Full-field Digital Mammography System Research Articles

TH‐A‐217BCD‐07: Validation of Breast Density Measurement Using Dual Energy Mammography: A Post Mortem Study

Purpose: To validate the use of dual energy mammography for the measurement of breast density in 40 post mortem ex vivo breast tissue samples. Methods: Twenty pairs of post mortem breast samples (n=40) were imaged with a full field digital mammography system. Low energy images were acquired at 28 kVp with a 50 μm rhodium filter at 60 mAs. High energy images were acquired at 49 kVp with a 300 μm copper filter at 30 mAs. Dual energy decomposition of the low and high energy images yielded individual pixel measurements of glandular and adipose equivalent material thicknesses. The decomposition was based on a previous calibration with glandular and adipose equivalent phantoms. Breast density (BD) was calculated as the ratio of glandular thickness over the sum total thickness. Each post mortem sample was then analyzed by chemical analysis based on desiccation, trituration and fat extraction to determine the weight and subsequent percent composition of water, lipid and lean (i.e. protein + mineral) contents. The fibroglandular ratio (FGR), a surrogate quantity to breast density, was calculated from the chemical analysis data as the ratio of the total volume of water and lean contents over the sum of all three contents. Results: Linear relationships between breast density and the water, lipid, and lean contents were all highly correlated. BD and FGR data were related by BD = 1.9 FGR ‐ 50 (r>0.99). Conclusions: The high correlation between breast composition data determined from images and data determined from chemical analysis serve to validate the use of dual energy mammography as a measurement technique. It is thought that more quantitative means of measuring breast density, like the one proposed here, will help to further enhance its use and utility as a marker and risk factor for the development of breast cancer.

Full Field Digital Mammography (FFDM) versus CMOS Technology versus Tomosynthesis (DBT) - Which System Increases the Quality of Intraoperative Imaging?

Aim: The aim of this prospective clinical study was to assess whether it would be possible to reduce the rate of re-excisions and improve the quality using CMOS technology or digital breast tomosynthesis (DBT) compared to a conventional FFDM system. Material and Methods: An invasive breast cancer (BI-RADS 5) was diagnosed in 200 patients in the period from 5/2011 to 1/2012. After histological verification, a breast-conserving therapy was performed with intraoperative imaging. Three different imaging systems were used: 1) Inspiration™ (Siemens, Erlangen, Germany), amorphous selenium, tungsten source, focus 0.1 mm, resolution 85 µm pixel pitch, 8 l/mm as the standard; 2) BioVision™ (Bioptics, Tucson, USA), flat panel photodiode array, tungsten source, focus 0.05, resolution 50 µm pixel pitch, 12 l/mm; 3) Tomosynthesis (Siemens, Erlangen, Germany), amorphous selenium, tungsten source, focus 0.1 mm, resolution 85 µm pixel pitch, 8 l/mm, range: 50°, 25 projections, scan time > 20 s, geometry: uniform scanning, reconstruction: filtered back projection. The 600 radiograms were prospectively shown to 3 radiologists. Results: Out of a total of 200 patients with histologically confirmed breast cancer (BI-RADS 6) 156 patients required no further operative therapy (re-excision) after breast-conserving therapy. A retrospective analysis (n = 44) showed an increase in sensitivity with tomosynthesis compared to the BioVision™ (CMOS technology) and the Inspiration™ at a magnification of 1.0 : 1.0 of 8 % (p < 0.05), i.e. re-excision would not have been necessary in 16 patients with tomosynthesis. Conclusions: The sensitivity of tomosynthesis for intraoperative radiography is significantly (p < 0.05) higher compared to both CMOS technology and an FFDM system with a conventional detector. Additional studies using higher magnification, e.g. 2.0 : 1.0, but no zooming will be necessary to evaluate the method further.

