Gaps in childhood immunizations and preventive care visits during the COVID-19 pandemic: a population-based cohort study of children in Ontario and Manitoba, Canada, 2016-2021.

OBJECTIVE: We aimed to estimate the changes to the delivery of routine immunizations and well-child visits through the pandemic. METHODS: Using linked administrative health data in Ontario and Manitoba, Canada (1 September 2016 to 30 September 2021), infants <12 months old (N=291,917 Ontario, N=33,994 Manitoba) and children between 12 and 24 months old (N=293,523 Ontario, N=33,001 Manitoba) exposed and unexposed to the COVID-19 pandemic were compared on rates of receipt of recommended a) vaccinations and b) well-child visits after adjusting for sociodemographic measures. In Ontario, vaccinations were captured using physician billings database, and in Manitoba they were captured in a centralized vaccination registry. RESULTS: Exposed Ontario infants were slightly more likely to receive all vaccinations according to billing data (62.5% exposed vs. 61.6% unexposed; adjusted Relative Rate (aRR) 1.01 [95% confidence interval (CI) 1.00-1.02]) whereas exposed Manitoba infants were less likely to receive all vaccines (73.5% exposed vs. 79.2% unexposed; aRR 0.93 [95% CI 0.92-0.94]). Among children exposed to the pandemic, total vaccination receipt was modestly decreased compared to unexposed (Ontario aRR 0.98 [95% CI 0.97-0.99]; Manitoba aRR 0.93 [95% CI 0.91-0.94]). Pandemic-exposed infants were less likely to complete all recommended well-child visits in Ontario (33.0% exposed, 48.8% unexposed; aRR 0.67 [95% CI 0.68-0.69]) and Manitoba (55.0% exposed, 70.7% unexposed; aRR 0.78 [95% CI 0.77-0.79]). A similar relationship was observed for rates of completed well-child visits among children in Ontario (aRR 0.78 [95% CI 0.77-0.79]) and Manitoba (aRR 0.79 [95% CI 0.77-0.80]). CONCLUSION: Through the first 18 months of the pandemic, routine vaccines were delivered to children < 2 years old at close to pre-pandemic rates. There was a high proportion of incomplete well-child visits, indicating that developmental surveillance catch-up is crucial.

RéSUMé: OBJECTIF: Nous avons voulu estimer les changements dans l'administration des vaccins de routine et dans les consultations pédiatriques pendant la pandémie. MéTHODE: À l'aide des données administratives sur la santé couplées de l'Ontario et du Manitoba, au Canada (1er septembre 2016 au 30 septembre 2021), nous avons comparé les taux de réception : a) des vaccins recommandés et b) des consultations pédiatriques recommandées pour les nourrissons de < 12 mois (N = 291 917 en Ontario, N = 33 994 au Manitoba) et pour les enfants de 12 à 24 mois (N = 293 523 en Ontario, N = 33 001 au Manitoba) exposés et non exposés à la pandémie de COVID-19, après ajustement en fonction de mesures sociodémographiques. En Ontario, les vaccins ont été saisis à l'aide de la base de données des factures des médecins; au Manitoba, ils ont été saisis dans un registre de vaccination centralisé. RéSULTATS: Les nourrissons exposés en Ontario étaient légèrement plus susceptibles de recevoir tous les vaccins selon les données de facturation (62,5 % pour les nourrissons exposés c. 61,6 % pour les nourrissons non exposés; risque relatif ajusté [RRa] 1,01 [intervalle de confiance (IC) de 95 % 1,00-1,02]), tandis que les nourrissons exposés au Manitoba étaient moins susceptibles de recevoir tous les vaccins (73,5 % pour les nourrissons exposés c. 79,2 % pour les nourrissons non exposés; RRa 0,93 [IC de 95 % 0,92-0,94]). Chez les enfants exposés à la pandémie, le total des vaccins reçus était un peu plus faible que chez les enfants non exposés (RRa en Ontario 0,98 [IC de 95 % 0,97-0,99]; RRa au Manitoba 0,93 [IC de 95 % 0,91-0,94]). Les nourrissons exposés à la pandémie étaient moins susceptibles d'avoir eu toutes les consultations pédiatriques recommandées en Ontario (33 % pour les nourrissons exposés, 48,8 % pour les nourrissons non exposés; RRa 0,67 [IC de 95 % 0,68-0,69]) comme au Manitoba (55 % pour les nourrissons exposés, 70,7 % pour les nourrissons non exposés; RRa 0,78 [IC de 95 % 0,77-0,79]). Une relation semblable a été observée pour les taux de consultations pédiatriques complètes chez les enfants en Ontario (RRa 0,78 [IC de 95 % 0,77-0,79]) et au Manitoba (RRa 0,79 [(IC de 95 % 0,77-0,80]). CONCLUSION: Au cours des 18 premiers mois de la pandémie, les vaccins de routine ont été administrés aux enfants de < 2 ans à des taux proches de ceux d'avant la pandémie. Il y a eu une forte proportion de consultations pédiatriques incomplètes, ce qui indique qu'il est essentiel de rattraper la surveillance du développement.

