Showing papers on "Mammography published in 1987"

Image feature analysis and computer-aided diagnosis in digital radiography. I. Automated detection of microcalcifications in mammography

Abstract: We have investigated the application of computer-based methods to the detection of microcalcifications in digital mammograms. The computer detection system is based on a difference-image technique in which a signal-suppressed image is subtracted from a signal-enhanced image to remove the structured background in a mammogram. Signal-extraction techniques adapted to the known physical characteristics of microcalcifications are then used to isolate microcalcifications from the remaining noise background. We employ Monte Carlo methods to generate simulated clusters of microcalcifications that are superimposed on normal mammographic backgrounds. This allows quantitative evaluation of detection accuracy of the computer method and the dependence of this accuracy on the physical characteristics of the microcalcifications. Our present computer method can achieve a true-positive cluster detection rate of approximately 80% at a false-positive detection rate of one cluster per image. The potential application of such a computer-aided system to mammographic interpretation is demonstrated by its ability to detect microcalcifications in clinical mammograms.

Mammographic parenchymal patterns and quantitative evaluation of mammographic densities: a case-control study.

Abstract: The classification of breast parenchymal patterns (N1, P1, P2, DY) and the percentage of the breast containing radiographic densities are two highly correlated radiographic measures proposed as predictors of the risk of breast cancer. In this case-control study, 160 cases of breast cancer and 160 matched controls from a mammography referral practice were compared to determine the risk of breast cancer associated with each of these two radiographic measures. The mammographic densities were quantified on caudal projections by means of a compensating polar planimeter. A relative risk estimate of 3.3 (p less than .05) was associated with the P2 + DY patterns compared with the N1 + P1 patterns. Significantly elevated risks of 4.3 to 5.5 also were observed among women whose breasts contained at least 25% mammographic densities, compared with women with less than 25% involvement. These radiographic measures tended to be more predictive of the risk of breast cancer in black women than in white women. Although the precise clinical roles of breast parenchymal patterns and densities have not been defined fully, the results of this study suggest that they are useful in the recognition of women at high risk of breast cancer. We make no claims that the findings of this study are sufficiently developed to be used as a basis for screening strategies.

Digital Mammography: ROC Studies of the Effects of Pixel Size and Unsharp-Mask Filtering on the Detection of Subtle Microcalcifications

Abstract: We investigated the spatial resolution requirement and the effect of unsharp-mask filtering on the detectability of subtle microcalcifications in digital mammography. Digital images were obtained by digitizing conventional screen-film mammograms with a 0.1 X 0.1 mm2 pixel size, processed with unsharp masking, and then reconstituted on film with a Fuji image processing/simulation system (Fuji Photo Film Co., Tokyo, Japan). Twenty normal cases and 12 cases with subtle microcalcifications were included. Observer performance experiments were conducted to assess the detectability of subtle microcalcifications in the conventional, the unprocessed digital, and the unsharp-masked mammograms. The observer response data were evaluated using receiver operating characteristic (ROC) and LROC (ROC with localization) analyses. Our results indicate that digital mammograms obtained with 0.1 X 0.1 mm2 pixels provide lower detectability than the conventional screen-film mammograms. The detectability of microcalcifications in the digital mammograms is improved by unsharp-mask filtering; the processed mammograms still provide lower accuracy than the conventional mammograms, however, chiefly because of increased false-positive detection rates for the processed images at each subjective confidence level. Viewing unprocessed digital and unsharp-masked images in pairs resulted in approximately the same detectability as that obtained with the unsharp-masked images alone. However, this result may be influenced by the fact that the same limited viewing time was necessarily divided between the two images.

Clinical, mammographic, and sonographic determination of preoperative breast cancer size.

Abstract: Clinical, mammographic, and sonographic preoperative size measurements were correlated with the values obtained at pathologic examination in a series of 31 patients with pathologically T1 (n = 23) and T2 (n = 8) breast carcinomas. Sonographic measurements demonstrated the highest correlation coefficient (r = 0.84), with the lowest residual standard deviation calculated in relation to the regression line. As a result, real-time sonography yielded the most accurate determination of breast cancer size in this series. Sonographic tumor size determination has proved valuable when mammography failed to delineate the tumor, particularly in patients with dense breasts. It may also be recommended in the evaluation of tumor response to nonsurgical conservative treatment.

US Preventive Services Task Force. Screening for breast cancer with breast self-examination. A critical review.

