Automatic Exposure Control During Computed Tomography Scans of the Head: Effects on Dose and Image Quality

Automatic exposure control (AEC) is effective at reducing potentially harmful radiation doses without sacrificing image quality for many types of computed tomography (CT) scans. However, there is a need for more information regarding the use of AEC for CT head scans. This study was conducted at Johnson County Community Hospital in Mountain City, TN. Preexisting adult CT head scans (n)60 were randomly selected to form 2 stratified samples, (n)30 each. One sample used a standard protocol, and the other used a protocol with a mA-modulated AEC system, Siemens CARE Dose 4D. Causal-comparative analyses were conducted, and it was determined that AEC was effective at maintaining subjective image quality while reducing radiation doses an average of 38% for adult CT head scans. It was concluded that using AEC was an effective tool to optimize radiation doses for adult CT head scans in one particular setting, but more research on this topic is needed

The History, Status, and Future of Tribal Self-Governance Under the Indian Self-Determination and Education Assistance Act

This year marks the 40th anniversary of the Indian Self-Determination and Education Assistance Act of 1975 (ISDEAA), a cornerstone of modern federal Indian policy. In 1988, amendments to the ISDEAA created the Tribal Self-Governance Demonstration Project. By providing a statutory basis for the broader movement of tribal self-governance, this legislation recognized and advanced the proposition that Indian tribes can provide better governmental services to their own members than can distant federal bureaucracies. Expanded and refined in subsequent legislation in 1994 and 2000, the Self-Governance Policy has proven so successful that today over 50% of all federal Indian programs are carried out by tribes rather than federal agencies. This article reviews the history of the self-governance program, identifies challenges to the continued growth of self-governance, and discusses possible directions that the program could take in the coming years

Distribution of Gaussian Process Arc Lengths

We present the first treatment of the arc length of the Gaussian Process (GP) with more than a single output dimension. GPs are commonly used for tasks such as trajectory modelling, where path length is a crucial quantity of interest. Previously, only paths in one dimension have been considered, with no theoretical consideration of higher dimensional problems. We fill the gap in the existing literature by deriving the moments of the arc length for a stationary GP with multiple output dimensions. A new method is used to derive the mean of a one-dimensional GP over a finite interval, by considering the distribution of the arc length integrand. This technique is used to derive an approximate distribution over the arc length of a vector valued GP in $\mathbb{R}^n$ by moment matching the distribution. Numerical simulations confirm our theoretical derivations.Comment: 10 pages, 4 figures, Accepted to The 20th International Conference on Artificial Intelligence and Statistics (AISTATS

A randomized trial of vertebroplasty for painful osteoporotic vertebral fractures

Background Vertebroplasty has become a common treatment for painful osteoporotic vertebral fractures, but there is limited evidence to support its use. Methods We performed a multicenter, randomized, double-blind, placebo-controlled trial in which participants with one or two painful osteoporotic vertebral fractures that were of less than 12 months\u27 duration and unhealed, as confirmed by magnetic resonance imaging, were randomly assigned to undergo vertebroplasty or a sham procedure. Participants were stratified according to treatment center, sex, and duration of symptoms (&lt;6 weeks or 6 weeks). Outcomes were assessed at 1 week and at 1, 3, and 6 months. The primary outcome was overall pain (on a scale of 0 to 10, with 10 being the maximum imaginable pain) at 3 months. Results A total of 78 participants were enrolled, and 71 (35 of 38 in the vertebroplasty group and 36 of 40 in the placebo group) completed the 6-month follow-up (91%). Vertebroplasty did not result in a significant advantage in any measured outcome at any time point. There were significant reductions in overall pain in both study groups at each follow-up assessment. At 3 months, the mean (&plusmn;SD) reductions in the score for pain in the vertebroplasty and control groups were 2.6&plusmn;2.9 and 1.9&plusmn;3.3, respectively (adjusted between-group difference, 0.6; 95% confidence interval, &ndash;0.7 to 1.8). Similar improvements were seen in both groups with respect to pain at night and at rest, physical functioning, quality of life, and perceived improvement. Seven incident vertebral fractures (three in the vertebroplasty group and four in the placebo group) occurred during the 6-month follow-up period. Conclusions We found no beneficial effect of vertebroplasty as compared with a sham procedure in patients with painful osteoporotic vertebral fractures, at 1 week or at 1, 3, or 6 months after treatment. (Australian New Zealand Clinical Trials Registry number, ACTRN012605000079640.)<br /

The Health Literacy Questionnaire (HLQ) at the patient-clinician interface: a qualitative study of what patients and clinicians mean by their HLQ scores

BackgroundThe Health Literacy Questionnaire (HLQ) has nine scales that each measure an aspect of the multidimensional construct of health literacy. All scales have good psychometric properties. However, it is the interpretations of data within contexts that must be proven valid, not just the psychometric properties of a measurement instrument. The purpose of this study was to establish the extent of concordance and discordance between individual patient and clinician interpretations of HLQ data in the context of complex case management.MethodsSixteen patients with complex needs completed the HLQ and were interviewed to discuss the reasons for their answers. Also, the clinicians of each of these patients completed the HLQ about their patient, and were interviewed to discuss the reasons for their answers. Thematic analysis of HLQ scores and interview data determined the extent of concordance between patient and clinician HLQ responses, and the reasons for discordance.ResultsHighest concordance (80%) between patient and clinician item-response pairs was seen in Scale 1 and highest discordance (56%) was seen in Scale 6. Four themes were identified to explain discordance: 1) Technical or literal meaning of specific words; 2) Patients&rsquo; changing or evolving circumstances; 3) Different expectations and criteria for assigning HLQ scores; and 4) Different perspectives about a patient&rsquo;s reliance on healthcare providers.ConclusionThis study shows that the HLQ can act as an adjunct to clinical practice to help clinicians understand a patient&rsquo;s health literacy challenges and strengths early in a clinical encounter. Importantly, clinicians can use the HLQ to detect differences between their own perspectives about a patient&rsquo;s health literacy and the patient&rsquo;s perspective, and to initiate discussion to explore this. Provision of training to better detect these differences may assist clinicians to provide improved care.The outcomes of this study contribute to the growing body of international validation evidence about the use of the HLQ in different contexts. More specifically, this study has shown that the HLQ has measurement veracity at the patient and clinician level and may support clinicians to understand patients&rsquo; health literacy and enable a deeper engagement with healthcare services.<br /

IXPE Mission System Concept and Development Status

The Goal of the Imaging X-Ray Polarimetry Explorer (IXPE) Mi SMEX), is to expand understanding of high-energy astrophysical processes and sources, in support of NASAs first science objective in Astrophysics: Discover how the universe works. IXPE, an international collaboration, will conduct X-ray imaging polarimetry for multiple categories of cosmic X-ray sources such as neutron stars, stellar-mass black holes, supernova remnants and active galactic nuclei. The Observatory uses a single science operational mode capturing the X-ray data from the targets. The IXPE Observatory consists of spacecraft and payload modules built up in parallel to form the Observatory during system integration and test. The payload includes three X-ray telescopes each consisting of a polarization-sensitive, gas pixel X-ray detector, paired with its corresponding grazing incidence mirror module assembly (MMA). A deployable boom provides the correct separation (focal length) between the detector units (DU) and MMAs. These payload elements are supported by the IXPE spacecraft which is derived from the BCP-small spacecraft architecture. This paper summarizes the IXPE mission science objectives, updates the Observatory implementation concept including the payload and spacecraft ts and summarizes the mission status since last years conference