Receipt of adequate prenatal care for privately sponsored versus government-assisted refugees in Ontario, Canada: a population-based cohort study.

BACKGROUND: Canada has 2 main streams of resettlement: government-assisted refugees and privately sponsored refugees, whereby citizens can privately sponsor refugees and provide resettlement services, including health care navigation. Our objective was to compare receipt of adequate prenatal care among privately sponsored and government-assisted refugees. METHODS: This population-based study used linked health administrative and demographic databases. We included all resettled refugees classified as female who landed in Ontario, Canada, between April 2002 and May 2017, and who had a live birth or stillbirth conceived at least 365 days after their landing date. Our primary outcome - adequacy of prenatal care - was a composite that comprised receipt of a first-trimester prenatal visit, the number of prenatal care visits recommended by the Society of Obstetricians and Gynaecologists of Canada and a prenatal fetal anatomy ultrasound. We accounted for potential confounding with inverse probability of treatment weighting, using a propensity score. RESULTS: We included 2775 government-assisted and 2374 privately sponsored refugees. Compared with privately sponsored refugees (62.3% v. 69.3%), government-assisted refugees received adequate prenatal care less often, with a weighted relative risk of 0.93 (95% confidence interval 0.88-0.95). INTERPRETATION: Among refugees resettled to Canada, a government-assisted resettlement model was associated with receiving less adequate prenatal care than a private sponsorship model. Government-assisted refugees may benefit from additional support in navigating health care beyond the first year after arrival.

Associations Between Parental Depression, Self-efficacy, and Early Childhood Development in Malnourished Haitian Children.

Background. Haiti lacks early childhood development data and guidelines in malnourished populations. Literature shows that developmental interventions are crucial for improving developmental outcomes malnourished children. This study examines the prevalence of early childhood development delays in a cohort of malnourished Haitian children and their associations with parental depression and self-efficacy. Methods. We used cross-sectional data from 42 patients 6 months to 2 years old in Saint-Marc, Haiti. We assessed their developmental status using the Ages and Stages Questionnaire. Parents were surveyed on depression symptoms and self-efficacy using validated surveys developed for low-resource settings. Demographic and socio-economic data were included. Prevalence of early childhood development delays and high parental depression risk were calculated. Multivariable logistic regression analyses were used to test whether parental depression risk and low self-efficacy were associated with a higher risk for childhood developmental delays. Results. Among participants, 45.2% (SD = 7.7%) of children with a recorded ASQ met age-specific cutoffs for developmental delay in one or more domains. 64.3% (SD = 7.4%) of parents were at high risk for depression. 47.6% (SD = 7.7%) of parents reported relatively low self-efficacy. Multivariable analysis showed that low parental self-efficacy was strongly associated with developmental delays (OR 17.5, CI 1.1-270.0) after adjusting for socioeconomic factors. Parental risk for depression was associated with higher odds (OR 4.6, CI 0.4-50.6) of children having developmental delays but did not reach statistical significance in this study. Conclusion. Parental self-efficacy was protectively associated with early childhood developmental delays in malnourished Haitian children. More research is needed to design contextually appropriate interventions.

Using Parent Target Problem Narratives to Evaluate Outcomes in Children with Autism Spectrum Disorder.

