Análisis de concordancia en la interpretación de imágenes mamográficas entre médicos radiólogos de Bogotá, D. C. / Analysis of agreement of the interpretation of mammographic images between radiologists: a pilot study in Bogotá, D. C.

Resumen Objetivo: Evaluar la concordancia entre médicos radiólogos de Bogotá, D.C., en la interpretación de estudios mamográficos con la categorización BI-RADS. Materiales y métodos: Estudio de corte trans-versal en 11 centros mamográficos de Bogotá, D.C., que incluye un tamaño de muestra de 323 exámenes mamográficos, en mujeres asintomáticas de 50 a 69 años, seleccionados de forma aleatoria y estratificada según su categorización BI-RADS. Mediante el índice kappa se determinó la concordancia de la categori-zación diagnóstica del sistema BI-RADS en los informes mamográficos entre los radiólogos de los centros mamográficos y el consenso de dos médicos radiólogos expertos del Instituto Nacional de Cancerología ESE. Resultados: Después del consenso entre los dos médicos radiólogos del Instituto Nacional de Can-cerología de Colombia, el análisis de concordancia con los médicos radiólogos de todas las instituciones demostró una tasa de acuerdo del 54,9% y un índice kappa (k) de 0,21 (IC 95%: 0,14-0,28) en la categori-zación BI-RADS. Cuando se agruparon las categorías BI-RADS 1 y 2 la proporción de coincidencias fue de 75,3% y el índice kappa (k) de 0,26 (IC 95%: 0,17-0,34). Discusión: Según los márgenes propuestos para el índice kappa, se encontró una concordancia débil en la categorización BI-RADS presentada en los reportes mamográficos por los médicos radiólogos expertos y los médicos radiólogos de los centros participantes del estudio. Lo anterior sugiere que aunque se ha adoptado el sistema estandarizado para el reporte mamográfico desde finales de la década de los noventa en Bogotá, D.C., existe una alta varia-bilidad dependiente del observador en el momento de la interpretación de las imágenes mamográficas.

AbstractIntroduction: Amongallcancers,breastcanceristheprimarycauseoffemalemortalityinColombia.Therefore,ithasbeenconsiderednecessarytostrengthenmammogram-basedearlydetectionprogramsbyimplementingqualityassuranceprograms,includingtheevalu-ationofthequalityofclinicalimagesandanalysisinthediagnosticconcordanceoftheBI-RADScategorization.Objective: Toevaluatetheinter-observervariabilityamongradiologistsintheinterpretationofmammogramscategorizedbymeansofBreastImagingReportingandDataSystem(BI-RADS).Methods: Thiscross-sectionalstudyincludesasampleof323mam-mographicexaminationsinasymptomaticwomenbetween50and69years.TheparticipantswererandomlyselectedandstratifiedaccordingtotheBI-RADScategorization,in11mam-mographiccentersinBogotá,D.C.,Colombia.Bymeansofthekappacoefficient,theconcor-danceamongtheconsensusoftwoexpertradiologistsoftheColombianInternationalCancerInstituteandradiologistsofthemammographycentersintheinterpretationofmammogramsbymeansoftheBI-RADScategorizationwasdetermined.Results: AfterreachingconsensusbetweentwoexpertradiologistsfromtheColombianNationalCancerInstitute,theanalysisofconcordancewiththeradiologistsofallinstitutionsshowedanagreementrateof54,9%andakappacoefficient(k)of0,21(95%CI:0,14-0,28).WhenBI-RADS-groupsIandIIwereclus-tered,boththeagreementrateaswellasthekappacoefficientincreasedto75,3%andk=0,26(95%CI:0,17-0,34),respectively.Discussion: TheresultsshowaweakconcordanceoftheBI-RADScategorizationpresentedinmammographicreports,suggestingthatthereisahighinter-observervariabilityatthetimeofinterpretationofmammographicimages

Evolution of Imaging in Breast Cancer.

The following topics are discussed in this article. A historical review of the evolution of breast cancer imaging from thermography through digital breast tomosynthesis, molecular breast imaging, and advanced breast magnetic resonance imaging. Discussion of multiple clinical trials, their strengths, and weaknesses. Historical perspective on the Mammography Quality Standards Act and its relationship with development and implementation of the Breast Imaging-Reporting and Data System (BI-RADS).

