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Background The incidence of distant-stage (metastatic) breast cancer at initial presentation has increased significantly in U.S. women under 40 years of age, but no clear trend in older women has been reported. Purpose To investigate trends in distant-stage breast cancer incidence using the latest available Surveillance, Epidemiology, and End Results (SEER) data, including the COVID-19 pandemic years 2020 and 2021. Materials and Methods In this retrospective study of 71 million to 80 million women annually, SEER 22 stage-specific breast cancer incidence rates from January 2004 to December 2021 were analyzed using Joinpoint software to evaluate trends in distant-stage disease in U.S. women overall, by age group, and by race and ethnicity. Results Distant-stage breast cancer incidence rates at presentation increased significantly for U.S. women overall, with an annual percentage change (APC) of 1.16% (95% CI: 0.92, 1.42; P < .001) over 2004-2021. Distant-stage disease increased consistently for women aged 20-39 years (APC, 2.91%; P < .001) and for women aged 75 years or older (APC, 1.44%; P < .001). For women aged 40-74 years, the distant-stage breast cancer incidence rate increased with an APC of 2.10% over 2004-2010 ( P = .002) and an APC of 2.73% over 2018-2021 ( P = 0.01). The interruption of care in 2020 due to COVID-19 affected distant-stage breast cancer detection, especially for older women from racial and ethnic minority groups. The incidence of distant-stage breast cancer increased over 2004-2021 for Asian women (APC, 2.90%; P < .001), Black women (0.86%; P = .008), and Hispanic women (1.56%; P < .001) and over 2004-2019 for Native American women (3.86%; P = .04). White women showed an increase over 2004-2012 (1.68%; P = .01) but no evidence of a trend over 2012-2021. Distant-stage cancer incidence rates were 55% higher in Black women than White women. Conclusion Distant-stage breast cancer incidence rates at presentation have increased significantly in U.S. women overall; in age groups 20-39 years, 40-74 years, and 75 years or older; and in Asian, Black, Hispanic, and Native American women. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Kim and Moy in this issue.

Background There is ongoing debate about recommendations for breast cancer screening strategies, specifically regarding the frequency of screening and the age at which to initiate screening. Purpose To compare estimates of breast cancer screening outcomes published by the Cancer Intervention and Surveillance Modeling Network (CISNET) to understand the benefits and risks of different screening scenarios. Materials and Methods Modeling estimates published by CISNET are based on hypothetical cohorts in the United States and compare women, starting at 40 years of age, who do and do not undergo breast cancer screening with mammography. The four scenarios assessed in this study, of multiple possible scenarios, were biennial screening ages 50-74 years (2009 and 2016 U.S. Preventive Services Task Force [USPSTF] recommendations), biennial screening ages 40-74 years (2023 USPSTF draft recommendation), annual screening ages 40-74 years, and annual screening ages 40-79 years. For each scenario, CISNET estimates of median lifetime benefits were compared. Risks that included false-positive screening results per examination and benign biopsies per examination were also calculated and compared. Results Estimates from CISNET 2023 showed that annual screening ages 40-79 years improved breast cancer mortality reduction compared with biennial screening ages 50-74 years and biennial screening ages 40-74 years (41.7%, 25.4%, and 30%, respectively). Annual screening ages 40-79 years averted the most breast cancer deaths (11.5 per 1000) and gained the most life-years (230 per 1000) compared with other screening scenarios (range, 6.7-11.5 per 1000 and 121-230 per 1000, respectively). False-positive screening results per examination were less than 10% for all screening scenarios (range, 6.5%-9.6%) and lowest for annual screening ages 40-79 years (6.5%). Benign biopsies per examination were less than 1.33% for all screening scenarios (range, 0.88%-1.32%) and lowest for annual screening ages 40-79 years (0.88%). Conclusion CISNET 2023 modeling estimates indicate that annual breast cancer screening starting at 40 years of age provides the greatest benefit to women and the least risk per examination. © RSNA, 2024 See also the editorial by Joe in this issue.

