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We report on some extensions and further developments of a well-known microcalcification detection algorithm based on adaptive noise equalization. Tissue equivalent phantom images with and without labeled microcalcifications were subjected to this algorithm, and analyses of results revealed some shortcomings in the approach. Particularly, it was observed that the method of estimating the width of distributions in the feature space was based on assumptions which resulted in the loss of similarity preservation characteristics. A modification involving a change of estimator statistic was made, and the modified approach was tested on the same phantom images. Other modifications for improving detectability such as downsampling and use of alternate local contrast filters were also tested. The results indicate that these modifications yield improvements in detectability, while extending the generality of the approach. Extensions to real mammograms and further directions of research are discussed.

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Unusual lesions of the breast can present a diagnostic challenge. These lesions include systemic diseases, benign tumors, and primary and metastatic malignancies. Lymphadenopathy is the most common mammographic finding associated with collagen vascular disease. Wegener granulomatosis may manifest as an irregular, high-density mass simulating breast cancer. Diabetic fibrous mastopathy manifests at mammography as very dense breast tissue and at ultrasonography (US) as an irregular, hypoechoic mass with striking posterior acoustic shadowing simulating malignancy. Fibromatosis simulates malignancy at mammography as an irregularly shaped, uncalcified, high-density mass and at US as an irregular, hypoechoic mass with posterior acoustic shadowing. At US, granular cell tumor may manifest as a solid, poorly marginated mass with marked posterior acoustic shadowing or may appear more benign. At mammography, hamartomas are typically well-circumscribed, round to oval masses with a thin, radiopaque pseudocapsule; at US, they manifest as a sharply defined, heterogeneous oval mass or as normal glandular tissue. Phyllodes tumor manifests at mammography as a large, well-circumscribed oval or lobulated mass; at US, it usually manifests as an inhomogeneous, solid-appearing mass. At mammography, primary breast lymphoma manifests as a relatively circumscribed mass or a solitary, indistinctly marginated, uncalcified mass. Metastatic lesions may manifest mammographically as single or multiple masses or as diffuse skin thickening; at US, they tend to have circumscribed margins with low-level internal echoes. Radiologists should be familiar with the characteristic mammographic appearances of these lesions and should consider benign and systemic causes in the differential diagnosis when malignant-appearing findings are encountered.

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Autologous myocutaneous flaps (AMFs) are used increasingly as a method of breast reconstruction after mastectomy for breast cancer. Autogenous breast reconstruction may be performed with a rectus abdominis, latissimus dorsi, or gluteus maximus myocutaneous flap. Mammographic imaging of AMFs is controversial but has been recommended by some authors because mammographic detection of nonpalpable local recurrences in AMFs continues to be reported. At mammography, AMFs have a predominantly fatty appearance with variable density due to the muscle component and postoperative scarring. Normal mammographic findings include the vascular pedicle, surgical clips, and surgical scars, which produce radiopaque lines in predictable locations. Abnormal mammographic findings include fat necrosis appearing as a spiculated mass, noncalcified or calcified lipid cysts, calcifications, lymph nodes, epidermal inclusion cysts, and locally recurrent carcinoma.

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Evaluation of mammograms for artifacts is essential for mammographic quality assurance. A variety of mammographic artifacts (i.e., variations in mammographic density not caused by true attenuation differences) can occur and can create pseudolesions or mask true abnormalities. Many artifacts are readily identified, whereas others present a true diagnostic challenge. Factors that create artifacts may be related to the processor (eg, static, dirt or excessive developer buildup on the rollers, excessive roller pressure, damp film, scrapes and scratches, incomplete fixing, power failure, contaminated developer), the technologist (eg, improper film handling and loading, improper use of the mammography unit and related equipment, positioning and darkroom errors), the mammography unit (eg, failure of the collimation mirror to rotate, grid inhomogeneity, failure of the reciprocating grid to move, material in the tube housing, compression failure, improper alignment of the compression paddle with the Bucky tray, defective compression paddle), or the patient (e.g., motion, superimposed objects or substances [jewelry, body parts, clothing, hair, implanted medical devices, foreign bodies, substances on the skin]). Familiarity with the broad range of artifacts and the measures required to eliminate them is vital. Careful attention to darkroom cleanliness, care in film handling, regularly scheduled processor maintenance and chemical replenishment, daily quality assurance activities, and careful attention to detail during patient positioning and mammography can reduce or eliminate most mammographic artifacts.

