided 3D-viewing techniques. However, their use is limited for military applications since goggles are not accepted by military users for several reasons. The proposed uncooled thermal imaging stereoscopic camera with a geometrical resolution of 640x480 pixel perfectly fits to the autostereoscopic display with a 1280x768 pixels. An eye tracker detects the position of the observer's eyes and computes the pixel positions for the left and the right eye. The pixels of the flat panel are located directly behind a slanted lenticular screen and the computed thermal images are projected into the left and the right eye of the observer. This allows a stereoscopic perception of the thermal image without any viewing aids. The complete system including camera and display is ruggedized. The paper discusses the interface and performance requirements for the thermal imager as well as for the display.

  2. Childhood body mass index and adult mammographic density measures that predict breast cancer risk.

    PubMed

    Hopper, John L; Nguyen, Tuong L; Stone, Jennifer; Aujard, Kelly; Matheson, Melanie C; Abramson, Michael J; Burgess, John A; Walters, E Haydn; Dite, Gillian S; Bui, Minh; Evans, Christopher; Makalic, Enes; Schmidt, Daniel F; Ward, Gail; Jenkins, Mark A; Giles, Graham G; Dharmage, Shyamali C; Apicella, Carmel

    2016-02-01

    The aim of the present study is to determine if body mass index (BMI) during childhood is associated with the breast cancer risk factor 'adult mammographic density adjusted for age and BMI'. In 1968, the Tasmanian Longitudinal Health Study studied every Tasmanian school child born in 1961. We obtained measured heights and weights from annual school medical records across ages 7-15 years and imputed missing values. Between 2009 and 2012, we administered to 490 women a questionnaire that asked current height and weight and digitised at least one mammogram per woman. Absolute and percent mammographic densities were measured using the computer-assisted method CUMULUS. We used linear regression and adjusted for age at interview and log current BMI. The mammographic density measures were negatively associated: with log BMI at each age from 7 to 15 years (all p < 0.05); with the average of standardised log BMIs across ages 7-15 years (p < 0.0005); and more strongly with standardised log BMI measures closer to age 15 years (p < 0.03). Childhood BMI measures explained 7 and 10 % of the variance in absolute and percent mammographic densities, respectively, and 25 and 20 % of the association between current BMI and absolute and percent mammographic densities, respectively. Associations were not altered by adjustment for age at menarche. There is a negative association between BMI in late childhood and the adult mammographic density measures that predict breast cancer risk. This could explain, at least in part, why BMI in adolescence is negatively associated with breast cancer risk. PMID:26907766

  3. Cloud Screening and Quality Control Algorithm for Star Photometer Data: Assessment with Lidar Measurements and with All-sky Images

    NASA Technical Reports Server (NTRS)

    Ramirez, Daniel Perez; Lyamani, H.; Olmo, F. J.; Whiteman, D. N.; Navas-Guzman, F.; Alados-Arboledas, L.

    2012-01-01

    This paper presents the development and set up of a cloud screening and data quality control algorithm for a star photometer based on CCD camera as detector. These algorithms are necessary for passive remote sensing techniques to retrieve the columnar aerosol optical depth, delta Ae(lambda), and precipitable water vapor content, W, at nighttime. This cloud screening procedure consists of calculating moving averages of delta Ae() and W under different time-windows combined with a procedure for detecting outliers. Additionally, to avoid undesirable Ae(lambda) and W fluctuations caused by the atmospheric turbulence, the data are averaged on 30 min. The algorithm is applied to the star photometer deployed in the city of Granada (37.16 N, 3.60 W, 680 ma.s.l.; South-East of Spain) for the measurements acquired between March 2007 and September 2009. The algorithm is evaluated with correlative measurements registered by a lidar system and also with all-sky images obtained at the sunset and sunrise of the previous and following days. Promising results are obtained detecting cloud-affected data. Additionally, the cloud screening algorithm has been evaluated under different aerosol conditions including Saharan dust intrusion, biomass burning and pollution events.

  4. Mammographic texture resemblance generalizes as an independent risk factor for breast cancer

    PubMed Central

    2014-01-01

    Introduction Breast density has been established as a major risk factor for breast cancer. We have previously demonstrated that mammographic texture resemblance (MTR), recognizing the local texture patterns of the mammogram, is also a risk factor for breast cancer, independent of percent breast density. We examine if these findings generalize to another population. Methods Texture patterns were recorded in digitalized pre-diagnosis (3.7 years) film mammograms of a nested case–control study within the Dutch screening program (S1) comprising of 245 breast cancers and 250 matched controls. The patterns were recognized in the same study using cross-validation to form resemblance scores associated with breast cancer. Texture patterns from S1 were examined in an independent nested case–control study within the Mayo Mammography Health Study cohort (S2) of 226 cases and 442 matched controls: mammograms on average 8.5 years prior to diagnosis, risk factor information and percent mammographic density (PD) estimated using Cumulus were available. MTR scores estimated from S1, S2 and S1 + S2 (the latter two as cross-validations) were evaluated in S2. MTR scores were analyzed as both quartiles and continuously for association with breast cancer using odds ratios (OR) and adjusting for known risk factors including age, body mass index (BMI), and hormone usage. Results The mean ages of S1 and S2 were 58.0 ± 5.7 years and 55.2 ± 10.5 years, respectively. The MTR scores on S1 showed significant capability to discriminate cancers from controls (area under the operator characteristics curve (AUC) = 0.63 ± 0.02, P <0.001), which persisted after adjustment for PD. S2 showed an AUC of 0.63, 0.61, and 0.60 based on PD, MTR scores trained on S2, and MTR scores trained on S1, respectively. When adjusted for PD, MTR scores of S2 trained on S1 showed an association with breast cancer for the highest quartile alone: OR in quartiles of controls as reference; 1

  5. Improving depth resolution in digital breast tomosynthesis by iterative image reconstruction

    NASA Astrophysics Data System (ADS)

    Roth, Erin G.; Kraemer, David N.; Sidky, Emil Y.; Reiser, Ingrid S.; Pan, Xiaochuan

    2015-03-01

    Digital breast tomosynthesis (DBT) is currently enjoying tremendous growth in its application to screening for breast cancer. This is because it addresses a major weakness of mammographic projection imaging; namely, a cancer can be hidden by overlapping fibroglandular tissue structures or the same normal structures can mimic a malignant mass. DBT addresses these issues by acquiring few projections over a limited angle scanning arc that provides some depth resolution. As DBT is a relatively new device, there is potential to improve its performance significantly with improved image reconstruction algorithms. Previously, we reported a variation of adaptive steepest descent - projection onto convex sets (ASD-POCS) for DBT, which employed a finite differencing filter to enhance edges for improving visibility of tissue structures and to allow for volume-of-interest reconstruction. In the present work we present a singular value decomposition (SVD) analysis to demonstrate the gain in depth resolution for DBT afforded by use of the finite differencing filter.

  6. Association between the Adherence to the International Guidelines for Cancer Prevention and Mammographic Density

    PubMed Central

    Castelló, Adela; Prieto, Leandro; Ederra, María; Salas-Trejo, Dolores; Vidal, Carmen; Sánchez-Contador, Carmen; Santamariña, Carmen; Pedraz, Carmen; Moreo, Pilar; Aragonés, Nuria; Pérez-Gómez, Beatriz; Lope, Virginia; Vioque, Jesús; Pollán, Marina

    2015-01-01

    Introduction Mammographic density (MD) is considered a strong predictor of Breast Cancer (BC). The objective of the present study is to explore the association between MD and the compliance with the World Cancer Research Fund and the American Institute for Cancer Research (WCRF/AICR) recommendations for cancer prevention. Methods Data of 3584 women attending screening from a population-based multicenter cross-sectional study (DDM-Spain) collected from October 7, 2007 through July 14, 2008, was used to calculate a score that measures the level of compliance with the WCRF/AICR recommendations: R1)Maintain adequate body weight; R2)Be physically active; 3R)Limit the intake of high density foods; R4)Eat mostly plant foods; R5)Limit the intake of animal foods; R6)Limit alcohol intake; R7)Limit salt and salt preserved food intake; R8)Meet nutritional needs through diet. The association between the score and MD (assessed by a single radiologist using a semi-quantitative scale) was evaluated using ordinal logistic models with random center-specific intercepts adjusted for the main determinants of MD. Stratified analyses by menopausal status and smoking status were also carried out. Results A higher compliance with the WCRF/AICR recommendations was associated with lower MD (OR1-unit increase = 0.93 95%CI:0.86;0.99). The association was stronger in postmenopausal women (OR = 0.91 95%CI:0.84;0.99) and nonsmokers (OR = 0.87;95%CI:0.80;0.96 for nonsmokers, OR = 1.01 95%CI:0.91;1.12 for smokers, P-interaction = 0.042). Among nonsmokers, maintaining adequate body weight (OR = 0.81 95%CI:0.65;1.01), practicing physical activity (OR = 0.68 95%CI:0.48;0.96) and moderating the intake of high-density foods (OR = 0.58 95%CI:0.40;0.86) and alcoholic beverages (OR = 0.76 95%CI:0.55;1.05) were the recommendations showing the strongest associations with MD. Conclusions postmenopausal women and non-smokers with greater compliance with the WCRF/AICR guidelines have lower MD. These results may

  7. The influence of mammographic density on breast tumor characteristics.

    PubMed

    Eriksson, Louise; Czene, Kamila; Rosenberg, Lena; Humphreys, Keith; Hall, Per

    2012-07-01

    Mammographic density (MD) is a well-established risk factor for breast cancer. Whether MD influences the tumor phenotype remains to be clarified. Previous studies are highly inconsistent and most lack important covariate information. This is a case-only study within a population-based case-control study. Cases were all postmenopausal women, aged 50-74 years, with incident breast cancer, diagnosed 1993-1995, and with no history of previous cancer (n = 2,720). 1,747 women with mammograms and information on tumor characteristics were included in analyses. MD was assessed using a computer-assisted thresholding technique. We used linear, logistic, and multinomial logistic regression, adjusting for possible confounders, to study density and tumor characteristics. PD was only statistically significantly associated with tumor size in our study (regression coefficient 0.031, p = 0.017). The effect of PD on tumor size was greater when mode of detection was excluded from the model (regression coefficient 0.043, p = 0.001). No other associations between PD and the tumor characteristics studied (lymph node metastasis, ER-status, PR-status, grade, and histopathological classification) were observed. In summary, PD was positively associated with tumor size in postmenopausal women. However, the relationship was at least partially confounded by mode of detection. Although there may be a true biological relationship between MD and more highly proliferative tumors, it also seems that part of this relationship is due to masking delaying diagnosis. In conclusion, PD does not seem to be differentially associated with tumor phenotype, except for tumor size, after taking mode of detection into consideration. PMID:22710708

  8. Intra-operative specimen analysis using faxitron microradiography for excision of mammographically suspicious, non-palpable breast lesions.

