Fast myocardial T1 mapping using cardiac motion correction.

PURPOSE: To improve the efficiency of native and postcontrast high-resolution cardiac T1 mapping by utilizing cardiac motion correction. METHODS: Common cardiac T1 mapping techniques only acquire data in a small part of the cardiac cycle, leading to inefficient data sampling. Here, we present an approach in which 80% of each cardiac cycle is used for T1 mapping by integration of cardiac motion correction. Golden angle radial data was acquired continuously for 8 s with in-plane resolution of 1.3 × 1.3 mm2 . Cine images were reconstructed for nonrigid cardiac motion estimation. Images at different TIs were reconstructed from the same data, and motion correction was performed prior to T1 mapping. Native T1 mapping was evaluated in healthy subjects. Furthermore, the technique was applied for postcontrast T1 mapping in 5 patients with suspected fibrosis. RESULTS: Cine images with high contrast were obtained, leading to robust cardiac motion estimation. Motion-corrected T1 maps showed myocardial T1 times similar to cardiac-triggered T1 maps obtained from the same data (1288 ± 49 ms and 1259 ± 55 ms, respectively) but with a 34% improved precision (spatial variation: 57.0 ± 12.5 ms and 94.8 ± 15.4 ms, respectively, P < 0.0001) due to the increased amount of data. In postcontrast T1 maps, focal fibrosis could be confirmed with late contrast-enhancement images. CONCLUSION: The proposed approach provides high-resolution T1 maps within 8 s. Data acquisition efficiency for T1 mapping was improved by a factor of 5 by integration of cardiac motion correction, resulting in precise T1 maps.

Simultaneous high-resolution cardiac T1 mapping and cine imaging using model-based iterative image reconstruction.

PURPOSE: To provide high-resolution cardiac T1 mapping of various cardiac phases and cine imaging within a single breath-hold using continuous golden ratio-based radial acquisition and model-based iterative image reconstruction. METHODS: Data acquisition was performed continuously using golden ratio-based radial sampling and multiple inversion pulses were applied independent of the heart rate. Native T1 maps of diastole and systole were reconstructed with in-plane resolution of 1.3 × 1.3 mm2 using model-based iterative image reconstruction. Cine images with 30 cardiac phases were reconstructed from the same data using kt-SENSE. The method was evaluated in a commercially available T1 phantom and 10 healthy subjects. In vivo T1 assessment was carried out segment-wise. RESULTS: Evaluation in the phantom demonstrated accurate T1 times (R2 > 0.99) and insensitivity to the heart rate. In vivo T1 values did not differ between systole and diastole, and T1 times assessed by the proposed approach were longer than measured with a modified Look-Locker inversion recovery (MOLLI) sequence, except for lateral segments. Cine images had a consistent dark-blood contrast and functional assessment was in agreement with assessment based on Cartesian cine scans (difference in ejection fraction: 0.26 ± 2.65%, P = 0.65). CONCLUSION: The proposed approach provides native T1 maps of diastole and systole with high spatial resolution and cine images simultaneously within 16 s, which could strongly improve the scan efficiency.

Persistence of Shifts in Beliefs Associated With Exposure to Alcohol Advertising Among Adolescents.

OBJECTIVE: The purpose of this study was to quantify the persistence of immediate changes in adolescents' alcohol-related beliefs associated with exposure to alcohol advertising. METHOD: Middle school students (N = 606) carried handheld devices for 14 days and logged all of their exposures to alcohol advertisements as they naturally occurred. Perceptions of the typical person one's age who drinks ("prototype perceptions") and perceived norms regarding alcohol use were assessed after each exposure to advertising and at random prompts issued daily throughout the assessment period. Generalized additive modeling was used to determine how long pro-drinking shifts in beliefs persisted after exposure to advertising. RESULTS: Following exposure to advertisements, positivity of youth's prototype perceptions immediately increased (ß = .07, 95% CI [.06, .09]) and then decreased (ß = -.05, 95% CI [-.07, -.03]) over the subsequent 1.5 days, whereas perceived normativeness of alcohol use immediately increased (ß = .04, 95% CI [.01, .06]) and then decreased (ß = -.03, 95% CI [-.05, -.01]) over the subsequent 2 days. Changes in beliefs occurring after 1.5 days for prototype perceptions and after 2 days for perceived norms were not statistically significant, suggesting that these beliefs were no longer affected by the advertising exposure. CONCLUSIONS: Findings are consistent with theories of alcohol advertising effects that presume that repeated exposure results in cumulative, enduring effects on beliefs. Given the rate of decay of alcohol advertising effects, it may be important to limit youth exposures to one every 2 days to avoid cumulative, lasting pro-drinking shifts in beliefs or to devise ways to interrupt cumulative effects with counter-messaging through media, parents, or other influential others at similar intervals.