Temporal performance of amorphous selenium mammography detectors.

We investigated temporal performance of amorphous selenium (a-Se) detectors specifically designed for mammographic imaging. Our goal is to quantify the inherent lag and ghosting of a-Se photoconductor as a function of imaging conditions. Two small area electroded a-Se samples, one positively and the other negatively biased on the entrance side of x rays, were used in the experiments. The study of lag and ghosting was performed by delivering a number of raw exposures as experienced in screening mammography to the samples at different electric field strength E(Se) while measuring the current through the a-Se sample. Ghosting at different operational conditions was quantified as the percentage x-ray sensitivity (x-ray generated photocurrent measured from the sample) reduction compared to before irradiation. Lag was determined by measuring the residual current of a-Se at a given time after the end of each x-ray exposure. Both lag and ghosting were measured as a function of E(Se) and cumulative exposure. The values of E(Se) used in our experiments ranged from 1 to 20 V/microm. It was found that ghosting increases with exposure and decreases with E(Se) for both samples because of the dominant effect of recombination between trapped electrons and x-ray generated holes. Lag on the other hand has different dependence on E(Se) and cumulative exposure. At E(Se) < or = 10 V/microm, the first frame lag for both samples changed slowly with cumulative exposure, with a range of 0.2%-1.7% for the positively biased sample and 0.5%-8% for the negatively biased sample. Overall the positively biased sample has better temporal performance than the negatively biased sample due to the lower density of trapped electrons. The impact of time interval between exposures on the temporal performance was also investigated. Recovery of ghosting with longer time interval was observed, which was attributed to the neutralization of trapped electrons by injected holes through dark current.

[Phantom study for the detection of simulated lesions in five different digital and one conventional mammography system]. / Phantomstudie zur Detektion simulierter Läsionen an fünf verschiedenen digitalen und einem konventionellen Mammographiesystem.

PURPOSE: Experimental phantom study for the detection of simulated lesions with five different digital and one conventional screen-film mammography system. MATERIALS AND METHODS: Three radiographs were obtained at various configurations of the phantom with one conventional screen-film system (Mammomat 3000 N) (Siemens), five digital systems (high resolution computed radiography system [Fuji/Siemens], one a-Si detector [GE Medical Systems], two a-Se detectors [Siemens; Hologic / Lorad] and one CCD detector [Fischer Imaging]), applying the same exposure parameters. The Wisconsin Mammographic Random Phantom, Model 152 A, was used. Five investigators with different experience in mammography (3 months to more than 4 years) evaluated the 18 randomly selected radiographs. RESULTS: No significant differences were found in the detection rate of simulated breast lesions for conventional screen-film mammography (84.9 %), high resolution computed radiography (86.7 %) and digital mammography with an a-Si detector (89.8 %). Highly significantly better results (p < 0.001) were found with the two a-Se systems (97.3 %) and the CCD system (100 %). CONCLUSION: Conventional screen-film mammography can be replaced by high resolution computed radiography and digital mammography with a-Si-, a-Se- and CCD-detectors. This has to be confirmed in further clinical studies.

Cassette-based digital mammography.

Over the past several years, digital mammography systems have been installed clinically across North America in small but growing numbers. A photostimulable phosphor-based full-field digital mammography image was evaluated in this investigation. Commonly known as computed radiography (CR), its use closely mimics the screen-film mammography paradigm. System performance using modulation transfer function (MTF) and detective quantum efficiency (DQE) metrics show MTF(2.5 mm(-1)) = 0.5, DQE(2.5 mm(-1)) = 0.3, and MTF(5.0 mm(-1)) = 0.2, DQE(5.0 mm(-1)) = 0.05, for a 26 kVp beam, 0.03 mm molybdenum tube filtration, 4.5 cm tissue attenuation, and 15 mR incident exposure to the detector. Slightly higher DQE values were measured at 32 kVp with 0.025 mm rhodium tube filtration. CR mammography advantages include the ability to use existing mammography machines, where multiple rooms can be converted to "digital" operation, which allows overall cost savings compared to integrated digital mammography systems. Chief disadvantages include the labor-intensive handling of the cassettes prior to and after the imaging exam, lack of a direct interface to the x-ray system for recording technique parameters, and relatively slow processing time. Clinical experience in an IRB-approved research trial has suggested that digital mammography with photostimulable storage phosphors and a dedicated CR reader is a viable alternative to conventional screen-film mammography.

