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1.
J Matern Fetal Neonatal Med ; 35(25): 10239-10245, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36117422

RESUMO

INTRODUCTION: A large fall in insulin requirements (FIR) in women with diabetes is associated with adverse clinical outcomes but previous studies have not examined its relation with serial ultrasound parameters. OBJECTIVE: To determine whether FIR is associated with alteration in umbilical artery Doppler parameters and fetal growth restriction (FGR) in women with preexisting diabetes. METHODS: Serial obstetric Doppler ultrasounds were conducted 2 weekly from 28 weeks gestation in women with Type 1 and Type 2 diabetes who were being treated with insulin. Estimated fetal weight (EFW), head circumference:abdominal circumference (HC:AC) ratio and umbilical artery doppler parameters (SD ratio) and pulsatility index (PI) were measured. Information on insulin dose was collected prospectively throughout pregnancy and women with FIR ≥ 15% were considered cases. Linear mixed effect models were used to assess the association between FIR and ultrasound parameters. RESULTS: One hundred and forty two women were included in the study (type 1 diabetes n = 41, type 2 diabetes n = 101). Thirty women demonstrated FIR ≥ 15%. There was no significant difference in the change of S/D ratio or PI over the third trimester in cases with FIR ≥ 15%, compared to the rest of the cohort, before or after adjusting for type of diabetes. Likewise there was no difference in EFW and HC:AC ratio with advancing gestation before or after adjusting for variables known to influence fetal growth. FGR rates (3.3 vs 8% p = 0.298) and high S/D ratio > 95% (13.3 vs 8%, p = 0.296) were similar between the two groups. CONCLUSIONS: FIR ≥ 15% was not associated with changes in placental flow or FGR however larger studies are needed to evaluate this further.


Assuntos
Diabetes Mellitus Tipo 2 , Recém-Nascido Pequeno para a Idade Gestacional , Recém-Nascido , Feminino , Gravidez , Humanos , Insulina , Estudos Prospectivos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Placenta , Artérias Umbilicais/diagnóstico por imagem , Retardo do Crescimento Fetal/diagnóstico por imagem , Ultrassonografia Pré-Natal , Peso Fetal , Idade Gestacional
2.
Int J Qual Health Care ; 34(2)2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35311894

RESUMO

BACKGROUND: Professional competencies are important for enhancing alignment between the needs of education, industry and health consumers, whilst describing public expectations around health professionals. The development of competency standards for the sonography profession defines the behaviours, skills and knowledge sonographers should demonstrate for each learning and experience level. OBJECTIVE: The objective of this project was to develop a set of professional competency standards for the sonography profession which described in depth the behaviours, skills and knowledge sonographers should demonstrate across multiple learning and experience levels. METHODS: Representatives of three Australian ultrasound professional associations and seven tertiary institutions involved in entry-level sonographer education in Australia formed a research team (RT). The RT recruited an expert panel that responded to six survey rounds. Using a Delphi methodology, the results and free-text comments from each previous round were fed back to participants in the subsequent survey rounds to achieve a consensus. RESULTS: The project developed a professional competency framework for sonographers, which included four major domains: detailed competency standards, sonographer knowledge, sonographer attitudes and a holistic competency matrix [https://doi.org/10.6084/m9.figshare.17148035.v2.]. CONCLUSION: The Delphi methodology is an effective way to develop professional competency standards. This paper describes the methods and challenges in developing such standards for sonographers which could be translated to other health professionals.


Assuntos
Pessoal de Saúde , Competência Profissional , Austrália , Competência Clínica , Consenso , Técnica Delphi , Humanos
3.
Ultrasound ; 30(4): 299-306, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36969539