Factors associated with younger adolescents' exposure to online alcohol advertising.

Little is known about the extent and nature of youth exposure to online alcohol advertising, or factors that may be associated with exposure. The current study recruited middle school students who completed a paper survey and then logged each alcohol advertisement that they encountered over a 2-week period using cell phones as part of an ecological momentary assessment design. We examined the percentage of youth who reported exposure to online alcohol advertising in the past 2 weeks, average weekly rate of exposure, types of online alcohol advertisements youth reported seeing, and factors that increased youths' risk of exposure to online alcohol advertising. Analyses are based on 485 participants (47% female; 25% Hispanic, 25% White, 27% Black; 6% Asian, 16% other). Youth logged exposures to a total of 3,966 (16,018 weighted for underreporting) alcohol advertisements across the monitoring period; 154 (568 weighted) or 3.6% were online ads. Seventeen percent of youth reported seeing any online alcohol ad; the majority of online ads seen were video commercials (44.8%) and banner/side ads (26.6%). Factors associated with greater ad exposure were being older, rebellious, and Black race; greater parental monitoring and more hours spent on social media were associated with less exposure. Findings provide important information about adolescents' exposure to online alcohol advertising and what might contribute to a greater likelihood of exposure. Given that online ad exposure is linked to drinking behavior, prevention programming for younger adolescents should continue to address this issue to help youth make healthy choices regarding alcohol use. (PsycINFO Database Record

Barriers to integrating the continuum of care for opioid and alcohol use disorders in primary care: A qualitative longitudinal study.

Untreated substance use disorders remain a pervasive public health problem in the United States, especially among medically-underserved and low-income populations, with opioid and alcohol use disorders (OAUD) being of particular concern. Primary care is an underutilized resource for delivering treatment for OAUD, but little is known about the organizational capacity of community-based primary care clinics to integrate treatment for OAUD. The objective of this study was to use an organizational capacity framework to examine perceived barriers to implementing the continuum of care for OAUD in a community-based primary care organization over three time points: pre-implementation (preparation), early implementation (practice), and full implementation. Clinic administrators and medical and mental health providers from two clinics participated in interviews and focus groups. Barriers were organized by type and size, and are presented over the three time points. Although some barriers persisted, most barriers decreased over time, and respondents reported feeling more efficacious in their ability to successfully deliver OAUD treatment. Findings contribute to the needed literature on building capacity to implement OAUD treatment in primary care and suggest that while barriers may be sizable and inevitable, successful implementation is still possible.

Cerebral blood flow response to hypoglycemia is altered in patients with type 1 diabetes and impaired awareness of hypoglycemia.

It is unclear whether cerebral blood flow responses to hypoglycemia are altered in people with type 1 diabetes and impaired awareness of hypoglycemia. The aim of this study was to investigate the effect of hypoglycemia on both global and regional cerebral blood flow in type 1 diabetes patients with impaired awareness of hypoglycemia, type 1 diabetes patients with normal awareness of hypoglycemia and healthy controls ( n = 7 per group). The subjects underwent a hyperinsulinemic euglycemic-hypoglycemic glucose clamp in a 3 T MR system. Global and regional changes in cerebral blood flow were determined by arterial spin labeling magnetic resonance imaging, at the end of both glycemic phases. Hypoglycemia generated typical symptoms in patients with type 1 diabetes and normal awareness of hypoglycemia and healthy controls, but not in patients with impaired awareness of hypoglycemia. Conversely, hypoglycemia increased global cerebral blood flow in patients with impaired awareness of hypoglycemia, which was not observed in the other two groups. Regionally, hypoglycemia caused a redistribution of cerebral blood flow towards the thalamus of both patients with normal awareness of hypoglycemia and healthy controls, consistent with activation of brain regions associated with the autonomic response to hypoglycemia. No such redistribution was found in the patients with impaired awareness of hypoglycemia. An increase in global cerebral blood flow may enhance nutrient supply to the brain, hence suppressing symptomatic awareness of hypoglycemia. Altogether these results suggest that changes in cerebral blood flow during hypoglycemia contribute to impaired awareness of hypoglycemia.