Comparison of Radiologist Performance with Photon-Counting Full-Field Digital Mammography to Conventional Full-Field Digital Mammography

The purpose of this study was to assess the performance of a MicroDose photon-counting full-field digital mammography (PCM) system in comparison to full-field digital mammography (FFDM) for area under the receiver-operating characteristic (ROC) curve (AUC), sensitivity, specificity, and feature analysis of standard-view mammography for women presenting for screening mammography, diagnostic mammography, or breast biopsy. A total of 133 women were enrolled in this study at two European medical centers, with 67 women who had a pre-existing 10-36 months FFDM enrolled prospectively into the study and 66 women who underwent breast biopsy and had screening PCM and diagnostic FFDM, including standard craniocaudal and mediolateral oblique views of the breast with the lesion, enrolled retrospectively. The case mix consisted of 49 cancers, 17 biopsy-benign cases, and 67 normal cases. Sixteen radiologists participated in the reader study and interpreted all 133 cases in both conditions, separated by washout period of ≥4 weeks. ROC curve and free-response ROC curve analyses were performed for noninferiority of PCM compared to FFDM using a noninferiority margin Δ value of 0.10. Feature analysis of the 66 cases with lesions was conducted with all 16 readers at the conclusion of the blinded reads. Mean glandular dose was recorded for all cases. The AUC for PCM was 0.947 (95% confidence interval [CI], 0.920-0.974) and for FFDM was 0.931 (95% CI, 0.898-0.964). Sensitivity per case for PCM was 0.936 (95% CI, 0.897-0.976) and for FFDM was 0.908 (95% CI, 0.856-0.960). Specificity per case for PCM was 0.764 (95% CI, 0.688-0.841) and for FFDM was 0.749 (95% CI, 0.668-0.830). Free-response ROC curve figures of merit were 0.920 (95% CI, 0.881-0.959) and 0.903 (95% CI, 0.858-0.948) for PCM and FFDM, respectively. Sensitivity per lesion was 0.903 (95% CI, 0.846-0.960) and 0.883 (95% CI, 0.823-0.944) for PCM and FFDM, respectively. The average false-positive marks per image of noncancer cases were 0.265 (95% CI, 0.171-0.359) and 0.281 (95% CI, 0.188-0.374) for PCM and FFDM, respectively. Noninferiority P values for AUC, sensitivity (per case and per lesion), specificity, and average false-positive marks per image were all statistically significant (P < .001). The noninferiority P value for free-response ROC was <.025, from the 95% CI for the difference. Feature analysis resulted in PCM being preferred to FFDM by the readers for ≥70% of the cases. The average mean glandular dose for PCM was 0.74 mGy (95% CI, 0.722-0.759 mGy) and for FFDM was 1.23 mGy (95% CI, 1.199-1.262 mGy). In this study, radiologist performance with PCM was not inferior to that with conventional FFDM at an average 40% lower mean glandular dose.

Characterization of the effects of the FineView algorithm for full field digital mammography

The aim of this study was to characterize the effect of an image processing algorithm (FineView) on both quantitative image quality parameters and the threshold contrast detail response of the GE Senographe DS full-field digital mammography system. The system was characterized using signal transfer property, pre-sampling modulation transfer function (MTF), normalized noise power spectrum (NNPS) and detective quantum efficiency (DQE) of the system. An algorithmic modulation transfer function (MTFa) was calculated from images acquired at a reduced detector air kerma (DAK) and with the FineView algorithm enabled. Two sets of beam conditions were used: Mo/Mo/28 kV and Rh/Rh/29 kV, both with 2 mm added Al filtration at the x-ray tube. Images were acquired with and without FineView at four DAK levels from 14 to 378 µGy. The threshold contrast detail response was assessed using the CDMAM contrast–detail test object which was imaged under standard clinical conditions with and without FineView at three DAK levels from 24 to 243 µGy. The images were scored by both human observers and by automated scoring software. Results indicated an improvement of up to 125% at 5 mm−1 in MTFa when FineView was activated, particularly at high DAK levels. A corresponding increase of up to 425% at 5 mm−1 was also seen in the NNPS, again with the same DAK dependence. FineView did not influence DQE, an indication that the signal to noise ratio transfer of the system remained unchanged. FineView did not affect the threshold contrast detectability of the system, a result that is consistent with the DQE results.

