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1.
Radiology residents' work hours and study habits 总被引:1,自引:0,他引:1
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Magnetic resonance (MR) imaging has been used in the temporomandibular joint (TMJ) primarily to define the disk position. This report examines altered morphology and signal intensity characteristics of the TMJ disk as they relate to the severity of internal derangement. Two hundred sixteen joints in 133 patients with a history of such derangement. were imaged with MR. Disk position, signal intensity, morphology, and the presence of osteoarthritis were determined for each joint. The normal disk was not anteriorly displaced and had a normal "bow-tie" shape. A grade 1 disk was anteriorly displaced and had a normal shape; a grade 2 disk was anteriorly displaced and had an abnormal shape. Forty (19%) joints were considered normal; none of these exhibited osteoarthritis. One hundred thirty-nine (64%) joints were grade 1; osteoarthritis was found in 17%. Thirty-seven (17%) were grade 2; osteoarthritis was found in 95%. All forty normal joints had high or intermediate signal intensity in the disk. Osteoarthritic joints had a higher percentage of disks with diminished intensity (P less than .0001). Severe or untreated osteoarthritis is known to be a complication of TMJ internal derangements; hence this grading system seems to correlate with the severity of internal derangement. 相似文献
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Renal gluconeogenesis and increased glucose utilization in shock 总被引:1,自引:0,他引:1
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Originally designed for use at medical-imaging x-ray energies, imaging systems comprising scintillating screens and amorphous Si detectors are also used at the megavoltage photon energies typical of portal imaging and industrial radiography. While image blur at medical-imaging x-ray energies is strongly influenced both by K-shell fluorescence and by the transport of optical photons within the scintillator layer, at higher photon energies the image blur is dominated by radiation scattered from the detector housing and internal support structures. We use Monte Carlo methods to study the blurring in a notional detector: a series of semi-infinite layers with material compositions, thicknesses, and densities similar to those of a commercially available flat-panel amorphous Si detector system comprising a protective housing, a gadolinium oxysulfide scintillator screen, and associated electronics. We find that the image blurring, as described by a point-spread function (PSF), has three length scales. The first component, with a submillimeter length scale, arises from electron scatter within the scintillator and detection electronics. The second component, with a millimeter-to-centimeter length scale, arises from electrons produced in the front cover of the detector. The third component, with a length scale of tens of centimeters, arises from photon scatter by the back cover of the detector. The relative contributions of each of these components to the overall PSF vary with incident photon energy. We present an algorithm that includes the energy-dependent sensitivity and energy-dependent PSF within a ray-tracing formalism. We find quantitative agreement (approximately 2%) between predicted radiographs with radiographs of copper step wedges, taken with a 9 MV bremsstrahlung source and a commercially available flat-panel system. The measured radiographs show the blurring artifacts expected from both the millimeter-scale electron transport and from the tens-of-centimeters length scale arising from the scattered photon transport. Calculations indicate that neglect of the energy-dependent blurring would lead to discrepancies in the apparent transmission of these wedges of the order of 9%. 相似文献
7.
Sophia A. Traven Russell A. Reeves Molly G. Sekar Harris S. Slone Zeke J. Walton 《The Journal of arthroplasty》2019,34(1):140-144
Background
While the 11-factor modified frailty index (mFI) has been shown to predict adverse outcomes in patients undergoing total joint arthroplasty, the 5-factor index has not been evaluated in this patient population. The goal of this study was to evaluate the utility of the mFI-5 as a predictor of morbidity and mortality in patients undergoing primary total hip and knee arthroplasty.Methods
A retrospective analysis of the American College of Surgeons National Surgical Quality Improvement Program's database for patients undergoing total hip arthroplasty and total knee arthroplasty between the years 2005 and 2016 was conducted. The 5-factor score, which includes the presence of comorbid diabetes, hypertension, congestive heart failure, chronic obstructive pulmonary disease, and functional status, was calculated for each patient. Multivariate logistic regression models were used to assess the relationship between the mFI-5 and postoperative complications while controlling for demographic variables.Results
One hundred forty thousand one hundred fifty-eight patients undergoing total hip arthroplasty and 226,398 patients undergoing total knee arthroplasty were identified. After adjusting for demographic variables and comorbid conditions, logistic regression analyses revealed that the mFI-5 was a strong predictor for total complications, Clavien-Dindo grade IV complications (cardiac arrest, myocardial infarction, septic shock, pulmonary embolism, postoperative dialysis, reintubation, and prolonged ventilator requirement), surgical site infections, readmission, and 30-day mortality (P < .001).Conclusions
The mFI-5 is an independent predictor of postoperative complications including life-threatening medical complications, surgical site infections, hospital readmission, and 30-day mortality after primary hip and knee arthroplasty. This clinical tool can be used to identify high-risk surgical patients and guide preoperative counseling to optimize outcomes.Level of Evidence