RESUMO

Introduction: Image optimisation is essential for acquisition of quality images in ultrasound and critical to the diagnostic ability of the examination. These skills are taught to sonography students early in their education, but research has found that retention of non-rehearsed knowledge decreases significantly after a year. The aim of this study was to determine which optimisation tools (knobology) final year sonography students use, how often and why they chose to adjust parameters and assess barriers to optimisation of knobology tools. Methods: A prospective study using data from an anonymous online survey of 34 final year sonography students. Results: Survey results showed that 19/34 (55%) of students "frequently" optimise all Doppler settings and 23/34 (67%) of students "frequently" optimise basic parameter settings (depth, focus, time gain compensation). Time constraints (24/34 (70%)) and loss of gained knowledge of sonography principles and instrumentation (17/34 (50%)) were the major barriers to the use of knobology. The majority 28/34 (82%) believed they would benefit from further training. Conclusion: This study demonstrates that although most students are optimising settings to improve image quality, sonography principles and instrumentation knowledge loss and time constraints prevent students from maximising machine capabilities. This study supports the need for further training prior to final year clinical placement.

4.
Australas J Ultrasound Med ; 24(1): 37-47, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34760610

RESUMO

OBJECTIVES: Placental related adverse pregnancy outcomes such as fetal growth restriction have significant short- and long-term implications for both mother and fetus. This study aimed to determine if conventional and novel early first trimester ultrasound measures are associated with small for gestational age (SGA) neonates. In addition, we aimed to assess whether a combination of ultrasound measures, maternal characteristics and biochemistry improved the prediction of this adverse pregnancy outcome. METHODS: This was a prospective cohort study including ultrasound measurements: trophoblast thickness (TT), trophoblast volume (TV), mean uterine artery pulsatility index, crown-rump length, fetal heart rate, mean sac diameter (MSD) and yolk sac diameter. Biochemical markers considered in the analysis were placental growth factor (PIGF), pregnancy - associated plasma protein A (PAPP-A), beta human chorionic gonadotropin and alpha fetoprotein. Regression models were fitted for ultrasound parameters using multiples of the median (MoM). All measures were compared with normal birthweight (BW) ≥10th centile and SGA (BW < 10th centile). Logistic regression analysis was used to create a clinical prediction model for SGA based on maternal characteristics, ultrasound measurements at <11 weeks gestational age and maternal biochemistry collected at 10-14 weeks. RESULTS: As compared to pregnancies delivered of babies with normal BW (n = 1068), MoM values for TT, TV, MSD, PAPP-A and PIGF were significantly reduced (P < 0.05) in pregnancies delivered of SGA babies (n = 73). The proposed logistic regression model includes maternal height, TV and PIGF resulting in an area under the receiver operator curve 0.70 (95% CI 0.63-0.76) for the prediction of SGA. CONCLUSION: A significantly decreased TV, measured <11 weeks gestation, is predictive of BW < 10th centile. With addition of maternal height and PIGF, this three-marker algorithm provided a reasonable predictive value for the development of SGA later in pregnancy.

5.
Australas J Ultrasound Med ; 23(1): 59-65, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34760584

RESUMO

INTRODUCTION: The thalamus is important for a wide range of sensorimotor and neuropsychiatric functions. Departure from normal reference values of the thalamus may be a biomarker for differences in neurodevelopment outcomes and brain anomalies perinatally. Antenatal measurement of thalamus is not currently included in routine fetal ultrasound as differentiation of thalamic borders is difficult. The aim of this work was to present a method to standardise the thalamus measure and provide normative data of the fetal transverse thalamic diameter between 18 and 22 weeks of gestational age. METHODS: Transverse thalamic diameter was measured by two sonographers on 1,111 stored ultrasound images at the standard transcerebellar plane. A 'guitar' shape representative structure is presented to demarcate the thalamic diameter. The relationship of the transverse thalamic diameter with gestational age, head circumference and transcerebellar diameter using linear regression modelling was assessed, and the mean of the thalamic diameter was calculated and plotted as a reference chart. RESULTS: Transverse thalamic diameter increased significantly with increasing gestational age, head circumference, and transcerebellar diameter linearly, and normal range thalamic charts are presented. The guitar shape provided good reproducibility of thalamic diameter measures. CONCLUSION: Measuring thalamus size in antenatal ultrasound examinations with reference to normative charts could be used to assess midline brain structures and predict neurodevelopment disorders and potentially brain anomalies.

