Biomedical subjects

K A McCarthy

Publications and source records attributed to K A McCarthy.

At least 37 records · Page 2Linked to original sources

PubMed1990

Medullary carcinoma of the breast. Overdiagnosis of a prognostically favorable neoplasm.

We reviewed 30 cases of breast cancer originally diagnosed as medullary carcinoma during a 10-year period. Of the 30, only 9 proved to be "typical medullary carcinoma" with the associated favorable prognosis. Seven of the remaining 21 cancers were reclassified as "atypical medullary carcinoma," and the remaining 14 were nonmedullary cancers. Overdiagnosis of medullary carcinoma could lead to inappropriately conservative therapy, since medullary carcinoma is a prognostically favorable neoplasm. Those involved with diagnosis and treatment of patients with breast cancer should be aware of this potential problem.

Adult↗

PubMed1990

Screening for asbestos-related pleural disease with digital storage phosphor radiography.

Digital storage phosphor radiography (SR) has a wide dynamic range and unique postprocessing capabilities that may improve the performance of screening studies for asbestos-related pleural disease compared with conventional film radiography (FR). In a group of 32 asbestos-exposed and nine control subjects with established pleural data, we compared the screening performance of FR and SR obtained with a single isoexposure, dual-energy technique (system resolution 0.2 mm, 10 bits). Performance was evaluated for 7320 observations by eight readers using a paired t test (P less than .02 with Bonferroni correction) of averaged receiver operating characteristic curve (ROC) areas (Az +/- standard error). We found that SR alone and SR supplemented by dual-energy soft-tissue and calcium images (SRde) were superior to FR in the overall detection of pleural abnormalities (Az = 0.90 +/- 0.01, 0.90 +/- 0.01, and 0.88 +/- 0.01, respectively). In the specific detection of pleural calcification, SRde was superior to FR (Az = 0.91 +/- 0.01 and 0.87 +/- 0.01, respectively; P less than 0.01). Analysis of variance indicated that SRde most closely reproduced an established pleural score based on the International Labor Organization (ILO) classification of the pneumoconioses (P less than 0.05, Scheffé's multiple comparison test). We conclude that isodose SR performs at least as well as FR in screening for asbestos-related pleural disease. SR supplemented by dual-energy images might improve the specific detection of pleural calcifications compared with FR.

Asbestosis↗

PubMed1990

Digital storage phosphor imaging versus conventional film radiography in CT-documented chest disease.

The advantages of imaging the chest with digital storage phosphor radiography (SR) may be nullified by its spatial resolution, which is lower than that of conventional film radiography (FR). To test the reader detection performance with the two modalities under clinical conditions, the authors compared 140-kVp isoexposure SR (system resolution: 0.2 mm, 10 bits) and FR images of a variety of chest abnormalities proved by computed tomography (CT) (157 patients, 244 abnormalities, 5,652 observations, six readers). In all tests, SR was as good as or better than FR (P less than .05). In overall detection, indicated by the average area of receiver operating characteristics, SR and FR were equivalent. SR was superior for mediastinal lesions and for pulmonary opacities greater than 2 cm in diameter. For all other types of pulmonary lesions and pleural abnormalities, SR and FR were equivalent. Currently available commercial SR systems can replace film radiographic systems in the detection of a wide variety of chest lesions. SR is likely to enable better visualization than FR in the detection of mediastinal and large pulmonary abnormalities.

Female↗

PubMed1990

Mixed form, diffusely scattered calcifications in breast cancer with apocrine features.

Diffusely scattered calcifications visible with mammography are almost always benign. Certain patterns, however, should arouse concern. For example, extensive comedocarcinoma is associated with large areas of mammographically visible calcium deposition. The authors identified 10 women in whom calcifications were visible throughout large volumes of breast tissue at mammography. The calcifications did not resemble those typical of extensive comedocarcinoma, yet they were associated with extensive breast cancer. Their mammographic pattern was characterized by a strikingly wild, chaotic appearance with profuse deposition of calcium. As in many cancers, the particles were heterogeneous, but unlike in most carcinomas, many deposits had a typically benign morphology. Histologic examination showed that even these typically benign calcifications were associated with malignant cells. The authors believe that the apocrine features displayed by many of the cancer cells in these 10 patients may explain the unusual profusion of calcium deposits.

