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2.
BMC Infect Dis ; 21(1): 936, 2021 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-34503458

RESUMEN

BACKGROUND: Refugees are at increased risk of developing tuberculosis (TB) soon after resettlement. Targeting high-risk populations for latent tuberculosis infection (LTBI) screening and treatment is an important measure towards eliminating TB in low incidence countries, however, there are low rates of screening and treatment completion in the LTBI cascade of care. The authors hypothesized that an interferon-gamma release assay (IGRA) screening strategy would lead to a higher proportion of refugees completing LTBI screening and treatment, compared to sequential screening with tuberculin skin test (TST) and confirmatory IGRA. METHODS: This retrospective cohort study included eligible refugees screened with a sequential strategy versus a solo-IGRA strategy at different time periods from a centralized refugee clinic. The primary outcome was the proportion completing LTBI screening in each cohort. RESULTS: A total of 471 subjects were included (240 in sequential screening, 231 in solo-IGRA screening). 54% of refugees completed LTBI screening with sequential testing, compared to 85% of those screened with a solo-IGRA. Time to completing screening was also shorter in the solo-QFT group (difference 16.5 days, p < 0.01, 95% confidence interval 9.3, 23.7). There was a higher incidence of LTBI diagnosis in the solo-IGRA group (41 versus 20, p = 0.002). Screening completion was predicted by solo-IGRA screening (aOR 3.74, 95% confidence interval 2.30, 6.09; p < 0.001) and if refugees were privately-sponsored (aOR 2.81, 95% confidence interval 1.53, 5.15; p = 0.001). Treatment completion rates did not differ between groups. CONCLUSION: This study has identified fewer dropouts in the LTBI cascade of care if a solo-IGRA strategy is used for screening. An IGRA should be strongly considered as the screening method for refugees arriving in low-incidence settings if resources are available.


Asunto(s)
Ensayos de Liberación de Interferón gamma , Tuberculosis Latente , Humanos , Tuberculosis Latente/diagnóstico , Tuberculosis Latente/epidemiología , Tamizaje Masivo , Estudios Retrospectivos , Prueba de Tuberculina
3.
Ultrasound Obstet Gynecol ; 56(5): 694-704, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-31682302