Exposure to alcohol advertising and adolescents' drinking beliefs: Role of message interpretation.

OBJECTIVE: Recent research revealed momentary associations between exposure to alcohol advertising and positive beliefs about alcohol among adolescents (Martino et al., 2016). We reanalyzed those data to determine whether associations depend on adolescents' appraisal of ads. METHOD: Over a 10-month period in 2013, 589 youth, ages 11-14, in the Los Angeles, CA, area, participated in a 14-day ecological momentary assessment, logging all exposures to alcohol advertisements as they occurred and completing brief assessments of their skepticism toward, liking of, and identification with any people in each ad, as well as their alcohol-related beliefs at the moment. Participants also completed measures of their alcohol- related beliefs at random moments of nonexposure throughout each day. Mixed-effects regression models compared beliefs about alcohol at moments of exposure to alcohol advertising that was appraised in a particular way (e.g., with liking, without liking) to beliefs at random moments. RESULTS: When youth encountered ads they appraised positively, their beliefs about alcohol were significantly more positive than when they were queried at random moments. Beliefs in the presence of ads that were not positively appraised were generally similar to beliefs at random moments. CONCLUSION: Youth are active participants in the advertising process. How they respond to and process alcohol advertising strongly moderates the association between exposure and alcohol-related beliefs. More effort is needed to identify attributes of alcohol advertisements, and of youth, that determine how youth process alcohol ads. This information can be used to either limit exposure to problematic ads or make youth more resilient to such exposure. (PsycINFO Database Record

Alcohol Advertising Exposure Among Middle School-Age Youth: An Assessment Across All Media and Venues.

OBJECTIVE: The purpose of this study was to quantify middle school youth's exposure to alcohol advertisements across media and venues, determine venues of greatest exposure, and identify characteristics of youth who are most exposed. METHOD: Over a 10-month period in 2013, 589 Los Angeles-area youth ages 11-14 from diverse racial/ethnic backgrounds completed a short paper-and-pencil survey assessing background characteristics and then participated in a 14-day ecological momentary assessment, logging all exposures to alcohol advertisements on handheld computers as they occurred. RESULTS: African American and Hispanic youth were exposed to an average of 4.1 and 3.4 advertisements per day, respectively, nearly two times as many as non-Hispanic White youth, who were exposed to 2.0 advertisements per day. Girls were exposed to 30% more advertisements than boys. Most exposures were to outdoor advertisements, with television advertisements a close second. CONCLUSIONS: Exposure to alcohol advertising is frequent among middle school-age youth and may put them at risk for earlier or more frequent underage drinking. Greater restrictions on alcohol advertising outdoors and on television should be considered by regulators and by the alcohol industry and should focus particularly on reducing exposure among minority youth.

Ecological Momentary Assessment of the Association Between Exposure to Alcohol Advertising and Early Adolescents' Beliefs About Alcohol.

PURPOSE: To evaluate the momentary association between exposure to alcohol advertising and middle-school students' beliefs about alcohol in real-world settings and to explore racial/ethnic differences in this association. METHODS: Middle-school students (N = 588) carried handheld data collection devices for 14 days, recording their exposures to all forms of alcohol advertising during the assessment period. Students also responded to three investigator-initiated control prompts (programmed to occur randomly) on each day of the assessment period. After each exposure to advertising and at each control prompt, students reported their beliefs about alcohol. Mixed-effects regression models compared students' beliefs about alcohol between moments of exposure to alcohol advertising and control prompts. RESULTS: Students perceived the typical person their age who drinks alcohol (prototype perceptions) more favorably and perceived alcohol use as more normative at times of exposure to alcohol advertising than at times of nonexposure (i.e., at control prompts). Exposure to alcohol advertising was not associated with shifts in the perceived norms of black and Hispanic students, however, and the association between exposure and prototype perceptions was stronger among non-Hispanic students than among Hispanic students. CONCLUSIONS: Exposure to alcohol advertising is associated with acute shifts in adolescents' perceptions of the typical person that drinks alcohol and the normativeness of drinking. These associations are both statistically and substantively meaningful.