    PubMed

    Muttalib, M; Tisdall, M; Scawn, R; Shousha, S; Cummins, R S; Sinnett, H D

    2004-08-01

    Recent advances in digital imaging have made Faxitron microradiography an attractive alternative to intra-operative conventional specimen radiography (CSR) for the excision of wire-localized breast lesions. Faxitron specimen analysis time, usefulness of digital image manipulation and re-excision rates were evaluated in comparison to CSR in 299 consecutive wire-localized excisions for mammographically suspicious non-palpable breast lesions (172 procedures with Faxitron, 127 with CSR) in a non-randomized study. The corresponding mean operation times were 34.7 vs. 42.7 min and the respective re-excision rates were 19.8% vs. 31.5% (no significant difference on chi analysis P < 0.1). Faxitron digital image manipulation led to cavity biopsies in 50% (60/121) of the cancer excisions. In 19 of these (16%), histological excision margins were converted from incomplete to complete. The shorter Faxitron mean operating time enables an additional wire-localized operation per theatre list. Digital imaging guides the surgeon for additional cavity biopsies, resulting in re-excision rates as good as CSR. PMID:15325665

  9. The integration of digital camera derived images with a computer based diabetes register for use in retinal screening.

    PubMed

    Taylor, D J; Jacob, J S; Tooke, J E

    2000-07-01

    Exeter district provides a retinal screening service based on a mobile non-mydriatic camera operated by a dedicated retinal screener visiting general practices on a 2-yearly cycle. Digital attachments to eye cameras can now provide a cost effective alternative to the use of film in population based eye screening programmes. Whilst the manufacturers of digital cameras provide a database for the storage of pictures, the images do not as yet interface readily with the rest of the patient's computer held data or allow for a sophisticated grading, reporting and administration system. The system described is a development of the Exeter diabetes register (EXSYST) which can import digitally derived pictures from either Ris-Lite TM and Imagenet TM camera systems or scanned Polaroids Pictures can be reported by the screener, checked by a consultant ophthalmologist via the hospital network, and a report, consisting of colour pictures, map of relevant pathology and referral recommendations produced. This concise report can be hard copied inexpensively on a high resolution ink-jet printer to be returned to the patient's general practitioner. Eye images remain available within the hospital diabetes centre computer network to facilitate shared care. This integrated system would form an ideal platform for the addition of computer based pathology recognition and total paperless transmission when suitable links to GP surgeries become available. PMID:10837903

  10. Influence Of Film And Processing On Film-Screen Image Noise

    NASA Astrophysics Data System (ADS)

    Holland, R. S.

    1982-12-01

    This paper describes experiments which explore the ways in which variations in film and processing influence noise through their effects on the sensitometric curve shape and silver granularity. These include comparisons of several film types and processing conditions for which total radiographic noise from screen exposures and granularity from light exposures are analyzed relative to the instantaneous gradient at the measured density. It is seen that film granularity may indeed contribute substantially to total noise under conditions of low quantum mottle visualization.

  11. Screening of adulterants in powdered foods and ingredients using line-scan Raman chemical imaging.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A newly developed line-scan Raman imaging system using a 785 nm line laser was used to authenticate powdered foods and ingredients. The system was used to collect hyperspectral Raman images in the range of 102–2865 wavenumber from three representative food powders mixed with selected adulterants eac...

  12. Electro- and photoluminescence imaging as fast screening technique of the layer uniformity and device degradation in planar perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Soufiani, Arman Mahboubi; Tayebjee, Murad J. Y.; Meyer, Steffen; Ho-Baillie, Anita; Sung Yun, Jae; MacQueen, Rowan W.; Spiccia, Leone; Green, Martin A.; Hameiri, Ziv

    2016-07-01

    In this study, we provide insights into planar structure methylammonium lead triiodide (MAPbI3) perovskite solar cells (PSCs) using electroluminescence and photoluminescence imaging techniques. We demonstrate the strength of these techniques in screening relatively large area PSCs, correlating the solar cell electrical parameters to the images and visualizing the features which contribute to the variation of the parameters extracted from current density-voltage characterizations. It is further used to investigate one of the major concerns about perovskite solar cells, their long term stability and aging. Upon storage under dark in dry glovebox condition for more than two months, the major parameter found to have deteriorated in electrical performance measurements was the fill factor; this was elucidated via electroluminescence image comparisons which revealed that the contacts' quality degrades. Interestingly, by deploying electroluminescence imaging, the significance of having a pin-hole free active layer is demonstrated. Pin-holes can grow over time and can cause degradation of the active layer surrounding them.

  13. A multi-image approach to CADx of breast cancer with integration into PACS

    NASA Astrophysics Data System (ADS)

    Elter, Matthias; Wittenberg, Thomas; Schulz-Wendtland, Rüdiger; Deserno, Thomas M.

    2009-02-01

    While screening mammography is accepted as the most adequate technique for the early detection of breast cancer, its low positive predictive value leads to many breast biopsies performed on benign lesions. Therefore, we have previously developed a knowledge-based system for computer-aided diagnosis (CADx) of mammographic lesions. It supports the radiologist in the discrimination of benign and malignant lesions. So far, our approach operates on the lesion level and employs the paradigm of content-based image retrieval (CBIR). Similar lesions with known diagnosis are retrieved automatically from a library of references. However, radiologists base their diagnostic decisions on additional resources, such as related mammographic projections, other modalities (e.g. ultrasound, MRI), and clinical data. Nonetheless, most CADx systems disregard the relation between the craniocaudal (CC) and mediolateral-oblique (MLO) views of conventional mammography. Therefore, we extend our approach to the full case level: (i) Multi-frame features are developed that jointly describe a lesion in different views of mammography. Taking into account the geometric relation between different images, these features can also be extracted from multi-modal data; (ii) the CADx system architecture is extended appropriately; (iii) the CADx system is integrated into the radiology information system (RIS) and the picture archiving and communication system (PACS). Here, the framework for image retrieval in medical applications (IRMA) is used to support access to the patient's health care record. Of particular interest is the application of the proposed CADx system to digital breast tomosynthesis (DBT), which has the potential to succeed digital mammography as the standard technique for breast cancer screening. The proposed system is a natural extension of CADx approaches that integrate only two modalities. However, we are still collecting a large enough database of breast lesions with images from

  14. Mammographic parasitic calcifications in South West Nigeria: prospective and descriptive study

    PubMed Central

    Adeniji-Sofoluwe, Adenike Temitayo; Obajimi, Millicent Olubunmi; Oluwasola, Abideen Olayiwola; Soyemi, Temitope O

    2013-01-01

    Introduction Lymphatic filariasis caused by nematode parasite Wuchereria bancrofti and Brugia Malayi is endemic in the tropics. In Nigeria, 25% of the population is infected. Lymph edema and elephantiasis are the predominant manifestations. Its infrequent manifestation is in the breast. This paper discusses the epidemiology, reviews literature, imaging options and mammographic appearances of these parasitic nematodes. Methods This prospective descriptive study reports on 39 cases of parasitic calcifications seen during mammography in the Radiology Department, University College Hospital between 2006 and 2012 in Ibadan, South West Nigeria. Each mammogram was reported by MO and ATS: assigned a final Bi-RADs category. Parasitic calcifications were further evaluated for distribution, and types of calcification. Results A total of 527 women had mammography done between 2006 and 2012. Thirty-nine women (7.4%) had parasitic breast calcifications. The ages of the women ranged between 38-71 years - mean of 52.36±8.72 SD. Twenty-three (59%) were post-menopausal, 16(41%) were pre-menopausal. The majority (31; 79.5%) were screeners while 8(20.5%) were follow up cases. Approximately half (51.3%) of the women had no complaints. Pain (23.1%) was the commonest presentation in the remaining half. Solitary calcifications were predominant (20) while only 3 cases had 10 calcifications. Left sided calcifications (53.8%) were the majority. Calcifications were subcutaneous in 2/3rds of the women (66.7%) while the Yoruba tribe (84.6%) was principal. Conclusion Parasitic breast calcifications can be misdiagnosed on mammography for suspicious micro-calcification. This publication should alert radiologists in a tropical country like Nigeria to increase diagnostic vigilance thereby preventing unnecessary anxiety and invasive work-up procedures. PMID:24255732

  15. Collection of sequential imaging events for research in breast cancer screening

    NASA Astrophysics Data System (ADS)

    Patel, M. N.; Young, K.; Halling-Brown, M. D.

    2016-03-01

    Due to the huge amount of research involving medical images, there is a widely accepted need for comprehensive collections of medical images to be made available for research. This demand led to the design and implementation of a flexible image repository, which retrospectively collects images and data from multiple sites throughout the UK. The OPTIMAM Medical Image Database (OMI-DB) was created to provide a centralized, fully annotated dataset for research. The database contains both processed and unprocessed images, associated data, annotations and expert-determined ground truths. Collection has been ongoing for over three years, providing the opportunity to collect sequential imaging events. Extensive alterations to the identification, collection, processing and storage arms of the system have been undertaken to support the introduction of sequential events, including interval cancers. These updates to the collection systems allow the acquisition of many more images, but more importantly, allow one to build on the existing high-dimensional data stored in the OMI-DB. A research dataset of this scale, which includes original normal and subsequent malignant cases along with expert derived and clinical annotations, is currently unique. These data provide a powerful resource for future research and has initiated new research projects, amongst which, is the quantification of normal cases by applying a large number of quantitative imaging features, with a priori knowledge that eventually these cases develop a malignancy. This paper describes, extensions to the OMI-DB collection systems and tools and discusses the prospective applications of having such a rich dataset for future research applications.