6.
Australas J Ultrasound Med ; 23(3): 194-206, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34760599

RESUMO

Numerous works of literature have assessed the use of ultrasound to detect carpal tunnel syndrome, suggesting various techniques and cut-off values. Currently, an effective parameter and cut-off value are still debated. The aim of this review is to determine if these parameters have sufficient rigour to allow their use in clinical practice. Twenty-one studies using sonographic parameters to identify carpal tunnel syndrome in comparison with electrodiagnostic testing (EDx) were selected for review. Methodological differences were found between studies in the use of EDx criteria, scanning and recruitment protocols, with participant biometrics often not reported. Parameters including the cross-sectional area of the median nerve at the level of the pisiform bone in addition to the wrist-to-forearm difference demonstrated high diagnostic utility for set cut-off values. Doppler techniques and mobility are promising, and further research is required to understand the effectiveness of these techniques.

7.
Australas J Ultrasound Med ; 23(4): 238-247, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34760602

RESUMO

INTRODUCTION/PURPOSE: Sonographers develop pain whilst scanning and may not consistently adhere to ergonomic recommendations. The aim was to quantify this within Australian sonography students and recent graduates and to determine whether a relationship exists between: (i) pain and failure to adhere to ergonomic recommendations; and (ii) theoretical and practical ergonomic education during university and clinical placement, and the adherence to recommendations. METHODS: Online questionnaire distributed to Australian student sonographers and sonographers until two years post-graduation. RESULTS: During scanning, 33/39(84.62%) experienced musculoskeletal pain, and 21/33 (63.64%) experienced pain less than 1.76 full-time equivalent (FTE) days during the two FTE week period. The majority, 37/39 (94.87%), were not consistently adhering to recommendations, with 25/37 (67.57%) only doing so for less than 2.1 FTE days during two FTE weeks. Failure to adhere to ergonomic recommendations and development of musculoskeletal scanning pain was positively correlated (r = 0.7 (P = 0.01)).All participants had received some form of ergonomic education. This education was theoretical and practical during university and clinical placement for 24/39 (61.54%); however, receiving this resulted in no difference for adherence to ergonomic recommendations. Qualitative data demonstrated high workloads, scanning patients with increased body habitus or limited mobility were potential barriers to adherence to ergonomic recommendations. DISCUSSION: Ergonomic education occurs, yet a lack of knowledge and adherence to recommendations continues. Considerations for other potential barriers are required. CONCLUSION: Ensuring students adhere to ergonomic recommendations post-graduation and identifying relevant barriers within the clinical environment are important. Future research to investigate potential barriers around ergonomic adherence is suggested.

8.
Fetal Diagn Ther ; 47(2): 129-137, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31280268

RESUMO

OBJECTIVE: Mean uterine artery pulsatility index (meanUAPI) is commonly measured at 11-13+6 weeks to predict adverse pregnancy outcomes including hypertensive disorders and small-for-gestational age. The aims of this study were to establish a population-specific reference range for meanUAPI at <11 weeks, to determine if an abnormal meanUAPI at <11 weeks was associated with adverse pregnancy outcome, and to assess changes in meanUAPI between <11 weeks and 11-13+6 weeks. METHODS: A prospective cohort was examined at <11 weeks and at 11-13+6 weeks to develop reference ranges for meanUAPI. Based on these regression models, meanUAPI Z-scores were compared between outcome groups using a two-sample t test. Longitudinal changes in the meanUAPI between <11 and 11-13+6 weeks were assessed by two-way mixed ANOVA. RESULTS: Prior to 11 weeks, there was no significant difference in meanUAPI between normal (n = 622) and adverse (n = 80) outcomes (mean [95% CI]: 2.62 [2.57-2.67] and 2.67 [2.50-2.84], respectively; p = 0.807). At 11-13+6 weeks, meanUAPI was significantly higher in the adverse (n = 66) compared with the normal (n = 535) outcome group (mean [95% CI]: 1.87 [1.70-2.03] and 1.67 [1.63-1.72], respectively; p = 0.040). There was a statistically significant decrease (p < 0.0001) in meanUAPI between the two time points. CONCLUSION: MeanUAPI measured at <11 weeks' gestation does not appear to be a useful marker for the prediction of placental-related adverse pregnancy outcomes, supporting an argument for the prediction of risk at 11-13+6 weeks' gestation.