Abstract: We reviewed evidence regarding breast self-examination (BSE) and screening for breast cancer. To our knowledge, no controlled prospective trial links BSE to lives saved from breast cancer. Compared with clinical breast examination and mammography, the estimated sensitivity of BSE is low (20% to 30%) and is lower among older women. The potential sensitivity of BSE should be higher because women can detect small lumps (0.3 cm) in silicone models. Instruction increases BSE frequency over the short term. Sensitivity also increases, but specificity decreases. The psychological effects of teaching and performing BSE are not yet clear. The cost of screening by BSE is unknown but depends on the accuracy of the test as well as the training method used. Breast self-examination has potential as a screening test for breast cancer, but many questions require scientific examination before this procedure can be advocated as a screening test for breast cancer. ( JAMA 1987;257:2196-2203)

Diagnostic reliability of combined physical examination, mammography, and fine‐needle puncture (“triple‐test”) in breast tumors: A prospective study

Abstract: A prospective study of 622 consecutively registered patients with 650 breast tumors was performed to appraise the reliability of combined physical examination, mammography, and fine-needle puncture (triple test) in the preoperative diagnosis of such tumors All malignant as well as benign test results were confirmed by subsequent histologic examination The diagnostic accuracy of the triple test at benign changes is comparable to that of histologic examination, but participation of experienced radiologists and cytologists as well as persons skilled in fine-needle puncture is required Twenty-eight percent of the planned excisional biopsies were made superfluous by the fine-needle puncture, which immediately revealed the tumor as a cyst, abscess, or hematoma For this reason, too, fine-needle puncture is recommended as a routine procedure

Nonpalpable lesions detected with mammography: review of 512 consecutive cases.

Abstract: The authors reviewed 512 consecutive cases in which biopsies were performed on nonpalpable lesions of the breast detected with mammography from 1970 to 1985. The positive predictive value (PPV) of different radiologic patterns was determined. Biopsy is advised in the presence of patterns such as parenchymal distortion, opacities with undefined borders, strongly suspect microcalcifications (rodlike or branching morphologic features, high spatial density), and stellate opacities, which yielded higher PPVs (0.11, 0.35, 0.56, and 0.75, respectively). The average detection rate of preclinical cancer was 0.7 per 1,000; wide variations were recorded during different periods in the study (0.2 per 1,000 and 1.3 per 1,000 in the first 4 years and the last 4 years of the study, respectively), for the different age groups considered (0.6 per 1,000 and 1.7 per 1,000 for the 30-39-year and over-59-year age groups, respectively), and for different reporting radiologists (0.5-1.9 per 1,000). The ratio of benign to malignant biopsy findings was 2.4:1 for the whole series, with wide variations encountered relative to the variables mentioned above.

Mammographic detection of recurrent cancer in the irradiated breast.

Abstract: Recurrence of cancer in the irradiated breast is an uncommon but potentially curable problem. Posttreatment mammograms were studied in 45 patients who had biopsies of an irradiated breast for suspected local recurrence to evaluate the usefulness of mammography in detecting such recurrences. Of 23 biopsy-proven recurrences, eight (35%) were detected by mammography only, nine (39%) were detected by physical examination only, and six (26%) were detected by both. Mammographic findings in recurrent malignancy included microcalcifications in six, microcalcifications associated with a mass in four, soft-tissue masses in three, and inflammatory changes in one. The results show that mammographic follow-up is complementary to physical examination in the detection of local recurrence in women who have undergone radiation therapy for early breast cancer.

Diagnosis and Differential Diagnosis of Breast Calcifications

Abstract: Very thorough knowledge of breast pathology is a sine qua non for interpretation of breast films ... progress in X-ray diagnosis could only be made by careful comparison of the film with the actual specimen. H.INGLEBY Multiplication of the same e"oneous diagnosis does not make that diagnosis co"ect. J.G.AzZOPARDI Paradoxically enough, our specialty considers the radiologist who mis takes a skin fibroma or the calcifications in a sponge kidney for a kid ney stone to lack basic knowledge, while the radiologist who imme diately calls for the surgeon because of a few white spots on a mammogram is thought to be acting according to the rules of medical practice. Misunderstandings and confusion with regard to breast pathology as well as the comfortable philosophy that superfluous biopsies are the price we have to pay for the early detection of carcinomas have in many places led to a loss of confidence in mammography. Yet this is a meth od with which carcinomas can be detected earlier than with any other imaging technique."

Scanned-projection digital mammography.

Abstract: The effectiveness of film–screen mammography is limited by tradeoffs between latitude and contrast, film granularity, and the need to increase dose when antiscatter methods are used. We are currently developing a scanned‐projection digital mammography (SPDM) system to overcome these limitations. The system consists of a pair of scanning slits, a high‐resolution x‐ray image intensifier tube, a linear photodiode array, and a digital display. The detective quantum efficiency of the SPDM system at spatial frequencies up to 3 cycles/mm is similar to that of mammographic film–screen combinations, but is lower at high frequencies. For low‐contrast objects as small as 0.1 mm in diameter, the signal‐to‐noise ratio is currently equal to that of optimally exposed mammographic film–screen images for equal dose to the breast and superior for regions which would be underexposed or overexposed on film. This is achieved by the use of a low‐noise detectorsystem, geometric magnification, and scatter elimination. Images of a contrast‐detail phantom and excised breast tissue illustrate the superior contrast sensitivity of SPDM.

