Gender Differences in Diagnostic Radiology Practice: An Observational Study.

PURPOSE: To investigate gender differences in diagnostic radiology practice, specifically, the differences in scope of practice, the frequency of consultations to other colleagues, and the error rates. MATERIAL AND METHODS: A retrospective observational study was performed including radiologists working for a European teleradiology provider between 2013 and 2019. Main outcome measures included the adjusted odds ratio of female gender for reporting cases in more than one subspecialty, the adjusted incidence rate ratio (IRR) of female gender for the count of second opinion requests to other colleagues, and the adjusted IRR of female gender for the count of radiologic errors. Multivariable adjustment was performed for covariates associated with experience, type of cases reported, part- or full-time employment, and reporting speed. RESULTS: A total of 213 radiologists (36% female) were included in the analysis of gender differences in scope of practice. Female gender was associated with a lower odds of reporting cases in more than one subspecialty with an odds ratio of 0.46 (95% confidence interval, 0.22-0.96). A total of 204 radiologists (36% female) were included in the analysis of gender differences in the count of second opinion requests to colleagues. There was a trend toward an association between female gender and higher odds of requesting a second opinion with an adjusted IRR of 1.6 compared with male gender, but it was not statistically significant (P = .08). A total of 199 radiologists were included (37% female) in the analysis of gender differences in the number of radiologic errors. Female gender was associated with a decrease in the odds of error with an IRR of 0.8 (95% confidence interval, 0.64-0.995). CONCLUSIONS: Female radiologists tend to have a narrower scope of practice and make fewer mistakes than their male counterparts, even after detailed adjustment for factors that might explain gender differences in scope of practice and errors.

History-dependence of muscle slack length in humans: effects of contraction intensity, stretch amplitude, and time.

The slack length of a relaxed skeletal muscle can be reduced by isometric contraction at short lengths ("contract-short conditioning"). This study explored how the effect of contract-short conditioning on muscle slack length is modified by 1) the intensity of the contraction, 2) the delay between the contraction and measurement of slack length, and 3) the amplitude of a stretch delivered to the relaxed muscle after the contraction. Muscle fascicles in the human vastus lateralis muscle were observed with ultrasound imaging while the relaxed muscle was lengthened by flexing the knee. The knee angle at which muscle fascicle slack was taken up was used as a proxy for muscle slack length. Conditioning the muscle with voluntary isometric (fixed-end) contractions at short muscle lengths reduced vastus lateralis muscle slack length, measured 60 s later, by a mean of 10°. This effect was independent of contraction intensity from 5% to 100% maximal voluntary contraction. The effect was largest when first observed 5 s after the contraction, decayed about one-third by 60 s, and then remained nearly constant until the last observation 5 min after the contraction. A slow stretch given to the relaxed muscle after contract-short conditioning increased slack length (i.e., reduced the effect of contract-short conditioning). Slack length increased nonlinearly with stretch amplitude. Very large stretches (>30°, possibly as large as 90°) were required to abolish the effect of contract-short conditioning. The phenomena described here share some characteristics with, and may involve similar mechanisms to, passive force enhancement and muscle thixotropy.NEW & NOTEWORTHY The slack length of a relaxed human skeletal muscle is not fixed; it can be modified by contraction and stretch. Contraction of the human vastus lateralis muscle at short lengths reduces the muscle's slack length. Even very weak contractions are sufficient to induce this effect. The effect persists for at least 5 min but can be reduced or abolished with a large-amplitude passive stretch.