Assuntos
Circulação Placentária , Fluxo Pulsátil , Ultrassonografia Doppler em Cores , Ultrassonografia Pré-Natal , Artéria Uterina/diagnóstico por imagem , Adolescente , Adulto , Feminino , Retardo do Crescimento Fetal/diagnóstico por imagem , Retardo do Crescimento Fetal/fisiopatologia , Idade Gestacional , Humanos , Recém-Nascido Pequeno para a Idade Gestacional , Pré-Eclâmpsia/diagnóstico por imagem , Pré-Eclâmpsia/fisiopatologia , Valor Preditivo dos Testes , Gravidez , Resultado da Gravidez , Estudos Prospectivos , Valores de Referência , Ultrassonografia Doppler em Cores/normas , Ultrassonografia Pré-Natal/normas , Artéria Uterina/fisiopatologia , Adulto Jovem
9.
IEEE J Transl Eng Health Med ; 7: 1800909, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31857918

RESUMO

OBJECTIVE: Large scale retrospective analysis of fetal ultrasound (US) data is important in the understanding of the cumulative impact of antenatal factors on offspring's health outcomes. Although the benefits are evident, there is a paucity of research into such large scale studies as it requires tedious and expensive effort in manual processing of large scale data repositories. This study presents an automated framework to facilitate retrospective analysis of large scale US data repositories. METHOD: Our framework consists of four modules: (1) an image classifier to distinguish the Brightness (B) -mode images; (2) a fetal image structure identifier to select US images containing user-defined fetal structures of interest (fSOI); (3) a biometry measurement algorithm to measure the fSOIs in the images and, (4) a visual evaluation module to allow clinicians to validate the outcomes. RESULTS: We demonstrated our framework using thalamus as the fSOI from a hospital repository of more than 80,000 patients, consisting of 3,816,967 antenatal US files (DICOM objects). Our framework classified 1,869,105 B-mode images and from which 38,786 thalamus images were identified. We selected a random subset of 1290 US files with 558 B-mode (containing 19 thalamus images and the rest being other US data) and evaluated our framework performance. With the evaluation set, B-mode image classification resulted in accuracy, precision, and recall (APR) of 98.67%, 99.75% and 98.57% respectively. For fSOI identification, APR was 93.12%, 97.76% and 80.78% respectively. CONCLUSION: We introduced a completely automated approach designed to analyze a large scale data repository to enable retrospective clinical research.

10.
Nat Commun ; 10(1): 3031, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292453

RESUMO

Maternal immune dysregulation seems to affect fetal or postnatal immune development. Preeclampsia is a pregnancy-associated disorder with an immune basis and is linked to atopic disorders in offspring. Here we show reduction of fetal thymic size, altered thymic architecture and reduced fetal thymic regulatory T (Treg) cell output in preeclamptic pregnancies, which persists up to 4 years of age in human offspring. In germ-free mice, fetal thymic CD4+ T cell and Treg cell development are compromised, but rescued by maternal supplementation with the intestinal bacterial metabolite short chain fatty acid (SCFA) acetate, which induces upregulation of the autoimmune regulator (AIRE), known to contribute to Treg cell generation. In our human cohorts, low maternal serum acetate is associated with subsequent preeclampsia, and correlates with serum acetate in the fetus. These findings suggest a potential role of acetate in the pathogenesis of preeclampsia and immune development in offspring.


