Showing papers on "Mammography published in 1979"

Breast cancer missed by mammography.

Abstract: Because a "negative" mammogram that is followed by a biopsy diagnostic of cancer is a matter of deep concern, a retrospective review was conducted of 48 such missed diagnoses at four Breast Cancer Detection Centers. The study group comprised 40,000 women participating in breast cancer screening examinations. From 3,271 biopsies during screening, 499 cancers had been found. Biopsies in the interval between screening examinations totaled 630 and yielded 48 malignancies. These 48 interval cancers were studied in an attempt to discover why they were not found on the preceding mammographic examination. Three major categories of error were disclosed and each is discussed: (1) poor radiographic technique; (2) absence of radiographic criteria of cancer; (3a) obvious oversight by the radiologist; and (3b) lack of recognition of subtle radiographic signs. This last reason is discussed in detail in the belief that better recognition of these indirect radiographic signs will lead to more accurate diagnoses, particularly in early cancers.

Mammogram Inspection by Computer

Abstract: We have considered the problem of computerized picture processing of mammographic images for the early detection of breast cancer by determination of the very significant microcalcifications. Brightness measures, gray-level statistics, and a compactness measure are applied in a decision tree to characterize the candidate objects. A verification technique was evaluated to differentiate between significant groups of microcalcifications and isolated objects as well as false alarms. Feasibility of the microcalcification detection algorithm was demonstrated in experiments using 132 mammogram subareas, each consisting of 512 ×512 picture elements.

Preoperative localization of nonpalpable breast lesions.

Abstract: Surgeons are increasingly required to resect nonpalpable breast lesions only detected by mammography. Methods for preoperative localization of such lesions were reviewed with emphasis on invasive radiologic techniques using injection, needle, and wire markers. Invasive localization of nonpalpable breast lesions is a relatively simple procedure that should be available wherever breast biopsies and mammography are performed. Its precision and success relate to the radiologist's experience in marker placement and to close cooperation between the radiologist and surgeon.

Computed tomographic mammography (CTM).

Abstract: Breasts of 724 patients were studied by physical examination, mammography, and computed tomographic mammography (CTM) using a scanner designed for evaluation of the breast. Among cases in which CTM was not accompanied by use of contrast material, there were 60 malignant lesions, of which 10% were missed by mammography, 32% by CTM, and 8% by both. Among cases where CTM was supplemented by a 50 ml injection of 75% contrast material, there were 63 malignant lesions, of which 14% were missed by mammography, 16% by CTM, and 3% by both. Among cases where CTM was supplemented by a 300 ml infusion of 30% contrast material, there were 41 malignant lesions, of which 7% were missed by mammography and 5% by CTM, but none by both. Clinically, 22% of the malignant lesions in the infusion series were occult. There were 44 benign lesions in patients studied with the infusion technique. With mammography 68% were suspicious for malignancy, and with CTM, 56%.

Screening is not diagnosis.

Abstract: Mammography and physical examination, usually employed as diagnostic tools, may be used to screen for early detection of breast cancer. A study of these modalities used to aggressively screen patients in Cincinnati and Milwaukee is presented and compared to more traditional methods of breast cancer detection and diagnosis as done in Louisville. For a similar-sized group over the same period, the rate of cancers detected in Louisville did not exceed that in Cincinnati-Milwaukee. Aggressive screening will not increase the overall number of detected cancers but will decrease the number of advanced cancers. Mammography as a screening device is not in itself a diagnostic tool, since its potential benefit is maximized only through the use of nondiagnostic, indirect radiographic criteria.

Specific value of computed tomographic breast scanner (CT/M) in diagnosis of breast diseases.

Abstract: CT/M study of the breast yields specific information about lesions and may provide the diagnosis when mammography fails to demonstrate the lesion or is unable to display the information necessary to make a definitive diagnosis. By using contrast medium to increase attenuation, very small carcinomas may be identified, even in dysplastic breasts.

Analysis of the significance of scattered radiation in reduced dose mammography, including magnification effects, scatter suppression, and focal spot and detector blurring.

Abstract: A systems analysis of reduced dose mammography with scatter removal has quantitatively specified the relationships between the several parameters in mammography systems. While the results are only preliminary in the sense that they need to be proven experimentally, they do seem to provide a good feel for the nature of the important trade‐offs. The major uncertainties in the analysis probably have to do with the formal equivalence, that is implicit in the aperture theory, between large area and detail contrast, as well as the output versus focal spot relationship that was adopted. Also, there are important questions about specifying motion unsharpness as a function of exposure time in mammography examinations.