Adult↗

PubMed1989

High frequency edge enhancement in the detection of fine pulmonary lines. Parity between storage phosphor digital images and conventional chest radiography.

Fine linear structures represent a severe test of the minimum spatial resolution that is needed for digital chest imaging. We studied the comparative observer performance of storage phosphor digital imaging (1760 X 2140 pixel matrix, 10 bits deep), and conventional radiography (Lanex medium screen, Ortho C film) in the detection of simulated fine pulmonary lines superimposed on the normal chest when exposure factors were identical (20mR skin entrance dose at 141 kVp). Receiver operating characteristics analysis of 2160 observations by six readers found that high frequency edge-enhanced digital images (ROC area: 0.78 +/- 0.06) performed better than unenhanced digital images (ROC area: 0.70 +/- 0.07) (P less than 0.01 for paired t-test), and that edge enhanced digital images performed on a par with conventional radiography (ROC area: 0.78 +/- 0.09). We conclude that for the detection of fine linear structures, storage phosphor digital images can perform on a par with higher resolution conventional chest radiographs when a high frequency edge-enhancement algorithm is employed.

Adult↗

PubMed1989

Asymmetric breast tissue.

A prospective study was undertaken to evaluate the significance of asymmetric breast tissue (asymmetric volume of breast tissue, asymmetrically dense breast tissue with preserved architecture, or asymmetrically prominent ducts) on mammograms. Of 8,408 mammograms obtained in 1985, 221 (3%) demonstrated asymmetric breast tissue. Follow-up was 36-42 months after the initial mammographic study. During this time none of the patients underwent biopsy on the basis of mammographic findings, although 20 underwent excisional biopsy because of clinical findings. Breast cancer was diagnosed in two patients and breast lymphoma in one patient. Biopsy specimens from the remaining 17 patients were benign. At mammography, all three malignant lesions had a palpable abnormality associated with the asymmetric tissue. Breast cancer was not found in any of the remaining 201 patients. Therefore, an asymmetric volume of breast tissue, asymmetrically dense breast tissue, or asymmetrically prominent ducts that do not form a mass, do not contain microcalcifications, or do not produce architectural distortion should be viewed with concern only when associated with a palpable asymmetry and are otherwise normal variations.

Adult↗

PubMed1989

Subtle gastric abnormalities in a canine model: detection with low-dose imaging with storage phosphors and its equivalence to conventional radiography.

The authors compared low-dose (32% of standard exposure) storage phosphor digital imaging (system resolution: 0.2-mm pixels, 10 bits) with isovoltage 75-kVp conventional radiography (standard exposure) in the detection of subtle simulated gastric abnormalities by using air contrast barium studies. Subtle simulated abnormalities (3-7-mm polyps, 4-15-mm ulcer craters, 4-11-mm-diameter edema, and 11-12-mm linear ulcers) were produced in resected canine stomachs. Receiver operating characteristic analysis of 1,800 observations by six readers indicated that the digital images with and without high-frequency edge enhancement were equivalent to conventional radiographs (mean receiver operating characteristic areas [+/- standard deviation]: 0.76 +/- 0.06, 0.78 +/- 0.04, and 0.77 +/- 0.04, respectively). The accuracy of the diagnosis was equivalent for all three modalities. The following mean accuracies of negative and positive responses, respectively, for unenhanced digital, edge-enhanced digital, and conventional images were determined: 0.71 +/- 0.05 and 0.41 +/- 0.07, 0.71 +/- 0.04 and 0.51 +/- 0.09, and 0.68 +/- 0.04 and 0.43 +/- 0.05. It was concluded that low-dose storage phosphor air-contrast barium studies were equivalent to conventional radiography in the detection of subtle gastric abnormalities.

Animals↗

PubMed1989

Nonpalpable lesions in the augmented breast: preoperative localization.

Special compression views of the breast were used to detect suspect lesions in eight women who had undergone augmentation mammoplasty. Hook-wire localization with the use of these views proved safe and accurate for preoperative localization in these women, one of whom had a very small cancer.

Breast↗

PubMed1989

Minimal-volume excision of nonpalpable breast lesions.