Assuntos
Acetatos/sangue , Feto/imunologia , Pré-Eclâmpsia/imunologia , Efeitos Tardios da Exposição Pré-Natal/imunologia , Linfócitos T Reguladores/imunologia , Acetatos/administração & dosagem , Acetatos/imunologia , Acetatos/metabolismo , Adulto , Animais , Animais Recém-Nascidos , Estudos de Casos e Controles , Desenvolvimento Infantil , Pré-Escolar , Suplementos Nutricionais , Feminino , Feto/citologia , Feto/diagnóstico por imagem , Microbioma Gastrointestinal/imunologia , Vida Livre de Germes/imunologia , Humanos , Tolerância Imunológica/imunologia , Lactente , Recém-Nascido , Estudos Longitudinais , Troca Materno-Fetal/imunologia , Camundongos , Tamanho do Órgão/imunologia , Pré-Eclâmpsia/sangue , Pré-Eclâmpsia/diagnóstico , Gravidez , Efeitos Tardios da Exposição Pré-Natal/patologia , Efeitos Tardios da Exposição Pré-Natal/prevenção & controle , Estudos Prospectivos , Timo/citologia , Timo/diagnóstico por imagem , Timo/crescimento & desenvolvimento , Timo/imunologia , Fatores de Transcrição/imunologia , Fatores de Transcrição/metabolismo , Ultrassonografia Pré-Natal , Adulto Jovem , Proteína AIRE
11.
Ultrasound Med Biol ; 45(5): 1259-1273, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30826153

RESUMO

Machine learning for ultrasound image analysis and interpretation can be helpful in automated image classification in large-scale retrospective analyses to objectively derive new indicators of abnormal fetal development that are embedded in ultrasound images. Current approaches to automatic classification are limited to the use of either image patches (cropped images) or the global (whole) image. As many fetal organs have similar visual features, cropped images can misclassify certain structures such as the kidneys and abdomen. Also, the whole image does not encode sufficient local information about structures to identify different structures in different locations. Here we propose a method to automatically classify 14 different fetal structures in 2-D fetal ultrasound images by fusing information from both cropped regions of fetal structures and the whole image. Our method trains two feature extractors by fine-tuning pre-trained convolutional neural networks with the whole ultrasound fetal images and the discriminant regions of the fetal structures found in the whole image. The novelty of our method is in integrating the classification decisions made from the global and local features without relying on priors. In addition, our method can use the classification outcome to localize the fetal structures in the image. Our experiments on a data set of 4074 2-D ultrasound images (training: 3109, test: 965) achieved a mean accuracy of 97.05%, mean precision of 76.47% and mean recall of 75.41%. The Cohen κ of 0.72 revealed the highest agreement between the ground truth and the proposed method. The superiority of the proposed method over the other non-fusion-based methods is statistically significant (p < 0.05). We found that our method is capable of predicting images without ultrasound scanner overlays with a mean accuracy of 92%. The proposed method can be leveraged to retrospectively classify any ultrasound images in clinical research.


Assuntos
Retardo do Crescimento Fetal/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Ultrassonografia Pré-Natal/métodos , Feminino , Humanos , Aprendizado de Máquina , Gravidez , Estudos Retrospectivos
12.
Aust N Z J Obstet Gynaecol ; 59(5): 641-648, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30724337

RESUMO

BACKGROUND: First-trimester miscarriage is common, with women increasingly offered an ultrasound scan early in the first trimester to assess the status of their pregnancy. Ultrasound is uniquely situated to significantly impact the clinical management of these women. AIMS: This study aims to determine whether there were any differences in the early ultrasound appearances of pregnancies that continued to be viable or resulted in miscarriage before 12 weeks gestation. MATERIALS AND METHODS: This was a prospective cohort study including ultrasound measurements: mean sac diameter (MSD), yolk sac diameter (YSD), crown-rump length (CRL), fetal heart rate (FHR), trophoblast thickness, trophoblast volume (TTV) and mean uterine artery pulsatility index (meanUAPI). Regression models were fitted for each parameter and Z-scores compared between cohorts that progressed or miscarried after the scan but before 12 weeks gestation. Logistic regression analysis was used to create a prediction model for miscarriage prior to 12 weeks gestation based on the standardised ultrasound measurements recorded during the early first-trimester scan. RESULTS: Comparison of Z-Scores for meanUAPI, TTV, FHR and MSD demonstrated significant variation between the two groups. The proposed logistic regression model resulted in an area under the receiver operator curve of 0.81. At a false-positive rate of 30%, the model resulted in a sensitivity of 76% (95% CI 64-89%). CONCLUSION: The combination of FHR, meanUAPI, TTV in a prediction model for miscarriage may prove to be of value for ongoing pregnancy management in the first trimester.