  16. Daily targeting of liver tumors: Screening patients with a mock treatment and using a combination of internal and external fiducials for image-guided respiratory-gated radiotherapy

    SciTech Connect

    Krishnan, Sunil; Briere, Tina Marie; Dong Lei; Murthy, Ravi; Ng, Chaan; Balter, Peter; Mohan, Radhe; Gillin, Michael T.; Beddar, A. Sam

    2007-12-15

    The feasibility and accuracy of using a mock treatment to screen suitable patients for respiratory-gated image-guided radiotherapy was investigated. Radio-opaque fiducials implanted adjacent to the liver tumor were used for online positioning to minimize the systematic error in patient positioning. The consistency in the degree of correlation between the external and internal fiducials was analyzed during a mock treatment. This technique could screen patients for gated therapy, reduce setup inaccuracy, and possibly individualize treatment margins.

  17. Screening of adulterants in powdered foods and ingredients using line-scan Raman chemical imaging

    NASA Astrophysics Data System (ADS)

    Qin, Jianwei; Chao, Kuanglin; Kim, Moon S.

    2015-05-01

    A newly developed line-scan Raman imaging system using a 785 nm line laser was used to authenticate powdered foods and ingredients. The system was used to collect hyperspectral Raman images in a wavenumber range of 102-2865 cm-1 from three representative food powders mixed with selected adulterants with a concentration of 0.5%, including milk and melamine, flour and benzoyl peroxide, and starch and maleic anhydride. An acoustic mixer was used to create food adulterant mixtures. All the mixed samples were placed in sample holders with a surface area of 50 mm×50 mm. Spectral and image processing algorithms were developed based on single-band images at unique Raman peaks of the individual adulterants. Chemical images were created to show identification, spatial distribution, and morphological features of the adulterant particles mixed in the food powders. The potential of estimating mass concentrations of the adulterants using the percentages of the adulterant pixels in the chemical images was also demonstrated.

  18. Various doses of soy isoflavones do not modify mammographic density in postmenopausal women

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soy isoflavones have functional similarity to human estrogens and may protect against breast cancer as a result of their antiestrogenic activity or increase risk as a result of their estrogen-like properties. We examined the relation between isoflavone supplementation and mammographic density, a str...

  19. Feasibility Study on Prenatal Cardiac Screening Using Four-Dimensional Ultrasound with Spatiotemporal Image Correlation: A Multicenter Study

    PubMed Central

    Chen, Sun; Ren, Yunyun; Chen, Ping; Niu, Jianmei; Li, Cao; Sun, Kun

    2016-01-01

    Objective This study aimed at investigating the feasibility of using the spatiotemporal image correlation (STIC) technology for prenatal cardiac screening, finding factors that influence the offline evaluation of reconstructed fetal heart, and establishing an optimal acquisition scheme. Methods The study included 452 gravidae presenting for routine screening at 3 maternity centers at 20–38 gestational weeks. The factors influencing the quality of STIC volume data were evaluated using t test, chi-square test, and logistic regression analysis. The predictive power was evaluated using the receiver operating characteristic (ROC) curve. Results Among the 452 fetuses enrolled, 353 (78.1%) were identified as successful and 99 (21.9%) as failure of evaluation of the reconstructed fetal heart. The total success rate of qualified STIC images was 78.1%. The display rates of reconstructed cardiac views were 86.5% (four-chamber view), 92.5% (left ventricular outflow tract view), 92.7% (right ventricular outflow tract view), 89.9% (three-vessel trachea view), 63.9% (aortic arch view), 81.4% (ductal arch view), 81% (short-axis view of great vessels), 80.1% (long-cava view), and 86.9% (abdominal view). A logistic regression analysis showed that more than 28 gestational weeks [OR = 0.39 (CI 95% 0.16, 0.19), P = 0.035], frequent fetal movements [OR = 0.37 (CI 95% 0.16, 0.87), P = 0.022], shadowing [OR = 0.36 (CI 95% 0.19, 0.72), P = 0.004], spine location at 10–2 o’clock [OR = 0.08 (CI 95% 0.02, 0.27), P = 0.0], and original cardiac view [OR = 0.51 (0.25, 0.89), P = 0.019] had a significant impact on the quality of STIC. The area under the ROC curve was 0.775. Conclusions Fetal cardiac-STIC seems a feasible tool for prenatal screening of congenital heart diseases. The influence factors on the quality of STIC images included the intensity of training, gestational age, fetal conditions and parameter settings. The optimal acquisition scheme may improve the application and

  20. Gamma-H2AX foci counting: image processing and control software for high-content screening

    NASA Astrophysics Data System (ADS)

    Barber, P. R.; Locke, R. J.; Pierce, G. P.; Rothkamm, K.; Vojnovic, B.

    2007-02-01

    Phosphorylation of the chromatin protein H2AX (forming γH2AX) is implicated in the repair of DNA double strand breaks (DSB's); a large number of H2AX molecules become phosphorylated at the sites of DSB's. Fluorescent staining of the cell nuclei for γH2AX, via an antibody, visualises the formation of these foci, allowing the quantification of DNA DSB's and forming the basis for a sensitive biological dosimeter of ionising radiation. We describe an automated fluorescence microscopy system, including automated image processing, to count γH2AX foci. The image processing is performed by a Hough transform based algorithm, CHARM, which has wide applicability for the detection and analysis of cells and cell colonies. This algorithm and its applications for cell nucleus and foci detection will be described. The system also relies heavily on robust control software, written using multi-threaded cbased modules in LabWindows/CVI that adapt to the timing requirements of a particular experiment for optimised slide/plate scanning and mosaicing, making use of modern multi-core processors. The system forms the basis of a general purpose high-content screening platform with wide ranging applications in live and fixed cell imaging and tissue micro arrays, that in future, can incorporate spectrally and time-resolved information.

  1. Phenotyping transgenic embryos: a rapid 3-D screening method based on episcopic fluorescence image capturing.

    PubMed

    Weninger, Wolfgang Johann; Mohun, Timothy

    2002-01-01

    We describe a technique suitable for routine three-dimensional (3-D) analysis of mouse embryos that is based on episcopic fluorescence images captured during serial sectioning of wax-embedded specimens. We have used this procedure to describe the cardiac phenotype and associated blood vessels of trisomic 16 (Ts16) and Cited2-null mutant mice, as well as the expression pattern of an Myf5 enhancer/beta-galactosidase transgene. The consistency of the images and their precise alignment are ideally suited for 3-D analysis using video animations, virtual resectioning or commercial 3-D reconstruction software packages. Episcopic fluorescence image capturing (EFIC) provides a simple and powerful tool for analyzing embryo and organ morphology in normal and transgenic embryos. PMID:11743576

  2. An image-based biosensor assay strategy to screen for modulators of the microRNA 21 biogenesis pathway.

    PubMed

    Shum, David; Bhinder, Bhavneet; Radu, Constantin; Farazi, Thalia; Landthaler, Markus; Tuschl, Thomas; Calder, Paul; Ramirez, Christina N; Djaballah, Hakim

    2012-08-01

    microRNAs (miRNAs) are evolutionary conserved, small endogenous non-coding, RNA molecules. Although their mode of action has been extensively studied, little is known about their biogenesis. As their altered expression has been implicated in many diseases, small molecules that would modulate their expression are sought after. They are generated through the concerted action of several complexes which promote their transcription, maturation, export, trafficking, and loading of mature miRNA into silencing complexes. An increasing number of studies have suggested that each of these steps serves as a regulatory junction in the process, and therefore provides an intervention point. For this purpose, we have developed a simple image-based assay strategy to screen for such modulators. Here, we describe its successful implementation which combines the use of a microRNA 21 (miR-21) synthetic mimic together with an EGFP based reporter cell line, where its expression is under the control of miR-21, to monitor EGFP expression in a format suitable for HTS. The strategy was further validated using a small panel of known gene modulators of the miRNA pathway. A screen was performed in duplicate against a library of 6,912 compounds and identified 48 initial positives exhibiting enhanced EGFP fluorescence intensity. 42 compounds were found to be inherently fluorescent in the green channel leaving the remaining 6 as potential inhibitors and with a positive rate of 0.09%. Taken together, this validated strategy offers the opportunity to discover novel and specific inhibitors of the pathway through the screening of diverse chemical libraries. PMID:22540737

  3. Novel Associations between Common Breast Cancer Susceptibility Variants and Risk-Predicting Mammographic Density Measures

    PubMed Central

    Stone, Jennifer; Thompson, Deborah J.; dos-Santos-Silva, Isabel; Scott, Christopher; Tamimi, Rulla M.; Lindstrom, Sara; Kraft, Peter; Hazra, Aditi; Li, Jingmei; Eriksson, Louise; Czene, Kamila; Hall, Per; Jensen, Matt; Cunningham, Julie; Olson, Janet E.; Purrington, Kristen; Couch, Fergus J.; Brown, Judith; Leyland, Jean; Warren, Ruth M. L.; Luben, Robert N.; Khaw, Kay-Tee; Smith, Paula; Wareham, Nicholas J.; Jud, Sebastian M.; Heusinger, Katharina; Beckmann, Matthias W.; Douglas, Julie A.; Shah, Kaanan P.; Chan, Heang-Ping; Helvie, Mark A.; Le Marchand, Loic; Kolonel, Laurence N.; Woolcott, Christy; Maskarinec, Gertraud; Haiman, Christopher; Giles, Graham G.; Baglietto, Laura; Krishnan, Kavitha; Southey, Melissa C.; Apicella, Carmel; Andrulis, Irene L.; Knight, Julia A.; Ursin, Giske; Grenaker Alnaes, Grethe I.; Kristensen, Vessela N.; Borresen-Dale, Anne-Lise; Gram, Inger Torhild; Bolla, Manjeet K.; Wang, Qin; Michailidou, Kyriaki; Dennis, Joe; Simard, Jacques; Paroah, Paul; Dunning, Alison M.; Easton, Douglas F.; Fasching, Peter A.; Pankratz, V. Shane; Hopper, John; Vachon, Celine M.