RESUMEN

OBJECTIVES: Our primary aim was to confirm whether intertwin discordance in ventricular strain and ductus venosus (DV) time intervals predicts twin-twin transfusion syndrome (TTTS). Secondary aims were to create gestational-age ranges for ventricular strain in uncomplicated monochorionic diamniotic (MCDA) twin pregnancies without selective intrauterine growth restriction (sIUGR) and to characterize the relationship of ventricular strain with gestational age in MCDA twin pregnancies with sIUGR that did not develop TTTS. METHODS: In the period 2015-2018, we enrolled 150 MCDA twin pregnancies consecutively into this prospective, blinded study of global longitudinal left and right ventricular strain. With the observer blinded to twin pairing and pregnancy outcome, videoclips of the four-chamber view, which had been recorded during ultrasound surveillance in the usual window for development of TTTS (16-26 completed gestational weeks), underwent offline measurement of strain. Uncomplicated MCDA twin pregnancies, without sIUGR, were used to test the association between strain, gestational age and estimated fetal weight using mixed-effects multilevel regression. Inter-rater reliability was tested in 208 strain measurements in 31 fetuses from pregnancies which did not develop TTTS and within-fetus variation was assessed in 16 such fetuses, in which multiple four-chamber views were taken on the same day. The effect of sIUGR on strain in otherwise uncomplicated MCDA twin pregnancy was analyzed. MCDA twin pregnancies were defined as 'pre-TTTS' when, having been referred for TTTS evaluation, they did not satisfy Quintero staging criteria, but subsequently developed TTTS requiring laser treatment. MCDA pregnancies which did not develop TTTS comprised the 'non-TTTS' group. Cardiovascular parameters measured in these cases included tissue Doppler parameters and DV early filling time as a percentage of the cardiac cycle (DVeT%). Intertwin strain and DVeT% discordance was compared between non-TTTS and pre-TTTS cases, matched for gestational age. RESULTS: Paired strain data were available for intertwin comparison in 127/150 MCDA twin pregnancies, comprising 14 pre-TTTS and 113 non-TTTS pregnancies, after exclusions. Scans were collected at a median frame rate of 97 (range, 28-220) Hz. Laser therapy was performed at a median gestational age of 20.6 (range, 17.2-26.6) weeks. There were no group differences in right (RV) or left (LV) ventricular strain discordance between 68/113 non-TTTS and 13/14 pre-TTTS MCDA twin pregnancies < 20 completed gestational weeks (RV, P = 0.338; LV, P = 0.932). DVeT% discordance > 3.6% was found in eight of 13 pre-TTTS pregnancies. In non-TTTS pregnancies, the estimated variability in ventricular strain within each twin during the day was high (RV, 19.7; LV, 12.9). However, within each pair (intertwin variation), variability was low (RV, 5.5; LV, 2.9). Interclass correlation reflecting the proportion of total variability represented by the variability between twin pairs was low (RV, 0.22; LV, 0.18). Both RV (P < 0.001) and LV (P = 0.025) strain showed a negative association with gestational age. Among non-TTTS MCDA twin pregnancies, LV strain was, on average, higher by 1.83 in sIUGR compared with normally grown fetuses (P = 0.023), with no statistically significant difference in RV strain (P = 0.271). CONCLUSIONS: Although ventricular strain has been reported previously as a possible predictor of developing TTTS, in this blinded, prospective study, we found no significant intergroup differences in ventricular strain in pre-TTTS compared with age-matched non-TTTS MCDA twin pregnancies. We recommend using DVeT% discordance as a more practical screening tool in MCDA twin pregnancies. This study also provides new information on the changes with gestational age, and the biological and technical variation, of global longitudinal ventricular strain in uncomplicated MCDA twin pregnancies and those with isolated sIUGR. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Corazón Fetal/fisiopatología , Feto/irrigación sanguínea , Ventrículos Cardíacos/fisiopatología , Embarazo Gemelar , Gemelos/estadística & datos numéricos , Adulto , Femenino , Retardo del Crecimiento Fetal/fisiopatología , Corazón Fetal/embriología , Peso Fetal , Transfusión Feto-Fetal/fisiopatología , Edad Gestacional , Ventrículos Cardíacos/embriología , Humanos , Análisis Multinivel , Circulación Placentaria , Embarazo , Estudios Prospectivos , Análisis de Regresión , Reproducibilidad de los Resultados , Método Simple Ciego , Ultrasonografía Prenatal
4.
Ultrasound Obstet Gynecol ; 51(3): 341-348, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28370497