To explore the value of accurate preoperative localization of occult breast lesions, we reviewed 100 consecutive needle-directed breast biopsies performed by the same surgeon over a 1-year period. A spring hookwire device for localization was inserted parallel to the chest wall. Two thirds of biopsies were performed under local anesthesia, and all were performed in an outpatient setting. Sixteen lesions were invasive carcinomas, and eight were ductal carcinomas in situ. In 96 lesions, the localizing wire was placed within 2 mm of the lesion, and in the remaining four it was within 5 mm of the abnormality. The mammographic lesion was excised in the first specimen in 96 cases. One patient required a second biopsy because of failure to excise the lesion in question after three specimens were taken. The only surgical complication was one hematoma, which resolved within 3 months. Median specimen volume for the entire series was 6.0 cm3. Median largest specimen diameter was 2.5 cm. Precise preoperative localization with a spring hookwire to within 2 mm of the mammographic lesion allows the surgeon to excise a median volume of 6 cm3 breast tissue with consistent retrieval of the lesion.

Biopsy↗

PubMed1988

A comparison of digitized storage phosphors and conventional mammography in the detection of malignant microcalcifications.

The detectability of malignant tumor-derived microcalcifications with conventional mammography was compared to that with digital images (2000 X 2510 pixels by 10 bits) derived from a storage phosphor-based digital radiography system capable of 5 line pair/mm resolution at identical exposure factors (30 kVp, 250 mAs, 65 cm film-focus distance). Microcalcifications (50-800 microns in diameter) were randomly superimposed on a preserved human breast specimen. ROC analysis based on 480 observations made by four readers indicated that the ability to detect the calcifications with digital images (ROC area = 0.871 +/- 0.066) was equivalent to conventional mammography (ROC area = 0.866 +/- 0.075) despite lower spatial resolution. With digital mammography, 62% of all clusters were correctly localized, but only 23.6% of the individual calcifications were counted. With conventional mammography 61% of all clusters were correctly localized, but significantly more of the individual calcifications (31.5%) were counted.

Breast Diseases↗

PubMed1988

Does preoperative needle localization lead to an increase in local breast cancer recurrence?

Between 1978 and 1981, 74 women with nonpalpable breast cancer underwent surgery after localization guides were placed. In 72 patients, guides were introduced parallel to the chest wall; in two the needle was positioned anteroposteriorly under computed tomographic guidance. Fifty-six cases (76%) were infiltrating cancer; 13 (17%), intraductal cancers; two (3%), inflammatory; and three (4%), lobular carcinoma in situ. Surgery was not used to treat the latter five patients. In the remaining 69 women, 42 (61%) were treated by means of modified radical mastectomy; six (9%), total mastectomy; 12 (17%), local excision and radiation therapy; and seven (10%), local excision alone; exact therapy for two women (3%) was unknown. At a minimum follow-up of 5 years, none of the 67 women in whom the parallel approach was used had a local recurrence. The authors conclude that preoperative placement of guides parallel to the chest wall does not appear to increase the risk of local breast cancer recurrence.

Breast Neoplasms↗

PubMed1988

Comparison of two screen-film combinations in contact and magnification mammography: detectability of microcalcifications.

A new dual-screen, dual-emulsion-film combination that allows a decrease in radiation dose of approximately 66% was compared with a widely used single-screen, single-emulsion-film system in contact and magnification mammography. Clustered microcalcifications randomly superimposed on a breast phantom were detected, and the location and number of individual calcifications were determined by four observers. The detectability of calcifications, determined with a receiver operating characteristic (ROC) analysis area, was 0.92 for magnification and 0.82 for contact mammography with the single-emulsion-film system, compared with 0.84 and 0.72, respectively, with the dual-emulsion-film system. More clusters were correctly located and more individual calcifications were counted with magnification than with contact mammography. The dual-emulsion-film system with the magnification technique performs as well as the single-emulsion-film system with the contact technique, while retaining a decrease in required dose of approximately 40%.

Breast Diseases↗

PubMed1987

Localization of occult breast lesions: practical solutions to problems of triangulation.