Assuntos
Aborto Espontâneo/diagnóstico por imagem , Ultrassonografia Pré-Natal , Adulto , Estudos de Coortes , Estatura Cabeça-Cóccix , Feminino , Frequência Cardíaca Fetal , Humanos , Valor Preditivo dos Testes , Gravidez , Primeiro Trimestre da Gravidez , Estudos Prospectivos , Fluxo Pulsátil , Artéria Uterina/fisiologia
13.
Australas J Ultrasound Med ; 21(3): 147-155, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34760515

RESUMO

AIM: Estimations of central adiposity in pregnancy is a difficult undertaking due to physiological changes that occur in the body. Therefore, the value of some anthropometric measures particularly in pregnancy, such as body mass index (BMI), waist and hip measures are in doubt. The aim was to compare ultrasound (US) measured abdominal subcutaneous fat (USSFT) with other simple anthropometric methods for obesity assessment, evaluating these measures in pregnancy. METHOD: Recruited from a larger study, anthropometric measurements were performed between 11-14 weeks' gestation on 575 women. Measuring height, weight, hip, waist circumference, skin-folds of the triceps, thigh and supra-iliac and USSFT. Percentage maternal fat mass was calculated using skin-fold measures. Correlations of these measures were performed to gauge relationships. RESULTS: The anthropometric measures demonstrated good correlation (0.54-0.93) between individual adipose measures skin-folds, waist, hip, waist to height ratio (WSR) and USSFT with BMI, percentage fat mass and weight. USSFT correlated well with all anthropometric measures (0.54-0.73) correlating best with waist, WSR, BMI and weight. Waist/hip ratio demonstrated a poor correlation with USSFT, BMI, percentage fat mass and weight (0.3-0.41). Mean anthropometric measures were stratified across BMI categories describing adiposity distribution. CONCLUSION: USSFT correlates well with most anthropometric measures in early pregnancy. Limitations of the gravid uterus on waist measurements, hydration and compressibility of skin-fold measures and pregnancy influences on weight and BMI assessments could be overcome using US measures. There is a potential for post hoc evaluation using US for pregnancy complications. Maternal research could benefit from a more accurate measure of adiposity.

14.
Australas J Ultrasound Med ; 21(4): 227-233, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34760527

RESUMO

INTRODUCTION: Chronic inflammation leads to adipose tissue (AT) fibrosis through excessive accumulation of extracellular matrix proteins. An increasing degree of fibrosis in AT is associated with increasing body mass index (BMI) and insulin resistance. Anecdotally AT has been observed to vary with ease of ultrasound penetration on medical examinations. Ultrasound strain elastography (SE) is a useful tool in assessing fibrosis in liver disease but has not previously been used to assess AT fibrosis. This study assesses the variance in density of the two anatomical layers of subcutaneous AT, superficial subcutaneous adipose tissue (SSAT) and deep subcutaneous adipose tissue (DSAT) in pregnancy using SE. METHOD: Women (n = 210) recruited in early pregnancy. Density of SSAT and DSAT were assessed using SE at five-time points throughout pregnancy and post-partum. Semi-quantitative density measures were achieved using two methods, strain values (SV) of the two layers and ImageJ software to calculate the percentage colour pixels in the elastography image and correlated with the SSAT/DSAT thickness and BMI. RESULTS: Adipose tissue demonstrated a difference in density with the SSAT layer being denser than DSAT. Correlation of tissue density measures with BMI was poor. There was slight change of AT density during pregnancy with a tendency towards harder SSAT and softer DSAT in the third trimester. Post-partum SSAT became softer associated with an increase in SSAT thickness. CONCLUSION: Elastography demonstrated density differences in adipose tissue. SE is a new method of assessing the AT demonstrating density differences in adipose tissue. Information on AT density may determine AT fibrosis and be valuable for metabolic disease risk.

