Phagocytic capability of the kidney: a possible mechanism for renal uptake of colloid in liver-spleen scanning.

Guinea pigs were given Trypan blue or India ink i.v. and i.m. to demonstrate whether proximal convoluted tubule cells of the normal kidney have potential phagocytic capability. Circulating colloidal particles of Trypan blue solution accumulated in these cells and the accumulation was related to the particle size, dose injection, and duration of experiment. These studies suggest an explanation for the clinical observation of renal visualization with 99mTc-sulfur colloid in patients with congestive heart failure.

Migration and embolization of macrophages to the lung--a possible mechanism for colloid uptake in the lung during liver scanning.

Estrogenic stimulation of the RES in animals will result in the mobilization of large numbers of phagocytic cells from their natural sites of storage, chiefly the liver, spleen, and bone marrow, into the intravascular space. These cells are trapped in the pulmonary capillary bed and retain their ability to phagocytize colloidal particles. This is suggested to be the mechanism whereby increased lung uptake of colloidal radiopharmaceuticals is observed in some patients with liver diseases or other conditions stimulating the RES. It is further postulated that the known increase of estrogenic hormones in some patients with liver disease may be the in vivo stimulation resulting in increased mobilization of RES cells to the lung and subsequent isotope entrapment. It is possible that prognostic information can be obtained from this finding; however, its exact significance cannot be determined from this present study.

The clinical efficacy and cost analysis of cranial computed tomography and the radionuclide brain scan.

Cranial computed tomography (CCT) has already been demonstrated to provide significant diagnostic information in patients with neurologic disease and to reduce the need for special neuroradiologic procedures. The important question remaining is: Should CCT replace the radionuclide brain scan (RBS) as the first diagnostic study in most patients with suspected intracranial pathology? Data are now available to define the costs and benefits of this substitution. The technical costs of CCT have been determined by a national survey and have shown to be $130 per patient at a volume of 50 patients per week. The costs of RBS at the Mallinckrodt Institute have been estimated at $51 per patient. Data from the literature indicate that CCT is slightly more sensitive and considerably more accurate than RBS. Eighteen to twenty-eight percent of patients studied by CCT and RBS have abnormalities (e.g. cerebral atrophy and ventricular dilatation) that are only detected by CCT, and the overall accuracy of CCT is 95%, while the accuracy of RBS is approximately 70%. Substituting CCT for RBS is cost-beneficial. Although CCT is more costly, it increases overall accuracy by approximately 25%. The cost benefit is further increased by the reduction of complicated diagnostic procedures (and associated hospitalization and morbidity) and improvement in diagnostic information for the individual patient. Substituting CCT for RBS may not be more costly because a positive RBS will be followed by CCT (because of increased diagnostic information), and a negative RBS may be followed by CCT (because of increased accuracy), whereas a positive or negative CCT is unlikely to be followed by RBS.

Results of the 1992 survey of the American Association of Academic Chief Residents in Radiology.

RATIONALE AND OBJECTIVES: The authors conducted the annual American Association of Academic Chief Residents in Radiology (A3CR2) survey of chief residents of academic radiology programs to evaluate commonalities and differences among radiology training programs. METHODS: The surveys were mailed to 125 accredited programs in the United States and Canada. The analysis of the returned surveys took into account the geographic region of the respondents. RESULTS: Chief residents from 72 training programs (58%) returned their completed surveys. There are important variations among training programs related to requirements for entry, salary, and night call, and how residents prepare for Board examinations. CONCLUSIONS: The A3CR2 annual survey provides important information for program directors regarding how their training practices might differ from others so that they might better evaluate their programs.

Differentiation of proximal bronchogenic carcinoma from postobstructive lobar collapse by magnetic resonance imaging. Comparison with computed tomography.

MRI and CT studies in 18 patients with proximal bronchogenic carcinoma and postobstructive lobar collapse were analyzed retrospectively. The relative abilities of these imaging techniques to identify central tumor by a contour abnormality and to distinguish tumor mass from collapsed lung by CT attenuation values and MRI signal intensities were compared. MRI and CT were equivalent in their ability to identify a contour abnormality, both succeeding in 13 of 18 (72%) patients. CT was more successful than MRI in differentiating tumor mass from collapsed lung. Dynamic computed tomography scanning differentiated tumor from collapsed lung in eight of ten (80%) patients. MRI demonstrated different signal intensities of tumor and collapsed lung in 8 of 18 (44%) patients. T2-weighted images more often separated tumor from collapsed lung than other imaging sequences.

Factors influencing choice of academic or practice careers in radiology.