Background National Center for Health Statistics (NCHS) data for U.S. women have shown a steady decline in breast cancer mortality rates since 1989. Purpose To analyze U.S. breast cancer mortality rates by age decade in women aged 20-79 years and in women aged 20-39 years and women aged 40-69 years. Materials and Methods The authors conducted a retrospective analysis of (a) female breast cancer mortality rates from NCHS data for 1969-2017 for all races and by race and (b) age- and delay-adjusted invasive breast cancer incidence rates from the Surveillance, Epidemiology, and End Results program. Joinpoint analysis was used to determine trends in breast cancer mortality, invasive breast cancer incidence, and distant-stage (metastatic) breast cancer incidence rates. Results Between 1989 and 2010, breast cancer mortality rates decreased by 1.5%-3.4% per year for each age decade from 20 to 79 years ( P < .001 for each). After 2010, breast cancer mortality rates continued to decline by 1.2%-2.2% per year in women in each age decade from 40 to 79 years ( P < .001 for each) but stopped declining in women younger than 40 years. After 2010, breast cancer mortality rates demonstrated nonsignificant increases of 2.8% per year in women aged 20-29 years ( P = .11) and 0.3% per year in women aged 30-39 years ( P = .70), results attributable primarily to changes in mortality rates in White women. A contributing factor is that distant-stage breast cancer incidence rates increased by more than 4% per year after the year 2000 in women aged 20-39 years. Conclusion Female breast cancer mortality rates have stopped declining in women younger than 40 years, ending a trend that existed from 1987 to 2010. Conversely, mortality rates have continued to decline in women aged 40-79 years. Rapidly rising distant-stage breast cancer rates have likely contributed to ending the decline in mortality rates in women younger than 40 years. © RSNA, 2021 Online supplemental material is available for this article.

Purpose To determine obligate overdiagnosis rates, defined as the percentage of women diagnosed with screen-detected breast cancer who die of causes other than breast cancer prior to clinical presentation of that cancer, for ductal carcinoma in situ (DCIS), invasive breast cancer, and all breast cancers. Materials and Methods Age-specific all-cause mortality rates from the Human Mortality Database, age-specific breast cancer incidence and mortality rates from Surveillance, Epidemiology, and End Results data, and estimates of mean lead times and lead time distributions from breast cancer screening trials are used to estimate obligate (or type 1) overdiagnosis rates for DCIS, invasive breast cancer, and all breast cancers (DCIS plus invasive) for U.S. women undergoing screening mammography. Mortality rates by age are used to estimate the number of women who die of causes other than breast cancer during the lead time afforded by screening mammography. Resulting age-dependent overdiagnosis rates, along with screen-detected breast cancer incidence by age, are used to estimate type 1 overdiagnosis rates for the U.S. screening population. Results Obligate overdiagnosis rates depend strongly on the age at which a woman is screened, ranging from less than 1% at age 40 years to 30%, 21%, and 22.5% at age 80 years for DCIS, invasive breast cancer, and all breast cancers, respectively. Type 1 overdiagnosis rates among screened women in the United States are estimated to be 9% for DCIS and approximately 7% for both invasive breast cancer and all breast cancers. Screening of women ages 40-49 years (or premenopausal women, as determined from patient history, starting at age 40 years) adds little to obligate overdiagnosis rates (0.15% for DCIS and less than 0.1% for invasive breast cancer and all breast cancers). Conclusion Type 1 overdiagnosis rates increase rapidly with age at screening. Obligate overdiagnosis occurs in 9% of DCIS and approximately 7% of both invasive breast cancer and all breast cancers in the U.S. mammographic screening population, with screening of women ages 40-49 years (or premenopausal women starting at age 40 years) making a negligible contribution of 0.15% to obligate overdiagnosis of DCIS and a contribution of less than 0.1% to the obligate overdiagnosis rates of invasive breast cancer and all breast cancers. © RSNA, 2017 Online supplemental material is available for this article.

Purpose To estimate the benefit-to-radiation risk ratios of mammography alone, breast-specific gamma imaging (BSGI) alone, and mammography plus BSGI in women with dense breasts who were asymptomatic and examined in the 2015 study by Rhodes et al. Materials and Methods This study uses previously published breast cancer detection rates and estimates of radiation dose and radiation risk and is, therefore, exempt from institutional review board approval. By using breast cancer detection rates for mammography alone, BSGI alone, and mammography plus BSGI from the study by Rhodes et al, as well as lifetime estimates of radiation-induced cancer mortality for mammography and BSGI on the basis of the Biologic Effects of Ionizing Radiation VII report, the benefit-to-radiation risk ratios of mammography alone, BSGI alone, and mammography plus BSGI performed annually over 10-year age intervals from ages 40 to 79 years are estimated. Results The benefit-to-radiation risk ratio is estimated to be 13 for women who are 40-49 years old and are screened with mammography, a figure that approximately doubles for each subsequent 10-year age interval up to 70-79 years old. For low-dose BSGI, annual screening benefit-to-radiation risk ratios are estimated to be 5 for women 40-49 years old and to double by age 70-79 years, while mammography plus BSGI has benefit-to-radiation risk ratios similar to those of BSGI alone. There are wide ranges for all of these estimates. Conclusion While lower dose (300 MBq) BSGI has estimated benefit-to-radiation risk ratios well in excess of 1 for screening of asymptomatic women with dense breasts who are 40 years old and older, it does not match the benefit-to-radiation risk ratio of screening mammography. © RSNA, 2016.

