Do not jump too quickly to conclusions

A great deal of misinformation has been promulgated about mammography screening. For example, there is no biological or scientific support for the use of the age of 50 years as a threshold for screening. Mammography screening can reduce deaths from breast cancer even if the rate of advanced cancers is not decreased. The suggestion that screening results in massive amounts of overdiagnosis is based upon faulty methodology. The results reported in the recent study by Nederend and colleagues may be due to the screening interval and thresholds used for intervention. What is clear, however, is that they do not show that screening is ineffective

Enhanced imaging of microcalcifications in digital breast tomosynthesis through improved image-reconstruction algorithms

PURPOSE: We develop a practical, iterative algorithm for image-reconstruction in under-sampled tomographic systems, such as digital breast tomosynthesis (DBT). METHOD: The algorithm controls image regularity by minimizing the image total $p$-variation (TpV), a function that reduces to the total variation when $p=1.0$ or the image roughness when $p=2.0$. Constraints on the image, such as image positivity and estimated projection-data tolerance, are enforced by projection onto convex sets (POCS). The fact that the tomographic system is under-sampled translates to the mathematical property that many widely varied resultant volumes may correspond to a given data tolerance. Thus the application of image regularity serves two purposes: (1) reduction of the number of resultant volumes out of those allowed by fixing the data tolerance, finding the minimum image TpV for fixed data tolerance, and (2) traditional regularization, sacrificing data fidelity for higher image regularity. The present algorithm allows for this dual role of image regularity in under-sampled tomography. RESULTS: The proposed image-reconstruction algorithm is applied to three clinical DBT data sets. The DBT cases include one with microcalcifications and two with masses. CONCLUSION: Results indicate that there may be a substantial advantage in using the present image-reconstruction algorithm for microcalcification imaging.Comment: Submitted to Medical Physic

Closed-loop control of compression paddle motion to reduce blurring in mammograms

Background: Since the introduction of full field digital mammography (FFDM) a large number of UK breast cancer screening centers have reported blurred images, which can be caused by movement at the compression paddle during image acquisition. Purpose: To propose and investigate the use of position feedback from the breast side of the compression paddle to reduce the settling time of breast side motion. Method: Movement at the breast side of the paddle was measured using two calibrated linear potentiometers. A mathematical model for the compression paddle, machine drive and breast was developed using the paddle movement data. Simulation software was used to optimize the position feedback controller parameters for different machine drive time constants and simulate the potential performance of the proposed system. Results: The results obtained are based on simulation alone and indicate that closed-loop control of breast side paddle position dramatically reduced the settling time from over 90 seconds to less than 4 seconds. The effect of different machine drive time constants on the open-loop response is insignificant. With closed-loop control, the larger the time constant the longer the time required for the breast side motion to settle. Conclusions: Paddle motion induced blur could be significantly reduced by implementing the proposed closed-loop control

Comments on John D. Keen and James E. Keen, What is the point: will screening mammography save my life? BMC Medical Informatics and Decision Making, 2009

This paper by John D. Keen and James E. Keen addresses a thorny subject. The numerical findings and commentaries in their paper will be disturbing to some readers and seem to defy logic and well established viewpoints. It may well generate angry letters to the editor. However such numerical analysis and reporting including civil discussion should be welcomed and are the basis for informed decision making – something that is highly needed in this field