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The capability to provide histologic diagnoses of nonpalpable lesions by performance of percutaneous needle biopsy has revolutionized breast imaging in the past decade. The radiologist who performs percutaneous breast biopsies assumes an increased level of responsibility for the patient regarding patient selection, lesion selection, performance of the biopsy procedure, interpretation of results, and patient follow-up. With variable and increasingly numerous options for the biopsy of breast lesions, careful attention must be paid to the selection of patients and types of lesions for different procedures. Critical technical considerations affect whether biopsy of a lesion can be optimally performed percutaneously, and these considerations must be factored into the recommendations for patient treatment. In addition, a limited preprocedural clinical assessment of the patient will allow a safer procedure to be performed expeditiously. Most breast abnormalities classified by using the ACR Lexicon as 4 (suggestive) or 5 (highly suggestive, likely malignant) are suitable for either percutaneous breast needle biopsy or needle localization and excisional biopsy. In general, those lesions classified as 3 (probably benign) carry a recommendation for early follow-up and not biopsy, because the likelihood of malignancy is small. A particular advantage of percutaneous biopsy is in the diagnosis of multicentric breast cancer. Core biopsy is less invasive and less costly than surgical biopsy, and it can be used to demonstrate multicentric disease, saving the patient a two-step surgery. However, several lesions are better treated by excision than by percutaneous biopsy. Among these are architectural distortion or loosely arranged, segmental or regional microcalcifications. For nonpalpable breast lesions visualized on mammography, sonography, or both, imaging-guided localization is required for precise needle placement either for wire localization or for percutaneous breast biopsy. The selection of which modality to use for guidance depends on (1) the adequacy of visualization of the lesion by the modality used, (2) the position of the lesion, (3) the ease of positioning the patient, (4) the skill of the operator, (5) the need to reduce radiation exposure, (6) the overall patient condition, and (7) size of the lesion. Fine-needle aspiration biopsy (FNAB) has a high sensitivity and specificity in the diagnosis of palpable breast lesions when the procedure is properly performed and interpreted. Variable results have been achieved with FNAB of nonpalpable breast lesions under imaging guidance. Three critical components are necessary to achieve reliable results by using FNAB. These include the following: (1) accuracy in needle placement, (2) skill in performance of FNAB, and (3) expert cytopathologic analysis. Accurate preoperative needle localization of nonpalpable breast lesions allows the radiologist to guide the surgeon performing an open biopsy and helps to ensure that the surgical procedure can be performed quickly and can be accomplished with the best possible cosmetic result for the patient. Lesions selected for needle localization and biopsy should undergo a complete tailored imaging evaluation before the needle localization is scheduled. Specimen radiography should be performed for all nonpalpable lesions. Once the lesion has been identified on specimen radiography, the radiologist can assist the pathologist in identifying the lesion microscopically by marking the lesion within the surgical specimen. We cover the technical and interpretative aspects of percutaneous breast biopsy and needle localization for surgical biopsy.

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PURPOSE: To determine the importance of a dilated duct pattern at mammography. MATERIALS AND METHODS: Mammograms obtained in 46 women with histopathologically proved, asymmetrically dilated ducts were retrospectively studied. The laterality and location of the asymmetrically dilated duct, the presence of branching, and associated findings such as microcalcifications, nipple discharge, and interval change were evaluated. RESULTS: Eleven patients (24%) had malignant results (ductal carcinoma in situ or invasive ductal carcinoma). Among these, six (54%) had suspicious microcalcifications. Nonsubareolar location and interval change are significant (P = .04) variables associated with malignancy. CONCLUSION: Mammographic asymmetrically dilated ducts in a nonsubareolar area that are associated with interval change, suspicious microcalcifications, or both warrant biopsy.

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OBJECTIVE: Sclerosing lobular hyperplasia is an infrequent benign lesion of the breast, defined as prominent hyperplasia of the lobules with sclerosis of the interlobular stroma. It commonly presents as a tumorlike mass clinically. Sclerosing lobular hyperplasia has been identified at biopsy at our institution with rare but increasing frequency. We reviewed the imaging features of 15 patients with biopsy-proven sclerosing lobular hyperplasia to determine if a characteristic imaging pattern could suggest this diagnosis. MATERIALS AND METHODS: The mammograms and sonograms of all women with pathologically proved sclerosing lobular hyperplasia seen between January 1986 and June 1993 were retrospectively reviewed by two of the authors who were familiar with the pathologic diagnosis. Imaging findings that led to biopsy or were present on the preoperative studies were reviewed. The study included 15 patients ranging in age from 21 to 46 years old, with a mean age of 32 years. Seven were black, and eight were white. All women had mammograms, three patients had prior mammograms for comparison, and sonography was done in all but one case. Presenting symptoms included a recently discovered breast lump in eight patients, breast tenderness in one patient, and a clear nipple discharge in one patient. The other five were asymptomatic and had screening mammograms. RESULTS: Eight patients (53%) had a well-defined mass on mammography, varying in size from 1.0 cm to 8.0 cm (mean, 3.7 cm). In one of these patients, the nodule was proved to be a fibroadenoma; sclerosing lobular hyperplasia was found only microscopically. Microcalcifications were present within the mass on mammography in one patient. Mammograms in two women showed asymmetric increased density compared with the opposite breast, and in five cases, the mammographic findings were interpreted as normal. Sonograms showed a solid, well-defined mass with either homogeneous or mixed echoes in 10 of 14 patients (71%). In only one of these nodules was acoustic enhancement present. In the other four women, sonograms were normal. No characteristic findings were identified that would suggest sclerosing lobular hyperplasia as a likely diagnosis preoperatively, and, in fact, in many cases a diagnosis of fibroadenoma was considered most probable. CONCLUSION: The imaging findings of sclerosing lobular hyperplasia are not sufficiently characteristic to distinguish the lesion from fibroadenomas and well-circumscribed carcinomas.