RESUMEN

OBJECTIVES: In twin-twin transfusion syndrome (TTTS), unbalanced transfer of vasoactive mediators and fluid from the donor to the recipient cotwin alters their cardiovascular function. The aims of this study were to describe the impact of TTTS on fetal cardiac function in a large cohort of monochorionic-diamniotic (MCDA) pregnancies, and determine the early hemodynamic response to selective fetoscopic laser photocoagulation (SFLP). METHODS: Echocardiography was performed in 145 MCDA pregnancies, including 26 uncomplicated MCDA, 61 TTTS Stages I+II and 58 TTTS Stages III+IV pregnancies, prior to SFLP for TTTS. Echocardiographic data after SFLP were available in a subset of 41/119 (34%) TTTS cases at a mean of 1.7 ± 1.9 days. Mitral (MAPSE) and tricuspid (TAPSE) annular systolic excursion, myocardial performance index (MPI), tissue Doppler velocities (E', A', S') and filling pressures (E/E') were measured and transformed into Z-scores. Ventricular pressure was estimated from peak atrioventricular regurgitation velocity. RESULTS: Left ventricular hemodynamics of the recipient twin were affected in early TTTS. In all stages of TTTS, left MPI and E/E' of the recipient twin were elevated in comparison to those of the donor (all P < 0.05), with reduced recipient left S' in TTTS Stages III+IV (P < 0.001). Ventricular pressure was elevated for gestational age (median, 42 mmHg (range, 20-65 mmHg)) in 11 of 14 recipients in which this parameter was measured. Between-group difference in right ventricular E/E' was significant only in TTTS Stages III+IV recipients compared with TTTS Stages I+II (P = 0.007) and uncomplicated MCDA (P = 0.041). Recipient left and right MPI decreased while S', MAPSE and TAPSE increased after SFLP; in donors, left E/E' and cardiac output increased. CONCLUSIONS: Cardiac function of the recipient twin in TTTS is abnormal, even in the early stages of the disease. Left ventricular filling pressures are elevated and systolic function is decreased before abnormalities in the right heart become apparent. SFLP produces rapid hemodynamic improvement. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Ecocardiografía Doppler , Corazón Fetal/diagnóstico por imagen , Transfusión Feto-Fetal/diagnóstico por imagen , Transfusión Feto-Fetal/fisiopatología , Ultrasonografía Prenatal , Adulto , Velocidad del Flujo Sanguíneo , Femenino , Corazón Fetal/fisiopatología , Transfusión Feto-Fetal/embriología , Edad Gestacional , Ventrículos Cardíacos/fisiopatología , Hemodinámica , Humanos , Embarazo , Gemelos
5.
Ultrasound Obstet Gynecol ; 52(2): 221-229, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-28976617

RESUMEN

OBJECTIVE: Fetal aortic stenosis may progress to hypoplastic left heart syndrome. Fetal valvuloplasty (FV) has been proposed to improve left heart hemodynamics and maintain biventricular (BV) circulation. The aim of this study was to assess FV efficacy by comparing survival and postnatal circulation between fetuses that underwent FV and those that did not. METHODS: This was a retrospective multicenter study of fetuses with aortic stenosis that underwent FV between 2005 and 2012, compared with contemporaneously enrolled natural history (NH) cases sharing similar characteristics at presentation but not undergoing FV. Main outcome measures were overall survival, BV-circulation survival and survival after birth. Secondary outcomes were hemodynamic change and left heart growth. A propensity score model was created including 54/67 FV and 60/147 NH fetuses. Analyses were performed using logistic, Cox or linear regression models with inverse probability of treatment weighting (IPTW) restricted to fetuses with a propensity score of 0.14-0.9, to create a final cohort for analysis of 42 FV and 29 NH cases. RESULTS: FV was technically successful in 59/67 fetuses at a median age of 26 (21-34) weeks. There were 7/72 (10%) procedure-related losses, and 22/53 (42%) FV babies were delivered at < 37 weeks. IPTW demonstrated improved survival of liveborn infants following FV (hazard ratio, 0.38; 95% CI, 0.23-0.64; P = 0.0001), after adjusting for circulation and postnatal surgical center. Similar proportions had BV circulation (36% for the FV cohort and 38% for the NH cohort) and survival was similar between final circulations. Successful FV cases showed improved hemodynamic response and less deterioration of left heart growth compared with NH cases (P ≤ 0.01). CONCLUSIONS: We report improvements in fetal hemodynamics and preservation of left heart growth following successful FV compared with NH. While the proportion of those achieving a BV circulation outcome was similar in both cohorts, FV survivors showed improved survival independent of final circulation to 10 years' follow-up. However, FV is associated with a 10% procedure-related loss and increased prematurity compared with the NH cohort, and therefore the risk-to-benefit ratio remains uncertain. We recommend a carefully designed trial incorporating appropriate and integrated fetal and postnatal management strategies to account for center-specific practices, so that the benefits achieved by fetal therapy vs surgical strategy can be demonstrated clearly. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Valvuloplastia con Balón , Corazón Fetal/diagnóstico por imagen , Síndrome del Corazón Izquierdo Hipoplásico/prevención & control , Estenosis de la Válvula Aórtica/embriología , Estenosis de la Válvula Aórtica/fisiopatología , Circulación Coronaria , Progresión de la Enfermedad , Femenino , Edad Gestacional , Hemodinámica , Humanos , Síndrome del Corazón Izquierdo Hipoplásico/embriología , Síndrome del Corazón Izquierdo Hipoplásico/fisiopatología , Recién Nacido , Embarazo , Resultado del Embarazo , Atención Prenatal , Puntaje de Propensión , Estudios Retrospectivos , Medición de Riesgo , Tasa de Supervivencia
10.
Phys Rev Lett ; 117(18): 182701, 2016 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-27835017

