61 research outputs found

    Methodological consensus on clinical proton MRS of the brain: Review and recommendations

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    © 2019 International Society for Magnetic Resonance in Medicine Proton MRS (1H MRS) provides noninvasive, quantitative metabolite profiles of tissue and has been shown to aid the clinical management of several brain diseases. Although most modern clinical MR scanners support MRS capabilities, routine use is largely restricted to specialized centers with good access to MR research support. Widespread adoption has been slow for several reasons, and technical challenges toward obtaining reliable good-quality results have been identified as a contributing factor. Considerable progress has been made by the research community to address many of these challenges, and in this paper a consensus is presented on deficiencies in widely available MRS methodology and validated improvements that are currently in routine use at several clinical research institutions. In particular, the localization error for the PRESS localization sequence was found to be unacceptably high at 3 T, and use of the semi-adiabatic localization by adiabatic selective refocusing sequence is a recommended solution. Incorporation of simulated metabolite basis sets into analysis routines is recommended for reliably capturing the full spectral detail available from short TE acquisitions. In addition, the importance of achieving a highly homogenous static magnetic field (B0) in the acquisition region is emphasized, and the limitations of current methods and hardware are discussed. Most recommendations require only software improvements, greatly enhancing the capabilities of clinical MRS on existing hardware. Implementation of these recommendations should strengthen current clinical applications and advance progress toward developing and validating new MRS biomarkers for clinical use

    Assessing willingness to test for HIV among men who have sex with men using conjoint analysis, evidence for uptake of the FDA-approved at-home HIV test.

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    Men who have sex with men (MSM) in the USA, represent a vulnerable population with lower rates of HIV testing. There are various specific attributes of HIV testing that may impact willingness to test (WTT) for HIV. Identifying specific attributes influencing patients' decisions around WTT for HIV is critical to ensure improved HIV testing uptake. This study examined WTT for HIV by using conjoint analysis, an innovative method for systematically estimating consumer preferences across discrete attributes. WTT for HIV was assessed across eight hypothetical HIV testing scenarios varying across seven dichotomous attributes: location (home vs. clinic), price (free vs. 50),samplecollection(fingerprickvs.blood),timelinessofresults(immediatevs.1−2weeks),privacy(anonymousvs.confidential),resultsgiven(byphonevs.in−person),andtypeofcounseling(brochurevs.in−person).Seventy−fiveMSMwererecruitedfromacommunity−basedorganizationprovidingHIVtestingservicesinLosAngelestoparticipateinconjointanalysis.WTTforHIVscorewasbasedona100−pointscale.Scoresrangedfrom32.2to80.3foreighthypotheticalHIVtestingscenarios.PriceofHIVtesting(freevs.50), sample collection (finger prick vs. blood), timeliness of results (immediate vs. 1-2 weeks), privacy (anonymous vs. confidential), results given (by phone vs. in-person), and type of counseling (brochure vs. in-person). Seventy-five MSM were recruited from a community-based organization providing HIV testing services in Los Angeles to participate in conjoint analysis. WTT for HIV score was based on a 100-point scale. Scores ranged from 32.2 to 80.3 for eight hypothetical HIV testing scenarios. Price of HIV testing (free vs. 50) had the highest impact on WTT (impact score = 31.4, SD = 29.2, p<0.0001), followed by timeliness of results (immediate vs. 1-2 weeks) (impact score = 13.9, SD = 19.9, p≤0.0001) and testing location (home vs. clinic) (impact score = 10.3, SD = 22.8, p=0.0002). Impacts of other HIV testing attributes were not significant. Conjoint analysis method enabled direct assessment of HIV testing preferences and identified specific attributes that significantly impact WTT for HIV among MSM. This method provided empirical evidence to support the potential uptake of the newly FDA-approved over-the-counter HIV home test kit with immediate results, with cautionary note on the cost of the kit

    Drug resistant HIV: Behaviors and characteristics among Los Angeles men who have sex with men with new HIV diagnosis.

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    Epidemiology of drug resistant HIV has focused on trends and less attention has been given to identification of factors, especially behaviors including substance use, in acquisition of drug-resistant HIV. From 2009 to 2012 The Metromates Study enrolled and followed for one year men who have sex with men (MSM) seeking testing for HIV in a community clinic in Los Angeles assessing those testing positive for acute and recent HIV infection. Behavioral data were collected via Computer-Assisted Self-Interview from 125 classified as newly HIV infected and 91 as chronically infected (newly HIV-diagnosed); specimens were available and viable for resistance testing for 154 of the 216 HIV positives with new diagnoses. In this community clinic we found prevalence of resistance among MSM with new HIV-diagnosis was 19.5% (n = 30/154) with no difference by recency of HIV infection. Sexual partnership characteristics were associated with resistance; those who reported transgendered sex partners had a higher prevalence of resistance as compared to those who did not report transgendered sex partners (40% vs. 17%; p value = 0.04), while those who reported having a main partner had a lower prevalence of drug resistance (12% vs. 24%; p value = 0.07). In multivariable analyses adjusting for HIV recency and antiviral use, reporting a main partner decreased odds [adjusted odds ratio (AOR) 0.34; 95% confidence interval (CI) 0.13-0.87], reporting a transgendered partnered increased odds (AOR = 3.37; 95% CI 0.95-12.43); and being African American increased odds of drug resistance (AOR = 5.63, 95%CI 1.41-22.38). This suggests African American MSM and TG individuals in Los Angeles represent pockets of exceptional risk that will require special approaches to prevention and care to enhance their own health and reduce their likelihood to support transmission of drug resistance in the US

    App-Based Sexual Partner Seeking and Sexually Transmitted Infection Outcomes: A Cross-Sectional Study of HIV-Negative Men Who Have Sex With Men Attending a Sexually Transmitted Infection Clinic in Los Angeles, California

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    BACKGROUND: Gay, bisexual, and other men who have sex with men (MSM) face higher rates of sexually transmitted infections (STIs) compared with the general population. The association between venues where sexual partners are met and STI transmission is dynamic and poorly understood, especially among those who use geosocial networking (GSN) apps. This study aimed to determine whether there is a difference in STI incidence between MSM who met their last sexual partner through a GSN app and MSM who met their last partner via other venues. METHODS: Data were analyzed from HIV-negative MSM attending the Los Angeles LBGT Center between August 2015 and July 2016 (n = 9499). Logistic regression models were used to investigate the relationship between STI incidence and whether or not an individual met his last partner through a GSN app. RESULTS: No relationship was detected between STI incidence and whether one's last sexual partner was met via GSN app. However, an association was detected between STI incidence and having used GSN apps to meet sexual partners in the past 3 months. A dose-response relationship was observed between the number of venues used to meet partners and testing positive for any STI (adjusted odds ratio, 1.08; 95% confidence interval, 1.02-1.14). CONCLUSIONS: The relationship between how people meet sexual partners and STI acquisition is much more nuanced than previously thought. Geosocial networking apps do not inherently expose users to high-risk reservoirs of STIs, but further understanding of the complexity of sexual networks and networking methods is warranted, given increasing rates of STIs
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