[Radiation exposure in x-ray mammography]. / Die Strahlenexposition bei der Röntgen-Mammographie.

When discussing the radiation risk of X-ray mammography, the magnitude of the dose applied has decisive importance. The radiation exposure of the breast is the predominant factor in risk considerations, since it contributes more than 98% to the effective dose of this examination. At present, it is generally assumed that, with regard to cancer induction by ionizing radiation, the glandular tissue is the most vulnerable part in the breast. Therefore, the average glandular dose, i.e., the mean value of the absorbed dose in the glandular tissue, is used for a description of the radiation risk. The average glandular dose cannot be measured directly, but is calculated under certain assumptions from the experimentally determined entrance surface air kerma or entrance surface dose by the use of a so-called conversion factors. During the seventies, i.e., in the era of the industrial type X-ray film, the mean value of the average glandular dose per exposure for a larger sample of patients (n > 100) was about 20 mGy. Due to the progress in radiographic technique such as, for example, the use of sensitive film-screen systems, optimized radiation qualities and modern automatic exposure control units this value has now decreased to about 1 mGy. Further dose reductions seem possible by the introduction of digital image receptors.

[Experimental studies on image quality in conventional film screen system, digital phosphor storage plate mammography in mangnification technique and digital mammography in CCD-technique]. / Experimentelle Untersuchungen zur Bildgüte konventioneller Film-Folien-Mammographie, digitaler Mammographie mit Speicherfolien in Vergrösserungstechnik und voll digitaler Mammographie in CCD-Technik.

UNLABELLED: Comparison of image quality between conventional film screen system, digital phosphor storage plate mammography in magnification technique and digital mammography in CCD-technique. MATERIALS AND METHODS: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system, two digital storage plate systems and two digital systems in CCD-technique. Additionally, the radiograms of one digital phosphor storage plate system were postprocessed emphasizing contrast and included in the comparison. RESULTS: The detectability of details was the best with the digital mammography in CCD-technique in comparison with the conventional film screen technique resp. digital phosphor storage plate in magnification technique. CONCLUSIONS: Based on these results there is the possibility to replace the conventional film screen system by further studies--this has to be confirmed.

[Intraoperative digital radiography for diagnosis of nonpalpable breast lesions]. / Digitale intraoperative Präparate-radiographie bei diagnostischen Exzisionen nicht palpabler Läsionen der Brust.

PURPOSE: A procedure for performing intraoperative digital radiography of diagnostic breast specimens directly in the operating suite with teleradiologic assessment by a radiologist is presented. The efficiency of this procedure is compared with that of conventional magnification mammography performed in the radiology department. MATERIAL AND METHODS: Thirty-six specimen radiographs obtained by conventional magnification mammography were compared with 38 intraoperative digital magnification radiographs (DIMA Soft P42 prototype, Feinfocus Inc., Garbsen). The radiographs were assessed for lesion conspicuity and time savings for the surgeon, anesthesiologist, and radiologist. RESULTS: The new procedure identified all 38 labeled pathological lesions, and the conventional technique likewise had a detection rate of 100% (36/36). The new technique resulted in considerable time savings for the surgeon and the radiologist. The duration of surgery was shorter and the time interval from removal of the specimen to reporting of the results was reduced from about 23 min to about 13 min. A single radiograph was sufficient for complete visualization of the specimen in all cases. CONCLUSION: Digital intraoperative specimen radiography considerably reduces the time of surgery depending on the local conditions and is highly accurate in locating a suspicious area within the tissue.

Mammographic determination of breast volume: comparing different methods.