15.
Obes Res Clin Pract ; 11(6): 655-664, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29102202

RESUMO

BACKGROUND: Abdominal adiposity and subcutaneous fat (SF), an important endocrine organ for health outcomes, can be divided into two layers, superficial (SSAT) and deep subcutaneous adipose tissue (DSAT) each with a different histological and metabolic function. The aim was to investigate longitudinal changes in maternal abdominal SF thickness and its layers throughout pregnancy and post-partum within body mass index (BMI) categories. METHODS: A prospective longitudinal study of 214 women was performed measuring abdominal SF using ultrasound at 12-14(M1), 18-20(M2), 26-29(M3) and 33-36 weeks' gestation (M4) and 6-8 weeks post-partum. SF thickness (SFT), SSAT and DSAT were measured. A ratio of DSAT/SSAT (D/S) was calculated. Measurements were compared to baseline and BMI evaluating for interaction with changes over time. RESULTS: Of the 214 women, 43.5%(93) were normal weight, 25.7%(55) overweight and 30.8%(66) obese. SFT and SSAT decreased from M1 to M4 for the overweight and obese whilst remaining stable for normal weight women. For all BMI categories SFT and SSAT increased post-partum. DSAT decreased significantly in the obese and overweight and increased significantly in the normal weight. Obese women had a higher D/S at M1 that decreased at M2 and remained constant to post-partum. D/S increased at M2 then decreased in the overweight. Normal weight women increased D/S at M2-M4. CONCLUSION: The results indicate a difference in distribution and mobilisation of fat in SSAT, and DSAT abdominal subcutaneous compartments within the different BMI categories in pregnancy. Understanding how fat mobilises during pregnancy may be fundamental to understanding obesity related complications.


Assuntos
Índice de Massa Corporal , Período Pós-Parto , Gordura Subcutânea Abdominal/diagnóstico por imagem , Ultrassonografia , Adulto , Feminino , Humanos , Estudos Longitudinais , Gravidez , Estudos Prospectivos , Adulto Jovem
16.
IEEE J Biomed Health Inform ; 21(4): 1069-1078, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-27333614

RESUMO

We derived an automated algorithm for accurately measuring the thalamic diameter from 2-D fetal ultrasound (US) brain images. The algorithm overcomes the inherent limitations of the US image modality: nonuniform density; missing boundaries; and strong speckle noise. We introduced a "guitar" structure that represents the negative space surrounding the thalamic regions. The guitar acts as a landmark for deriving the widest points of the thalamus even when its boundaries are not identifiable. We augmented a generalized level-set framework with a shape prior and constraints derived from statistical shape models of the guitars; this framework was used to segment US images and measure the thalamic diameter. Our segmentation method achieved a higher mean Dice similarity coefficient, Hausdorff distance, specificity, and reduced contour leakage when compared to other well-established methods. The automatic thalamic diameter measurement had an interobserver variability of -0.56 ± 2.29 mm compared to manual measurement by an expert sonographer. Our method was capable of automatically estimating the thalamic diameter, with the measurement accuracy on par with clinical assessment. Our method can be used as part of computer-assisted screening tools that automatically measure the biometrics of the fetal thalamus; these biometrics are linked to neurodevelopmental outcomes.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Neuroimagem/métodos , Tálamo/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Algoritmos , Feminino , Humanos , Modelos Estatísticos , Gravidez
17.
Australas J Ultrasound Med ; 20(4): 141-146, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34760487

RESUMO

The placenta is the link between mother and fetus and its function is central to a successful pregnancy. The predominant theory within the literature is that the development of placental dysfunction is a result of abnormal trophoblast invasion early in pregnancy. Knowledge of the development of the early placenta and the establishment of the fetomaternal circulation assists in understanding the origins of placental dysfunction which manifest later in pregnancy. Perinatally, chronic placental dysfunction may result in a growth-restricted fetus, maternal problems such as gestational hypertension, pre-eclampsia, eclampsia and pregnancy complications such as placental abruption, preterm labour and delivery. In addition, the growth-restricted fetus and the mother are at an increased risk of a myriad of disorders later in life. The role of ultrasound in the assessment of first trimester pregnancy is evolving with the potential for value in the prediction of placental function in later pregnancy. This review will address two aims, first to describe the development of the placenta from fertilisation to 12 weeks' gestation, correlating this with first trimester ultrasound findings. Second, to describe the link between placental development and function later in pregnancy. Understanding the link between early placental development and later placental function is essential in directing the focus of new research addressing the role of ultrasound in the first trimester in the prediction of adverse obstetric outcomes.