Purpose: To compare radiation doses and lifetime attributable risks (LARs) of radiation-induced cancer incidence and mortality from breast imaging studies involving the use of ionizing radiation., Materials and Methods: Recent literature on radiation doses from radiologic procedures and organ doses from nuclear medicine procedures, along with Biologic Effects of Ionizing Radiation (BEIR) VII age-dependent risk data, is used to estimate LARs of radiation-induced cancer incidence and mortality from breast imaging studies involving ionizing radiation, including screen-film mammography, digital mammography, digital breast tomosynthesis, dedicated breast computed tomography, breast-specific gamma imaging (BSGI), and positron emission mammography (PEM)., Results: Two-view digital mammography and screen-film mammography involve average mean glandular radiation doses of 3.7 and 4.7 mGy, respectively. According to BEIR VII data, these studies are associated, respectively, with LARs of fatal breast cancer of 1.3 and 1.7 cases per 100,000 women aged 40 years at exposure and less than one case per one million women aged 80 years at exposure. Annual screening digital or screen-film mammography performed in women aged 40-80 years is associated with an LAR of fatal breast cancer of 20-25 cases in 100,000. A single BSGI study involving a label-recommended dose of 740-1100 MBq (20-30 mCi) of technetium 99m-sestamibi is estimated to involve an LAR of fatal cancer that is 20-30 times that of digital mammography in women aged 40 years. A single PEM study involving a labeled dose of 370 MBq (10 mCi) of fluorine 18 fluorodeoxyglucose is estimated to involve an LAR of fatal cancer that is 23 times higher than that of digital mammography in women aged 40 years., Conclusion: A single BSGI or PEM study is associated with a fatal radiation-induced cancer risk higher than or comparable to that of annual screening mammography in women aged 40-80 years.

Purpose: To determine which factors contributed to the Digital Mammographic Imaging Screening Trial (DMIST) cancer detection results., Materials and Methods: This project was HIPAA compliant and institutional review board approved. Seven radiologist readers reviewed the film hard-copy (screen-film) and digital mammograms in DMIST cancer cases and assessed the factors that contributed to lesion visibility on both types of images. Two multinomial logistic regression models were used to analyze the combined and condensed visibility ratings assigned by the readers to the paired digital and screen-film images., Results: Readers most frequently attributed differences in DMIST cancer visibility to variations in image contrast--not differences in positioning or compression--between digital and screen-film mammography. The odds of a cancer being more visible on a digital mammogram--rather than being equally visible on digital and screen-film mammograms--were significantly greater for women with dense breasts than for women with nondense breasts, even with the data adjusted for patient age, lesion type, and mammography system (odds ratio, 2.28; P < .0001). The odds of a cancer being more visible at digital mammography--rather than being equally visible at digital and screen-film mammography--were significantly greater for lesions imaged with the General Electric digital mammography system than for lesions imaged with the Fischer (P = .0070) and Fuji (P = .0070) devices., Conclusion: The significantly better diagnostic accuracy of digital mammography, as compared with screen-film mammography, in women with dense breasts demonstrated in the DMIST was most likely attributable to differences in image contrast, which were most likely due to the inherent system performance improvements that are available with digital mammography. The authors conclude that the DMIST results were attributable primarily to differences in the display and acquisition characteristics of the mammography devices rather than to reader variability.