Effects of exposure equalization on image signal‐to‐noise ratios in digital mammography: A simulation study with an anthropomorphic breast phantom

The scan equalization digital mammography (SEDM) technique combines slot scanning and exposure equalization to improve low-contrast performance of digital mammography in dense tissue areas. In this study, full-field digital mammography (FFDM) images of an anthropomorphic breast phantom acquired with an anti-scatter grid at various exposure levels were superimposed to simulate SEDM images and investigate the improvement of low-contrast performance as quantified by primary signal-to-noise ratios (PSNRs). We imaged an anthropomorphic breast phantom (Gammex 169 "Rachel," Gammex RMI, Middleton, WI) at various exposure levels using a FFDM system (Senographe 2000D, GE Medical Systems, Milwaukee, WI). The exposure equalization factors were computed based on a standard FFDM image acquired in the automatic exposure control (AEC) mode. The equalized image was simulated and constructed by superimposing a selected set of FFDM images acquired at 2, 1, 1/2, 1/4, 1/8, 1/16, and 1/32 times of exposure levels to the standard AEC timed technique (125 mAs) using the equalization factors computed for each region. Finally, the equalized image was renormalized regionally with the exposure equalization factors to result in an appearance similar to that with standard digital mammography. Two sets of FFDM images were acquired to allow for two identically, but independently, formed equalized images to be subtracted from each other to estimate the noise levels. Similarly, two identically but independently acquired standard FFDM images were subtracted to estimate the noise levels. Corrections were applied to remove the excess system noise accumulated during image superimposition in forming the equalized image. PSNRs over the compressed area of breast phantom were computed and used to quantitatively study the effects of exposure equalization on low-contrast performance in digital mammography. We found that the highest achievable PSNR improvement factor was 1.89 for the anthropomorphic breast phantom used in this study. The overall PSNRs were measured to be 79.6 for the FFDM imaging and 107.6 for the simulated SEDM imaging on average in the compressed area of breast phantom, resulting in an average improvement of PSNR by ∼35% with exposure equalization. We also found that the PSNRs appeared to be largely uniform with exposure equalization, and the standard deviations of PSNRs were estimated to be 10.3 and 7.9 for the FFDM imaging and the simulated SEDM imaging, respectively. The average glandular dose for SEDM was estimated to be 212.5 mrad, ∼34% lower than that of standard AEC-timed FFDM (323.8 mrad) as a result of exposure equalization for the entire breast phantom. Exposure equalization was found to substantially improve image PSNRs in dense tissue regions and result in more uniform image PSNRs. This improvement may lead to better low-contrast performance in detecting and visualizing soft tissue masses and micro-calcifications in dense tissue areas for breast imaging tasks.

Patient doses from screen-film and full-field digital mammography in a population-based screening programme

The aim of this study was to compare mean glandular dose (MGD) in all full-field digital mammography (FFDM) and screen film mammography (SFM) systems used in a national mammography screening program. MGD from 31 screening units (7 FFDM and 24 SFM), based on an average of 50 women at each screening unit, representing 12 X-ray models (6 FFDM and 6 SFM) from five different manufacturers were calculated. The MGD was significantly lower for FFDM compared with SFM (craniocaudal): 1.19 versus 1.27 mGy, respectively, mediolateral oblique: 1.33 versus 1.45 mGy, respectively), but not all of the FFDM units provided lower doses than the SFM units. Comparing FFDMs, the photon counting scanning-slit technology provides significantly lower MGDs than direct and indirect conversion digital technology. The choice of target/filter combination influences the MGD, and has to be optimised with regard to breast thickness.