This paper examines the reliability and validity of parent target problems (PTPs) in a multi-site randomized controlled trial of parent training (PT) versus psychoeducation (PEP) in children (150 boys, 19 girls; mean age 4.7 ± 1.2 years) with autism spectrum disorder (ASD) and disruptive behavior. At baseline, treatment blind, independent evaluators asked parents to nominate the child's top two problems. Each problem was documented in a brief narrative. Narratives were reviewed and revised at follow-up visits during the six-month trial. When the trial was completed, five judges, blind to treatment condition, independently rated change from baseline on a 9-point scale (1 = normal; 2 = markedly improved; 3 = definitely improved; 4 = equivocally improved; 5 = no change; 6 = possibly worse; 7 = definitely worse; 8 = markedly worse; 9 = disastrously worse) at Weeks 8, 12, 16, and 24 (inter-rater intraclass correlation = 0.78). PTP scores for the two target problems were averaged across the five raters, yielding a mean score for each child at each time point. Mean PTP scores showed improvement in both treatment groups over the 24-week study. Compared to PEP, PTP ratings showed a steeper decline in PT based on significant interaction of group and time (t(df) = 2.14(155.9), p = 0.034; Week 24 effect size = 0.75). In categorical analysis, we compared cutoffs mean PTP scores of 3.0 (definitely improved), 3.25, and 3.5 with the positive response rate on the Clinical Global Impressions-Improvement scale from the original study. Sensitivities ranged from 52-78%. PTP narratives offer a systematic, reliable, and valid way to track child-specific outcomes in clinical trials and clinical practice.

Reliability and validity of the Pediatric Anxiety Rating Scale modified for autism spectrum disorder.

LAY ABSTRACT: Many youth with autism spectrum disorder have anxiety, but it can be difficult to assess anxiety with existing measures. We modified the Pediatric Anxiety Rating Scale for youth with autism spectrum disorder and tested the new measure in a group of 116 youth (age: 5-17 years) with autism spectrum disorder. The Pediatric Anxiety Rating Scale for youth with autism spectrum disorder is an interview that a clinician usually completes with the child and parent together. We modified the interview questions and scoring instructions based on feedback from parents of children with autism spectrum disorder and from a panel of experts in autism spectrum disorder and anxiety. Unlike many other anxiety measures, the Pediatric Anxiety Rating Scale for youth with autism spectrum disorder relies less on a child's verbal expression of anxiety and more on signs that a parent can easily observe. Training clinicians to administer and score the Pediatric Anxiety Rating Scale for youth with autism spectrum disorder was uncomplicated, and raters showed excellent agreement on video-recorded interviews. Youth who were not currently in treatment for anxiety had stable Pediatric Anxiety Rating Scale for youth with autism spectrum disorder scores with repeat measurement over a 1-month period. The Pediatric Anxiety Rating Scale for youth with autism spectrum disorder is a useful clinician-rated measure of anxiety in youth with autism spectrum disorder and fills a gap for assessing anxiety in this population.

A Pilot Study of Cardiovascular Reactivity in Children With Autism Spectrum Disorder.

In preparation for a larger case-control study of children with autism spectrum disorder (ASD) and anxiety, we conducted a pilot study using a noninvasive electrocardiographic device to measure cardiovascular reactivity in 10 children (age range 9-14) with ASD. The 45-minute procedure included 6 conditions: baseline rest, an interview about school, interim rest, an unfair computerized ball-toss game followed by a fair version of the game, and a final rest. Data were successfully collected for 95% of all conditions. Omnibus Skillings-Mack tests suggested that heart rate variability variables including mean heart rate, mean RR interval, and root mean square of successive differences showed statistically significant variation across conditions. The procedure appears feasible and may be an informative biomarker of anxiety in ASD.

Development of the Parent-Rated Anxiety Scale for Youth With Autism Spectrum Disorder.