Purpose: To retrospectively compare the accuracy for cancer diagnosis of digital mammography with soft-copy interpretation with that of screen-film mammography for each digital equipment manufacturer, by using results of biopsy and follow-up as the reference standard., Materials and Methods: The primary HIPAA-compliant Digital Mammographic Imaging Screening Trial (DMIST) was approved by the institutional review board of each study site, and informed consent was obtained. The approvals and consent included use of data for future HIPAA-compliant retrospective research. The American College of Radiology Imaging Network DMIST collected screening mammography studies performed by using both digital and screen-film mammography in 49 528 women (mean age, 54.6 years; range, 19-92 years). Digital mammography systems from four manufacturers (Fischer, Fuji, GE, and Hologic) were used. For each digital manufacturer, a cancer-enriched reader set of women screened with both digital and screen-film mammography in DMIST was constructed. Each reader set contained all cancer-containing studies known for each digital manufacturer at the time of reader set selection, together with a subset of negative and benign studies. For each reader set, six or 12 experienced radiologists attended two randomly ordered reading sessions 6 weeks apart. Each radiologist identified suspicious findings and rated suspicion of breast cancer in identified lesions by using a seven-point scale. Results were analyzed according to digital manufacturer by using areas under the receiver operating characteristic curve (AUCs), sensitivity, and specificity for soft-copy digital and screen-film mammography. Results for Hologic digital are not presented owing to the fact that few cancer cases were available. The implemented design provided 80% power to detect average AUC differences of 0.09, 0.08, and 0.06 for Fischer, Fuji, and GE, respectively., Results: No significant difference in AUC, sensitivity, or specificity was found between Fischer, Fuji, and GE soft-copy digital and screen-film mammography. Large reader variations occurred with each modality., Conclusion: No statistically significant differences were found between soft-copy digital and screen-film mammography for Fischer, Fuji, and GE digital mammography equipment.

Purpose: To retrospectively compare the accuracy of digital versus film mammography in population subgroups of the Digital Mammographic Imaging Screening Trial (DMIST) defined by combinations of age, menopausal status, and breast density, by using either biopsy results or follow-up information as the reference standard., Materials and Methods: DMIST included women who underwent both digital and film screening mammography. Institutional review board approval at all participating sites and informed consent from all participating women in compliance with HIPAA was obtained for DMIST and this retrospective analysis. Areas under the receiver operating characteristic curve (AUCs) for each modality were compared within each subgroup evaluated (age < 50 vs 50-64 vs >or= 65 years, dense vs nondense breasts at mammography, and pre- or perimenopausal vs postmenopausal status for the two younger age cohorts [10 new subgroups in toto]) while controlling for multiple comparisons (P < .002 indicated a significant difference). All DMIST cancers were evaluated with respect to mammographic detection method (digital vs film vs both vs neither), mammographic lesion type (mass, calcifications, or other), digital machine type, mammographic and pathologic size and diagnosis, existence of prior mammographic study at time of interpretation, months since prior mammographic study, and compressed breast thickness., Results: Thirty-three centers enrolled 49 528 women. Breast cancer status was determined for 42,760 women, the group included in this study. Pre- or perimenopausal women younger than 50 years who had dense breasts at film mammography comprised the only subgroup for which digital mammography was significantly better than film (AUCs, 0.79 vs 0.54; P = .0015). Breast Imaging Reporting and Data System-based sensitivity in this subgroup was 0.59 for digital and 0.27 for film mammography. AUCs were not significantly different in any of the other subgroups. For women aged 65 years or older with fatty breasts, the AUC showed a nonsignificant tendency toward film being better than digital mammography (AUCs, 0.88 vs 0.70; P = .0025)., Conclusion: Digital mammography performed significantly better than film for pre- and perimenopausal women younger than 50 years with dense breasts, but film tended nonsignificantly to perform better for women aged 65 years or older with fatty breasts., ((c) RSNA, 2008.)

Patient and technical factors may lead to unwanted artifacts at breast magnetic resonance (MR) imaging. Use of a properly functioning high-field-strength MR imaging system, a dedicated bilateral breast coil, and an optimal imaging protocol provides a solid framework for performing high-quality breast MR imaging. Problems related to breast positioning, selection of imaging volume, and phase-encoding direction can be overcome by training and providing feedback to MR imaging technologists. Common artifacts seen at breast MR imaging include motion, suboptimal fat suppression, metallic susceptibility, phase wrap, radiofrequency noise, and chemical shift. Once they are recognized, many of these artifacts can be corrected. Protocol monitoring and imaging-based feedback from the interpreting radiologist are essential for minimizing artifacts and optimizing breast MR imaging., (Copyright RSNA, 2007.)