Dual-energy contrast-enhanced digital mammography: initial clinical results

To assess the diagnostic accuracy of Dual-Energy Contrast-Enhanced Digital Mammography (CEDM) as an adjunct to mammography (MX) versus MX alone and versus mammography plus ultrasound (US). 120 women with 142 suspect findings on MX and/or US underwent CEDM. A pair of low- and high-energy images was acquired using a modified full-field digital mammography system. Exposures were taken in MLO at 2min and in CC at 4min after the injection of 1.5ml/kg of an iodinated contrast agent. One reader evaluated MX, US and CEDM images during 2 sessions 1month apart. Sensitivity, specificity, and area under the ROC curve were estimated. The results from pathology and follow-up identified 62 benign and 80 malignant lesions. Areas under the ROC curves were significantly superior for MX+CEDM than it was for MX alone and for MX+US using BI-RADS. Sensitivity was higher for MX+CEDM than it was for MX (93% vs. 78%; p < 0.001) with no loss in specificity. The lesion size was closer to the histological size for CEDM. All 23 multifocal lesions were correctly detected by MX+CEDM vs. 16 and 15 lesions by MX and US respectively. Initial clinical results show that CEDM has better diagnostic accuracy than mammography alone and mammography+ultrasound.

FDA & Digital Mammography: Why Has FDA Required Full Field Digital Mammography Systems to Be Regulated as Potentially Dangerous Devices for More Than 10 Years?

Digital mammography is routinely used in the US to screen asymptomatic women for breast cancer and currently over 50% of US screening centers employ the technology. In spite of FDAs knowledge that digital mammography requires less radiation than film mammography and that its equivalence has been proven in a prospective randomized trial, the agency has failed to allow the technology market access via the 510(k) pre market clearance pathway. As a result of the restrictive Pre Market Approval process, only four suppliers have received FDA approval. The resulting lack of a competitive market has kept costs high, restricted technological innovation, and impeded product improvements as a result of PMA requirements. Meanwhile, at least twelve companies are on the market in the EU and the resulting competitive market has lowered costs and provided increased technological choice. A cultural change with new leadership occurred in the early 90's at FDA. The historical culture at the Center for Devices and Radiological Health of collaboration and education gave way to one characterized by a lack of reliance on outside scientific expertise, tolerance of decision making by unqualified reviewers, and an emphasis on enforcement and punishment. Digital mammography fell victim to this cultural change and as a result major innovations like breast CT and computer aided detection technologies are also withheld from the market. The medical device law, currently under review by the Institute of Medicine, should be amended by the Congress so that new technologies can be appropriately classified in accordance with the risk based assessment classification system detailed in Chapter V of the Federal Food, Drug, and Cosmetic Act. A panel of scientific experts chartered by the NIH or IOM should determine the classification appropriate for new technologies that have no historical regulatory framework. This would be binding on FDA. Unless the law is changed we will likely again experience additional debacles similar to that of digital mammography where important technology has been withheld from millions of women for more than a decade.

Scatter correction in digital mammography based on image deconvolution

X-ray scatter is a major cause of nonlinearity in densitometry measurements using digital mammography. Previous scatter correction techniques have primarily used a single scatter point spread function to estimate x-ray scatter. In this study, a new algorithm to correct x-ray scatter based on image convolution was implemented using a spatially variant scatter point spread function which is energy and thickness dependent. The scatter kernel was characterized in terms of its scattering fraction (SF) and scatter radial extent (k) on uniform Lucite phantoms with thickness of 0.8–8.0 cm. The algorithm operates on a pixel-by-pixel basis by grouping pixels of similar thicknesses into a series of mask images that are individually deconvolved using Fourier image analysis with a distinct kernel for each image. The algorithm was evaluated with three Lucite step phantoms and one anthropomorphic breast phantom using a full-field digital mammography system at energies of 24, 28, 31 and 49 kVp. The true primary signal was measured with a multi-hole collimator. The effect on image quality was also evaluated. For all 16 studies, the average mean percentage error in estimating the true primary signal was found to be −2.13% and the average rms percentage error was 2.60%. The image quality was seen to improve at every energy up to 25% at 49 kVp. The results indicate that a technique based on a spatially variant scatter point spread function can accurately estimate x-ray scatter.

