Graduate medical education in the United States.

The annual surveys of residency programs on which this report is based have had a higher than 90% response rate for the past 5 years. The count of available residency positions is a fluid entity and seems to be dependent on many factors, including funding and the number of qualified candidates seen by program directors. The number of GY-1 positions has not changed significantly during the past 3 years. The number of reported unfilled positions, including GY-1 unfilled positions, has increased each year since 1985. The total number of residents on duty decreased slightly in 1988. This decrease may be due to a lower response rate. The number of new entry residents (GY-1) has been decreasing since 1985. Thirty-nine percent of residents were training in family practice, internal medicine, or pediatrics. The number and percent of women in residency programs have remained steady. The percentage of FMG residents decreased slightly to 15.3% in 1988. The number of black non-Hispanic residents decreased in 1988, and the percentage of all residents who are black decreased slightly. The number of graduates of osteopathic medical schools in ACGME programs has increased 39% since 1986. The number of institutions involved in graduate medical education has not changed significantly during the past 3 years, although the number of institutions that are not hospitals has increased since 1983. Ninety-five percent of all types of institutions have some type of affiliation with a US medical school.

Optical spectroscopy. Pre-mammography marker.

Non-invasive optical spectroscopy consistently delineates compositional and physiologic properties of breast tissues serving as a pre-mammography risk marker for cancer or yielding a high assurance of no such risk. We believe this new non-imaging approach depends on biochemistry of tissues rather than on the macroscopic physical properties involved with most breast imaging modalities. After establishing the procedure as inexpensive, physician independent, simple, requiring only a few minutes and appealing to women, it was carried out in two institutions on 1739 women referred for routine mammography. Of 166 breast biopsies on these women 77 were cancer by histology. An automated computerized analysis of the spectroscopic data yielded a sensitivity of 87 per cent, a specificity of 74 per cent and a negative predictive value of 99 per cent. Optical spectroscopy shows promise in identifying women at a higher risk for developing cancer, cases of non-infiltration carcinomas where dense breasts limit mammographic detection, and even clustered calcifications not associated with a mass. The relative risk of breast cancer was 16.5 times as great with a positive spectroscopic value at a sensitivity range of 87 per cent. Placement of 87 per cent of all breast cancer cases in a subset of 28.7 per cent of all women will yield a population of women in whom mammography will be approximately four times as efficient.

Automated water-path full-breast sonography: correlation with histology of 176 solid lesions.

A comparative study with mammography and physical examination showed that automated water-path whole-breast sonography contributed to the care of at least one-half of 786 study patients (separate report). Clinical application then followed in an additional 2530 women in whom there were 107 biopsy-proven cancers, 69 discrete biopsied benign lesions, and 121 biopsies of poorly defined lesions, usually some form of fibrocystic disease without a discrete mass. Breast sonography demonstrated 72% of the cancers and detected six cancers not seen on mammography. Although there was considerable overlapping of sonographic characteristics of benign and malignant diseases, most lesions were differentiated. Only 10% of the solid benign lesions had some characteristic of malignancy, and in 90% of the infiltrating duct carcinomas, findings suggested the histologic diagnosis. While breast sonography must be considered a complement to physical examination and mammography, the procedure can reliably differentiate the histologic types of at least 83% of discrete benign lesions and 75% of cancers. In 90% of all solid breast lesions, sonography differentiated benign and malignant processes.

Detection of breast carcinoma: comparison of automated water-path whole-breast sonography, mammography, and physical examination.

A comparative study of independently conducted physical examination, x-ray mammography, and sonography of the breast was carried out on 786 women having 77 excisional biopsies with 31 proven breast carcinomas. On breast sonography, 68% of the carcinomas were demonstrated with three false-positive diagnoses, compared with 65% cancer detection rate on physical examination with 37 false positives, and 77% detection rate on mammography with 15 false positives. Sonography was considered complementary to the other methods and of distinct usefulness after mammography (1) to examine the dense breast; (2) to study dense, poorly demonstrated areas; (3) to differentiate cystic from solid masses; and (4) to study breasts with augmentation mammoplasties. There were no added benefits in mammographically normal fatty breasts. The procedure was readily accepted by both women and their referring physicians.

Enhanced-image mammography.

A blurred-mass subtraction technique has been developed for mammography, which enhances small-object contrast and visibility throughout the breast area. The procedure is easy to implement and requires no additional exposure. Perception of low-contrast objects is improved by eliminating extreme light- and dark-image areas. Contrast of structures within certain portions of the breast is increased by compression into the high-contrast portion of the film characteristic curve. Detail visibility is also increased by the edge enhancement produced by this process. This paper describes the enhancement process and gives an analysis of its capabilities and limitations.

Intramammary lymph nodes.

Radiographic, gross, and histopathologic studies on 158 whole breasts with primary operable carcinoma revealed intramammary lymph nodes in 28%, and of these breasts, 10% contained a metastatic deposit of carcinoma. Cancerous and noncancerous nodes were found in all quadrants of the breast with the positive ones being in the same quadrant as the carcinoma only 50% of the time. There was no demonstrable connection with the usual lymphatic drainage of the breast. With Stage II carcinoma, positive intramammary lymph nodes had no direct effect on prognosis, merely representing advanced disease and indicating a greater likelihood of axillary metastatic disease. There was a trend toward poorer prognosis in Stage I lesions with positive intramammary lymph nodes. This may indicate the Stage I carcinomas that have a similar prognosis as Stage II tumors. Conceivably, a Stage Ia, positive intramammary lymph node(s) but normal axillary lymph nodes, could be defined and used.

Grids in mammography.

A special soft-tissue grid reduced scattered radiation to the receptor and resulted in improved contrast and visibility of small structures to the degree that increased kVp could be used during screen-film mammography. The reduction in radiation to the skin that is associated with the more penetrating higher kVp technique more than compensated for the Bucky factor of the grid. This technique allowed for better penetration of the base of large, dense breasts without the use of vigorous compression. Results that were obtained with a faster (2X) film are also presented and discussed.

Enhanced image mammography.

A blurred mass subtraction technique has been developed for mammography that will enhance small object contrast and visibility throughout the breast area. The procedure is easy to implement and requires no additional exposure. Perception of low-contrast objects is improved by eliminating extreme light and dark image areas. Contrast of structures within certain parts of the breast is increased by compression into the high-contrast part of the film characteristic curve. Detail visibility is also increased by the edge enhancement produced by this process. This paper describes the enhancement process and gives an analysis of its capabilities and limitations.