    2015-01-01

    Mammographic density measures adjusted for age and body mass index (BMI) are heritable predictors of breast cancer risk but few mammographic density-associated genetic variants have been identified. Using data for 10,727 women from two international consortia, we estimated associations between 77 common breast cancer susceptibility variants and absolute dense area, percent dense area and absolute non-dense area adjusted for study, age and BMI using mixed linear modeling. We found strong support for established associations between rs10995190 (in the region of ZNF365), rs2046210 (ESR1) and rs3817198 (LSP1) and adjusted absolute and percent dense areas (all p <10−5). Of 41 recently discovered breast cancer susceptibility variants, associations were found between rs1432679 (EBF1), rs17817449 (MIR1972-2: FTO), rs12710696 (2p24.1), and rs3757318 (ESR1) and adjusted absolute and percent dense areas, respectively. There were associations between rs6001930 (MKL1) and both adjusted absolute dense and non-dense areas, and between rs17356907 (NTN4) and adjusted absolute non-dense area. Trends in all but two associations were consistent with those for breast cancer risk. Results suggested that 18% of breast cancer susceptibility variants were associated with at least one mammographic density measure. Genetic variants at multiple loci were associated with both breast cancer risk and the mammographic density measures. Further understanding of the underlying mechanisms at these loci could help identify etiological pathways implicated in how mammographic density predicts breast cancer risk. PMID:25862352

  4. Relation between clinical and mammographic diagnosis of breast problems and the cancer/biopsy rate

    PubMed Central

    Sterns, Ernest E.

    1996-01-01

    Objective To determine the sensitivity of mammographic and clinical assessment of breast problems, independent of one another, on the ratio of cancers found to biopsies performed (cancer/biopsy rate). Design A review of diagnoses from prospectively recorded and independently assessed clinical and mammographic examinations. Setting The breast clinic in a university-affiliated hospital. Patients Patients were considered in two age groups — under 50 years and 50 years and over; 1251 patients underwent breast biopsy between September 1976 and November 1994 after clinical assessment and mammography. Main Outcome Measure The cancer diagnosis rate found on biopsy as a result of clinical and mammographic findings. Results In both age groups, mammography was significantly (p < 0.001) more sensitive than clinical assessment in cancer diagnosis but gave a significantly (p < 0.0001) higher rate of false-positive results. The cancer diagnosis rate was highest when lesions were assessed both clinically and mammographically as malignant but was of diagnostic benefit only to women in the under-50-year age group. The cancer rate was 12% when both assessments indicated a benign process and only 2% in women under age 50 years with clinically benign conditions who did not have mammography. Twenty-one percent of the biopsies were obtained in women with clinically normal breasts because of a mammographic abnormality and 17% of all the cancers found were clinically occult. Conclusions The sensitivity of clinical assessment, particularly in premenopausal women is low and the false-positive mammography rate is high, but the cancer/biopsy rate is sufficiently high to warrant breast biopsy if either diagnostic modality suggests a cancer. When neither modality suggests cancer, the cancer/biopsy rate is 12% in both age groups. PMID:8769923

  5. Dietary phytoestrogen intake and mammographic density -- results of a pilot study.

    PubMed

    Nagel, Gabriele; Mack, U; von Fournier, D; Linseisen, J

    2005-09-12

    The influence of dietary phytoestrogens provided by Western diets on mammographic density is not well established. Soy and soy products as source of isoflavones were found to be inversely associated with high mammographic density, a marker for breast cancer risk. Another class of phytoestrogens, the lignans, which are more frequent in Western diets, are rarely investigated. Within the European Prospective Investigation into Cancer and Nutrition cohort in Heidelberg (EPIC-Heidelberg) we explored the feasibility of mammogram collection and measurement of mammographic density in order to investigate the association between dietary phytoestrogen intake and breast density patterns. Wolfe classification was used to summarize mammographic density. Dietary habits were assessed by means of a validated food frequency questionnaire. - Out of the 505 randomly selected women, 317 (63%) returned the questionnaire and 310 (61.4%) women provided informed consent to collect mammograms. Dietary intake of seven women with dense patterns (DY) was compared with 47 women without dense patterns. A high dietary intake of fibre (p-value = 0.008) and secoisolariciresinol (p-value = 0.043) is inversely associated with non-dense breast patterns. This is also observed for a high dietary intake of soy-products (p-value = 0.004) and, in tendency, genistein (p-value = 0.069). After adjustment for energy intake and age the groups of dense and non-dense mammographic patterns were different regarding the intake of carbohydrate (p = 0.032), soy-products (p = 0.020), fibre (p = 0.046), and secoisolariciresinol (p = 0.027). - Our results suggest an inverse association between dietary lignan intake and breast density, similar to the findings for isoflavones. To our knowledge this is the first report on this association, but due to the risk of chance finding, this has to be confirmed in a study with sufficient statistical power. PMID:16183551

  6. A genome-wide imaging-based screening to identify genes involved in synphilin-1 inclusion formation in Saccharomyces cerevisiae

    PubMed Central

    Zhao, Lei; Yang, Qian; Zheng, Ju; Zhu, Xuefeng; Hao, Xinxin; Song, Jia; Lebacq, Tom; Franssens, Vanessa; Winderickx, Joris; Nystrom, Thomas; Liu, Beidong

    2016-01-01

    Synphilin-1 is a major component of Parkinson’s disease (PD) inclusion bodies implicated in PD pathogenesis. However, the machinery controlling synphilin-1 inclusion formation remains unclear. Here, we investigated synphilin-1 inclusion formation using a systematic genome-wide, high-content imaging based screening approach (HCI) in the yeast Saccharomyces cerevisiae. By combining with a secondary screening for mutants showing significant changes on fluorescence signal intensity, we filtered out hits that significantly decreased the expression level of synphilin-1. We found 133 yeast genes that didn’t affect synphilin-1 expression but that were required for the formation of synphilin-1 inclusions. Functional enrichment and physical interaction network analysis revealed these genes to encode for functions involved in cytoskeleton organization, histone modification, sister chromatid segregation, glycolipid biosynthetic process, DNA repair and replication. All hits were confirmed by conventional microscopy. Complementation assays were performed with a selected group of mutants, results indicated that the observed phenotypic changes in synphilin-1 inclusion formation were directly caused by the loss of corresponding genes of the deletion mutants. Further growth assays of these mutants showed a significant synthetic sick effect upon synphilin-1 expression, which supports the hypothesis that matured inclusions represent an end stage of several events meant to protect cells against the synphilin-1 cytotoxicity. PMID:27440388

  7. Concept learning by monkeys with video picture images and a touch screen.

    PubMed Central

    Bhatt, R S; Wright, A A

    1992-01-01

    Two rhesus monkeys were trained in a same/different task to discriminate digitized computer-stored picture stimuli. The pictures were digitized from 35-mm slides and presented in pairs on a computer monitor. The monkeys were required to touch the pictures and then make a choice response to indicate whether the pictures were identical or nonidentical. The response areas and stimuli were located to the sides of the picture stimuli. Responses were defined and monitored by an infrared matrix touch screen. After learning the same/different task, both monkeys showed performance accuracy with novel picture stimuli similar to that with training picture stimuli. This accurate novel-picture transfer indicates that a same/different concept had been learned, a concept similar to the one they had previously demonstrated in a different apparatus with rear-projected slide stimuli and a response lever. PMID:1573373

  8. The use of magnetic nanoparticles in thermal therapy monitoring and screening: Localization and imaging (invited)

    NASA Astrophysics Data System (ADS)

    Weaver, John B.

    2012-04-01

    Magnetic nanoparticles have many diagnostic and therapeutic applications. A method termed magnetic spectroscopy of nanoparticle Brownian motion (MSB) was developed to interrogate in vivo the microscopic environment surrounding magnetic nanoparticles. We can monitor several effects that are important in thermal therapy and screening including temperature measurement and the bound state distribution. Here we report on simulations of nanoparticle localization. Measuring the spatial distribution of nanoparticles would allow us to identify ovarian cancer much earlier when it is still curable or monitor thermal therapies more accurately. We demonstrate that with well-designed equipment superior signal to noise ratio (SNR) can be achieved using only two harmonics rather than using all the harmonics containing signal. Alternatively, smaller magnetic field amplitudes can be used to achieve the same SNR. The SNR is improved using fewer harmonics because the noise is limited.

  9. Discovery of a novel HIV-1 integrase inhibitor from natural compounds through structure based virtual screening and cell imaging.

    PubMed

    Gu, Wan-Gang; Zhang, Xuan; Ip, Denis Tsz-Ming; Yang, Liu-Meng; Zheng, Yong-Tang; Wan, David Chi-Cheong

    2014-09-17

    The interaction between HIV-1 integrase and LEDGF/P75 has been validated as a target for anti-HIV drug development. Based on the crystal structure of integrase in complex with LEDGF/P75, a library containing 80 thousand natural compounds was filtered with virtual screening. 11 hits were selected for cell based assays. One compound, 3-(1,3-benzothiazol-2-yl)-8-{[bis(2-hydroxyethyl)amino]methyl}-7-hydroxy-2H-chromen-2-one (D719) inhibited integrase nuclear translocation in cell imaging. The binding mode of D719 was analyzed with molecular simulation. The anti-HIV activity of D719 was assayed by measuring the p24 antigen production in acute infection. The structure characteristics of D719 may provide valuable information for integrase inhibitor design. PMID:25128456

  10. DetectTLC: Automated Reaction Mixture Screening Utilizing Quantitative Mass Spectrometry Image Feature

    PubMed Central

    Kaddi, Chanchala D.; Bennett, Rachel V.; Paine, Martin R. L.; Banks, Mitchel D.; Weber, Arthur L.; Fernández, Facundo M.; Wang, May D.