Factors, both personal and job-related in nature, that influence career choice among radiology residents are identified. Twenty-six third and fourth year radiology residents at two separate locations, and 17 age-matched and sex-matched internal medicine residents completed a 30-minutes interview and rated themselves on a series of job-related competencies. Data were collected on five groups of variables: demographic data, residency-related variables, factors that influence career choice, self-descriptions, and personal competencies. The results indicate that residents who choose academic careers and those who plan to have private practice careers differ substantially in their reasons for career choice. An academic career is chosen because of its atmosphere, emphasis on research and specialized techniques, and opportunity for teaching. In contrast, private practice careers are selected because of the autonomy they allow, the accompanying lifestyle, and financial reimbursement.

Results of the 1994 survey of the American Association of Academic Chief Residents in Radiology.

RATIONALE AND OBJECTIVES: Radiology chief residents are surveyed annually and the data are used to improve the training of diagnostic radiology residents. METHODS: Questionnaires were mailed to accredited programs in the United States and Canada. A variety of demographic and common-interest questions were asked. For the first time, an individual resident questionnaire also was included. RESULTS: Completed surveys from 53 programs (42%) were returned. The percentage of female residents was similar to that reported in other recent surveys. Resident salaries continued to increase. Residency selection remained highly competitive. Residents indicated that the utility of a fellowship in radiology exceeded the utility of clinical training in other fields prior to the radiology residency. Residents agreed with recommendations by the American Association of Academic Chief Residents in Radiology concerning proposed changes in the American Board of Radiology (ABR) examinations. CONCLUSION: The information derived from the surveys on resident selection, the utility of preradiology clinical training, and the ABR examination may be useful for residents, program directors, and departmental chairs.

Results of and comments on the 2000 survey of the American Association of Academic Chief Residents in Radiology.

RATIONALE AND OBJECTIVES: The American Association of Academic Chief Residents in Radiology (A3CR2) annually surveys radiology residency programs on issues related to training. The objective is to highlight national similarities, differences, and trends to help programs establish standards and improve residency training. MATERIALS AND METHODS: Questionnaires were mailed to 180 accredited diagnostic radiology residency training programs in the United States. The survey covered the usual general topics and more specific topics considered every 4 years; for 2000 the latter were on-call issues and the chief residency year. RESULTS: Completed surveys were returned from 63 programs (35%). Important findings included increased caseload and call commitments, especially for smaller programs. Resident salaries appear to have increased more than the consumer price index. Nonemergent after-hour coverage and teleradiology are now a large part of the resident work practice. Women continue to be underrepresented, with a trend downward. Chief residents are more involved in organizing preparation for board examinations and have greater office facilities and more administrative duties. CONCLUSION: This survey provided useful insights. All levels of residency face increased workloads. On-call hours have not changed, but the work has intensified and the use of teleradiology has increased. Many programs have adopted a "night-float" system, and nonemergent after-hours coverage should be considered in any program evaluation. Continued vigilance and sustained efforts are required to ensure that radiology is considered as a specialty by both men and women. With increased demands on attending physicians' time, chief residents may need to take on more administrative responsibilities.

Results of and comments on the 1998 survey of the American Association of Academic Chief Residents in Radiology.

RATIONALE AND OBJECTIVES: The American Association of Academic Chief Residents in Radiology annually surveys residency programs on a variety of issues related to residency training. The survey allows for comparison between programs regarding training and follows trends on current issues. MATERIALS AND METHODS: Questionnaires were mailed to all accredited programs in the United States (188 programs). The questionnaire consisted of questions regarding general demographic information and specific topics regarding residency training. The 1998 survey focused on turf issues, teleradiology use, residency selection, and prior training. RESULTS: Completed surveys from 61 programs (32.4%) were returned. Important findings included (a) the ongoing turf battles regarding vascular and obstetric-gynecologic ultrasound, both in general hospital and emergency department patients, (b) the use of teleradiology by most residents, and (c) the low percentage of women in radiology residency programs. CONCLUSION: The information obtained during yearly surveys is useful for program evaluation and future planning. Current survey results indicate an increasing use of teleradiology in residency over the past 4 years. The turf battles in ultrasonography (both vascular and obstetric) have remained unchanged over the same time frame.

Results of the 1993 survey of the American Association of Academic Chief Residents in Radiology.