OBJECTIVE: Anxiety is common in youth with autism spectrum disorder (ASD). There is no accepted outcome measure for anxiety in this population. METHOD: Following a series of focus groups with parents of youth with ASD, we generated 72 items (scored 0-3). Parents of 990 youth with ASD (aged 5-17 years; 80.8% male) completed an online survey. Factor analysis and item response theory analyses reduced the content to a single factor with 25 items. Youth with at least mild anxiety (n = 116; aged 5-17 years; 79.3% male) participated in a comprehensive clinical assessment to evaluate the validity and reliability of the 25-item Parent-Rated Anxiety Scale for ASD (PRAS-ASD). RESULTS: In the online sample, the mean PRAS-ASD score was 29.04 ± 14.9 (range, 0-75). The coefficient α was 0.93. The item response theory results indicated excellent reliability across a wide range of scores with low standard errors. In the clinical sample (n = 116), the PRAS-ASD mean was 31.0 ± 15.6 (range, 1-65). Pearson correlations with parent ratings of ASD symptom severity, repetitive behavior, and disruptive behavior ranged 0.33 to 0.66, supporting divergent validity of the PRAS-ASD. Pearson correlation with a parent-rated measure of anxiety used in the general pediatric population of 0.83 supported convergent validity. A total of 40 participants (32 boys, 8 girls; mean age, 11.9 ± 3.4 years) returned at time 2 (mean, 12.2 days) and time 3 (mean, 24.2 days). Intraclass correlation showed test-retest reliabilities of 0.88 and 0.86 at time 2 and time 3, respectively. CONCLUSION: The 25-item PRAS-ASD is a reliable and valid scale for measuring anxiety in youth with ASD.

Genetic landscape of pediatric movement disorders and management implications.

OBJECTIVE: To identify underlying genetic causes in patients with pediatric movement disorders by genetic investigations. METHODS: All patients with a movement disorder seen in a single Pediatric Genetic Movement Disorder Clinic were included in this retrospective cohort study. We reviewed electronic patient charts for clinical, neuroimaging, biochemical, and molecular genetic features. DNA samples were used for targeted direct sequencing, targeted next-generation sequencing, or whole exome sequencing. RESULTS: There were 51 patients in the Pediatric Genetic Movement Disorder Clinic. Twenty-five patients had dystonia, 27 patients had ataxia, 7 patients had chorea-athetosis, 8 patients had tremor, and 7 patients had hyperkinetic movements. A genetic diagnosis was confirmed in 26 patients, including in 20 patients with ataxia and 6 patients with dystonia. Targeted next-generation sequencing panels confirmed a genetic diagnosis in 9 patients, and whole exome sequencing identified a genetic diagnosis in 14 patients. CONCLUSIONS: We report a genetic diagnosis in 26 (51%) patients with pediatric movement disorders seen in a single Pediatric Genetic Movement Disorder Clinic. A genetic diagnosis provided either disease-specific treatment or effected management in 10 patients with a genetic diagnosis, highlighting the importance of early and specific diagnosis.

Community engagement in global health education supports equity and advances local priorities: an eight year Ecuador-Canada partnership.

BACKGROUND: Global health education initiatives inconsistently balance trainee growth and benefits to host communities. This report describes a global health elective for medical trainees that focuses on community engagement and participatory research to provide mutually beneficial outcomes for the communities and trainees. METHODS: An eight-year university-community partnership, the Chilcapamba to Montreal Global Health Elective is a two-month shared decision-making research and clinical observership experience in rural Ecuador for medical trainees at McGill University, Canada. Research topics are set by matching community-identified priorities with skillsets and interests of trainees, taking into consideration local potential impact. RESULTS: Community outcomes included development of a Community Health Worker program, new collaborations with local organizations, community identification of health priorities, and generation of health improvement recommendations. Collaborative academic outputs included multiple bursary awards, conference presentations and published manuscripts. CONCLUSION: This medical global health elective engages communities using participatory research to prioritise socially responsible and locally beneficial outcomes.

Localizing Global Medicine: Challenges and Opportunities in Cervical Screening in an Indigenous Community in Ecuador.

This participatory research study examines the tensions and opportunities in accessing allopathic medicine, or biomedicine, in the context of a cervical cancer screening program in a rural indigenous community of Northern Ecuador. Focusing on the influence of social networks, the article extends research on "re-appropriation" of biomedicine. It does so by recognizing two competing tensions expressed through social interactions: suspicion of allopathic medicine and the desire to maximize one's health. Semistructured individual interviews and focus groups were conducted with 28 women who had previously participated in a government-sponsored cervical screening program. From inductive thematic analysis, the article traces these women's active agency in navigating coherent paths of health. Despite drawing on social networks to overcome formidable challenges, the participants faced enduring system obstacles-the organizational effects of the networks of allopathic medicine. Such obstacles need to be understood to reconcile competing knowledge systems and improve health care access in underresourced communities.

An Electronic Competency-Based Evaluation Tool for Assessing Humanitarian Competencies in a Simulated Exercise.