    2016-01-01

    Full characterization of complex reaction mixtures is necessary to understand mechanisms, optimize yields, and elucidate secondary reaction pathways. Molecular-level information for species in such mixtures can be readily obtained by coupling mass spectrometry imaging (MSI) with thin layer chromatography (TLC) separations. User-guided investigation of imaging data for mixture components with known m/z values is generally straightforward; however, spot detection for unknowns is highly tedious, and limits the applicability of MSI in conjunction with TLC. To accelerate imaging data mining, we developed DetectTLC, an approach that automatically identifies m/z values exhibiting TLC spot-like regions in MS molecular images. Furthermore, DetectTLC can also spatially match m/z values for spots acquired during alternating high and low collision-energy scans, pairing product ions with precursors to enhance structural identification. As an example, DetectTLC is applied to the identification and structural confirmation of unknown, yet significant, products of abiotic pyrazinone and aminopyrazine nucleoside analog synthesis. PMID:26508443

  11. DetectTLC: Automated Reaction Mixture Screening Utilizing Quantitative Mass Spectrometry Image Features

    NASA Astrophysics Data System (ADS)

    Kaddi, Chanchala D.; Bennett, Rachel V.; Paine, Martin R. L.; Banks, Mitchel D.; Weber, Arthur L.; Fernández, Facundo M.; Wang, May D.

    2016-02-01

    Full characterization of complex reaction mixtures is necessary to understand mechanisms, optimize yields, and elucidate secondary reaction pathways. Molecular-level information for species in such mixtures can be readily obtained by coupling mass spectrometry imaging (MSI) with thin layer chromatography (TLC) separations. User-guided investigation of imaging data for mixture components with known m/z values is generally straightforward; however, spot detection for unknowns is highly tedious, and limits the applicability of MSI in conjunction with TLC. To accelerate imaging data mining, we developed DetectTLC, an approach that automatically identifies m/z values exhibiting TLC spot-like regions in MS molecular images. Furthermore, DetectTLC can also spatially match m/z values for spots acquired during alternating high and low collision-energy scans, pairing product ions with precursors to enhance structural identification. As an example, DetectTLC is applied to the identification and structural confirmation of unknown, yet significant, products of abiotic pyrazinone and aminopyrazine nucleoside analog synthesis.

  12. Screening of adulterants in milk powder using a high-throughput Raman chemical imaging method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Milk is one of the most common targets for economically motivated adulteration. Adulterants in milk can cause illness and death when consumed, thus rapid and accurate detection method is needed for authenticating milk products. Our previous studies based on a point-scan Raman imaging system have dem...

  13. DetectTLC: Automated Reaction Mixture Screening Utilizing Quantitative Mass Spectrometry Image Features.

    PubMed

    Kaddi, Chanchala D; Bennett, Rachel V; Paine, Martin R L; Banks, Mitchel D; Weber, Arthur L; Fernández, Facundo M; Wang, May D

    2016-02-01

    Full characterization of complex reaction mixtures is necessary to understand mechanisms, optimize yields, and elucidate secondary reaction pathways. Molecular-level information for species in such mixtures can be readily obtained by coupling mass spectrometry imaging (MSI) with thin layer chromatography (TLC) separations. User-guided investigation of imaging data for mixture components with known m/z values is generally straightforward; however, spot detection for unknowns is highly tedious, and limits the applicability of MSI in conjunction with TLC. To accelerate imaging data mining, we developed DetectTLC, an approach that automatically identifies m/z values exhibiting TLC spot-like regions in MS molecular images. Furthermore, DetectTLC can also spatially match m/z values for spots acquired during alternating high and low collision-energy scans, pairing product ions with precursors to enhance structural identification. As an example, DetectTLC is applied to the identification and structural confirmation of unknown, yet significant, products of abiotic pyrazinone and aminopyrazine nucleoside analog synthesis. Graphical Abstract ᅟ. PMID:26508443

  14. A novel imaging platform for non-invasive screening of abnormal glucose tolerance.

    PubMed

    Jeong, Bosu; Jung, Chang Hee; Lee, Yong-Ho; Shin, Il-Hyung; Kim, Hansuk; Bae, Soo-Jin; Lee, Dae-Sic; Kang, Eun Seok; Kang, Uk; Kim, Jong Jin; Park, Joong-Yeol

    2016-06-01

    Optical measurement of skin auto-fluorescence (SAF), most likely emanating from accumulated advanced glycation end-products (AGEs), has been proposed for the noninvasive diagnosis of glucose intolerance in clinical settings. Here, we developed a novel imaging system with transmission geometry for SAF measurement and compared its diagnostic performance in a Korean population. PMID:27321320

  15. The diffusion of screening programmes in Italy, years 2011-2012.

    PubMed

    Zappa, Marco; Carozzi, Francesca Maria; Giordano, Livia; Sassatelli, Romano; Federici, Antonio; Zorzi, Manuel; Federici, Antonio

    2015-01-01

    In this report, we present the results of cancer screening programmes in Italy for the years 2011-2012. This report is produced by the National centre for screening monitoring (ONS), together with the Italian professional multidisciplinary screening groups: GISMa (Italian group for mammographic screening), GISCor (Italian group for colorectal screening), and GISCi (Italian group for cervical screening). Since 2004, ONS has been monitoring and supporting Italian screening programmes, in accordance with a decree issued by the Ministry of Health. Multidisciplinary groups work with ONS and provide the know-how required to promote the quality of public health programmes. The following is a brief outline of the Italian screening programme setting: screening programmes (cervical, mammographic, colorectal) have been a Basic Healthcare Parameter (livello essenziale di assistenza, LEA) since 2001; guidelines are provided by the Ministry of Health's Department of Prevention in agreement with regional governments; regional governments are responsible for the organization, management, and quality assurance of screening programmes; since 2004, ONS has been responsible for monitoring and promoting screening programmes nationwide; the results of the screening programmes of each region are evaluated annually by the Ministry of Health in terms of coverage and impact. PMID:26405771

  16. Image resolution in the midsagittal plane of the Orthopantomograph-10 using Lanex regular and T-Mat G screen-film combination.

    PubMed

    Chen, S K; Hollender, L

    1992-10-01

    Image resolution was measured in the midsagittal plane of the Orthopantomograph-10 with the use of Lanex regular and T-Mat G screen-film combination. A thin platinum edge phantom was used to obtain images for calculation of the edge response functions. Subsequently, line spread functions and modulation transfer functions of the system were calculated. Noise equivalent passband values, which were expressed in line pairs per millimeter, were derived to describe the image resolution. The noise equivalent passband values derived in this study were generally smaller than those reported in a previous study. The width of the image layer was found to be uniform at different vertical levels. PMID:1408031

  17. Automatic detection of hidden threats in the TeraSCREEN passive millimeter-wave imaging subsystem

    NASA Astrophysics Data System (ADS)

    Madhogaria, Satish; Schikora, Marek

    2015-05-01

    Passive millimeter-wave imaging systems can play a significant role in security applications. Especially, the detection of hidden threats for border security is a growing field. In this paper we propose a novel approach for automatic threat detection using multiple 94 GHz passive millimeter-wave images. Herein, we discuss four steps essential to solving the task: pre-processing, region-of-interest extraction, threat extraction in each frame and, finally, intelligent fusion of the results from all frames. Besides, showing that the proposed method works reliably for the data-set at hand, we also discuss the advantages of using this method in contrast to state-of-the-art methods.

  18. How I report breast magnetic resonance imaging studies for breast cancer staging and screening.

    PubMed

    Vinnicombe, Sarah

    2016-01-01

    Magnetic resonance imaging (MRI) of the breast is the most sensitive imaging technique for the diagnosis and local staging of primary breast cancer and yet, despite the fact that it has been in use for 20 years, there is little evidence that its widespread uncritical adoption has had a positive impact on patient-related outcomes.This has been attributed previously to the low specificity that might be expected with such a sensitive modality, but with modern techniques and protocols, the specificity and positive predictive value for malignancy can exceed that of breast ultrasound and mammography. A more likely explanation is that historically, clinicians have acted on MRI findings and altered surgical plans without prior histological confirmation. Furthermore, modern adjuvant therapy for breast cancer has improved so much that it has become a very tall order to show a an improvement in outcomes such as local recurrence rates.In order to obtain clinically useful information, it is necessary to understand the strengths and weaknesses of the technique and the physiological processes reflected in breast MRI. An appropriate indication for the scan, proper patient preparation and good scan technique, with rigorous quality assurance, are all essential prerequisites for a diagnostically relevant study.The use of recognised descriptors from a standardised lexicon is helpful, since assessment can then dictate subsequent recommendations for management, as in the American College of Radiology BI-RADS (Breast Imaging Reporting and Data System) lexicon (Morris et al., ACR BI-RADS® Atlas, Breast Imaging Reporting and Data System, 2013). It also enables audit of the service. However, perhaps the most critical factor in the generation of a meaningful report is for the reporting radiologist to have a thorough understanding of the clinical question and of the findings that will influence management. This has never been more important than at present, when we are in the throes of a

  19. Screening of Protein Crystallization Trials by Second Order Nonlinear Optical Imaging of Chiral Crystals (SONICC)

    PubMed Central

    Haupert, Levi; Simpson, Garth

    2011-01-01

    Second order nonlinear optical imaging of chiral crystals (SONICC) is a promising new method for the sensitive and selective detection of protein crystals. Relevant general principles of second harmonic generation, which underpins SONICC, are reviewed. Instrumentation and methods for SONICC measurements are described and critically assessed in terms of performance trade-offs. Potential origins of false-positives and false-negatives are also discussed. PMID:22101350

  20. Content-based image retrieval applied to BI-RADS tissue classification in screening mammography

    PubMed Central

    de Oliveira, Júlia Epischina Engrácia; de Albuquerque Araújo, Arnaldo; Deserno, Thomas M

    2011-01-01

    AIM: To present a content-based image retrieval (CBIR) system that supports the classification of breast tissue density and can be used in the processing chain to adapt parameters for lesion segmentation and classification. METHODS: Breast density is characterized by image texture using singular value decomposition (SVD) and histograms. Pattern similarity is computed by a support vector machine (SVM) to separate the four BI-RADS tissue categories. The crucial number of remaining singular values is varied (SVD), and linear, radial, and polynomial kernels are investigated (SVM). The system is supported by a large reference database for training and evaluation. Experiments are based on 5-fold cross validation. RESULTS: Adopted from DDSM, MIAS, LLNL, and RWTH datasets, the reference database is composed of over 10 000 various mammograms with unified and reliable ground truth. An average precision of 82.14% is obtained using 25 singular values (SVD), polynomial kernel and the one-against-one (SVM). CONCLUSION: Breast density characterization using SVD allied with SVM for image retrieval enable the development of a CBIR system that can effectively aid radiologists in their diagnosis. PMID:21286492

  1. An automated high-content screening image analysis pipeline for the identification of selective autophagic inducers in human cancer cell lines.