RESUMEN

The ^{19}Ne(p,γ)^{20}Na reaction is the second step of a reaction chain which breaks out from the hot CNO cycle, following the ^{15}O(α,γ)^{19}Ne reaction at the onset of x-ray burst events. We investigate the spectrum of the lowest proton-unbound states in ^{20}Na in an effort to resolve contradictions in spin-parity assignments and extract reliable information about the thermal reaction rate. The proton-transfer reaction ^{19}Ne(d,n)^{20}Na is measured with a beam of the radioactive isotope ^{19}Ne at an energy around the Coulomb barrier and in inverse kinematics. We observe three proton resonances with the ^{19}Ne ground state, at 0.44, 0.66, and 0.82 MeV c.m. energies, which are assigned 3^{+}, 1^{+}, and (0^{+}), respectively. In addition, we identify two resonances with the first excited state in ^{19}Ne, one at 0.20 MeV and one, tentatively, at 0.54 MeV. These observations allow us for the first time to experimentally quantify the astrophysical reaction rate on an excited nuclear state. Our experiment shows an efficient path for thermal proton capture in ^{19}Ne(p,γ)^{20}Na, which proceeds through ground state and excited-state capture in almost equal parts and eliminates the possibility for this reaction to create a bottleneck in the breakout from the hot CNO cycle.

11.
Ultrasound Obstet Gynecol ; 48(6): 744-751, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26989864

RESUMEN

OBJECTIVES: To evaluate changes in ductus venosus (DV) waveforms and the timing of these changes in twin-twin transfusion syndrome (TTTS), to relate these to disease severity and to assess the clinical applicability of the suggested measurements in the prediction of TTTS. METHODS: DV time intervals and velocity-time integrals (VTI) normalized to cardiac cycle and total VTI, respectively, as well as velocity ratios were analyzed in 149 monochorionic diamniotic (MCDA) twin pairs. Pregnancies were assigned to the following groups: uncomplicated MCDA (n = 29); TTTS Stages I+II (n = 50); TTTS Stages III+IV (n = 49); and pre-TTTS (n = 21), of which 14 remained stable and seven progressed to TTTS. Intertwin differences were calculated as larger/recipient minus smaller/donor and related to disease severity. Receiver-operating characteristics curve analysis was used to distinguish TTTS vs uncomplicated MCDA and pre-TTTS progressing to TTTS vs non-progressing pre-TTTS. Intra- and interobserver reliability of measurement of DV parameters were evaluated using intraclass correlation coefficients (ICCs). RESULTS: No intertwin differences in DV parameters were found in uncomplicated MCDA pregnancies. Diastolic VTIs and filling times were significantly shorter in recipient twins in TTTS cases and in larger pre-TTTS twins in comparison with their cotwins. Time intervals, VTIs and velocity ratios correlated significantly with Quintero stages. An intertwin difference in early filling time (eT) normalized to cardiac cycle, eT (%) ≤ -3.6%, could differentiate TTTS from uncomplicated MCDA pregnancies (82.8% sensitivity; 79.8% specificity) and eT (%) ≤ -2.8% predicted progression to TTTS (73.1% sensitivity; 67.4% specificity). CONCLUSIONS: DV flow profiles and timing of waveform events are already altered in pre-TTTS and early-stage disease, reflecting abnormal ventricular filling and circulatory imbalance. Intertwin comparison of filling times and VTI may allow prediction of evolving TTTS in MCDA pregnancies. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Transfusión Feto-Fetal/diagnóstico por imagen , Vena Porta/fisiopatología , Ultrasonografía Prenatal/métodos , Femenino , Transfusión Feto-Fetal/fisiopatología , Edad Gestacional , Humanos , Variaciones Dependientes del Observador , Embarazo , Curva ROC , Reproducibilidad de los Resultados , Gemelos Monocigóticos
12.
Ultrasound Obstet Gynecol ; 48(3): 373-81, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26843026

