Women with poor access to physicians are much less likely to undergo mammography. Improving the frequency and scope of mammography recommendation by primary care providers is the single most important direct contribution the medical community can make toward increasing mammography use.

HE PROVISION OF SCREENING mammography differs greatly between the United States and the United Kingdom. In the United States, screening is provided in diverse settings, such as private practice, health maintenance organizations, and academic medical centers 1 ; whereas in the United Kingdom, a single organized screening program run by the National Health Service provides virtually all mammographic screening for women aged 50 years or older. 2,3 There are also differences between the ages of women screened; the recommended interval between mammographic examinations; the proportion of women recalled for additional imaging examinations, such as diagnostic mammography or ultrasound; and the methods used to further evaluate findings considered suspicious for cancer. 4-6 However, it is not clear if there are actual differences in the performance and outcomes of screening mammography between the 2 countries. Comparing the performance of screening mammography between the 2 countries may suggest methods to improve mammography practice. We compared recall (the percentage of mammograms in which there is a recommendation for prompt additional testing, clinical evaluation, or percutaneous biopsy), surgical biopsy, and cancer detection rates for screening mammography among similarly aged women between the United States and the United Kingdom.

Raising the annual volume requirements in the Mammography Quality Standards Act might improve the overall quality of screening mammography in the United States.

ObjectiveTo determine patient, institution, and machine characteristics that contribute to variation in radiation doses used for computed tomography (CT).DesignProspective cohort study.SettingData were assembled and analyzed from the University of California San Francisco CT International Dose Registry.ParticipantsStandardized data from over 2.0 million CT examinations of adults who underwent CT between November 2015 and August 2017 from 151 institutions, across seven countries (Switzerland, Netherlands, Germany, United Kingdom, United States, Israel, and Japan).Main outcome measuresMean effective doses and proportions of high dose examinations for abdomen, chest, combined chest and abdomen, and head CT were determined by patient characteristics (sex, age, and size), type of institution (trauma center, care provision 24 hours per day and seven days per week, academic, private), institutional practice volume, machine factors (manufacturer, model), country, and how scanners were used, before and after adjustment for patient characteristics, using hierarchical linear and logistic regression. High dose examinations were defined as CT scans with doses above the 75th percentile defined during a baseline period.ResultsThe mean effective dose and proportion of high dose examinations varied substantially across institutions. The doses varied modestly (10-30%) by type of institution and machine characteristics after adjusting for patient characteristics. By contrast, even after adjusting for patient characteristics, wide variations in radiation doses across countries persisted, with a fourfold range in mean effective dose for abdomen CT examinations (7.0-25.7 mSv) and a 17-fold range in proportion of high dose examinations (4-69%). Similar variation across countries was observed for chest (mean effective dose 1.7-6.4 mSv, proportion of high dose examinations 1-26%) and combined chest and abdomen CT (10.0-37.9 mSv, 2-78%). Doses for head CT varied less (1.4-1.9 mSv, 8-27%). In multivariable models, the dose variation across countries was primarily attributable to institutional decisions regarding technical parameters (that is, how the scanners were used).ConclusionsCT protocols and radiation doses vary greatly across countries and are primarily attributable to local choices regarding technical parameters, rather than patient, institution, or machine characteristics. These findings suggest that the optimization of doses to a consistent standard should be possible.Study registrationClinicaltrials.gov NCT03000751.

Objective There is increasing evidence that altered glutamate (Glu) homeostasis is involved in the pathophysiology of multiple sclerosis (MS). The aim of this study was to evaluate the in vivo effects of excess brain Glu on neuroaxonal integrity measured by N-acetylaspartate (NAA), brain volume, and clinical outcomes in a large, prospectively followed cohort of MS subjects. Methods We used multivoxel spectroscopy at 3T to longitudinally estimate Glu and NAA concentrations from large areas of normal-appearing white and gray matter (NAWM and GM) in MS patients (n = 343) with a mean follow-up time of 5 years. Using linear mixed-effects models, Glu was examined as a predictor of NAA decline, annualized percentage brain volume change, and evolution of clinical outcomes (Multiple Sclerosis Functional Composite [MSFC], Paced Auditory Serial Addition Test-3 [PASAT], and Expanded Disability Status Scale). Glu/NAA ratio was tested as a predictor of brain volume loss and clinical outcomes. Results Baseline Glu[NAWM] was predictive of accelerated longitudinal decline in NAA[GM] (–0.06mM change in NAA[GM]/yr for each unit increase in Glu; p = 0.004). The sustained elevation of Glu[NAWM] was predictive of a loss of 0.28mM/yr in NAA[NAWM] (p < 0.001) and 0.15mM/yr in NAA[GM] (p = 0.056). Each 10% increase in Glu/NAA[NAWM] was associated with a loss of 0.33% brain volume/yr (p = 0.001), 0.009 standard deviations/yr in MSFC z-score (p < 0.001), and 0.17 points/yr on the PASAT (p < 0.001). Interpretation These results indicate that higher Glu concentrations increase the rate of NAA decline, and higher Glu/NAA[NAWM] ratio increases the rate of decline of brain volume, MSFC, and PASAT. This provides evidence of a relationship between brain Glu and markers of disease progression in MS.