    PubMed

    Kriston-Vizi, Janos; Lim, Ching Aeng; Condron, Peter; Chua, Kelvin; Wasser, Martin; Flotow, Horst

    2010-08-01

    Automated image processing is a critical and often rate-limiting step in high-content screening (HCS) workflows. The authors describe an open-source imaging-statistical framework with emphasis on segmentation to identify novel selective pharmacological inducers of autophagy. They screened a human alveolar cancer cell line and evaluated images by both local adaptive and global segmentation. At an individual cell level, region-growing segmentation was compared with histogram-derived segmentation. The histogram approach allowed segmentation of a sporadic-pattern foreground and hence the attainment of pixel-level precision. Single-cell phenotypic features were measured and reduced after assessing assay quality control. Hit compounds selected by machine learning corresponded well to the subjective threshold-based hits determined by expert analysis. Histogram-derived segmentation displayed robustness against image noise, a factor adversely affecting region growing segmentation. PMID:20547532

  2. Magnetic induction imaging with optical atomic magnetometers: towards applications to screening and surveillance

    NASA Astrophysics Data System (ADS)

    Marmugi, Luca; Hussain, Sarah; Deans, Cameron; Renzoni, Ferruccio

    2015-10-01

    We propose a new approach, based on optical atomic magnetometers and magnetic induction tomography (MIT), for remote and non-invasive detection of conductive targets. Atomic magnetometers overcome the main limitations of conventional MIT instrumentation, in particular their poor low-frequency sensitivity, their large size and their limited scalability. Moreover, atomic magnetometers have been proven to reach extremely high sensitivities, with an improvement of up to 7 orders of magnitude in the 50 MHz to DC band, with respect to a standard pick-up coil of the same size. In the present scheme, an oscillating magnetic field induces eddy currents in a conductive target and laser-pumped atomic magnetometers, either stand-alone or in an array, detect the response of the objects. A phase-sensitive detection scheme rejects the background, allowing remote detection of the secondary field and, thus, mapping of objects, hidden in cargos, underwater or underground. The potential for extreme sensitivity, miniaturization, dynamic range and array operation paves the way to a new generation of non-invasive, active detectors for surveillance, as well as for real-time cargo screening.

  3. Discussing the benefits and harms of screening mammography.

    PubMed

    Brennan, Meagan; Houssami, Nehmat

    2016-10-01

    Mammographic screening programs were established around the world following randomised clinical trials showing that women who were screened had a significant reduction in the risk of dying from breast cancer. Now, decades later, several harms of screening have become apparent and the degree of risk reduction is being debated. This article aims to provide clinicians with evidence-based information about the benefits and harms of screening mammography to enable them to confidently discuss the issues with their patients. The issues around screening for breast cancer in asymptomatic women at average risk are complex. Women need accurate, balanced information to make an informed decision about whether they wish to participate in screening. The decision will vary from one woman to another, depending on her level of anxiety about cancer and recall, her personal values and her philosophy about health care. PMID:27621253

  4. Effect of developer temperature changes on the sensitometric properties of direct exposure and screen-film imaging systems.

    PubMed

    Kircos, L T; Staninec, M; Chou, L S

    1989-02-01

    A heat exchanger was developed and incorporated into the recirculation system of a dental processor to maintain strict temperature control. Without the heat exchanger, developer temperature rose steadily over 8 h to a maximum of 35.7 degrees C: with the heat exchanger it was maintained, regardless of ambient conditions, at the desired temperature with virtually no fluctuation. Sensitometric properties of base and fog, speed, and average gradient were measured for D and E speed films and Lanex Regular/T-Mat G and Lanex Fast/T-Mat Hscreen-film systems at developer temperatures of 21.1, 23.8, 26.7, 29.4 and 32.2 degrees C. Small changes in these properties were found for D and E speed films: on the other hand, Lanex Regular/T-Mat G showed a 65% increase in base and fog and Lanex Fast/T-Mat H a 43% increase in average gradient over the temperature range studied. Although these changes may not be clinically significant for intra-oral and dental radiography, the variations in image quality may compromise controlled imaging experiments and clinically compromise radiographic quality when using screen-film systems. PMID:2599232

  5. A study of X-ray luminescence and spectral compatibility of europium-activated yttrium-vanadate (YVO4: Eu) screens for medical imaging applications

    NASA Astrophysics Data System (ADS)

    Panayiotakis, G.; Cavouras, D.; Kandarakis, I.; Nomicos, C.

    1996-04-01

    The X-ray luminescence efficiency of laboratory-prepared YVO4 : Eu screens and their spectral compatibility to common optical detectors were studied under medical fluoroscopy conditions. YVO4 : Eu screens were prepared by sedimentation and with different coating thickness. Luminescence efficiency of the YVO4 : Eu screens was measured at various X-ray tube voltages (50 250 kVp) and for screens of different coating thicknesses (20 180 mg/cm2). Spectral response was also measured and spectral matching factors between the YVO4 : Eu screens and some common optical detectors (photocathodes, photodiodes, photographic emulsion) were calculated. Experimental results on efficiency were fitted by formulas of the theoretical model developed by Hamaker and Ludwig in order to determine phosphor intrinsic X-ray-to-light conversion efficiency and intrinsic optical characteristics, such as coefficients related to light scattering and absorption. Although the luminescence efficiency of YVO4 : Eu screens was found to be relatively low (3 11 μW s/mR m2), the matching factor of YVO4 : Eu screens with some red sensitive optical detectors was excellent, of the order of 0.96. High spectral compatibility may indicate that YVO4 : Eu scintillators could be used in medical image detectors.

  6. Computer-assisted screening of Ziehl-Neelsen-stained tissue for mycobacteria. Algorithm design and preliminary studies on 2,000 images.

    PubMed

    Tadrous, Paul J

    2010-06-01

    Screening Ziehl-Neelsen (ZN)-stained sections for acid-alcohol-fast bacilli (AAFB) is laborious, and sparse bacilli are easily missed. This article presents an automatic screening algorithm using digital image analysis designed to assist human diagnosis of tissue sections. The algorithm uses multiderivative source potentiators and suppressors feeding into interconnected product nodes that result in a probability value for each image (the likelihood that it contains AAFB) and a spatial probability map showing the position of any bacillus. For the study, 3,000 images from ZN-stained tissues were captured, 1,000 were used to train the algorithm, and 2,000 were used to test it. The algorithm successfully ranked AAFB-containing images as the highest in the data sets, despite only single bacilli being present in sparse images (occupying 0.0024% of the image) and despite tissue and staining artifacts. These results suggest that this automated screening assistance method has the potential to save time and money, which is especially important in resource-poor health services. PMID:20472842

  7. Chip-based generation of carbon nanodots via electrochemical oxidation of screen printed carbon electrodes and the applications for efficient cell imaging and electrochemiluminescence enhancement.

    PubMed

    Xu, Yuanhong; Liu, Jingquan; Zhang, Jizhen; Zong, Xidan; Jia, Xiaofang; Li, Dan; Wang, Erkang

    2015-06-01

    A portable lab-on-a-chip methodology to generate ionic liquid-functionalized carbon nanodots (CNDs) was developed via electrochemical oxidation of screen printed carbon electrodes. The CNDs can be successfully applied for efficient cell imaging and solid-state electrochemiluminescence sensor fabrication on the paper-based chips. PMID:25959400

  8. Background Parenchymal Uptake During Molecular Breast Imaging and Associated Clinical Factors

    PubMed Central

    Hruska, Carrie B.; Rhodes, Deborah J.; Conners, Amy Lynn; Jones, Katie N.; Carter, Rickey E.; Lingineni, Ravi K.; Vachon, Celine M.

    2015-01-01

    OBJECTIVE The purposes of this study were to describe the prevalence of background parenchymal uptake categories observed at screening molecular breast imaging (MBI) and to examine the association of background parenchymal uptake with mammographic density and other clinical factors. MATERIALS AND METHODS Adjunct MBI screening was performed for women with dense breasts on previous mammograms. Two radiologists reviewed images from the MBI examinations and subjectively categorized background parenchymal uptake into four groups: photopenic, minimal-mild, moderate, or marked. Women with breast implants or a personal history of breast cancer were excluded. The association between background parenchymal uptake categories and patient characteristics was examined with Kruskal-Wallis and chi-square tests as appropriate. RESULTS In 1149 eligible participants, background parenchymal uptake was photopenic in 252 (22%), minimal-mild in 728 (63%), and moderate or marked in 169 (15%). The distribution of categories differed across BI-RADS density categories (p < 0.0001). In 164 participants with extremely dense breasts, background parenchymal uptake was photopenic in 72 (44%), minimal-mild in 55 (34%), and moderate or marked in 37 (22%). The moderate-marked group was younger on average, more likely to be premenopausal or perimenopausal, and more likely to be using postmenopausal hormone therapy than the photopenic or minimal-mild groups (p < 0.0001). CONCLUSION Among women with similar-appearing mammographic density, background parenchymal uptake ranged from photopenic to marked. Background parenchymal uptake was associated with menopausal status and postmenopausal hormone therapy but not with premenopausal hormonal contraceptives, phase of menstrual cycle, or Gail model 5-year risk of breast cancer. Additional work is necessary to fully characterize the underlying cause of background parenchymal uptake and determine its utility in predicting subsequent risk of breast cancer. PMID

  9. Assessment of 1183 screen-detected, category 3B, circumscribed masses by cytology and core biopsy with long-term follow up data.