RESUMEN

OBJECTIVES: Fetal aortic valvuloplasty (FV) aims to prevent fetal aortic valve stenosis progressing into hypoplastic left heart syndrome (HLHS), which results in postnatal univentricular (UV) circulation. Despite increasing numbers of FVs performed worldwide, the natural history of the disease in fetal life remains poorly defined. The primary aim of this study was to describe the natural history of fetal aortic stenosis, and a secondary aim was to test previously published criteria designed to identify cases of emerging HLHS with the potential for a biventricular (BV) outcome after FV. METHODS: From a European multicenter retrospective study of 214 fetuses with aortic stenosis (2005-2012), 107 fetuses in ongoing pregnancies that did not undergo FV were included in this study and their natural history was reported. We examined longitudinal changes in Z-scores of aortic and mitral valve and left ventricular dimensions and documented direction of flow across the foramen ovale and aortic arch, and mitral valve inflow pattern and any gestational changes. Data were used to identify fetuses satisfying the Boston criteria for emerging HLHS and estimate the proportion of these that would have been ideal FV candidates. We applied the threshold score whereby a score of 1 was assigned to fetuses for each Z-score meeting the following criteria: left ventricular length and width > 0; mitral valve diameter > -2; aortic valve diameter > -3.5; and pressure gradient across either the mitral or aortic valve > 20 mmHg. We compared the predicted circulation with known survival and final postnatal circulation (BV, UV or conversion from BV to UV). RESULTS: Among the 107 ongoing pregnancies there were eight spontaneous fetal deaths and 99 livebirths. Five were lost to follow-up, five had comfort care and four had mild aortic stenosis not requiring intervention. There was intention-to-treat in these 85 newborns but five died prior to surgery, before circulation could be determined, and thus 80 underwent postnatal procedures with 44 BV, 29 UV and seven BV-to-UV circulatory outcomes. Of newborns with intention-to-treat, 69/85 (81%) survived ≥ 30 days. Survival at median 6 years was superior in cases with BV circulation (P = 0.041). Those with a postnatal UV circulation showed a trend towards smaller aortic valve diameters at first scan than did the BV cohort (P = 0.076), but aortic valve growth velocities were similar in both cohorts to term. In contrast, the mitral valve diameter was significantly smaller at first scan in those with postnatal UV outcomes (P = 0.004) and its growth velocity (P = 0.008), in common with the left ventricular inlet length (P = 0.004) and width (P = 0.002), were reduced significantly by term in fetuses with UV compared with BV outcome. Fetal data, recorded before 30 completed gestational weeks, from 70 treated neonates were evaluated to identify emerging HLHS. Forty-four had moderate or severe left ventricular depression and 38 of these had retrograde flow in the aortic arch and two had left-to-right flow at atrial level and reversed a-waves in the pulmonary veins. Thus 40 neonates met the criteria for emerging HLHS and BV circulation was documented in 13 (33%). Of these 40 cases, 12 (30%) had a threshold score of 4 or 5, of which five (42%) had BV circulation without fetal intervention. CONCLUSIONS: The natural history in our cohort of fetuses with aortic stenosis and known outcomes shows that a substantial proportion of fetuses meeting the criteria for emerging HLHS, with or without favorable selection criteria for FV, had a sustained BV circulation without fetal intervention. This indicates that further work is needed to refine the selection criteria to offer appropriate therapy to fetuses with aortic stenosis. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Valvuloplastia con Balón , Enfermedades Fetales/cirugía , Ultrasonografía Prenatal , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/epidemiología , Circulación Coronaria , Europa (Continente)/epidemiología , Femenino , Enfermedades Fetales/diagnóstico por imagen , Enfermedades Fetales/epidemiología , Corazón Fetal , Edad Gestacional , Humanos , Lactante , Recién Nacido , Embarazo , Resultado del Embarazo , Estudios Retrospectivos
14.
Ultrasound Obstet Gynecol ; 48(2): 193-9, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26663469