OBJECTIVE: The purpose of this study was to compare the accuracy and reproducibility of different methods for calculating breast volume when using measurements made on mammograms. MATERIALS AND METHODS: The volumes of 32 breasts were determined by pathologic evaluation of mastectomy specimens. Two radiologists independently measured breast height and width on the preoperative craniocaudal mammograms and measured height, width, and width at half-height on mediolateral oblique mammograms. Compression thicknesses used on the craniocaudal and mediolateral oblique projections were recorded. Volume was then calculated using six different formulas. The accuracy of each method was determined and compared using bivariate and univariate linear regression analyses. Interobserver variability in measurement was also assessed. RESULTS: The most accurate method for calculating breast volume was the one that assumed a half-elliptic cylinder shape for the compressed breast in the craniocaudal projection. Measurements made on the craniocaudal view were more reproducible than those made on the mediolateral oblique view. CONCLUSION: Breast volume can be accurately and reproducibly determined on mammograms by making two measurements on the craniocaudal view and knowing the compression thickness. This information may be useful to plastic surgeons, investigators who study parenchymal patterns, and physicians who examine cancer patients being considered for breast conservation surgery.

Arterial calcification found on breast cancer screening mammograms and cardiovascular mortality in women: The DOM Project. Doorlopend Onderzoek Morbiditeit en Mortaliteit.

Breast arterial calcification (BAC) has been associated with diabetes and hypertension. This prompted the authors to study the relation between BAC and cardiovascular mortality in a cohort of 12,239 women aged 50-68 years who participated in a population-based breast cancer screening project (DOM Project) in Utrecht, the Netherlands, during the period 1975-1977. Mortality data from 16-19 years of follow-up were available. The occurrence of outcome events was compared in terms of hazard ratios. Cardiovascular risk factors, including age, diabetes mellitus, hypertension, parity, Quetelet index, and smoking, were studied to identify possible confounders. Arterial calcification was seen in 9% of the women. The hazard ratio for overall mortality was 1.29 (95% confidence interval 1.06-1.58) in women with BAC detected on screening mammograms in comparison with women without BAC after correction for the above-mentioned factors. An excess of all-cause mortality was found in diabetic women with BAC (hazard ratio = 1.74, 95% confidence interval 1.19-2.56), which was also present in subgroups of coronary mortality. These results indicate that BAC is associated with an increased risk of subsequent cardiovascular death in women over age 50 years and in diabetic women in particular.

Breast arterial calcifications: association with diabetes mellitus and cardiovascular mortality. Work in progress.

PURPOSE: To determine the relationship between breast arterial calcification, diabetes mellitus, and subsequent cardiovascular and noncardiovascular mortality. MATERIALS AND METHODS: A prospective cohort study was carried out in 12,239 women aged 50-68 years who participated in a breast cancer screening program. The screening mammograms were coded for the presence of breast arterial calcification. Diabetes (n = 442) was defined as use of insulin or oral hypoglycemic agents, use of a restricted diet for diabetes, or the presence of glucosuria. Data were available from questionnaires and urine glucose tests. Hazard ratios, which were adjusted for age, smoking, parity, and obesity, were calculated from mortality data after 16-19 years of follow-up. RESULTS: Breast arterial calcification was seen in 9.0% (1,107 of 12,239) of all women and in 15.4% (68 of 442) of the diabetic women. An excess cardiovascular mortality of 40% (hazard ratio = 1.4; 95% confidence interval = 1.1, 1.8) was found for all women with breast arterial calcification. In diabetic women, the presence of breast arterial calcification was associated with a 90% (hazard ratio = 1.9; 95% confidence interval = 1.1, 3.2) increase in cardiovascular mortality. CONCLUSION: Breast arterial calcification represents an independent risk factor for cardiovascular mortality in women over 50 years of age, especially in those with diabetes.

Peripheral blood eosinophilia, hyperimmunoglobulinemia A and fatigue: possible complications following rupture of silicone breast implants.

BACKGROUND: Silicone breast implantation has been considered quite safe and of major cosmetic value. Immunologic sequelae such as collagen vascular diseases have not been confirmed in large studies. OBJECTIVE: We describe a 55-year-old woman who developed severe fatigue, peripheral blood eosinophilia, and hyperimmunoglobulinemia A after rupture of a silicone breast implant during closed manual manipulation to lyse fibrotic tissue. METHODS: We charted evidence for eosinophilia over a 19-year period and determined quantitative immunoglobulins, and lymphocyte subsets by FACS analysis. RESULTS: Peripheral eosinophilia in 1976 was 693/mm3 and increased to 1360/mm3 after rupture of the implant in 1992. Serum immunoglobulin A was 332 mg/dL in 1976 and ranged after rupture from 473 to 627 mg/dL without other cause. Fatigue was not reversed with a parenteral corticosteroid injection. CD4 and CD8 subsets were normal but 40% of CD3 cells were Ia positive although not CD25 positive (IL2 receptor). Only 5% of B cells were CD19 CD23 positive despite the high concentration of serum IgA. CONCLUSION: This case is an example of a previously unreported apparent adverse effect of silicone-breast implant rupture with persisting eosinophilia, hyperimmunoglobulinemia A, and fatigue.