METHODS: The evaluation tool was first derived from the formerly Consortium of British Humanitarian Agencies' (CBHA; United Kingdom), now "Start Network's," Core Humanitarian Competency Framework and formatted in an electronic data capture tool that allowed for offline evaluation. During a 3-day humanitarian simulation event, participants in teams of eight to 10 were evaluated individually at multiple injects by trained evaluators. Participants were assessed on five competencies and a global rating scale. Participants evaluated both themselves and their team members using the same tool at the end of the simulation exercise (SimEx). RESULTS: All participants (63) were evaluated. A total of 1,008 individual evaluations were completed. There were 90 (9.0%) missing evaluations. All 63 participants also evaluated themselves and each of their teammates using the same tool. Self-evaluation scores were significantly lower than peer-evaluations, which were significantly lower than evaluators' assessments. Participants with a medical degree, and those with humanitarian work experience of one month or more, scored significantly higher on all competencies assessed by evaluators compared to other participants. Participants with prior humanitarian experience scored higher on competencies regarding operating safely and working effectively as a team member. CONCLUSION: This study presents a novel electronic evaluation tool to assess individual performance in five of six globally recognized humanitarian competency domains in a 3-day humanitarian SimEx. The evaluation tool provides a standardized approach to the assessment of humanitarian competencies that cannot be evaluated through knowledge-based testing in a classroom setting. When combined with testing knowledge-based competencies, this presents an approach to a comprehensive competency-based assessment that provides an objective measurement of competency with respect to the competencies listed in the Framework. There is an opportunity to advance the use of this tool in future humanitarian training exercises and potentially in real time, in the field. This could impact the efficiency and effectiveness of humanitarian operations. Evans AB , Hulme JM , Nugus P , Cranmer HH , Coutu M , Johnson K . An electronic competency-based evaluation tool for assessing humanitarian competencies in a simulated exercise. Prehosp Disaster Med. 2017;32(3):253-260.

The Chilcapamba-McGill Partnership: Exploring Access to Maternal and Newborn Care in Indigenous Communities of Ecuador.

BACKGROUND: Based on a participatory research (PR) partnership between Family Medicine at McGill University, Canada and the Andean community of Chilcapamba, Ecuador, a medical student study focused on maternal and newborn health. OBJECTIVES: To evaluate the access to maternal and newborn care and the occurrence of intrafamilial violence in women with children 5 years of age or less in three indigenous communities of Ecuador. METHODS: A semistructured survey explored the perinatal and intrapartum care as well as intrafamilial violence. RESULTS: All women (N = 30) received prenatal care, 29 received postnatal care from a physician and 77% gave birth at the hospital. Eighty percent of women experienced intrafamilial violence; 73% reported psychological and 53% physical violence. CONCLUSIONS: There is good access to maternal and newborn health care, although the reported level of violence is high. Results were shared with the community and will be used in a local community health worker (CHW) training program. Our project highlights the importance of PR to investigate sensitive health challenges.

Imported pediatric malaria at the Hospital for Sick Children, Toronto, Canada: a 16 year review.

BACKGROUND: Children under 5 represent 86% of annual malaria deaths in the world. Following increasing trends in international travel, cases of imported malaria are rising in North America. We describe the epidemiology of malaria diagnosed at a tertiary care pediatric center in the multicultural city of Toronto. METHOD: Retrospective chart review of all laboratory confirmed malaria from birth to <18 years between July 1, 1997 and June 30, 2013. Epidemiological data, travel history, chemoprophylaxis history, as well as clinical presentation, diagnosis and treatment were extracted. RESULTS: In total 107 children were diagnosed with malaria in the 16 year time period. Plasmodium falciparum malaria was identified in 76 (71%), Plasmodium vivax in 28 (26%). Median age of infected children was 6.7 years where 35% of children were born in Canada, 63% were recent or previous immigrants. Of those who resided in Canada, reason for travel included visiting friends or relatives (VFR) 95% and tourism or education (5%). Most common countries of infection were Ghana (22%), Nigeria (20%) and India (14%). Median parasitemia at presentation to our institution was 0.4% (IQR 0.1-2.3) with a maximum parasitemia of 31%. Nineteen (18%) met the WHO criteria for severe malaria due to hyperparasitemia, with 3 of these cases also meeting clinical criteria for severe malaria. One third of patients had a delay in treatment of 2 or more days. Ten percent of children had seen two or more primary health care professionals prior to admission. Prophylaxis was documented in 22 (21%), and out of those, 6 (27%) were appropriate for the region of travel and only 1 case was documented as adherent to their prescription. There were no cases of fatality. CONCLUSION: Malaria continues to be a significant disease in returning travelers and immigrant or refugee populations. An increase in physician awareness is required. Appropriate pre-travel advice, insect protection measures, effective chemoprophylaxis is needed to reduce the incidence and improve the management of imported pediatric malaria.

