Assessment of MRI issues at 3-Tesla for metallic surgical implants: findings applied to 61 additional skin closure staples and vessel ligation clips

<p>Abstract</p> <p>Purpose</p> <p>Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts.</p> <p>Methods</p> <p>A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC) and a vessel ligation clip (Hemoclip Traditional, stainless steel; Teleflex Medical, Durham, NC) that represented the largest metallic sizes made from materials with the highest magnetic susceptibilities (i.e., based on material information) among 61 other surgical implants (52 metallic implants, 9 nonmetallic implants) underwent evaluation for magnetic field interactions, MRI-related heating, and artifacts using standardized techniques. MRI-related heating was assessed by placing each implant in a gelled-saline-filled phantom with MRI performed using a transmit/receive RF body coil at an MR system reported, whole body averaged SAR of 2.9-W/kg for 15-min. Artifacts were characterized using T1-weighted, SE and GRE pulse sequences.</p> <p>Results</p> <p>Each surgical implant showed minor magnetic field interactions (20- and 27-degrees, which is acceptable from a safety consideration). Heating was not substantial (highest temperature change, ≤ 1.6°C). Artifacts may create issues if the area of interest is in the same area or close to the respective surgical implant.</p> <p>Conclusions</p> <p>The results demonstrated that it would be acceptable for patients with these metallic surgical implants to undergo MRI at 3-Tesla or less. Because of the materials and dimensions of the surgical implants that underwent testing, these findings pertain to 61 additional similar implants.</p

Application of Plasticity Theory to Reinforced Concrete Deep Beams

yesThis paper reviews the application of the plasticity theory to reinforced concrete deep beams. Both the truss analogy and mechanism approach were employed to predict the capacity of reinforced concrete deep beams. In addition, most current codes of practice, for example Eurocode 1992 and ACI 318-05, recommend the strut-and-tie model for designing reinforced concrete deep beams. Compared with methods based on empirical or semi-empirical equations, the strut-and-tie model and mechanism analyses are more rational, adequately accurate and sufficiently simple for estimating the load capacity of reinforced concrete deep beams. However, there is a problem of selecting the effectiveness factor of concrete as reflected in the wide range of values reported in the literature for deep beams

Convalescent Pulmonary Dysfunction Following Hantavirus Pulmonary Syndrome in Panama and the United States

The objective of this study was to document persistent pulmonary symptoms and pulmonary function abnormalities in adults surviving hantavirus pulmonary syndrome (HPS). Acute infection by most hantaviruses result in mortality rates of 25–35%, while in Panama the mortality rate of 10% is contrasted by an unusually high incidence. In all types of HPS, the viral prodrome, cardiopulmonary phase due to massive pulmonary capillary leak syndrome, and spontaneous diuresis are followed by a convalescent phase with exertional dyspnea for 3–4 weeks, but the frequency of persistent symptoms is not known. In this observational study of a convenience sample, 14 survivors of HPS caused by Choclo virus infection in Panama and 9 survivors of HPS caused by Sin Nombre virus infection in New Mexico completed a questionnaire and pulmonary function tests up to 8 years after infection. In both groups, exertional dyspnea persisted for 1–2 years after acute infection in 43% (Panama) and 77% (New Mexico) of survivors surveyed. Reduction in midexpiratory flows (FEF25–75%), increased residual volume (RV), and reduced diffusion capacity (DLCO/VA) also were common in both populations; but the severity of reduced expiratory flow did not correlate with exertional dyspnea. Symptoms referable to previous hantavirus infection had resolved within 3 years of acute infection in most but not all patients in the Panama group. Temporary exertional dyspnea and reduced expiratory flow are common in early convalescence after HPS but resolves in almost all patients

Distinguishing Asthma Phenotypes Using Machine Learning Approaches.