Mammographic Parenchymal Patterns and Risk of Breast Cancer 1

Abstract: A 15-year prospective study of mammographic parenchymal patterns in 7,123 women over 30 with 658 prevalent and 131 incident primary breast neoplasms demonstrated that no pat­ tern is a reliable indicator of initial or developing cancer. Cancer in glandular breasts is less frequent, more difficult to detect by mammography, and tends to remain prevalent compared with the more frequent tumors in fatty breasts. As women get older. their breasts assume similar patterns and the incidence of both prevalent and incident tumors increases. Paren­ chymal patterns cannot signify which breasts may remain glandular, nor which women may be at risk of cancer. IN[)~X TERMS: Breast. parenchymal pattern. Breast neoplasms. diagnosis ELECTION of women most susceptible to breast can­ cer would extend the usefulness of mammography. Following a screening examination, the small segment of the population at high risk could be studied repeatedly while reducing radiation exposure to the general popula­ tion, increasing the benefit-to-risk ratio, and lowering the cost. The urgency of such a selection process has been emphasized by Urban, who insists that in an active breast service, mammography should be employed in all women over 30 (18). Wide-field mammography of the intact breast represents an extrapolation of previous efforts to estimate the risk of breast cancer based on histopathological pat­ terns of fibroglandular tissues (14, 20). Pre-biopsy mam­ mography, radiography of biopsy specimens, and studies of the entire breast correlated closely with histopatholog­ ical studies of small fragments of breast tissue (5, 8) and confirmed the close association between ductal epithelial hyperplasia and breast cancer. Although this process could be recognized on mammography, no clear-cut radio­ graphic patterns of breast cancer emerged. Several retrospective studies have revealed the de­ velopment of cancer after earlier mammograms had been judged negative and have also suggested a propensity toward cancer in breasts with certain types of parenchymal patterns (9, 11, 13, 16,22). Although these observers used similar breast pattern categories, estimates of the use­ fulness of these patterns in predicting risk of breast cancer varied widely. Since our findings, based on a prospective study, differed from those of some other workers (6, 10), it seemed pertinent to re-examine our data over a longer follow-up period.

Breast cancer screening with mammography: a population-based, randomized trial with mammography as the only screening mode.

Abstract: A population-based, randomized breast cancer screening project was undertaken using mammography alone. Of 17,447 invited women aged 50-69, 12,765 (73%) attended the screening. On the basis of the screening films, malignancy was suspected in 405 women (3.2%) who were recalled for complete mammography. Additional films showed that the suspicion of malignancy was false in 194 women. The remaining 211 women (1.7%) were referred for clinical and cytological examination. Of these, 159 had surgery. Breast cancer was proved in 97 women, corresponding to a prevalence rate of 7.6/1000. Fifty-three (55%) of the carcinomas were either in situ or invasive with a diameter of less than or equal to 1 cm. Axillary metastases were found in 19 patients (19.6%). Cancers detected at screening were significantly less advanced than those in the control group. There was a remarkably high frequency of tubular carcinoma among cancers detected at screening.

Mammographic parenchymal patterns and risk of breast cancer.

Abstract: A 15-year prospective study of mammographic parenchymal patterns in 7,123 women over 30 with 658 prevalent and 131 incident primary breast neoplasms demonstrated that no pattern is a reliable indicator of initial or developing cancer. Cancer in glandular breasts is less frequent, more difficult to detect by mammography, and tends to remain prevalent compared with the more frequent tumors in fatty breasts. As women get older, their breasts assume similar patterns and the incidence of both prevalent and incident tumors increases. Parenchymal patterns cannot signify which breasts may remain glandular, nor which women may be at risk of cancer.

Factors associated with breast structure in breast cancer patients

Abstract: The breast duct patterns and radiographic density, or dysplasia, of 104 breast cancer patients in Hawaii were examined by mammography. The proportions of the four types of breast structure were analyzed for possible relation with age, menopausal state, height, weight, and race. Multiple regression analysis indicated that menopausal state appears to be more important than age per se for the general change in breast structure. Low body weight, but not race, is associated with prominent duct patterns and dysplasia.

Microfocal spot magnification mammography using xeroradiographic and screen-film recording systems.

Abstract: Direct radiographic magnification (1.5×) of the breast, using a microfocal spot x-ray tube and either a xeroradiographic or screen-film recording system, produces images superior in quality (improved resolution, reduced noise) to conventional contact mammograms. Six hundred twenty-one patients had a single magnification mammogram in addition to conventional mammography; 216 subsequently underwent biopsy within one month of study. The additional magnification mammogram increased the diagnostic accuracy of the conventional examination in 40% of the pathologically proved cases, particularly among those for which conventional mammograms were interpreted as equivocal for malignancy. The superior image quality of magnification mammograms appears useful in distinguishing malignant from benign breast disease.