The cost and impact of the interim federal health program cuts on child refugees in Canada.

INTRODUCTION: On June 30, 2012, Interim Federal Health Program (IFHP) funding was cut for refugee claimant healthcare. The potential financial and healthcare impacts of these cuts on refugee claimants are unknown. METHODS: We conducted a one-year retrospective chart review spanning 6 months before and after IFHP funding cuts at The Hospital for Sick Children, a tertiary care children's hospital in Toronto. We analyzed emergency room visits characteristics, admission rates, reasons for admission, and financial records including billing from Medavie Blue Cross. RESULTS: There were 173 refugee children visits to the emergency room in the six months before and 142 visits in the six months after funding cuts. The total amount billed to the IFHP program during the one-year of this study was $131,615. Prior to the IFHP cuts, 46% of the total emergency room bills were paid by IFHP compared to 7% after the cuts (p<0.001). INTERPRETATION: After the cuts to the IFHP, The Hospital for Sick Children was unable to obtain federal health coverage for the vast majority of refugee claimant children registered under the IFHP. This preliminary analysis showed that post-IFHP cuts healthcare costs at the largest tertiary pediatric institution in the country increased.

Emulating natural disturbances for declining late-successional species: a case study of the consequences for cerulean warblers (Setophaga cerulea).

Forest cover in the eastern United States has increased over the past century and while some late-successional species have benefited from this process as expected, others have experienced population declines. These declines may be in part related to contemporary reductions in small-scale forest interior disturbances such as fire, windthrow, and treefalls. To mitigate the negative impacts of disturbance alteration and suppression on some late-successional species, strategies that emulate natural disturbance regimes are often advocated, but large-scale evaluations of these practices are rare. Here, we assessed the consequences of experimental disturbance (using partial timber harvest) on a severely declining late-successional species, the cerulean warbler (Setophaga cerulea), across the core of its breeding range in the Appalachian Mountains. We measured numerical (density), physiological (body condition), and demographic (age structure and reproduction) responses to three levels of disturbance and explored the potential impacts of disturbance on source-sink dynamics. Breeding densities of warblers increased one to four years after all canopy disturbances (vs. controls) and males occupying territories on treatment plots were in better condition than those on control plots. However, these beneficial effects of disturbance did not correspond to improvements in reproduction; nest success was lower on all treatment plots than on control plots in the southern region and marginally lower on light disturbance plots in the northern region. Our data suggest that only habitats in the southern region acted as sources, and interior disturbances in this region have the potential to create ecological traps at a local scale, but sources when viewed at broader scales. Thus, cerulean warblers would likely benefit from management that strikes a landscape-level balance between emulating natural disturbances in order to attract individuals into areas where current structure is inappropriate, and limiting anthropogenic disturbance in forests that already possess appropriate structural attributes in order to maintain maximum productivity.

The spot sign is more common in the absence of multiple prior microbleeds.

BACKGROUND AND PURPOSE: Mural thickening and permeability changes in patients with amyloid angiopathy (CAA) and chronic hypertension are implicated in the pathophysiology of multiple, chronic subclinical microbleeds. The Spot sign, contrast extravasation on CT angiography, predicts hematoma expansion and is presumed to represent acute vessel damage. We hypothesize that the Spot sign is more common in patients without multiple prior chronic microbleeds. METHODS: A retrospective study was conducted of 59 patients presenting within 6 hours of primary intracranial hemorrhage onset undergoing CT angiography and MRI. CT angiography spot sign presence was documented blinded to MRI. Hematoma expansion was defined as >6 mL or 30% enlargement. The Boston criteria were applied to microbleed interpretation dichotomizing subjects into probable and negative CAA. Basal ganglia, thalamic, and brain stem microbleed location were interpreted as chronic hypertensive pattern. Univariate logistic regression and ordinal logistic regression analysis identified significant predictive factors between spot-positive and -negative patients or microbleed pattern. RESULTS: The incidence of spot positivity was 42%, 22%, and 0% for CAA-negative, chronic hypertensive, and CAA-positive patients, respectively (P=0.01). CAA-negative patients had higher baseline National Institutes of Health Stroke Scale (P=0.039), larger follow-up hematoma volume (P=0.02), and poorer Rankin score (P=0.049) than chronic hypertensive or CAA-positive patients. After age adjustment, spot-positive (P=0.023), age-related white matter change (P=0.041), number of microbleeds (P<0.0001), and modified Rankin score (P=0.027) remained significantly different between groups. CONCLUSIONS: Boston criteria-defined CAA-negative status demonstrates the highest risk of spot positivity compared with patients with probable CAA and chronic hypertension.