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The role of the diagnostic radiologist in breast cancer has expanded during the eight-decade history of breast imaging. The radiologist's role now encompasses both breast cancer diagnosis and treatment. This article traces the expansion of the radiologist's role through the history of mammography. The current roles of the radiologist in breast cancer diagnosis are discussed, including screening mammography in the asymptomatic patient, problem-solving breast imaging, breast ultrasound, and galactography. The radiologist's roles in breast cancer treatment that are discussed include preoperative needle localization, percutaneous breast biopsy, and evaluation of the postoperative breast.

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The majority of microcalcifications found on mammograms are associated with benign disease; however, some types accompany malignant disease. By correlating histologic with mammographic findings, the radiologist may gain an understanding of the morphologic characteristics and distribution of microcalcifications. We present radiologic and histologic images from a series of cases of nonpalpable, clustered microcalcifications. Such microcalcifications can be divided into two basic histologic groups: lobular and ductal. Although rounded, similarly shaped lobular calcifications can be differentiated mammographically from ductal calcifications with their irregular margins and varying size and shape, both types can be associated with benign and malignant processes. Biopsy is usually needed to confirm the diagnosis when clustered microcalcifications are found at mammography.

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A growing body of research suggests a link between psychosocial factors and breast cancer. Research in this area often contains methodological problems, however, such as small sample size, inadequate comparison groups, omission of important control variables, inclusion of only a few psychosocial variables, and failure to analyze moderating effects. To overcome these problems, the present study examined the link between breast cancer and multiple psychosocial variables (life events, coping, Type A behavior pattern, availability of social support) among 1,052 women with and without breast cancer. After controlling for history of breast cancer and age, we found very few significant relationships between psychosocial variables and breast cancer. Furthermore, the relationship between life events and breast cancer was not moderated by coping, Type A, or availability of social support. Methodological and substantive reasons for these findings are discussed.

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Lobular carcinoma in situ (lobular neoplasia; LCIS) of the breast is most commonly an incidental microscopic finding in breast tissue removed for some other reason. The authors reviewed the clinical and mammographic features and surgical findings in 26 cases of LCIS not associated with other breast abnormalities. In 16 instances, needle localization was performed before removal of the tissue, which yielded LCIS on histologic examination. Calcifications were the most common reason for biopsy, although there were no distinctive mammographic features of LCIS.

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The mammographic appearance of breast hamartoma, a benign cause of a breast mass, is characteristic. We present four cases from the University of Virginia to review the mammographic, pathologic, and clinical features of this unusual entity.

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As a pilot study for a national campaign to promote the use of screening mammography, the Virginia Division of the American Cancer Society conducted a breast cancer awareness project with mammography screening. An important part of the program was the development of a quality assurance program for mammography. Guidelines were established for equipment, image recorders, processing, dose, and patient positioning. A survey of information about the mammographic equipment was conducted, and the mammograms from each facility were reviewed. A total of 63 mammographic units in 56 facilities statewide were included in the month-long program during which approximately 9,000 women were screened.

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Screening mammography results in improved detection and survival for women with breast cancer. Interval mammographic changes may be one of the major indications for biopsy. Four hundred fifty-two needle localization biopsies carried out for microcalcifications, mass, asymmetric density, or a combination of calcifications with mass or asymmetric density detected 95 cancers (21%). Interval mammographic changes detected 35 cases (17.9%). Invasive cancers constituted 51% of the initial group but only 34% of the cancers detected because of interval change. Benign breast disease occurred in 160 of 195 women who had undergone biopsy because of interval changes. These changes continued into the postmenopausal period. Hyperplasia and/or atypia was found in 57 (35%) of 160 of the interval group. Interval mammographic abnormalities detect significant pathologic changes in the breast and should be considered a major indication for breast biopsy.

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