Hooked-wire-directed breast biopsy and overpenetrated mammography.

Abstract: Six hundred fifty-three biopsies were performed for clinically occult, mammographically detected breast abnormalities. One hundred forty-seven cancers (22.5%) were found. Eighty-nine of those cancers (60.5%) were noninvasive. None of the in situ lesions had involved axillary lymph nodes. Of the 58 invasive cancers, only six (10.3%) had metastases to axillary nodes. Fifty-four patients (36.7%) were treated by mastectomy while 93 patients (63.3%) were treated conservatively, 20 by biopsy only, and 73 by lumpectomy, axillary node dissection, and radiation therapy. Only four patients (0.7%) had significant complications.

Breast imaging: dual-energy projection radiography with digital radiography.

Abstract: Dual-energy projection radiography was applied to breast examinations. To perform the dual-energy subtraction radiography with use of a digital radiography unit, high- and low-energy projections were made at an appropriate time interval under differing x-ray exposure conditions. Dual-energy projection radiography appears to offer clear, detailed images and may be a useful supplement to standard mammography.

Breast self-examination for the early detection of breast cancer: a USSR/WHO controlled trial in Leningrad

Abstract: Breast self-examination (BSE) is of great potential value for the early detection of breast cancer, especially in areas where mammography and regular examinations by physicians are not practicable. However, BSE cannot be recommended for routine public health practice until there is good evidence that it is effective in reducing mortality from breast cancer. Prospective controlled trials of BSE were therefore initiated in 1985 in Leningrad and Moscow, under the auspices of WHO, in order to establish the value of this potentially cost-effective technique. More than 62 000 women aged 40-64 years have been enrolled in the BSE and control groups in Leningrad and another 88 000 will be added in the next three years. This paper presents the results of the study in Leningrad after the first 15 months.

Occult breast cancer: prevalence and radiographic detectability.

Abstract: The radiographic detectability of occult breast cancer has been difficult to determine. A prospective study of breast disease was carried out that involved the performance of subcutaneous mastectomies in 519 consecutive cases of traumatic or initially unexplained death in New Mexico. Routine mammograms and radiographs of 1-cm specimens were obtained. At least 18 biopsies were performed in each subject. Carcinoma was identified in ten subjects; one subject had metastatic carcinoma from the lung, and two subjects had bilateral breast cancer, for a total of 11 breast cancers identified with microscopic examination. Two of the cancers were seen on whole-breast mammograms, and six were seen on radiographs of thin-section specimens. Four of the 11 breast cancers were apparent only on histologic study of breast tissue that was not suggestive of malignancy. No cancer was found in subjects under the age of 39 years. Five carcinomas were found in the 40-69-year age group; six were found in the 70-year and over age group. No correlation was noted between the radiographic Wolfe parenchymal patterns and the prevalence of breast cancer.

Role of fine needle aspiration cytology in breast cancer screening.

Abstract: In a six year period up to the end of December 1985 fine needle aspiration cytology specimens of the breast were obtained from 562 apparently healthy women invited to participate in a breast cancer screening programme. Of these, 397 had a biopsy and 173 cancers were confirmed histologically. For the diagnosis of cancer, the procedure was less successful than in symptomatic cases. The main factors influencing success were the aspirator, the small size of many cancers, and the occult nature of the lesions seen only on mammography. Retrospective analysis of the figures shows that combining the results of FNA cytology in a triple assessment with physical and mammographical findings for restricted selection means that the number of benign biopsy specimens could be reduced considerably.

Nonpalpable breast lesions: accuracy of prebiopsy mammographic diagnosis.

Abstract: Mammograms of 220 patients who underwent spot localization for removal of nonpalpable breast lesions were reviewed for accuracy of interpretation. Results of subsequent biopsy indicated malignancy in 77 cases. The interpretations of mammograms obtained before biopsy were incorrect in 71 cases (27 false-negative and 44 false-positive studies). Among the false-negative cases, 70% of the abnormalities were determined histologically to be noninfiltrative cancers. An aggressive screening program with preoperative localization and biopsy is needed in questionable cases, since mammographic signs of early or nonpalpable malignancy are often subtle and nonspecific.

Light scan evaluation of nonpalpable breast lesions.