Magnetic resonance (MR) imaging, when used in conjunction with mammography and ultrasonography, can be a powerful tool for breast imaging. There are various clinical scenarios in which MR imaging may provide key information that leads to an alteration in treatment plans (eg, by demonstrating features that were occult at physical examination or conventional imaging). Although many benign and malignant entities enhance at contrast material-enhanced breast MR imaging, the morphologic characteristics and kinetic profiles of lesions help narrow the differential diagnosis. To optimize the quality of the morphologic and kinetic information yielded by breast MR imaging, the radiologist must attend to various practical and technical prerequisites: A bilateral breast coil should be used with prone positioning of the patient. An MR imaging system with a high-field-strength magnet is needed, and the magnetic field must be homogeneous across the field of view, which should include both breasts. A T2-weighted sequence should be applied first to identify any cysts and should be followed by three-dimensional imaging with a T1-weighted spoiled gradient-echo sequence after the intravenous administration of a gadolinium chelate. To minimize artifacts, a direction other than the anterior-posterior direction should be selected for phase encoding. To suppress the signal from fat, a frequency-selective pulse should be applied during imaging, or the unenhanced MR imaging data should be subtracted from the contrast-enhanced MR imaging data during postprocessing. The imaging section thickness should be 3 mm or less, the pixel size should be less than 1 mm in each in-plane direction, and the total acquisition time should be less than 2 minutes., (Copyright RSNA, 2006.)

Purpose: To evaluate a computer-aided diagnosis multimodality intelligent workstation as an aid to radiologists in the interpretation of mammograms and breast sonograms., Materials and Methods: An institutional review board approved the protocol for an observer study with signed consent, as well as the retrospective use of the mammograms, sonograms, and clinical data with waiver of consent. The HIPAA-compliant observer study was conducted with five breast radiologists and five breast imaging fellows, all of whom gave confidence ratings and patient management decisions, both without and with the computer aid, for 97 lesions that were unknown to both the observers and the computer. The performance of each observer without and with the computer aid was quantified by using four performance measures: area under the receiver operating characteristic curve (A(z)) value, partial A(z) value, sensitivity, and specificity. The statistical significance of the differences in the performance measures without and with the computer aid was determined by using a two-tailed t test for paired data., Results: Use of the computer aid resulted in an improvement of the average performance of the 10 observers, as measured by means of a statistically significant increase in A(z) value (0.87-0.92; P < .001), partial A(z) value (0.47-0.68; P < .001), and sensitivity (0.88-0.93; P = .005). A statistically significant difference was not found in the specificity without and with the computer aid (0.66-0.69; P = .20)., Conclusion: Use of multimodality intelligent workstations can improve the performance of radiologists in the task of differentiating malignant and benign lesions at mammography and sonography., (RSNA, 2006)

This study was approved by the Institutional Review Board (IRB) of the American College of Radiology Imaging Network (ACRIN) and each participating site and by the IRB and the Cancer Therapy Evaluation Program at the National Cancer Institute. The study was monitored by an independent Data Safety and Monitoring Board, which received interim analyses of data to ensure that the study would be terminated early if indicated by trends in the outcomes. The ACRIN, which is funded by the National Cancer Institute, conducted the Digital Mammographic Imaging Screening Trial (DMIST) primarily to compare the diagnostic accuracy of digital and screen-film mammography in asymptomatic women presenting for screening for breast cancer. Over the 25.5 months of enrollment, a total of 49 528 women were included at the 33 participating sites, which used five different types of digital mammography equipment. All participants underwent both screen-film and digital mammography. The digital and screen-film mammograms of each subject were independently interpreted by two radiologists. If findings of either examination were interpreted as abnormal, subsequent work-up occurred according to the recommendations of the interpreting radiologist. Breast cancer status was determined at biopsy or follow-up mammography 11-15 months after study entry. In addition to the measurement of diagnostic accuracy by using the interpretations of mammograms at the study sites, DMIST included evaluations of the relative cost-effectiveness and quality-of-life effects of digital versus screen-film mammography. Six separate reader studies using the de-identified archived DMIST mammograms will also assess the diagnostic accuracy of each of the individual digital mammography machines versus screen-film mammography machines, the effect of breast density on diagnostic accuracy of digital and screen-film mammography, and the effect of different rates of breast cancer on the diagnostic accuracy in a reader study.

