How accurate was GMENAC?--A retrospective review of supply projections for diagnostic radiologists.

In 1982, the Graduate Medical Education National Advisory Committee (GMENAC), a prominent national panel, predicted there would be 25,650 full-time equivalent (FTE) diagnostic radiologists, a 34% oversupply, by 1990. The radiologists involved in GMENAC, however, using models developed by the American College of Radiology, projected 19,800 FTE diagnostic radiologists in 1990, which was similar to the GMENAC estimate of need. The disagreement arose principally from different assumptions about residents entering the specialty. Recent data show there actually were approximately 21,900 FTE diagnostic radiologists in 1990. The radiologists' projection was 10% below this figure; the GMENAC projection was 17% above it. GMENAC erred principally in assuming diagnostic radiology residencies would not replace general radiology residencies, but rather be an addition to them. The radiologists erred principally in their assumption about the effects of the financial problems of hospitals on the number of residency positions. Accurate long-term projection of physician supply in individual specialties may well not be feasible.     

Analysis of signal-to-noise behavior in Cartesian continuous sampling sequences: predictions and experimental validation of opportunities for improved image SNR.

Image signal-to-noise ratio (SNR) limits many MRI applications. Here we propose a method to improve SNR based on continuous sampling (CS) during each TR without significant increases in acquisition time. The general concept of CS is defined here as sampling the NMR signal immediately after slice excitation including ramp times, both the dephase and rephase lobes, the phase-encoding (PE) gradient application, and the slice refocusing gradient. This study analyzes several cases of CS and demonstrates a specific case where sampling occurs during an isolated and balanced readout gradient in order to increase SNR in a rectilinear Cartesian sequence without significantly increasing overall acquisition time. The noise correlation consequences of rectilinear CS are mathematically derived and proven through simulation. The SNR improvement of up to approximately 40% measured in both phantom and asymptomatic human volunteer images is comparable to theoretical prediction of increased SNR proportional to the increase in the square root of the sampling time.     

Juvenile Rheumatoid Arthritis: Benefits from Massage Theraphy

Studied children with mild to moderate juvenile rheumatoid arthritiswho were massaged by their parents 15 minutes a day for 30 days(and a control group engaged in relaxation therapy). The children'sanxiety and stress hormone (cortisol) levels were immediatelydecreased by the massage, and over the 30-day period their paindecreased on self-reports, parent reports, and their physician'sassessment of pain (both the incidence and severity) and pain-limitingactivities     

A dose titration study evaluating terazosin, a selective, once-a-day alpha 1-blocker for the treatment of symptomatic benign prostatic hyperplasia.

The efficacy and safety of terazosin, a selective long-acting alpha-1-adrenergic blocker, were evaluated in 45 normotensive patients with symptomatic benign prostatic hyperplasia ranging from 50 to 76 years old. All patients underwent a complete urodynamic evaluation and transrectal prostatic ultrasonography before enrollment into the study. The dose of terazosin was titrated to 5 mg. per day for a 1-month interval, provided adverse drug reactions were not observed. Of the patients 39 (87%) completed the dose titration study. The parameters used to assess the effectiveness of terazosin included peak and mean urinary flow rates, micturition symptom scores and the global assessment by the patient of symptomatic improvement. Over-all, the mean systolic and diastolic blood pressures changed by less than 1%. The peak and mean urinary flow rates increased by 42 and 48%, respectively. The obstructive and irritative symptom scores improved by 63 and 35%, respectively. Over-all, 30 of the 45 participants (67%) indicated that the voiding symptoms were markedly improved while on terazosin. Five patients did not complete the dose titration study due to development of adverse drug reactions, including erectile dysfunction (7%), tiredness (7%), light-headedness (4%), palpitations (4%), nasal congestion (2%) and asymptomatic hypotension (2%). There were 25 patients (55%) followed on terazosin for 4 to 10 months (mean 6.5 months). The improvements in urinary flow rates and symptom scores were maintained for this interval. Although this preliminary experience with terazosin is encouraging, the ultimate role of terazosin for the long-term treatment of benign prostatic hyperplasia needs further evaluation.     