Digital mammography in Japan

Digital mammography has been proposed as an alternative to screen-film mammography. Previous publications have reported the equivalent performance of digital and film mammography [1, 2], and digital mammography has some advantages over film mammography [3, 4],including many technical advantages, including image-enhancement capability, faster image acquisition, and better storage and transmission for archiving. Its full potential can only be achieved through soft-copy reading. More than 70% of the facilities in Japan have digital mammography systems. However, most of the digital mammography systems use computed radiographic mammography and only about 10% of the facilities have fullfield digital mammography systems. In addition, there are few facilities with soft-copy reading of digital mammography in Japan. This situation is remarkable, because most of the digital mammography systems worldwide are fullfield digital mammography systems with soft-copy reading. Because the soft-copy reading of digital mammography involves very complex processes, some issues have been raised. For the special articles in this issue, a group of recognized and experienced experts, based on the Mammography Subcommittee of the Japan Radiological Society, were assembled. These experts have put together a monograph on digital mammography. The special articles provide a comprehensive review and update on digital mammography, especially in Japan. They will serve as an excellent reference source for anyone interested in digital mammography.

Design and characterization of a spatially distributed multibeam field emission x‐ray source for stationary digital breast tomosynthesis

Digital breast tomosynthesis (DBT) is a limited angle computed tomography technique that can distinguish tumors from its overlying breast tissues and has potentials for detection of cancers at a smaller size and earlier stage. Current prototype DBT scanners are based on the regular full-field digital mammography systems and require partial isocentric motion of an x-ray tube over certain angular range to record the projection views. This prolongs the scanning time and, in turn, degrades the imaging quality due to motion blur. To mitigate the above limitations, the concept of a stationary DBT (s-DBT) scanner has been recently proposed based on the newly developed spatially distributed multibeam field emission x-ray (MBFEX) source technique using the carbon nanotube. The purpose of this article is to evaluate the performance of the 25-beam MBFEX source array that has been designed and fabricated for the s-DBT system. The s-DBT system records all the projection images by electronically activating the multiple x-ray beams from different viewing angles without any mechanical motion. The configuration of the MBFEX source is close to the published values from the Siemens Mammomat system. The key issues including the x-ray flux, focal spot size, spatial resolution, scanning time, beam-to-beam consistency, and reliability are evaluated using the standard procedures. In this article, the authors describe the design and performance of a distributed x-ray source array specifically designed for the s-DBT system. They evaluate the emission current, current variation, lifetime, and focal spot sizes of the source array. An emission current of up to 18 mA was obtained at 0.5 x 0.3 mm effective focal spot size. The experimentally measured focal spot sizes are comparable to that of a typical commercial mammography tube without motion blurring. Trade-off between the system spatial resolution, x-ray flux, and scanning time are also discussed. Projection images of a breast phantom were collected using the x-ray source array from 25 different viewing angles without motion. These preliminary results demonstrate the feasibility of the proposed s-DBT scanner. The technology has the potential to increase the resolution and reduce the imaging time for DBT. With the present design of 25 views, they demonstrated experimentally the feasibility of achieving 11 s scanning time at full detector resolution with 0.5 x 0.3 mm source resolution without motion blur. The flexibility in configuration of the x-ray source array will also allow system designers to consider imaging geometries that are difficult to achieve with the conventional single-source rotating approach.