Purpose: To assess the relationship between radiologists' perception of and experience with medical malpractice and their patient-recall rates in actual community-based clinical settings., Materials and Methods: All study activities were approved by the institutional review boards of the involved institutions, and patient and radiologist informed consent was obtained where necessary. This study was performed in three regions of the United States (Washington, Colorado, and New Hampshire). Radiologists who routinely interpret mammograms completed a mailed survey that included questions on demographic data, practice environment, and medical malpractice. Survey responses were linked to interpretive performance for all screening mammography examinations performed between January 1, 1996, and December 31, 2001. The odds of recall were modeled by using logistic regression analysis based on generalized estimating equations that adjust for study region., Results: Of 181 eligible radiologists, 139 (76.8%) returned the survey with full consent. The analysis included 124 radiologists who had interpreted a total of 557 143 screening mammograms. Approximately half (64 of 122 [52.4%]) of the radiologists reported a prior malpractice claim, with 18 (14.8%) reporting mammography-related claims. The majority (n = 51 [81.0%]) of the 63 radiologists who responded to a question regarding the degree of stress caused by a medical malpractice claim described the experience as very or extremely stressful. More than three of every four radiologists (ie, 94 [76.4%] of 123) expressed concern about the impact medical malpractice has on mammography practice, with over half (72 [58.5%] of 123) indicating that their concern moderately to greatly increased the number of their recommendations for breast biopsies. Radiologists' estimates of their future malpractice risk were substantially higher than the actual historical risk. Almost one of every three radiologists (43 of 122 [35.3%]) had considered withdrawing from mammogram interpretation because of malpractice concerns. No significant association was found between recall rates and radiologists' experiences or perceptions of medical malpractice., Conclusion: U.S. radiologists are extremely concerned about medical malpractice and report that this concern affects their recall rates and biopsy recommendations. However, medical malpractice experience and concerns were not associated with recall or false-positive rates. Heightened concern of almost all radiologists may be a key reason that recall rates are higher in the United States than in other countries, but this hypothesis requires further study., (Copyright RSNA, 2005)

Purpose: To evaluate the current (2001-2002) capacity of community-based mammography facilities to deliver screening and diagnostic services in the United States., Materials and Methods: Institutional review board approvals and patient consent were obtained. A mailed survey was sent to 53 eligible mammography facilities in three states (Washington, New Hampshire, and Colorado). Survey questions assessed equipment and staffing availability, as well as appointment waiting times for screening and diagnostic mammography services. Criterion-related content and construct validity were obtained first by means of a national advisory committee of academic, scientific, and clinical colleagues in mammography that reviewed literature on existing surveys and second by pilot testing a series of draft surveys among community mammography facilities not inclusive of the study facilities. The final survey results were independently double entered into a relational database with programmed data checks. The data were sent encrypted by means of file transfer protocol to a central analytical center at Group Health Cooperative. A two-sided P value with alpha = .05 was considered to show statistical significance in all analyses., Results: Forty-five of 53 eligible mammography facilities (85%) returned the survey. Shortages of radiologists relative to the mammographic volume were found in 44% of mammography facilities overall, with shortages of radiologists higher in not-for-profit versus for-profit facilities (60% vs 28% reported). Shortages of Mammography Quality Standards Act-qualified technologists were reported by 20% of facilities, with 46% reporting some level of difficulty in maintaining qualified technologists. Waiting times for diagnostic mammography ranged from less than 1 week to 4 weeks, with 85% performed within 1 week. Waiting times for screening mammography ranged from less than 1 week to 8 weeks, with 59% performed between 1 week and 4 weeks. Waiting times for both diagnostic and screening services were two to three times higher in high-volume compared with low-volume facilities., Conclusion: Survey results show shortages of radiologists and certified mammography technologists., ((c) RSNA, 2005.)

Purpose: To prospectively compare full-field digital mammography (FFDM) with screen-film mammography (SFM) for cancer detection in a screening population., Materials and Methods: At two institutions, 4,945 FFDM examinations were performed in women aged 40 years and older presenting for SFM. Two views of each breast were acquired with each modality. SFM and FFDM images were interpreted independently. Findings detected with either SFM or FFDM were evaluated with additional imaging and, if warranted, biopsy., Results: Patients in the study underwent 152 biopsies, which resulted in the diagnosis of 35 breast cancers. Twenty-two cancers were detected with SFM and 21 with FFDM. Four were interval cancers that became palpable within 1 year of screening and were considered false-negative findings with both modalities. The difference in cancer detection rate was not significant. FFDM had a significantly lower recall rate (11.5%; 568 of 4,945) than SFM (13.8%; 685 of 4,945) (P <.001, McNemar chi(2) model; P <.03, generalized estimating equations model). The positive biopsy rate for findings detected with FFDM (30%; 21 of 69) was higher than that for findings detected with SFM (19%; 22 of 114), but this difference was not significant., Conclusion: No difference in cancer detection rate has yet been observed between FFDM and SFM. FFDM has so far led to fewer recalls than SFM.