Asthma is not a single disease, but an umbrella term for a number of distinct diseases, each of which are caused by a distinct underlying pathophysiological mechanism. These discrete disease entities are often labelled as asthma endotypes. The discovery of different asthma subtypes has moved from subjective approaches in which putative phenotypes are assigned by experts to data-driven ones which incorporate machine learning. This review focuses on the methodological developments of one such machine learning technique-latent class analysis-and how it has contributed to distinguishing asthma and wheezing subtypes in childhood. It also gives a clinical perspective, presenting the findings of studies from the past 5 years that used this approach. The identification of true asthma endotypes may be a crucial step towards understanding their distinct pathophysiological mechanisms, which could ultimately lead to more precise prevention strategies, identification of novel therapeutic targets and the development of effective personalized therapies

Improvements in Ability to Detect Undiagnosed Diabetes by Using Information on Family History Among Adults in the United States

Family history is an independent risk factor for diabetes, but it is not clear how much adding family history to other known risk factors would improve detection of undiagnosed diabetes in a population. Using the National Health and Nutrition Examination Survey for 1999−2004, the authors compared logistic regression models with established risk factors (model 1) with a model (model 2) that also included familial risk of diabetes (average, moderate, and high). Adjusted odds ratios for undiagnosed diabetes, using average familial risk as referent, were 1.7 (95% confidence interval (CI): 1.2, 2.5) and 3.8 (95% CI: 2.2, 6.3) for those with moderate and high familial risk, respectively. Model 2 was superior to model 1 in detecting undiagnosed diabetes, as reflected by several significant improvements, including weighted C statistics of 0.826 versus 0.842 (bootstrap P = 0.001) and integrated discrimination improvement of 0.012 (95% CI: 0.004, 0.030). With a risk threshold of 7.3% (sensitivity of 40% based on model 1), adding family history would identify an additional 620,000 (95% CI: 221,100, 1,020,000) cases without a significant change in false-positive fraction. Study findings suggest that adding family history of diabetes can provide significant improvements in detecting undiagnosed diabetes in the US population. Further research is needed to validate the authors’ findings

Fatigue, quality of life and physical fitness following an exercise intervention in multiple myeloma survivors (MASCOT): an exploratory randomised Phase 2 trial utilising a modified Zelen design

Background: Exercise may improve fatigue in multiple myeloma survivors, but trial evidence is limited, and exercise may be perceived as risky in this older patient group with osteolytic bone destruction. Methods: In this Phase 2 Zelen trial, multiple myeloma survivors who had completed treatment at least 6 weeks ago, or were on maintenance only, were enrolled in a cohort study and randomly assigned to usual care or a 6-month exercise programme of tailored aerobic and resistance training. Outcome assessors and usual care participants were masked. The primary outcome was the FACIT-F fatigue score with higher scores denoting less fatigue. Results: During 2014–2016, 131 participants were randomised 3:1 to intervention (n = 89) or usual care (n = 42) to allow for patients declining allocation to the exercise arm. There was no difference between groups in fatigue at 3 months (between-group mean difference: 1.6 [95% CI: −1.1–4.3]) or 6 months (0.3 [95% CI: −2.6–3.1]). Muscle strength improved at 3 months (8.4 kg [95% CI: 0.5–16.3]) and 6 months (10.8 kg [95% CI: 1.2–20.5]). Using per-protocol analysis, cardiovascular fitness improved at 3 months (+1.2 ml/kg/min [95% CI: 0.3–3.7]). In participants with clinical fatigue (n = 17), there was a trend towards less fatigue with exercise over 6 months (6.3 [95% CI: −0.6–13.3]). There were no serious adverse events. Conclusions: Exercise appeared safe and improved muscle strength and cardiovascular fitness, but benefits in fatigue appeared limited to participants with clinical fatigue at baseline. Future studies should focus on patients with clinical fatigue. Clinical trial registration: The study was registered with ISRCTN (38480455) and is completed

Impact of Disease Management on Utilization and Adherence With Drugs and Tests: The case of diabetes treatment in the Florida: A Healthy State (FAHS) program

OBJECTIVE—The purpose of this study was to evaluate the effect of telephonic care management within a diabetes disease management program on adherence to treatment with hypoglycemic agents, ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), statins, and recommended laboratory tests in a Medicaid population