RESUMEN

OBJECTIVES: Twin-twin transfusion syndrome (TTTS) complicates 10-15% of monochorionic diamniotic (MCDA) twin pregnancies. The donor response to hypovolemia allows the transfer of vasoactive mediators to the recipient, causing increased recipient afterload and hypertension. Our objective was to apply a novel speckle-tracking technique to measure the aortic fractional area change (AFAC) during the cardiac cycle in MCDA twins with and without TTTS, and identify intertwin differences in AFAC and parameters of cardiac function. METHODS: High-frame rate four-chamber views of the fetal heart, including the mid-thoracic aorta, were collected prospectively in MCDA twin pairs referred to our center between June 2014 and April 2015. Using speckle-tracking software, the endovascular border of the aorta was traced manually during systole, with guidance on cardiac cycle timing by anatomical M-mode. AFAC, defined as the difference between maximum and minimum area divided by minimum area, expressed as a percentage, was calculated offline and averaged over three cardiac cycles. Tissue Doppler and displacement were used to measure long-axis cardiac function. Intra- and interclass correlation coefficients were used to test observer variability. RESULTS: Fifty-one MCDA twin pregnancies were included, comprising uncomplicated MCDA (n = 14), TTTS Stages 1/2 (n = 21) and TTTS Stages 3/4 (n = 16). Median gestational age was 20.4 (range, 16.2-27.5) weeks. Mean ± SD heart rate was 142.6 ± 7.2 bpm with no significant intertwin pair differences. AFAC was significantly higher in recipients than in donors of TTTS pairs (Stages 1/2: 72.3 ± 29.9% vs 43.7 ± 19.3%, P < 0.001; Stages 3/4: 75.2 ± 29.2% vs 42.5 ± 18.4%, P = 0.002), consistent with higher recipient pulse pressure. No intertwin differences in AFAC were seen in uncomplicated MCDA pairs. Inter- and intraclass correlation coefficients for AFAC were 0.894 and 0.888. AFAC correlated significantly with combined cardiac output (r = 0.252, P = 0.011) and left and right E/E' ratio (left: r = 0.302, P = 0.004; right: r = 0.247, P = 0.030). CONCLUSION: AFAC is a quantifiable and reproducible method to assess aortic distensibility and is a promising tool to monitor the response to prelaser therapeutic interventions in pregnancies with TTTS. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Aorta/fisiopatología , Ecocardiografía Doppler/métodos , Transfusión Feto-Fetal/diagnóstico por imagen , Ultrasonografía Prenatal/métodos , Adolescente , Adulto , Aorta/diagnóstico por imagen , Aorta/embriología , Estudios de Casos y Controles , Femenino , Corazón Fetal/fisiopatología , Transfusión Feto-Fetal/fisiopatología , Edad Gestacional , Humanos , Embarazo , Embarazo Gemelar , Estudios Prospectivos , Reproducibilidad de los Resultados , Gemelos Monocigóticos , Adulto Joven
15.
Ultrasound Obstet Gynecol ; 48(4): 496-503, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26423314