TU‐B‐303A‐01: Digital Mammography: A Radiologist's Perspective

Full Field Digital Mammography (FFDM) systems are rapidly gaining in popularity and are replacing conventional film‐screen mammography (FSM) systems in breast centers throughout the country. Radiolgists are faced with unique challenges brought about by this transition of technology.In this lecture, the utility of full field digital mammography in clinical practice will be presented. Some of the challenges faced by radiologists who have transitioned from film screen mammography to digital mammography will also be discussed, and case examples illustrating the utility of FFDM will be presented. The clinical utility of computer‐aided detection (CAD) software packages will also be addressed.Learning objectives:1. Understand the clinical impact that full‐field digital mammography has had on the daily practice of breast imaging.2. Recognize the advantages and disadvantages of FFDM systems.3. Understand some of the challenges that breast imagers face when transitioning from FSM to FFDM systems.4. Understand how computer‐aided detection (CAD) systems are used in clinical practice.

MO‐B‐303A‐01: Digital Mammography Update: Design and Characteristics of Current Systems

Full Field Digital Mammography (FFDM) systems are fast becoming popular and replacing conventional film‐screen mammography systems. FFDM systems use a digital detector instead of screen‐film to capture the image of the breast. Several FFDM systems based on different digital detector design and materials are currently available. Some systems are characterized as direct conversion detectors and some are based on indirect conversion process. The digital detectors can be characterized by image quality metrics such as detector quantum efficiency (DQE) and modulation transfer function (MTF).In this lecture, the physics and technology of the digital detectors used in FFDM will be discussed as well as the advantages and applications arising due to the availability of these systems will be presented. The most recent commercially available systems will also be discussed.Learning Objectives:1. Understand the physics of digital detector technology2. Understand the image quality metrics such as DQE and MTF3. Recognize that vendors use varying detector technology in FFDM systems4. Appreciate the advantages and disadvantages of digital mammography systems

SU‐FF‐I‐137: Scatter Correction in Quantitative Dual Energy Mammography

Purpose: To investigate the performance of a new algorithm designed to correct x‐ray scatter and estimate the primary intensity in mammography. Method and Materials: The algorithm is based on image convolution and implements a spatially variant scatter point spread function which is energy and thickness dependent. The scatter kernel was characterized in terms of its scattering fraction and radial extent on uniform PMMA phantoms with thicknesses of 0.8 – 8.0 cm. The algorithm operates on a pixel by pixel basis by grouping pixels of similar thicknesses into a series of mask images that are then individually deconvolved using Fourier image analysis with a distinct kernel for each image. The algorithm was tested with four experimental phantoms, three step phantoms made of PMMA and one anthropomorphic breast phantom on a full field digital mammography system at energies of 24, 28, 31, and 49 kVp. The true primary signal was measured with a multi hole collimator. Results: For all 16 studies, the average mean percentage error in estimating the true primary signal was found to be −2.13% and the average rms percentage error was 2.60%. Conclusion: The new algorithm allows improved accuracy in estimating primary image intensity. It is also expected to improve the accuracy of quantitative dual energy mammography.

Detective quantum efficiency measured as a function of energy for two full-field digital mammography systems