    PubMed

    Farshid, G; Downey, P; Gill, Pg; Pieterse, S

    2008-04-01

    Discrete masses are commonly detected during mammographic screening and most such lesions are benign. For lesions without pathognomonically benign imaging features that are still regarded likely to be non-malignant (Tabar grade 3) reliable biopsy results would be a clinically useful alternative to mammographic surveillance. Appropriate institutional guidelines for ethical research were followed. Between Jan 1996--Dec 2005 grade 3B discrete masses detected in the setting of a large, population based, breast cancer screening programme are included. Patient demographics, fine needle aspiration biopsy (FNAB), core and surgical biopsy results are tabulated. The final pathology of excised lesions was obtained. Information regarding interval cancers was obtained from the State Cancer Registry records and also through long term follow-up of clients in subsequent rounds of screening. A total of 1183 lesions, mean diameter of 13.3 mm (+/-8.3 mm) and mean client age of 55.1 years (+/-8.8 years) are included. After diagnostic work up, 98 lesions (8.3%) were malignant, 1083 were non-malignant and a final histologic diagnosis was not established in two lesions. In the 27 months after assessment, no interval cancers were attributable to these lesions and during a mean follow up of 54.5 months, available in 84.9% of eligible women, only one cancer has developed in the same quadrant as the original lesion, although the two processes are believed to be unrelated. FNAB performed in 1149 cases was definitive in 80.5% cases (882 benign, 43 malignant) with a negative predictive value (NPV) of 99.8% (880 of 882) and a positive predictive value (PPV) of 95.2% (40 of 42, both intraductal papillomas). Core biopsy was performed in 178 lesions, mostly for indefinite cytology. Core biopsy was definitive in 79.8% cases (57% benign 22% malignant) with a PPV of 100% and NPV of 99.0%. In experienced hands FNAB is an accurate first line diagnostic modality for the assessment of 3B screen

  10. Light emission efficiency and imaging performance of Y3Al5O12: Ce (YAG: Ce) powder screens under diagnostic radiology conditions

    NASA Astrophysics Data System (ADS)

    Cavouras, D.; Kandarakis, I.; Nikolopoulos, D.; Kalatzis, I.; Kagadis, G.; Kalivas, N.; Episkopakis, A.; Linardatos, D.; Roussou, M.; Nirgianaki, E.; Margetis, D.; Valais, I.; Sianoudis, I.; Kourkoutas, K.; Dimitropoulos, N.; Louizi, A.; Nomicos, C.; Panayiotakis, G.

    2005-06-01

    In this study Y3Al5O12: Ce powder scintillator was evaluated for use in X-ray imaging detectors. This phosphor, also known as YAG: Ce scintillator or P-46 phosphor, is a non-hygroscopic, emitting green light with very short decay time. These properties are very attractive for X-ray imaging. Y3Al5O12: Ce powder was used to prepare various test screens (33 166 mg/cm2). Absolute luminescence efficiency measurements were performed for various X-ray tube voltages (50 130 kVp). In addition parameters related to image quality such as the modulation transfer function and the detective quantum efficiency were examined. A theoretical model, describing radiation and light transfer, was employed to fit experimental data and to estimate values of optical parameters. Absolute efficiency was found to decrease with X-ray tube voltage. Highest efficiency was obtained for the 107 mg/cm2 screen. Light attenuation coefficients were close to those of green emitting rare earth scintillators. At low spatial frequencies the detective quantum efficiency was high for the 107 166 mg/cm2 screens. The light emission efficiency and imaging performance of Y3Al5O12: Ce was not better than currently employed scintillators. However due to its very fast response and high spectral compatibility to optical sensors it may be considered for use in digital imaging detectors.

  11. Automated analysis of siRNA screens of cells infected by hepatitis C and dengue viruses based on immunofluorescence microscopy images

    NASA Astrophysics Data System (ADS)

    Matula, Petr; Kumar, Anil; Wörz, Ilka; Harder, Nathalie; Erfle, Holger; Bartenschlager, Ralf; Eils, Roland; Rohr, Karl

    2008-03-01

    We present an image analysis approach as part of a high-throughput microscopy siRNA-based screening system using cell arrays for the identification of cellular genes involved in hepatitis C and dengue virus replication. Our approach comprises: cell nucleus segmentation, quantification of virus replication level in the neighborhood of segmented cell nuclei, localization of regions with transfected cells, cell classification by infection status, and quality assessment of an experiment and single images. In particular, we propose a novel approach for the localization of regions of transfected cells within cell array images, which combines model-based circle fitting and grid fitting. By this scheme we integrate information from single cell array images and knowledge from the complete cell arrays. The approach is fully automatic and has been successfully applied to a large number of cell array images from screening experiments. The experimental results show a good agreement with the expected behaviour of positive as well as negative controls and encourage the application to screens from further high-throughput experiments.

  12. Chest radiographic image quality: comparison of asymmetric screen-film, digital storage phosphor, and digital selenium drum systems--preliminary study.

    PubMed

    Beute, G H; Flynn, M J; Eyler, W R; Samei, E; Spizarny, D L; Zylak, C J

    1998-01-01

    Conventional screen-film radiography does not display all regions of the thorax satisfactorily. Three chest radiographic techniques display both the lung and the mediastinum with good contrast. These techniques are asymmetric screen-film (ASF), digital storage phosphor (DSP), and digital selenium drum (DSD) imaging. ASF systems use two asymmetric screen-film combinations to produce a wide-latitude image of the thorax with good contrast in the lungs. In DSP systems, image data are acquired digitally with a wide dynamic range by using the optical output of a photostimulable phosphor plate; in DSD systems, the wide-range digital image data are acquired by using the electronic charge generated on a drum coated with a thin layer of amorphous selenium. The appearance of a DSP or DSD radiograph is then determined by user-selected image processing operations: tone scaling, spatial frequency processing, and dynamic range compensation. Digital chest radiographs processed with strong regional equalization provide both excellent contrast in the lungs and effective display of the mediastinum and chest wall. At visual comparison, the high lung contrast and good mediastinal, retrocardiac, and subdiaphragmatic detail provided by the DSD method distinguish it from the other two methods. PMID:9599395

  13. Performance of x-ray imaging systems with optical coupling for demagnification between scintillator and CCD readout

    NASA Astrophysics Data System (ADS)

    Roehrig, Hans; Yu, Tong; Schempp, William V.

    1994-11-01

    This paper discusses the performance of x-ray imaging devices employing optical coupling between the x-ray detector (phosphor screen) and the readout (CCD). Optical coupling can be performed with the aid of a lens or with the aid of a fiber-optic taper. Conventional wisdom predicts that fiber-optic coupling is superior on account of superior light collection efficiency. For the same demagnification, fiber-optic tapers usually have a higher numerical aperture in the object plane than a lens. This paper presents a review of critical imaging system components and provides a comparison of factors such as light collection efficiency, phosphor screen light output and CCD sensitivity. The paper presents data obtained with two commercially available x-ray imaging systems, one a lens coupled system, the other a fiber- optically coupled system. These systems are used for mammographically guided stereotactic breast biopsy to determine the x-, y-, and z-coordinates of the lesion to be biopsied. The paper concludes that a lens coupled x-ray imaging system can be superior to a fiber-optic one, particularly with respect to Detective Quantum Efficiency. This superiority is based on a quantum gain of about 5 CCD electrons per absorbed x-ray photon, which is (however barely) sufficient to preserve most of the information collected by the system's Lanex screen.

  14. Dialkoxyquinazolines: Screening Epidermal Growth Factor ReceptorTyrosine Kinase Inhibitors for Potential Tumor Imaging Probes

    SciTech Connect

    VanBrocklin, Henry F.; Lim, John K.; Coffing, Stephanie L.; Hom,Darren L.; Negash, Kitaw; Ono, Michele Y.; Hanrahan, Stephen M.; Taylor,Scott E.; Vanderpoel, Jennifer L.; Slavik, Sarah M.; Morris, Andrew B.; Riese II, David J.

    2005-09-01

    The epidermal growth factor receptor (EGFR), a long-standingdrug development target, is also a desirable target for imaging. Sixteendialkoxyquinazoline analogs, suitable for labeling with positron-emittingisotopes, have been synthesized and evaluated in a battery of in vitroassays to ascertain their chemical and biological properties. Thesecharacteristics provided the basis for the adoption of a selection schemato identify lead molecules for labeling and in vivo evaluation. A newEGFR tyrosine kinase radiometric binding assay revealed that all of thecompounds possessed suitable affinity (IC50 = 0.4 - 51 nM) for the EGFRtyrosine kinase. All of the analogs inhibited ligand-induced EGFRtyrosine phosphorylation (IC50 = 0.8 - 20 nM). The HPLC-estimatedoctanol/water partition coefficients ranged from 2.0-5.5. Four compounds,4-(2'-fluoroanilino)- and 4-(3'-fluoroanilino)-6,7-diethoxyquinazoline aswell as 4-(3'-chloroanilino)- and4-(3'-bromoanilino)-6,7-dimethoxyquinazoline, possess the bestcombination of characteristics that warrant radioisotope labeling andfurther evaluation in tumor-bearing mice.