Practitioner compression force variation in mammography : a 6 year study

The application of breast compression in mammography may be more heavily influenced by the practitioner rather than the client. This could affect image quality and will affect client experience. This study builds on previous research to establish if mammography practitioners vary in the compression force they apply over a six year period. This longitudinal study assessed 3 consecutive analogue screens of 500 clients within one screening centre in the UK. Recorded data included: practitioner code, applied pressure (daN), breast thickness (mm), BI-RADS® density category and breast dose. Exclusion criteria included: previous breast surgery, previous/ongoing assessment, breast implants. 344 met inclusion criteria. Data analysis: assessed variation of compression force (daN) and breast thickness (mm) over 3 sequential screens to determine whether compression force and breast thickness were affected by practitioner variations. Compression force over the 3 screens varied significantly; variation was highly dependent upon the practitioner who performed the mammogram. Significant thickness and compression force differences over the 3 screens were noted for the same client (<0.0001). The amount of compression force applied was highly dependent upon the practitioner. Practitioners fell into one of three practitioner compression groups by their compression force mean values; high (mean 12.6daN), intermediate (mean 8.9daN) and low (mean 6.7daN). For the same client, when the same practitioner performed the 3 screens, maximum compression force variations were low and not significantly different (p>0.31). When practitioners from different compression force groups performed 3 screens, maximum compression force variations were higher and significantly different (p<0.0001). The amount of compression force used is highly dependent upon practitioner rather than client. This has implications for radiation dose, patient experience and image quality consistency

Carcinoma Mixed within Milk of Calcium in a Breast: a Case Report

Milk of calcium located in the breast is typically a benign entity. However, carcinoma may incidentally arise adjacent to or even within milk of calcium. Consequently, the characteristics of all observed calcific particles should be carefully analyzed. In this study, we report a case of carcinoma presented as malignant microcalcifications mixed within milk of calcium in a breast

Compression forces used in the Norwegian Breast Cancer Screening Program

Objectives: Compression is used in mammography to reduce breast thickness, which is claimed to improve image quality and reduce radiation dose. In the Norwegian Breast Cancer Screening Program (NBCSP), the recommended range of compression force for full field digital mammography is 11-18 kg (108-177 Newton [N]). This is the first study to investigate the compression force used in the program. Methods: The study included information from 17,951 randomly selected women screened with FFDM at 14 breast centres in the NBCSP, January-March 2014. We investigated the applied compression force on left breast in craniocaudal (CC) and mediolateral oblique (MLO) view for breast centres, mammography machines within the breast centres and for the radiographers. Results: The mean compression force for all mammograms in the study was 116N and ranged from 91 to 147N between the breast centres. The variation in compression force was wider between the breast centres than between mammography machines (range 137-155N) and radiographers (95-143N) within one breast centre. Approximately 59% of the mammograms in the study complied with the recommended range of compression force. Conclusions: A wide variation in applied compression force was observed between the breast centres in the NBCSP. This variation indicates a need for evidence-based recommendations for compression force aimed at optimizing the image quality and individualising breast compression. Advances in knowledge: There was a wide variation in applied compression force between the breast centres in the NBCSP. The variation was wider between the breast centres than between mammography machines and radiographers within one breast centre

Pregnancy-Associated Breast Disease: Radiologic Features and Diagnostic Dilemmas

In this paper, we evaluate the radiological features of pregnancy-associated breast lesions and discuss the difficulties in diagnosis by imaging. We selected patients who were diagnosed with pregnancy-associated breast lesions during the previous 5 years. All patients complained of palpable lesions in the breast and underwent ultrasonographic (US) examination, the first choice for examination of pregnancy-related breast lesions. Any suspicious lesions found by the US were recommended for a US-guided core biopsy, US-guided fine needle aspiration (FNA), or surgery. Various breast lesions were detected during pregnancy and lactation, including breast cancer, mastitis and abscesses, lactating adenoma, galactoceles, lobular hyperplasia, and fibroadenomas. The imaging features of pregnancy-associated breast lesions did not differ from the features of non-pregnancy-associated breast lesions; however, some pregnancy-associated benign lesions had suspicious sonographic features. A US-guided core biopsy was necessary for differentiating benign from malignant. In patients with breast cancer, the cancer was often advanced at the time of diagnosis. In conclusion, various pregnancy-related breast lesions were detected and the imaging of these lesions had variable findings. Breast ultrasound could be an excellent imaging modality for diagnosis and differentiation between benign and malignant lesions. However, when the imaging results are suspicious, a biopsy should be performed to obtain a pathologic diagnosis