18.
J Med Imaging Radiat Sci ; 47(3S): S21-S28, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31047483

RESUMO

INTRODUCTION: Mammography is the standard screening modality for breast cancer; however, sensitivity reduces with increasing breast density, resulting in the potential for masking of cancer. Ultrasound is a potential supplemental screening tool, but its routine use is controversial. METHODS: A database search was performed with keywords "ultrasound" and "breast density and screening", including variations. Articles were included if they assessed the use of hand-held ultrasound as a supplemental screening modality in women with dense breasts. DISCUSSION: Twelve articles were identified. No high-level evidence articles were identified. Cancer detection rates increased with the addition of ultrasound-to-mammography screening protocols. However, this was associated with increased costs per cancer detected, an increased biopsy rate, and a low positive predictive value. The survival benefit, cost versus benefit, and psychological impact of the addition of ultrasound is unknown. CONCLUSIONS: The addition of ultrasound to a screening program in an asymptomatic population of women with dense breast tissue detects additional cancers compared with mammography alone. Knowledge regarding a survival or cost benefit associated with increased cancer detection, and the psychological impact of the addition of ultrasound is unknown. Further research is needed to assess whether the addition of ultrasound is cost-effective with respect to clinical outcome and survival.

19.
Front Pediatr ; 2: 112, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25368857

RESUMO

OBJECTIVE: To investigate the effect of the interaction between gestational diabetes mellitus (GDM) and maternal body mass index (BMI) on the individual neonatal growth parameters. DESIGN: Retrospective cohort study. SETTING: A tertiary maternity service in Sydney, Australia, between 2005 and 2009. POPULATION: A cohort of 8859 women. METHODS: Generalized linear models. MAIN OUTCOME MEASURES: Neonatal growth parameters, represented by z-scores for infant birth weight (BW), birth length (BL), and head circumference (HC) in GDM and non-GDM groups. RESULTS: Only GDM alone had an independent and positive effect on BL (p = 0.02) but not on BW or HC. In addition, in pregnancies complicated with GDM, the association between maternal weight and BW was significantly stronger (p < 0.001). In combination, GDM and maternal BMI significantly affected z-score differences between BW and BL (p < 0.001), in that underweight mothers had babies that were lighter relative to their length and inversely obese mothers had babies that were heavier relative to their length. CONCLUSION: GDM independently influences BL and increases the association between maternal BMI and BW. In accordance with the hypothesis of the fetal origins of health and disease, the pronounced effects of GDM on fetal growth patterns demonstrated in this study are likely to influence long-term health outcomes in children.

20.
Front Surg ; 1: 28, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25593952

RESUMO

Methadone maintenance therapy is the standard of care in many countries for opioid-dependent women who become pregnant. Despite recent evidence showing significant neurodevelopmental changes in children and adults exposed to both licit and illicit substances in utero, data on the effects of opioids in particular remains scarce. The purpose of this study was to examine the effects of opiate use, in particular methadone, on various fetal cortical and biometric growth parameters in utero using ultrasound measurements done at 18-22 weeks gestation. Head circumference (HC), bi-parietal diameter, lateral ventricle diameter, transcerebellar diameter, thalamic diameter, cisterna magna diameter, and femur length were compared between fetuses born to methadone-maintained mothers and non-substance using controls. A significantly larger thalamic diameter (0.05 cm, p = 0.01) was observed in the opiate-exposed group. Thalamic diameter/HC ratio was also significantly raised (0.03 mm, p = 0.01). We hypothesize here that the increase in thalamic diameter in opiate-exposed fetuses could potentially be explained by regional differences in opioid and serotonin receptor densities, an alteration in monoamine neurotransmitter systems, and an enhancement of the normal growth increase that occurs in the thalamus during mid-gestation.

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