Purpose: To assess possible changes in quality control (QC) practices at mammography sites in the United States., Materials and Methods: Mammography site surveys were conducted in 1990, 1992, and 1995 through the Colorado Mammography Advocacy Project (CMAP). Data from mammography sites applying for American College of Radiology (ACR) accreditation were collected between August 1987 and August 1993 through the ACR Mammography Accreditation Program. Data from both of these surveys were analyzed to assess temporal changes in mammography QC practices in the United States between 1987 and 1995., Results: CMAP results indicated statistically significant improvement in medical physicist QC practices between 1990 and 1992 and in technologist QC practices between 1990 and 1995. Improvements in radiologic technologist QC practices coincided with increases in radiologic technologist continuing education in mammography. ACR results indicated statistically significant improvement in technologist QC practices between 1988 and 1992., Conclusion: There have been substantial improvements in QC practices at mammography sites in the United States during the past decade.

The American College of Radiology has published a report that describes desirable features for new mammography x-ray units that will contribute to high-quality imaging. It encompasses all aspects of x-ray equipment performance including mechanical considerations, the x-ray tube focal spot and spectrum, generator performance, collimation, scatter rejection, and the automatic exposure control. The report is intended to provide guidance to equipment manufacturers and to purchasers of mammography systems with regard to basic performance levels that should be expected.

This article provides an introduction to the basic physical principles of magnetic resonance (MR) imaging. Essential basic concepts such as nuclear magnetism, tissue magnetization, precession, excitation, and tissue relaxation properties are presented. Hydrogen spin density and tissue relaxation times T1, T2, and T2* are explained. The basic elements of a planar MR pulse sequence are described: section selection during tissue excitation, phase encoding, and frequency encoding during signal measurement.

Not all sites performing mammography produce optimal images at acceptably low doses. To address this situation, a voluntary accreditation program was instituted through the American College of Radiology. Each site applying for accreditation completes a detailed questionnaire about facilities and equipment, personnel, and quality control. Each unit at each site is evaluated by a medical physicist for clinical and phantom image quality and for average glandular dose. Although a site is accredited for 3 years, the performance of each unit is audited annually. Of 11,162 units for which accreditation was sought, only 5,856 (68%) passed at the first attempt, with another 18% passing after reapplication. The major reason for failure was inadequate clinical images, followed by inadequate phantom images, both inadequate clinical and phantom images, and inadequate quality control records. In a performance audit of 20 new units, an average of 5.8 problems were encountered per unit, the majority of which adversely affected image quality. These results support the requirement of equipment performance audits and raise the question of whether similar problems exist in other areas of medical imaging.

Despite recent improvements in mammography equipment and technique, the radiographically dense breast remains difficult to image. The problems in imaging the dense breast account for a large percentage of the cases of mammographically "missed" carcinomas. Other imaging modalities--such as ultrasonography, transillumination, thermography, computed tomography, magnetic resonance imaging, and radionuclide imaging--have been investigated for use in breast cancer detection. This overview discusses the current problems associated with imaging of the radiographically dense breast and suggests some avenues for investigation to develop solutions to these problems.

This study assessed the enhancement of liver-lesion contrast by using low levels of iron oxide contrast agent at four common magnetic resonance (MR) imaging field strengths: 0.15, 0.35, 0.5, and 1.5 T. Adenocarcinomas were percutaneously inserted into the livers of 15 rats. Iron oxide was given intravenously in concentrations of 0 (control group), 2.5, 5, 10, and 20 mumol/kg to three rats in each concentration group. All images were acquired between 1 and 24 hours after injection. Liver-lesion contrast ratios and contrast-to-noise ratios (C/Ns) were calculated. Results showed increased liver-lesion contrast and C/Ns with increased iron oxide concentration up to 10-20 mumol/kg at all four magnetic field strengths. At 0.15 T, iron oxide produced lower gains in tumor-liver contrast. At middle and high magnetic field strengths, liver-lesion contrast was similar for each level of iron oxide concentration, but C/Ns were markedly higher at 1.5 T than at middle field strength. Low levels of iron oxide contrast agent are effective at magnetic field strengths of 0.35 T and above, producing the greatest increase in C/N at middle field strengths.