Abstract: Transillumination light scanning of the breast was performed immediately before needle localization of 112 nonpalpable mammographic abnormalities detected in 103 patients. Twenty-four cancers were diagnosed in 23 patients. The positive predictive value for mammography was 21%. Ten (42%) of these nonpalpable cancers were not visible on transillumination light scanning. Eleven of 16 invasive ductal cancers and three of seven intraductal cancers were evident on transillumination light scans, but a single case of lobular carcinoma in situ was not evident. There were 12 false-positive light scan examinations. Transillumination light scanning had a 58% sensitivity, an 86% specificity, a 54% positive predictive value, and an 88% negative predictive value for small breast lesions. Therefore, the authors are unable to recommend delaying biopsy in patients with mammographic abnormalities on the basis of a negative light scan study.

Method and device for mammographic stereotactic punction of pathological lesions in the female breast

Abstract: Method and apparatus for stereotactic localization of cancer suspect lesions of the female breast in connection with X-ray mammography. The object is imaged in two directions, and the position of the lesions is calculated from the parallax displacement between the two images. The X-ray tube and the film are held stationary, and the parallax displacement is effected by moving the object laterally.

Factors which influence the occurrence of vascular calcification in the breast

Abstract: Breast arterial calcification, as seen on mammography, increases in frequency with advancing age, especially after menopause. No association was found with systemic hypertension. The number of diabetics in the series was too small for comparative purposes. An early menopause and a history of pregnancy were factors which influenced incidence. Oral contraception was associated with a lower incidence of calcification before, but not after menopause. On the other hand, hormonal preparations taken for menopausal symptoms were associated with a lower incidence of calcification in postmenopausal women.

Light scanning versus mammography in breast cancer detection.

Abstract: Transillumination light scanning of the breast was compared with screen-film mammography in a prospective study of 1,110 women referred to an outpatient imaging department. Each method was interpreted independently of the other but with knowledge of physical examination findings. Of 24 biopsy-proved cancers, 14 (58%) were detected with light scanning and 21 (88%) with mammography. The 77 false-positive light scan examinations were attributed to technical factors and the inability of light scanning to distinguish malignant from benign conditions on the basis of imaging features. Of the ten false-negative light scan examinations, two were retrospectively reclassified as positive, but light scans in the other eight cases remained normal in appearance. The authors conclude that transillumination light scanning is not competitive with mammography as a screening method for breast cancer detection. furthermore, they were unable to identify a select subpopulation of women who might benefit from light scanning as an adjunct to mammography.

Breast cancer detection : mammography and other methods in breast imaging

Abstract: Addresses mammography and the advantages and limitations of other breast imaging methods. The first section discusses the establishment of X-ray mammography as the safest and most accurate noninvasive method of early breast cancer detection; the second section emphasizes the signs of early cancer, the "complete" mammographic examination, and the "team approach" to diagnosis; the final section presents the benefits of mammography and its unmatched value in screening for breast cancer.

Computer aids to mammographic diagnosis.

Abstract: The improvement of mammographic specificity was investigated by means of identifying specific radiological features. Data are presented on the first 500 patients studied who had previously undergone mammography followed by biopsy. The presence of specific mammographic features on each radiograph, first determined by retrospective examination, was entered into a computer database. Subsequent discriminant function analysis demonstrated the importance of a small number of features whose presence could be used in an algorithm to predict diagnostic outcome. Using this algorithm, this feature-identification approach correctly identified 87.6% of benign and 79% of malignant cases. Specificity was improved to 88% as compared with the original radiological diagnosis of 49%. It is argued that this approach is very promising and a computer-assisted diagnosis based on these findings is described.

Fibrocystic breast disease.

Abstract: Fibrocystic breast disease is characterized by breast pain, lumpiness or cysts. The few patients who have atypia on breast biopsy are at substantially increased risk for the development of breast cancer. Management of fibrocystic breast disease involves monitoring for breast cancer by repeated physical and mammographic examinations. Alleviation of symptoms may be attempted by reassurance, reduction of methylxanthine intake and treatment with danazol.

The predictive value of positive test results in screening for breast cancer by mammography in the Nijmegen programme.

Abstract: After 10 years of screening for breast cancer by mammography in Nijmegen, the predictive value of positive screening results (PV+) was evaluated. The percentage of women with breast cancer in the group of referred women (PV+) for women under age 50 was 16-26%, regardless of the number of screening examinations they had. The percentage of women with breast cancer in the group of women who were biopsied was 25-40%, regardless of the number of examinations. For women aged 50 and over the predictive value was 34-57% and 58-90% respectively. It was further evaluated whether characteristics such as age, Quetelet index, parity, and Wolfe-classification could be used to increase the PV+ in women who were identified as positive by mammography. A logistic regression model analysis showed that true-positive and false-positive cases differ significantly only in terms of age and breast complaints. Although the model had a good fit, it could not be used to distinguish false-positive from true-positive test results.