RATIONALE AND OBJECTIVES: A survey of chief residents of academic radiology programs is conducted annually on behalf of the American Association of Academic Chief Residents in Radiology (A3CR2). Data are obtained to improve the training of diagnostic radiology residents and to increase the understanding of radiologists and their associates about issues of interest to radiologists in training. METHODS: Questionnaires were mailed to 133 accredited programs in the United States and Canada. A wide variety of demographic and common interest questions were asked. The analysis took into account geographic location of the responders and the size of the residency program. Comparisons were made to the data from prior years. RESULTS: Completed surveys from 93 programs (70%) were returned. The percentage of women residents is increasing. Important regional and size variations exist in several areas including salary, workload, prior clinical training, resident/fellow ratios, post residency plans, and call schedules. Although many chief residents feel knowledgeable about the health care system, opinions about the future of radiology and medical care are tentative. CONCLUSIONS: This survey provides important demographic information about academic radiology residency programs. The summary information regarding plans for fellowship training, resident call schedules, and opinions about socioeconomic issues may be useful for chief residents, program directors, and departmental chairmen.

Results of the 1996 survey of the American Association of Academic Chief Residents in Radiology.

RATIONALE AND OBJECTIVES: Diagnostic radiology chief residents were surveyed on issues related to residency training to compare features and gauge trends in training. METHODS: Questionnaires were mailed to accredited programs in the United States. A variety of demographic and common-interest questions were asked. RESULTS: Forty-three percent of surveys were returned. The percentage of female residents was similar to that reported in other recent surveys; however, the percentage of women among 1st-year residents had decreased. Resident salaries had increased, although the average salary for a 4th-year resident had decreased when adjusted for inflation. Most 1st-year residents started participating in overnight hospital coverage by their 12th month of residency, and the total number of call days during residency correlated inversely with the size of the residency program. Almost half of residency programs used a night-float resident to provide after-hours coverage. CONCLUSION: The information derived from the survey should be useful for program evaluation and future planning.

Results of the 1997 survey of the American Association of Academic Chief Residents in Radiology.

RATIONALE AND OBJECTIVES: The American Association of Academic Chief Residents in Radiology annually surveys residency programs on a variety of issues related to residency training. The survey results allow individual programs to compare features of their programs with national averages and to gauge trends in radiology residency training. MATERIALS AND METHODS: Questionnaires were mailed to the chief residents in 180 accredited radiology residency programs in the United States. A variety of demographic and common-interest questions were asked. The 1997 survey focused on American Board of Radiology (ABR) examination preparation, residency curriculum, and socioeconomic issues relevant to graduating radiology residents. RESULTS: Completed surveys from 73 programs (41%) were returned. Areas of curriculum concern among chief residents reflected primarily current turf issues. A higher than expected percentage of residents considered their training to be inadequate in nonneurologic magnetic resonance imaging and chest, musculoskeletal, and genitourinary radiology. Job security is a major emerging concern for radiology residents who are considering careers in private practice. The practice of remembering and transcribing questions from the ABR written examination is common, and these questions are a valued resource in preparing for the diagnostic section of the written examination. Most residents attend a commercial review course before the oral examination, and the majority of programs also provide internal review courses. CONCLUSION: A higher than expected percentage of chief residents expressed concern regarding training in subspecialties of radiology that are neither areas of turf dispute nor areas where certificate of additional qualification examinations are offered. Radiology programs and residents expend substantial resources on preparation for the ABR examinations in addition to the usual 4-year curriculum. The most valued resource for the diagnostic section of the examination is almost certainly not equally available. Radiology residents are increasingly concerned about future job security.

Radiologic evaluation of the mediastinum.

New imaging techniques have had a major impact on radiologic evaluation of the mediastinum. Computed tomography has led the way in defining internal anatomy noninvasively. Ultrasound plays a small but well-defined role in the evaluation of certain mediastinal masses. Digital vascular imaging has, in certain instances, replaced conventional angiography, though it seems unlikely to render conventional angiography obsolete. Other modalities such as magnetic resonance imaging are being applied and promise to become even more important in the near future. Finally, mediastinal sampling by needle biopsy under radiologic guidance has been shown to be a reliable technique when appropriately utilized.

The utility of computed tomography in evaluation of extracranial diseases.

The application of CT to the extracranial portions of the body has only been possible since 1975, when technological advances made scanning in less than 20 seconds available to radiologists. Our experience during the first 5 years with body CT have been rewarding and we have demonstrated several significant contributions in the radiologic diagnosis of disease entities that have changed the ideal approach to the evaluation of many patients. The introduction and development of body CT has also been controversial on several issues, primarily related to cost. Increasing clinical experience will improve our definition of the strengths and limitations of CT and allow a more precise definition of the efficient utilization of this new technology. Improvements continue to be reported and it is safe to predict that CT will have further applications to clinical diagnosis in the near future.