III. 相似文献8.
Background
The social–ecological environment of undocumented children of migrant workers includes varying levels of risk factors. Growing up in these conditions compromises children’s development on all levels. Many of these children are in need of psychotherapy, however, due to limited resources, only a few of them receive mental health aid.Objective
The present research undertook to construct and examine the effectiveness of a specialized group intervention program to enhance children’s self-efficacy and mental health.Methods
Participants were 70 children aged 8–12 of illegal migrant workers in Israel. The repeated measures design included completion of a self-efficacy scale and emotional, behavioral and social difficulties child-report and teacher-report measures. Children were randomly allocated to either an intervention or control group.Results
The first hypotheses predicting a greater improvement in self-efficacy between the pre-test and post-test for children in the intervention as opposed to control group was confirmed. The second hypothesis predicting a greater reduction in the self- and teacher-reports of emotional, social and behavioral difficulties was confirmed. The third hypothesis predicting a moderating relation between self-efficacy, group type and time on the dependent variables was confirmed only for children’s self-report of their difficulties.Conclusions
Findings provide evidence for the effectiveness of this short term playful intervention program for this group of disadvantaged children, suggesting its application to other at-risk groups of children. 相似文献9.
10.
Charles Cody White Venkatraman Kothandaraman Jackie Lin Meghana Rao Alyssa Greenhouse William R. Barfield Russell Chapin Harris S. Slone Richard J. Friedman Josef K. Eichinger 《Arthroscopy》2021,37(1):17-25
PurposeTo determine whether change in shoulder position between internal rotation (IR) and external rotation (ER) during magnetic resonance arthrography (MRA) affects previously defined capsular measurements and to determine the utility of rotation in the diagnosis of instability.MethodsA retrospective study was conducted of patients who received a shoulder MRA with humeral IR and ER views. Patients with an arthroscopically confirmed diagnosis of instability and those with clinically stable shoulders, no history of instability, and no MRA findings of instability were identified and compared. Humeral rotation, glenoid retroversion, humeral head subluxation, capsular length, and capsular area using axial sequences of IR and ER views were recorded. Analysis compared IR, ER, and Δ capsular measurements between groups using independent t tests and univariate and multivariate regression.ResultsThirty-one subjects who were diagnosed with instability were included, along with 28 control subjects. Capsular length, capsular area, and humeral subluxations were significantly greater with ER compared with IR views (P < .001, P < .001, P < .001). Patients with instability displayed greater ER capsular length (P = .0006) and ER capsular area (P = .005) relative to controls. Multivariate logistic regression identified age, weight, sex, ER capsular length, and retroversion to be significant predictors of instability. ER capsular length independently predicts instability with 86% sensitivity and 84% specificity. Interobserver reliability using the intraclass correlation coefficient was rated good or excellent on all measurements.ConclusionVariance in humeral rotation during shoulder MRA significantly affects capsular measurements. Rotational views increase the utility of capsular measurements when assessing for instability, particularly capsular length and capsular area. The implementation of ER positioning enhances the ability to examine capsular changes of the shoulder joint and can assist in the diagnosis of instability.Level of EvidenceIII, retrospective comparative study 相似文献