Relation between mammary cancer growth kinetics and the intervals between screenings

Abstract: The purpose of this study was to consider the time interval for periodic mammographic screening for breast cancer. One hundred fifteen breast cancers occurring in 10,128 women receiving over 30,000 mammograms over a four year period were reviewed. Tumors were diagnosed at three time intervals: 1) first screening (39/115); 2) annual examination (27/115); and 3) at an examination that occurred less than twelve months from a previous annual examination (10/115). Also, there were tumors that grew to palpable dimensions and were self-detected between annual examinations (39/115). Our opinion is that screening intervals should be individualized to each patient according to risk factors and suspicious mammographic findings. Further, there is a significant number of breast cancers that grow too fast to be detected effectively by annual mammography. Suspicious mammographic findings did not exist before these cancers reached palpable dimensions. Other risk factors characterizing the hosts who develop these fast growing cancers are yet to be determined. Cancer 43:857–862, 1979.

Population screening for breast cancer by single-view mammography in a geographic region in Sweden.

Abstract: Single-view mammography was used for the screening of a total population of women living in a defined geographic region in Sweden; 37,640 women were invited and 31,074 participated. The average participation rate was 82.6%, and in the age group 40-69 years it was 91.7%. The rate of referrals from screening to clinical examination was 1.2%. Of 209 surgical biopsies performed, 130 primary mammary carcinomas were detected, 91% of which had no clinically detectable metastatic nodes. Because of the few false-positive cases, the low rate of benign biopsy specimens, the high rate of early detected carcinomas, and the low costs, screening by single-view mammography is considered a satisfactory method, provided the positioning of the oblique view is correct and the image quality is high.

Annual clinical examination: the best available screening test for breast cancer.

Abstract: MAMMOGRAPHY is a rewarding method of screening for breast cancer.1 However, surgeons have been disturbed by the fact that many clinically detected small solid breast lumps not demonstrated by mammography are found to be malignant on biopsy. We therefore carried out a prospective study to determine the sensitivity of four screening methods — annual clinical examination, mammography, thermography and breast self-examination — in the detection of cancer of the breast. Our results demonstrate that the most rewarding screening tool is clinical examination. Methods From the patients referred to St. Michael's Hospital Breast Clinic over the past six years, we selected . . .

Sensitivity of mammography and physical examination of the breast for detecting breast cancer.

Abstract: Mammography and physical examination of the breast are evaluated as screening instruments for detecting breast cancer based on local biopsy data obtained from women enrolled in a national breast cancer screening program. One hundred thirteen cancers (15.5% of women who underwent biopsy) were detected. The individual sensitivities of mammography and physical examination for detecting breast cancer are 62% and 24%, respectively. The sensitivity of the two methods combined is 75% (85 of 113). Thirty-seven cancers were in situ or minimally invasive (≤1 cm in greatest dimension). Eighty-one percent (30 of 37) of these small cancers were detected by screening, and they comprised 35% (30 of 85) of all cancers detected by mammography, physical examination, or both. Improved survival is anticipated due to this high rate of discovery of small cancers. ( JAMA 242:2080-2083, 1979)

Prognostic factors of breast neoplasms detected on screening by mammography and physical examination.

Abstract: A total of 183 neoplasms detected on screening women between the ages of 45 and 64 by mammography and physical examination were analyzed according to multiple histologic parameters. In general, tumors apparent only on mammography should be associated with favorable long-term survival because of their early stage. These lesions had histologic features indicating significant potential for subsequent metastatic spread. This analysis strongly suggests that mammographic screening of asymptomatic women both above and below 50 years of age can substantially reduce breast cancer mortality.

Focal spot size and scatter suppression in magnification mammography.

Abstract: The improved image quality using magnification in film-screen mammography is related to a complicated interplay between focal spot size, x-ray tube output, detector resolution and sensitivity, air gap size, and target dimensions. Preliminary clinical evaluation of magnification mammography indicates that accuracy of diagnosis has been considerably enhanced. Additional technical and clinical evaluations are continuing, as suggested by mathematical modeling, in order to determine the best possible magnification protocols. While a small focal spot (less than 300 micrometers) is highly recommended for both contact and magnification with the film-screen systems, the smallest focal spot sizes (150 micrometers and smaller) may neither be necessary nor the best in all situations of reduced dose magnification mammography.