Hyperpolarized 3He magnetic resonance imaging of chronic obstructive pulmonary disease: reproducibility at 3.0 tesla.

RATIONALE AND OBJECTIVES: We assessed subjects with stage II and stage III chronic obstructive pulmonary disease (COPD) and age-matched healthy volunteers at a single center using (3)He magnetic resonance imaging (MRI) at 3.0 T. Measurements of the (3)He apparent diffusion coefficient (ADC) and center coronal slice (3)He ventilation defect volume (VDV) were examined for same-day and 7-day reproducibility as well as subgroup comparisons. MATERIALS AND METHODS: Twenty-four subjects who provided written informed consent (15 males; mean age 67 +/-7 years) with stage II (n = 9), stage III COPD (n = 7), and age-matched healthy volunteers (n = 8) were enrolled based on their age and pulmonary function test results. All subjects underwent plethysmography, spirometry, and MRI at 3.0 T. The time frame between scans was 7 +/- 2 minutes (same-day rescan) and again 7 +/- 2 days later (7-day rescan). (3)He ADC and VDV reproducibility was evaluated using linear regression, intraclass correlation coefficients (ICC) and Lin's concordance correlation coefficients (CCC). RESULTS: ADC reproducibility was high for same-day rescan (r(2) = 0.934) and 7-day rescan (r(2) = 0.960, ICC and CCC of 0.96 and 0.98, respectively). Same-day rescan VDV reproducibility evaluated using the ICC and CCC (0.97 and 0.98, respectively) as well as linear regression (r(2) = 0.941) was also high, but VDV 7-day rescan reproducibility was lower and significantly different (r(2) = 0.576, P < .001, ICC 0.74, CCC 0.75, P < .01). CONCLUSIONS: Hyperpolarized (3)He MRI was well-tolerated in subjects with stage II and stage III COPD. Seven-day repeated scanning was highly reproducible for ADC and moderately reproducible for VDV.

Mapping and quantifying hyperpolarized 3He magnetic resonance imaging apparent diffusion coefficient gradients.

We measured hyperpolarized 3He magnetic resonance imaging (MRI) apparent diffusion coefficients (ADC) and quantified ADC gradients in each three-by-three voxel region of interest (ROI). Such local ADC gradients can be represented in vector maps showing the magnitude (|G3x3|) and direction of ADC gradients, providing a qualitative visualization tool and quantitative measurement of airway and air space heterogeneity. Twenty-four subjects (15 male, mean age=67+/-7 yr) with global initiative for chronic obstructive lung disease (GOLD) stage II (n=9, mean age 68+/-6 yr), GOLD stage III chronic obstructive pulmonary disease (COPD; n=7, mean age 67+/-8 yr), and age-matched healthy volunteers (n=8, mean age 67+/-6 yr) were enrolled based on their age and spirometry results. Hyperpolarized 3He MRI was performed on a whole body 3.0 Tesla system. Mean 3He ADC and ADC standard deviation were calculated for the center coronal slice, and the mean magnitude and direction of the ADC gradient vectors were calculated for each three-by-three voxel matrix (|G3x3|). While the 3He ADC standard deviation was not significantly different, mean |G3x3| was significantly different between subjects with stage II (0.14+/-0.03 cm/s) and stage III COPD (0.19+/-0.03 cm/s; P<0.005) and between healthy subjects (0.12+/-0.03 cm/s) and those with stage II COPD (P<0.02). The second order statistic |G3x3| may provide a sensitive measure of ADC heterogeneity for ROI representing 9.4x9.4x30 mm or 2.6 cm3 of lung tissue.