  15. Tactile Imaging of an Imbedded Palpable Structure for Breast Cancer Screening

    PubMed Central

    2015-01-01

    Apart from texture, the human finger can sense palpation. The detection of an imbedded structure is a fine balance between the relative stiffness of the matrix, the object, and the device. If the device is too soft, its high responsiveness will limit the depth to which the imbedded structure can be detected. The sensation of palpation is an effective procedure for a physician to examine irregularities. In a clinical breast examination (CBE), by pressing over 1 cm2 area, at a contact pressure in the 70–90 kPa range, the physician feels cancerous lumps that are 8- to 18-fold stiffer than surrounding tissue. Early detection of a lump in the 5–10 mm range leads to an excellent prognosis. We describe a thin-film tactile device that emulates human touch to quantify CBE by imaging the size and shape of 5–10 mm objects at 20 mm depth in a breast model using ∼80 kPa pressure. The linear response of the device allows quantification where the greyscale corresponds to the relative local stiffness. The (background) signal from <2.5-fold stiffer objects at a size below 2 mm is minimal. PMID:25148477

  16. Geomatics for precise 3D breast imaging.

    PubMed

    Alto, Hilary

    2005-02-01

    Canadian women have a one in nine chance of developing breast cancer during their lifetime. Mammography is the most common imaging technology used for breast cancer detection in its earliest stages through screening programs. Clusters of microcalcifications are primary indicators of breast cancer; the shape, size and number may be used to determine whether they are malignant or benign. However, overlapping images of calcifications on a mammogram hinder the classification of the shape and size of each calcification and a misdiagnosis may occur resulting in either an unnecessary biopsy being performed or a necessary biopsy not being performed. The introduction of 3D imaging techniques such as standard photogrammetry may increase the confidence of the radiologist when making his/her diagnosis. In this paper, traditional analytical photogrammetric techniques for the 3D mathematical reconstruction of microcalcifications are presented. The techniques are applied to a specially designed and constructed x-ray transparent Plexiglas phantom (control object). The phantom was embedded with 1.0 mm x-ray opaque lead pellets configured to represent overlapping microcalcifications. Control points on the phantom were determined by standard survey methods and hand measurements. X-ray films were obtained using a LORAD M-III mammography machine. The photogrammetric techniques of relative and absolute orientation were applied to the 2D mammographic films to analytically generate a 3D depth map with an overall accuracy of 0.6 mm. A Bundle Adjustment and the Direct Linear Transform were used to confirm the results. PMID:15649085

  17. Fractal dimension and lacunarity analysis of mammographic patterns in assessing breast cancer risk related to HRT treated population: a longitudinal and cross-sectional study

    NASA Astrophysics Data System (ADS)

    Karemore, Gopal; Nielsen, Mads

    2009-02-01

    Structural texture measures are used to address the aspect of breast cancer risk assessment in screening mammograms. The current study investigates whether texture properties characterized by local Fractal Dimension (FD) and Lacunarity contribute to asses breast cancer risk. FD represents the complexity while the Lacunarity characterize the gappiness of a fractal. Our cross-sectional case-control study includes mammograms of 50 patients diagnosed with breast cancer in the subsequent 2-4 years and 50 matched controls. The longitudinal double blind placebo controlled HRT study includes 39 placebo and 36 HRT treated volunteers for two years. ROIs with same dimension (250*150 pixels) were created behind the nipple region on these radiographs. Box counting method was used to calculate the fractal dimension (FD) and the Lacunarity. Paired t-test and Pearson correlation coefficient were calculated. It was found that there were no differences between cancer and control group for FD (P=0.8) and Lacunarity (P=0.8) in crosssectional study whereas earlier published heterogeneity examination of radiographs (BC-HER) breast cancer risk score separated groups (p=0.002). In the longitudinal study, FD decreased significantly (P<0.05) in the HRT treated population while Lacunarity remained insignificant (P=0.2). FD is negatively correlated to Lacunarity (-0.74, P<0.001), BIRADS (-0.34, P<0.001) and Percentage Density (-0.41, P<0.001). FD is invariant to the mammographic texture change from control to cancer population but marginally varying in HRT treated population. This study yields no evidence that lacunarity or FD are suitable surrogate markers of mammographic heterogeneity as they neither pick up breast cancer risk, nor show good sensitivity to HRT.

  18. Incorporation of clinical data into a computerized method for the assessment of mammographic breast lesions

    NASA Astrophysics Data System (ADS)

    Huo, Zhimin; Giger, Maryellen L.

    2000-06-01

    We previously developed a computerized method to classify mammographic masses as benign or malignant. In this method, mammographic features that are similar to the ones used by radiologists are automatically extracted to characterize a mass lesion. These features are then merged by an artificial neural network (ANN), which yields an estimated likelihood of malignancy for each mass. The performance of the method was evaluated on an independent database consisting of 110 cases (60 benign and 50 malignant cases). The method achieved an Az of 0.91 from round-robin analysis in the task of differentiating between benign and malignant masses using the computer-extracted features only. As the most important clinical risk factor for breast cancer, age achieved a performance level (Az equals 0.79) similar to that (Az equals 0.77 and 0.80) of the computer-extracted spiculation features, which are the most important indicators for malignancy of a mass, in differentiating between the malignant and benign cases. In this study, age is included as an additional input feature to the ANN. The performance of the scheme (Az equals 0.93) is improved when age is included. However, the improvement is not found to be statistically significant. Our results indicated that age may be a strong feature in predicting malignancy of a mass. For this database, however, the inclusion of age may not have a strong impact on the determination of the likelihood for a mammographic mass lesion when the major mammographic characteristics (e.g., spiculation) of a mass are accurately extracted and analyzed along with other features using an artificial neural network.

  19. [Giant cystosarcoma phylloides: mammographic and sonographic findings in an unusual case].

    PubMed

    Schön, G; Strasser, K; Dünser, M; Buchberger, W; Margreiter, R

    1994-01-01

    Cystosarcoma phylloides (also called phylloides tumour) is a rare fibroepithelial mixed tumour which accounts for 0.3 to 1% of all breast neoplasms. Diagnosis can be strongly suspected after clinical, mammographical and especially sonographical findings. Neither mammography nor sonography and even not aspiration cytology can be reliably used to differentiate between benign and malignant tumours. In the following a patient is presented in whom cystosarcoma phylloides attained, even for this kind of tumour, an unusually large dimension. PMID:8136391

  20. Vision Screening

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Visi Screen OSS-C, marketed by Vision Research Corporation, incorporates image processing technology originally developed by Marshall Space Flight Center. Its advantage in eye screening is speed. Because it requires no response from a subject, it can be used to detect eye problems in very young children. An electronic flash from a 35 millimeter camera sends light into a child's eyes, which is reflected back to the camera lens. The photorefractor then analyzes the retinal reflexes generated and produces an image of the child's eyes, which enables a trained observer to identify any defects. The device is used by pediatricians, day care centers and civic organizations that concentrate on children with special needs.

  1. A Novel Reporter System for Molecular Imaging and High Throughput Screening of Anticancer Drugs

    PubMed Central

    Wang, Chunxia; Virostko, John; Manning, H. Charles; Pham, Wellington; Bauer, Joshua

    2013-01-01

    Apoptosis is irreversible programmed cell death characterized by a cellular cascade activation of caspase-3, which subsequently degrades proteins and other components of cells with a motif sequence. Here we report a novel reporter system to detect apoptosis, growth arrest and cell death based on controlled and self-amplified protein degradation. The key element of the reporter system is an apoptotic sensor chimerical protein which consists of three components, the procaspase 3, ubiquitin (Ub), and a strong consensus sequence of N-degron. Between each of these units, there is a DEVD (Asp-Glu-Val-Asp) sequence, which acts as the cleavage target of caspase-3. This non-conventional signal loss approach is much more sensitive than other native methods based on signal gain. The superior sensitivity is demonstrated by its effective application in 386-well HTS with lower drug concentrations and short incubation time. The HTS selection process using this reporter system is very simple and economic. The simplicity eliminates potential errors introduced by multiple steps; there is no need for any substrate. Furthermore the cells in the assay need not be disrupted and the morphology of the cells can provide additional information on mechanisms; the intact cells after HTS can also be used for other analytic analysis. This system thus has a potentially important role in the discovery and development of new anticancer drugs, it also appears to be very versatile, can be used both in vitro and in vivo, with different linked reporter genes, it can be used for a variety of imaging applications. PMID:23881799

  2. A prospective study of variability in mammographic density during the menstrual cycle.

    PubMed

    Morrow, Monica; Chatterton, Robert T; Rademaker, Alfred W; Hou, Nanjiang; Jordan, V Craig; Hendrick, R Edward; Khan, Seema A

    2010-06-01

    Mammographic breast density has been proposed as a surrogate endpoint in breast cancer prevention studies, but little is known about its variability over time, particularly in relation to menstrual cycle phase. The purpose of this study was to assess variation in breast density on digital mammograms using quantitative and qualitative density measures. Menstrual cycle phase was determined by salivary estradiol and progesterone assays. 73 healthy subjects with regular menses had 1-3 mammograms with paired saliva collection during a 12-month period. The mean difference in density as a percentage of the mean density was calculated for follicular-luteal (n = 50), luteal-luteal (n = 26) and follicular-follicular (n = 23) pairs in the same woman using the same breast. Two density measures (measurement of dense area and BIRADS) were used. The mean luteal density exceeded the mean follicular density by 7.1-9.2%, but density differences between luteal pairs and follicular pairs did not exceed 5%. The intraclass correlation for measurement of dense area was greater than 85% in all phases of the menstrual cycle, but was below 50% for BIRADS for luteal-follicular and follicular-follicular pairs. Our study provides estimates of the amount of variation in mammographic density during the menstrual cycle, and that inherent in repeated density measurement in premenopausal women, and suggests that menstrual phase of mammographic evaluation should be controlled for in intervention studies where density is being used as a surrogate measure. PMID:19669673

  3. Development of an image-based screening system for inhibitors of the plastidial MEP pathway and of protein geranylgeranylation

    PubMed Central

    Hartmann, Michael; Gas-Pascual, Elisabet; Hemmerlin, Andrea; Rohmer, Michel; Bach, Thomas J.

    2015-01-01

    In a preceding study we have recently established an in vivo visualization system for the geranylgeranylation of proteins in a stably transformed tobacco BY-2 cell line, which involves expressing a dexamethasone-inducible GFP fused to the prenylable, carboxy-terminal basic domain of the rice calmodulin CaM61, which naturally bears a CaaL geranylgeranylation motif (GFP-BD-CVIL). By using pathway-specific inhibitors it was there demonstrated that inhibition of the methylerythritol phosphate (MEP) pathway with oxoclomazone and fosmidomycin, as well as inhibition of protein geranylgeranyl transferase type 1 (PGGT-1), shifted the localization of the GFP-BD-CVIL protein from the membrane to the nucleus. In contrast, the inhibition of the mevalonate (MVA) pathway with mevinolin did not affect this localization. Furthermore, in this initial study complementation assays with pathway-specific intermediates confirmed that the precursors for the cytosolic isoprenylation of this fusion protein are predominantly provided by the MEP pathway. In order to optimize this visualization system from a more qualitative assay to a statistically trustable medium or a high-throughput screening system, we established now new conditions that permit culture and analysis in 96-well microtiter plates, followed by fluorescence microscopy. For further refinement, the existing GFP-BD-CVIL cell line was transformed with an estradiol-inducible vector driving the expression of a RFP protein, C-terminally fused to a nuclear localization signal (NLS-RFP). We are thus able to quantify the total number of viable cells versus the number of inhibited cells after various treatments.