This paper presents detective quantum efficiency (DQE) data measured for a range of x-ray beam qualities for two full-field digital mammography (FFDM) systems: a caesium iodide (CsI) detector-based unit and a system designed around an amorphous selenium (a-Se) x-ray detector. Four beam qualities were studied for each system, covering mean energies from 17.8 keV to 23.4 keV for the CsI system and 17.8 keV to 24.7 keV for the a-Se unit. These were set using 2, 4, 6 and 7 cm polymethylmethacralate (PMMA) and typical tube voltage and target/filter combinations selected by the automatic exposure control (AEC) program used clinically on these systems. Normalized noise power spectra (NNPS) were calculated from flood images acquired at these beam qualities for a target detector air kerma of 100 µGy. Modulation transfer function (MTF) data were acquired at 28 kV and Mo/Mo target/filter setting. The DQE was then calculated from the MTF and NNPS results. For comparison, the quantum detective efficiency (QDE) and energy absorption efficiency (EAE) were calculated from tabulated narrow beam spectral data. With regard to detector response, some energy dependence was noted for pixel value plotted against air kerma at the detector. This amounted to a change in the gradient of the detector response of approximately 15% and 30% per keV for the CsI- and a-Se-based systems, respectively. For the DQE results, a reduction in DQE(0) of 22% was found for the CsI-based unit as beam quality changed from 25 kV Mo/Mo and 2 cm PMMA to 32 kV Rh/Rh and 7 cm PMMA. For the a-Se system, a change in beam quality from 25 kV Mo/Mo and 2 cm PMMA to 34 kV Mo/Rh and 7 cm PMMA led to a reduction in DQE(0) of 8%. Comparing measured data with simple calculations, a reduction in x-ray quantum detection efficiency of 27% was expected for the CsI-based system, while a reduction of 11% was predicted for the a-Se system.

First clinical experience of contrast enhanced digital mammography (CEDM) for the detection of breast carcinomas.

Abstract Abstract #5001 Purpose: CEDM is a recent development of digital mammography using the intra-venous injection of an iodinated contrast agent in conjunction with a mammography examination. The objective of this paper is to present two techniques developed to perform CEDM examinations, the preliminary clinical experiences and potential clinical applications of this new breast imaging procedure.&amp;#x2028; Material and methods: Between 2005 and 2008, 140 consenting women with suspicious findings on mammography and or ultrasonography underwent CEDM using modified full-field digital mammography systems (GE Healthcare, Chalfont St-Giles, UK). A temporal subtraction sequence with acquisition of high-energy images before and after contrast medium injection was used for the first 20 patients. A dual energy technique with acquisition of a pair of low and high-energy images only after contrast medium injection was used for the other 120 patients.&amp;#x2028; Results: CEDM, either using temporal or dual energy technique, improved the probability of malignancy and the BIRADS assessment compared to conventional mammography alone. The temporal subtraction technique offered the possibility to analyze the kinetic curve of enhancement of breast lesions, similar to breast MRI. Dual energy technique did not provide information about the kinetic of tumor enhancement but allowed the acquisition of multiples views of the same breast or bilateral examination and was less sensitive to patient motion than temporal CEDM. The potential clinical applications are the determination of the extent of disease, the assessment of recurrent disease, the clarification of mammographically equivocal lesions, the detection of occult lesions on standard mammography, particularly in dense breast, and the monitoring of the response to chemotherapy.&amp;#x2028; &amp;#x2028; &amp;#x2028; &amp;#x2028; Conclusion: Initial clinical experience has shown the ability of CEDM to map the distribution of neovasculature induced by cancer using mammography. CEDM should result in a simple way to enhance the detection and the characterization of breast lesions and to provide some prognostic factors of breast carcinomas. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5001.

Comparison of Anode/Filter Combinations in Digital Mammography with Respect to the Average Glandular Dose

To investigate the average glandular dose (AGD) applied for clinical digital mammograms acquired with the anode/filter combinations molybdenum/molybdenum (Mo/Mo), molybdenum/rhodium (Mo/Rh), and tungsten/rhodium (W/Rh). Using the method of Dance, the AGD was evaluated from the exposure data of 4867 digital mammograms at two sites equipped with a full-field digital mammography (FFDM) system based on an amorphous selenium detector. 1793 images were acquired and analyzed with Mo/Mo, 643 with Mo/Rh, and 2431 with W/Rh. In the Mo/Mo cases the mean compressed breast thickness was 46 +/- 10 mm with an average AGD of 2.29 +/- 1.31 mGy. For the Mo/Rh cases with a mean compressed thickness of 64 +/- 9 mm, we obtained 2.76 +/- 1.31 mGy. The W/Rh cases with a mean compressed thickness of 52 +/- 13 mm resulted in 1.26 +/- 0.44 mGy. The image quality was assessed as normal and adequate for diagnostic purposes in all cases. Applying a W/Rh beam quality permits the reduction of the patient dose by approximately 50 % when using an FFDM system based on amorphous selenium. The dose reduction becomes larger as the breast thickness increases. The results are in agreement with simulations and phantom studies known from the literature.