RESUMEN

OBJECTIVE: To compare automated measurements of the fetal left myocardial performance index (MPI) with manual measurements for absolute value, repeatability and waveform acceptability. METHODS: This was a multicenter international online study using images from uncomplicated, morphologically normal singleton pregnancies (16-38 weeks' gestation). Single Doppler ultrasound cardiac cycle images of 25 cases were selected, triplicated and randomized (n = 75). Six senior observers, unaware of the repetition of images, manually calculated MPI for each waveform and the results were compared with automation. Intraobserver repeatability and interobserver reproducibility were assessed using intraclass correlation coefficients (ICCs) and 95% CI. The agreement between each observer's manual MPI measurements and corresponding automated measurements was evaluated using Bland-Altman plots and ICCs with 95% CI. The degree of variation between experts in the classification of fetal MPI waveform quality was assessed using individual cardiac cycle left MPI images previously classified by two authors as 'optimal', 'suboptimal' or 'unacceptable', with 30 images selected for each quality group. Ten images in each category were duplicated and the resulting 120 images were randomized and then classified online by five observers. The kappa statistic (κ) was used to demonstrate interobserver and intraobserver agreement and agreement of classifications by the five observers. RESULTS: The automated measurement software returned the same value for any given image, resulting in an ICC of 1.00. Manual measurements had intraobserver repeatability ICC values ranging from 0.69 to 0.97, and the interobserver reproducibility ICC was 0.78. Comparison of automated vs manual MPI absolute measurements for each observer gave ICCs ranging from 0.77 to 0.96. Interobserver image quality classification agreement gave k = 0.69 (P < 0.001), and the intraobserver agreement was variable (κ ranging from 0.40 to 0.81). CONCLUSIONS: Automated fetal MPI provides superior repeatability and reproducibility to manual methodology. Additionally, experts vary significantly when classifying suitability of fetal MPI waveforms. Automated MPI may facilitate clinical translation by removing human subjectivity. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Ecocardiografía Doppler/métodos , Corazón Fetal/diagnóstico por imagen , Ultrasonografía Prenatal/métodos , Femenino , Edad Gestacional , Humanos , Variaciones Dependientes del Observador , Embarazo , Estudios Prospectivos , Reproducibilidad de los Resultados , Programas Informáticos
17.
Rev Sci Instrum ; 86(5): 055101, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26026552

RESUMEN

We present the design, description, calibration procedure, and an analysis of systematic effects for an apparatus designed to measure the rotation of the plane of polarization of a transversely polarized slow neutron beam as it passes through unpolarized matter. This device is the neutron optical equivalent of a crossed polarizer/analyzer pair familiar from light optics. This apparatus has been used to search for parity violation in the interaction of polarized slow neutrons in matter. Given the brightness of existing slow neutron sources, this apparatus is capable of measuring a neutron rotary power of dϕ/dz = 1 × 10(-7) rad/m.