Radiology practices and their contracts with hospitals, 1989-1990: a representative sample survey

Because of concern about pressures from hospitals for changes in their contracts with radiology practices, the American College of Radiology undertook a stratified sample survey of radiology practices and their contracts with hospitals in late 1989 and early 1990. After three remailings, the survey obtained 904 valid responses for a 64% response rate. It found (weighting data to represent all radiology practices in the nation) that 91% of radiology practices provide services in hospitals. There are contracts at 57% of these hospital sites, and hospitals use tax-exempt bond financing in 54% of the sites with contracts. One year is the most common duration of contracts, and 90 days is the most common cancellation period (89% of contracts can be canceled during the contract's term). Eighty-six percent of contracts are exclusive; 73% are automatically renewable ("evergreen"). Separate billing exists in well over 90% of hospitals with contracts. Two percent of contracts require radiologists to provide equipment; 4% require them to provide support staff. There are fixed-fee arrangements in 9% of contracts and percent compensation arrangements in 3%. Hospitals share in radiologists' fees as a charge for contractual privileges in 5% of contracts. Twenty-seven percent of contracts require hospital approval for radiologists' fee increases; 19% require radiologists to participate with Blue Shield or Medicare. If a contract characteristic is predominant nationally, it is predominant in every region, for solo, small, medium, and large practices, and whether or not hospitals use tax-exempt bond financing. There is, however, some modest variation in frequency of contract provisions. Multivariate analysis shows that most such variation reflects true effects of region and other variables, not statistical artifacts. Region was a statistically significant determinant of 11 of 17 contract characteristics studied. Practice size was a statistically significant determinant of only about half as many characteristics. The survey found some interference in the independence of radiology practices (e.g., required hospital approval of fee increases), questionable clauses (e.g., mandated provision of equipment), and even illegal ones (hospitals charging a fee for contract privileges). Knowledge of the survey findings can make individual radiology practices more effective in negotiations with hospitals and assist the profession in forming a strategy to oppose disadvantageous and illegal provisions.     

The job market in diagnostic radiology 1999: updated findings from a help wanted index of job advertisements

OBJECTIVE. The purpose of this article is to report 1999 data on the job market in diagnostic radiology detected using a help wanted index of job advertisements and to profile trends in practice type, location, and subspecialty using our previously published data as a basis for comparison. MATERIALS AND METHODS. Each advertised job for a diagnostic radiologist in the American Journal of Roentgenology and RADIOLOGY: between January 1991 and December 1999 was coded by practice type, location, and subspecialty. RESULTS. In 1999, 3926 positions were advertised for diagnostic radiologists, representing a 75% increase from 1998. Private practice jobs, which represented 53% of advertisements from 1991 through 1994 and 64% of ads from 1995 through 1998, increased to 66% of ads in 1999. Geographic trends in 1999 were characterized by a relative increase of jobs in the Midwest and California and a decrease in percentage (but increase in total number of ads) in the Northeast and Southwest. The demand for subspecialists continued in 1999, with only 34% of ads placed for general radiologists. A relative increase in demand for neuroradiologists, mammographers, and abdominal imagers was also seen in 1999 in comparison with previously published data from 1995 through 1998. CONCLUSION. The demand for diagnostic radiologists continues to rise, with more ads placed in 1999 than any other year from 1991 through 1998. Using a help wanted index of job advertisements, we have created an indicator of changes in the diagnostic radiology job market with specific reference to practice type, geographic location, and subspecialty training.     

A search for thermal excursions from ancient extraterrestrial impacts using Hadean zircon Ti-U-Th-Pb depth profiles

Few terrestrial localities preserve more than a trace lithic record prior to ca. 3.8 Ga greatly limiting our understanding of the first 700 Ma of Earth history, a period inferred to have included a spike in the bolide flux to the inner solar system at ca. 3.85–3.95 Ga (the Late Heavy Bombardment, LHB). An accessible record of this era may be found in Hadean detrital zircons from the Jack Hills, Western Australia, in the form of μm-scale epitaxial overgrowths. By comparing crystallization temperatures of pre-3.8 Ga zircon overgrowths to the archive of zircon temperature spectra, it should, in principle, be possible to identify a distinctive impact signature. We have developed Ti-U-Th-Pb ion microprobe depth profiling to obtain age and temperature information within these zircon overgrowths and undertaken a feasibility study of its possible use in identifying impact events. Of eight grains profiled in this fashion, four have overgrowths of LHB-era age. Age vs. temperature profiles reveal a period between ca. 3.85–3.95 Ga (i.e., LHB era) characterized by significantly higher temperatures (approximately 840–875 °C) than do older or younger zircons or zircon domains (approximately 630–750 °C). However, temperatures approaching 900 °C can result in Pb isotopic exchange rendering interpretation of these profiles nonunique. Coupled age-temperature depth profiling shows promise in this role, and the preliminary data we report could represent the first terrestrial evidence for impact-related heating during the LHB.