Characterization of microcalcification: can digital monitor zooming replace magnification mammography in full-field digital mammography?

The aim of this study was to compare the diagnostic accuracy and image quality of microcalcifications in zoomed digital contact mammography with digital magnification mammography. Three radiologists with different levels of experience in mammography reviewed 120 microcalcification clusters in 111 patients with a full-field digital mammography system relying on digital magnification mammogram (MAG) images and zoomed images from contact mammography (ZOOM) using commercially available zooming systems on monitors. Each radiologist estimated the probability of malignancy and rated the image quality and confidence rate. Performance was evaluated by sensitivity, specificity, positive predictive value, negative predictive value, and receiver operating characteristic (ROC) analysis. All three radiologists rated MAG images higher than ZOOM images for sensitivity with statistical significance (average value, 92% vs. 87%, P<0.05) and performance by ROC analysis improved with MAG imaging. The confidence rate for diagnosis decision and the assessment of lesion characteristics were also better in MAG images than in ZOOM images with statistical significance (P<0.0001). Digital magnification mammography can enhance diagnostic performance when characterizing microcalcifications. Images zoomed from digital contact mammography cannot serve as an alternative to direct magnification digital mammography.

The future of breast radiography: European perspective

Digital technology has entered the practice of mammography. In the coming years, digital mammography will be gradually implemented in most European countries and will change the practice of mammography also from the radiographer's perspective. A computed radiography system is a quick simple conversion from analogue to digital; there is little change in workflow, whereas the introduction of full field digital mammography systems using direct radiography detectors implies a significant change. The X-ray film is replaced by solid-state detectors that convert X-rays into electrical signals, producing images that can be studied instantly on a computer screen. Thus, there are no cassettes, no markers, no bucky to change, no darkroom, no waiting to check films, and no viewboxes. Digital mammography provides higher resolution, which may improve detection, but it also pronounces folds and wrinkles, due to less optimal positioning. Considering the professional status of the radiographer, we encounter major differences in the various European countries. On the one hand, in some countries, screening radiographers are involved in film-reading and diagnostic procedures. On the other hand, the radiographer might just be the one pressing the button. Breast centres should employ well-trained specialized breast radiographers, as full members of the multidisciplinary team. They should be involved in the minimal invasive biopsy, ultrasound and magnetic resonance imaging techniques, as well as in upcoming new techniques, such as tomosynthesis, automated three-dimensional breast ultrasound, dual-energy contrast enhanced mammography, and so forth.

MO‐A‐351‐01: Digital Mammography Update: Design and Characteristics of Current Systems

Full Field Digital Mammography (FFDM) systems are fast becoming popular and replacing conventional film‐screen mammography systems. FFDM systems use a digital detector instead of screen‐film to capture the image of the breast. Several FFDM systems based on different digital detector design and materials are currently available. Some systems are characterized as direct conversion detectors and some are based on indirect conversion process. The digital detectors can be characterized by image quality metrics such as detector quantum efficiency (DQE) and modulation transfer function (MTF).In this lecture, the physics and technology of the digital detectors used in FFDM will be discussed as well as the advantages and applications arising due to the availability of these systems will be presented. The most recent commercially available systems will also be discussed.Educational Objectives:1. Understand the physics of digital detector technology.2. Understand the image quality metrics such as DQE and MTFRecognize that vendors use varying detector technology in FFDM systems.3. Appreciate the advantages and disadvantages of digital mammography systems.