19.
Ultrasound Obstet Gynecol ; 44(5): 538-44, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24975801

RESUMEN

OBJECTIVES: Fetal aortic valvuloplasty may prevent the progression of aortic stenosis to hypoplastic left heart syndrome and allow biventricular rather than univentricular postnatal treatment. This study aimed to investigate whether blinded simulation of a multidisciplinary team approach aids interpretation of multicenter data to uncover institutional bias in postnatal decision-making following fetal cardiac intervention for aortic stenosis. METHODS: The study included 109 cases of prenatally diagnosed aortic stenosis from 13 European countries, of which 32 had undergone fetal cardiac intervention. The multidisciplinary team, blinded to fetal cardiac intervention, institutional location and postnatal treatment, retrospectively assigned a surgical pathway (biventricular or univentricular) based on a review of recorded postnatal imaging and clinical characteristics. The team's decisions were the numerical consensus of silent voting, with case review when a decision was split. Funnel plots showing concordance between the multidisciplinary team and the local team's surgical choice (first pathway) and with outcome (final pathway) were created. RESULTS: In 105 cases the multidisciplinary team reached a consensus decision regarding the surgical pathway, with no decision in four cases because the available imaging records were inadequate. Blinded multidisciplinary team consensus for the first pathway matched the decision of the surgical center in 93/105 (89%) cases, with no difference in agreement between those that had undergone successful fetal cardiac intervention (n = 32) and no (n = 74) or unsuccessful (n = 3) valvuloplasty (no fetal cardiac intervention) (κ = 0.73 (95% CI, 0.38-1.00) vs 0.74 (95% CI, 0.51-0.96)). However, funnel plots comparing multidisciplinary team individual decisions with those of the local teams displayed more discordance (meaning biventricular-univentricular conversion) for the final surgical pathway following fetal cardiac intervention than they did for cases without such intervention (36/74 vs 34/130; P = 0.002), and identified one outlying center. CONCLUSIONS: The use of a blinded multidisciplinary team to simulate decision-making and presentation of data in funnel plots may assist in the interpretation of data submitted to multicenter studies and permit the identification of outliers for further investigation. In the case of aortic stenosis, a high level of agreement was observed between the multidisciplinary team and the surgical centers, but one outlying center was identified.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Toma de Decisiones , Enfermedades Fetales/cirugía , Síndrome del Corazón Izquierdo Hipoplásico/prevención & control , Grupo de Atención al Paciente/normas , Práctica Profesional/normas , Estenosis de la Válvula Aórtica/embriología , Consenso , Humanos , Síndrome del Corazón Izquierdo Hipoplásico/embriología , Política Organizacional
20.
Ultrasound Obstet Gynecol ; 43(6): 652-7, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24347245

RESUMEN

OBJECTIVES: To compare cardiac function at 10 years of age in four groups of monochorionic diamniotic (MCDA) twin pairs: uncomplicated MCDA twins (n = 6) (Group 1); twins that had had twin-twin transfusion syndrome (TTTS) managed by amnioreduction (TTTS-amnio, n = 9) (Group 2) or laser photocoagulation (TTTS-laser, n = 10) (Group 3); and dichorionic diamniotic controls (DCDA, n = 6) (Group 4). METHODS: Echocardiograms optimizing apical four-chamber and short-axis left ventricular views were stored for offline speckle-tracking analysis, blinded to twin type. Myocardial long-axis shortening and lengthening velocities were measured using pulsed Doppler ultrasound at the cardiac base. M-mode measurements of fractional shortening (short axis) and maximal excursion of the atrioventricular annulus (four-chamber) were recorded. Syngo Vector Velocity Imaging software tracked left ventricular myocardial motion offline to produce free wall strain, strain rate and rotation. Intertwin pair and group differences were investigated using ANOVA. RESULTS: Cardiac measurements were within the normal ranges for 10-year-olds. No significant within-twin-pair and intergroup differences were found in current size, heart rates, strain or strain rate. Compared to DCDA controls, TTTS twins showed less cardiac rotation (TTTS-laser, P < 0.001 and TTTS-amnio, P = 0.054) with significant intertwin reduction in the ex-recipient (TTTS-amnio, P = 0.006) and larger MCDA twins (P = 0.027) compared with their cotwins. A similar pattern was seen in left ventricular early diastolic mitral valve tissue velocity (MVE') in all monochorionic groups, but only achieving significance in TTTS-amnio twins (P = 0.037). Intrapair differences in rotation and MVE' were significantly different following treatment at Quintero stages III or IV. CONCLUSIONS: Within-twin-pair patterns of left ventricular rotation and diastolic function differ at 10 years of age in ex-recipients of TTTS twins treated with amnioreduction compared with those treated by laser photocoagulation and controls. .


Asunto(s)
Terapias Fetales/métodos , Transfusión Feto-Fetal/fisiopatología , Corazón/fisiología , Análisis de Varianza , Estudios de Casos y Controles , Niño , Ecocardiografía , Femenino , Transfusión Feto-Fetal/terapia , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Embarazo , Valores de Referencia , Gemelos Monocigóticos , Función Ventricular Izquierda/fisiología
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