The preoperative triangulation and localization of some occult breast lesions can be complicated if the lesion is located deep in the breast. Based on the authors' experience of 1,400 localization procedures, standard breast positions were modified to help locate lesions that were difficult to see in two projections. Standard compression plates were also modified, allowing placement of fenestrations over deep lesions--especially those in the axillary tail of the breast--to facilitate safe, accurate localization.

Breast Neoplasms↗

PubMed1987

Mammographic density and physical assessment of the breast.

We studied the relationship between the radiographic density of the breast as measured by parenchymal pattern vs age, breast size, thickness after compression, and compressibility. Two hundred consecutive women were evaluated. None of the three parameters or the patient's age correlated with the degree of radiographic density. Although more older women had lucent parenchyma, 37% of women more than 50 years of age had dense patterns. Thus, these factors cannot be used to predict radiographic density. Phototiming is required to maintain image quality, and only a test exposure can accurately predict breast density.

Adult↗

PubMed1987

Localization of breast lesions identified on only one mammographic view.

Occasionally, a breast lesion is visible in only one mammographic projection. A simplified method of using parallax in a dedicated mammographic system has been devised to locate accurately lesions that are not visible in two orthogonal projections. In eight patients, a parallax approach from essentially a single mammographic position was used to place a hookwire preoperatively at nonpalpable suspicious abnormalities detected by mammography. Needles were inserted parallel to the chest wall while the breast was compressed in the mammographic unit. In each case, the tissue containing the lesion was pierced by a needle chosen to be longer than the distance from the skin to the abnormality. Simple geometric ratios were used to determine the position of the lesion along the needle shaft after slightly changing the mammographic projection and viewing the needle obliquely. In all cases, this parallax approach permitted accurate localization of the lesion.

Breast Diseases↗

PubMed1987

The halo sign and malignant breast lesions.

The halo sign, described as a complete or partial radiolucent ring surrounding the periphery of a breast mass, has long been considered a mammographic sign indicating a benign process. The phenomenon is most frequently seen with cysts and fibroadenomas. Over the past 8 years, 25 malignant breast lesions with a partial or complete halo on mammography have been identified in 19 women. These cases suggest that a halo sign does not guarantee a benign process.

Adult↗

PubMed1986

Sonographic monitoring of LHRH analogue therapy in idiopathic precocious puberty in young girls.

Precocious puberty in young girls is defined as the development of secondary sexual characteristics and gonadal growth before 8 years of age. Approximately 60% of isosexual precocious development in girls has no organic cause and is termed idiopathic precocious puberty. Thirteen young girls with idiopathic precocious puberty were treated with LHRH analogue under a well-established protocol. Pelvic ultrasound was added to the protocol to examine ultrasound's role in supplying a morphologic parameter of suppression of the pubertal process. Initially, 11 patients had ovarian volumes greater than normal, and ovarian cysts measuring 0.5 cm to 4 cm in diameter were identified in seven patients. All 13 patients had enlarged pretreatment uteri greater than 3 cm in length. Eleven of these patients had a pubertal or adult uterine configuration. After 1 year of therapy, 11 patients had normal prepubertal ovarian volumes, and 12 of 13 patients had a decrease in ovarian volume. No demonstrable cysts were present at 1 year. Eleven had a reduction in uterine length. Nine of the 11 patients with a pubertal uterine configuration reverted to a more prepubertal-like morphology. The sonographic morphologic changes correlated well with laboratory and clinical data indicating suppression of the hypothalamic-pituitary-gonadal axis.

Child↗

PubMed1986

Breast cancer metastasis to intramammary lymph nodes.

Metastatic disease to the intramammary lymph nodes from breast cancer may be seen mammographically. In the four cases reviewed, the affected intramammary lymph nodes were enlarged (1 cm or greater in diameter), homogeneous, and well circumscribed. All lacked the lucent center or hilar notch characteristic of benign intramammary nodes. Differentiation of malignant from benign causes of intramammary lymph node enlargement, such as inflammation or hyperplasia, is impossible by mammography. Biopsy is recommended for all intramammary lymph nodes of 1 cm or greater that are not fat infiltrated unless the patient clearly has an associated dermatitis or mastitis. Metastatic disease to the intramammary lymph nodes may be the first clinical and/or mammographic sign of breast cancer and may significantly affect prognosis.

Aged↗