[Lobular cancer transformation of the female breast. Mammography diagnosis and clinical relevance]. / Läppchenkanzerisierung der weiblichen Mamma. Mammographische Diagnostik und klinische Relevanz.

Lobular cancerisation was diagnosed in 101 women between 1976 and 1980. Calcification in the mammograms and follow-up without mastectomy were analysed. Therapy was simple biopsy, because the term lobular cancerisation was not established at that time. Surgery was done at the University Clinic for Women and the Elim Hospital at Hamburg. Retrospective analysis of the specimens was performed at the Department of Gynaecological Histopathology of the Hamburg University Clinic. Mammograms were available in 72 cases, showing calcifications in 40 cases. It was impossible to match the calcifications in the mammograms and the histological slides. Hence, a further 23 cases from 1980 to 1990 were analysed, suffering from lobular cancerisation and ductal carcinoma in situ (DCIS). Comparing 13 mammograms showing calcifications, with large-area scans, only two showed corresponding calcifications. Based on these data a specific diagnosis of lobular cancerisation by mammography is impossible. The follow-up of 88 patients with breast-preserving surgery and lobular cancerisation showed ipsilateral invasive carcinoma in three cases (0.35% in a total of 100 follow-up years), ipsilateral DCIS in five, and contralateral invasive breast cancer in one case. The therapy of lobular cancerisation should depend on the coexisting DCIS. There is no additional risk of local recurrence by lobular cancerisation.

X-ray imaging with amorphous selenium: optimal spectra for digital mammography.

The optimum x-ray spectra for acquisition of digital mammographic images using an amorphous selenium (a-Se) photoconductor are investigated. The recorded images consist of latent charge distributions on the surface of an a-Se plate, which are then read out using two methods, laser discharge, or flat panel recharge. The investigation is based on a model of the breast previously developed for a phosphor-based digital readout system, and has been extended to include the effects specific to the use of photoconductors. The effects of plate thickness, x-ray scatter, readout noise, dose, and the kind of breast tissue on the nature of the optimum spectrum are explored for the two readout methods. The results indicate that use of a kilovoltage setting in the current mammographic range, and a molybdenum target spectrum is appropriate for digital readout of a-Se detectors. This conclusion contrasts with the appreciably higher kilovoltages traditionally used with the xerographic (toner) readout of latent charge images on a-Se.

[Imaging methods in diagnosis and differential diagnosis of breast cancer]. / Bildgebende Verfahren zur Diagnostik und Differentialdiagnostik des Mammakarzinoms.

The diagnosis of breast cancer is primarily based on X-ray mammography. Under optimal conditions, a sensitivity of approximately 90% can be achieved. When strict criteria of indication are observed for the additional use of ultrasound or contrast-enhanced MRI, the sensitivity can be increased to about 98%. In addition, the differential diagnosis between benign and malignant lesions can be improved and the rate of biopsies due to false-positive mammograms can be reduced. However, further investigation with ultrasound or MRI of dense or mastopathic breasts that are clinically asymptomatic is not indicated, since it reduces specificity without significant gain of sensitivity.

Parenchymal patterns of the breast defined by real time ultrasound.

The association of mammographic parenchymal patterns of the breast with breast cancer risk has been studied extensively but there is little information about the distribution of different patterns in populations at different risks for breast cancer. Such information could be obtained if a risk-free method of breast examination were available that could be applied to the general population. We have evaluated real time ultrasound for this application by comparing the parenchymal pattern as assessed by mammography with the extent of echogenicity in the breast on ultrasound examination in 102 subjects. Subjects were examined by both methods, the mammographic and ultrasound images independently classified, and the proportion of the breast occupied by radiological density or ductal prominence compared with the extent of echogenic areas on ultrasound. These two methods of classifying mammographic parenchymal patterns were found to be strongly correlated. Real time ultrasound may therefore be useful in the epidemiological study of mammographic pattern and breast cancer risk.