Mammography in symptomatic women 50 years of age and under, and those over 50.

Abstract: Our experience with the use of mammography as a diagnostic aid in symptomatic women with breast complaints has been presented. One-third of all cancers were found in women 50 years of age and under. The detection of cancer by mammography in the younger age group was similar to that experienced in the older age group. Radiation exposure by mammography has diminished markedly during the last 15 years—only one-third to one rad per exposure with modern technique. Recent hysterical criticism of the use of mammography in women under 50 years of age is unwarranted in the light of current findings. This diagnostic modality should be utilized when indicated in all age groups over 30. It is probable that screening clinics should include all women over 35 years of age. Cancer 43:878–882, 1979.

Ultrasonic mammographic parenchymal patterns: a preliminary report.

Abstract: Ultrasound has been suggested as a lower risk alternative to mammography for detecting breast abnormalities. Mammograms and ultrasonograms of 32 women patients were compared, revealing three distinct ultrasonic parenchymal patterns which corresponded to previously reported mammographic patterns: fatty (N1), ductal (P1 or P2), and dysplastic (DY). These constitute a new system of parenchymal classification, to our knowledge.

Efficiency of single-view mammography: rate of interval cancer cases.

Abstract: A nonselected population of women screened by single-view mammography was followed up to 2 years after screening, and breast carcinoma cases diagnosed were registered; 28,350 women were followed for 1 year. At screening, 132 invasive carcinoma cases were detected, and during the first year after screening, 10 cases were detected. According to an efficiency index, which takes into consideration both detections at screening and interval cases, the 1-year efficiency was 93%. The efficiency of single-view mammography for breast cancer screening was found to be satisfactory.

The status of film/screen mammography. Results of the BENT study.

Abstract: Results of the Breast Exposure: Nationwide Trends (BENT) study are presented. In this study, data were collected from 42 states and several other jurisdictions and the number of facilities found to have unusually high or low exposures during mammography was determined. Surveyors trained by representatives of the Bureau of Radiological Health then worked with these facilities to determine the source of the problem and recommend corrective measures. Contrast was found to be reduced by high "inherent" filtration, high kVp, or inappropriate imaging conditions, while resolution was impaired by excessive exposure time, as well as inappropriate imaging conditions. These and other problems are discussed and correlated with image quality.

Low-dose Mammography: Application to Medical Practice

Abstract: DURING the past few years, there has been improvement of mammographic technology, enabling reduction of radiation dose, enhancement of image quality, and increased detection of breast cancers at an early curable stage. These advances are the result of two new imaging systems: (1) reduced-dose xeromammography, an electrostatic process using highly filtered x-rays to record on special paper an image composed of blue toner particles (Fig 1 and 2), and (2) screen-film combinations specifically designed for mammography. Reduced Dosage Formerly, all mammographic examinations were performed with nonscreen film, and skin exposure doses of 7 to 15 rads per exposure were necessary. Now, skin doses are reduced to 0.5 to 0.9 rads per exposure. The relationship between skin exposure dose and absorbed breast tissue dose was difficult to assess, but now it can be accurately measured by refined dosimetric techniques. For a typical two-view examination, the midbreast tissue dose is 0.08 to

A study of mammographic exposure and detail visibility using three systems: Xerox 125, Min-R, and Xonics XERG.

Abstract: A breast phantom of novel design has been used to measure visiblity of simulated calcific and soft-tissue fibrillar details in mammography, as well as to determine the roentgen exposure vs. depth. Exposure data were combined with a model of the breast as compressed during mammography to compute the mean exposure to the ductal parenchyma (MDE). Three different imaging systems were compared over a wide range of x-ray beam energies and breast characteristics. "Dosage" criteria other than the MDE are discussed.

Historical Review Of Mammographic Imaging Techniques In Terms Of Image Quality And Reduced Radiation Dose

Abstract: The field of mammography has changed dramatically during the past ten years. The introduction of new imaging techniques combined with the renewed interest in breast imaging has given mammography comparable status to other diagnostic radiology procedures. Mammography has been applied as a tool for mass screening for breast cancer. Several controversial reports have implied that in mass screening mammography more cancers may be induced than detected due to the radiation exposure to the breast. Such reports have put mammography on the defensive, not only for mass screening, but for conventional mammography in symptomatic women. Therefore, during the past few years great emphasis has been placed on dose reduction in breast imaging procedures. Dose reduction can be accomplished in many ways but usually at the cost of reduced image quality. In this presentation some of the factors affecting image quality will be discussed in order to provide some insight into the present status of mammography as a result of low dose techniques.