Image quality is the cornerstone to the practice of high-quality mammography. To ensure high quality in the practice of mammography, the American College of Radiology has established a voluntary program for the accreditation of mammographic screening sites. Between August 15, 1987, and February 1, 1989, 647 mammography units completed the accreditation program. Data collected from those units are presented, demonstrating that broad ranges of image quality and dose currently exist among mammographic screening sites. Reasons are discussed for the wide ranges observed, and steps are proposed to narrow the ranges of image quality and dose in the practice of mammography.

The influence of signal averaging (n), repetition time (TR), and echo delay (TE) on systematic noise (cardiac, vascular, respiratory, and peristaltic ghost artifacts) and statistical noise (thermal effects) was determined in eight healthy volunteers and 57 patients. Systematic noise was the dominant factor degrading abdominal magnetic resonance (MR) images. Signal averaging was the primary determinant of both statistical and systematic image noise, fitting a power function (n)b with b = 0.44 and -0.42, respectively, close to the expected b = -0.5 power function. All types of ghosting showed the same sensitivity to signal averaging. Normalized systematic noise increased slightly with TR (b = 0.16) and increased markedly with TE (b = 0.40). These data indicate that the short TR, short TE technique is a powerful method for reducing motion artifacts on breathhold images and can be combined with signal averaging to further suppress artifacts, improve signal-to-noise ratio, and maximize anatomic resolution.

Magnitude-reconstructed short inversion-time (TI) inversion-recovery (IR) sequences have the advantage of reducing the signal of fat while providing additive T1 and T2 contrast. A double-echo short TI IR sequence was implemented to offer different degrees of T1- and T2-dependent image contrast. In 50 consecutive patients with proved liver tumors (30 metastases, 13 hemangiomas, seven other primary liver tumors), images obtained with a double-echo IR sequence at a repetition time (TR) of 1,500 msec, echo time (TE) of 30 and 60 msec, and TI of 80 msec (TR/TE/TI = 1,500/30, 60/80) were compared with those obtained with spin-echo (SE) sequences at a TR of 275 msec and a TE of 14 msec (TR/TE = 275/14) and 2,350/60, 120, 180. Metastases-liver contrast-to-noise ratios were highest at SE 275/14, followed by IR 1,500/30/80 and SE 2,350/180. IR 1,500/30/80 and SE 275/14 sequences consistently showed higher sensitivity for the detection of metastases than T2-weighted SE sequences. Differential diagnosis of benign and malignant lesions was more reliable with T2-weighted SE sequences than T2-weighted short TI IR sequences.

To study the effect of hydrogen spin density (N[H]) on magnetic resonance (MR) image contrast in white matter disease of the brain, T1, T2, and N[H] values were determined for normal white matter and idiopathic white matter lesions (IWMLs) in 21 patients by using multiple spin-echo (SE) sequences. T1 values of IWMLs were significantly greater than those of normal white matter in all patients studied, and T2 values of IWMLs were significantly greater in 20 of 21 patients. N[H] values of IWMLs were greater in 20 of 21 patients, with statistically significant differences from those of normal white matter in 17 of those 20 patients. Averaged over all 21 patients studied, N[H] values of IWMLs were 20% higher than N[H] values of normal white matter. The effect of unequal N[H] values on contrast between IWMLs and normal tissues is to reduce contrast on short SE sequences with a short repetition time (TR) and a short echo time (TE), while enhancing contrast between IWMLs and normal tissues on long TR/TE SE sequences. Elevated N[H] values in IWMLs have a minimal effect on contrast in conventional inversion-recovery (IR) sequences but substantially enhance contrast between IWMLs and normal brain tissues in short inversion time IR sequences.

The pulse-sequence equations for spin-echo magnetic resonance imaging were used to determine interpulse delay times that give the highest signal-to-noise ratio from a single tissue. This theoretical result was then verified experimentally using 1-, 2-, and 5-mM/l copper sulfate solutions imaged on a 0.15-T resistive system. Theoretical analysis determined the spin-echo interpulse delay times that maximize the signal-to-noise ratio from a single tissue as TEopt = TEmin, the minimum echo delay time permitted by the system, and, to a good approximation, TRopt = 1.27 T1 + 1.90 TEmin, with T1 the longitudinal magnetic relaxation time of the tissue. Phantom measurements of the signal-to-noise ratio in a typical imaging system confirmed the theoretically determined TRopt values to within 7%.