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3.
Ultrasound Med Biol ; 49(1): 3-17, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36207224

RESUMO

Organ congestion from venous hypertension is an important pathophysiological mechanism mediating organ injury in several clinical contexts including critical illness, congestive heart failure and end-stage chronic kidney disease. However, the practical evaluation of venous congestion is often challenging at the bedside because of the limitations of traditional methods. Point-of-care ultrasound (POCUS) enables the clinician to assess venous velocity profiles during the cardiac cycle using Doppler modalities. Venous Doppler profile abnormalities at multiple sites are detected when elevated venous pressure results in hemodynamic changes within the systemic venous circulation. The detection of these abnormal Doppler profiles may identify patients with clinically significant systemic venous congestion. These patients have been reported to be at increased risk of medical complications. Improving the evaluation of venous congestion may lead to individualized treatment and improved patient outcomes. In this review, we describe the physiologic principles necessary to understand venous Doppler assessment. We also propose a nomenclature for the description of venous Doppler profiles. Finally, we provide a narrative review of the current clinical evidence related to use of venous Doppler assessment in various clinical contexts.


Assuntos
Insuficiência Cardíaca , Hiperemia , Humanos , Hiperemia/complicações , Ultrassonografia Doppler/métodos , Insuficiência Cardíaca/complicações , Veias , Hemodinâmica
4.
Ultrasound Med Biol ; 49(1): 225-236, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36244920

RESUMO

Ultrafast ultrasound is an emerging imaging modality derived from standard medical ultrasound. It allows for a high spatial resolution of 100 µm and a temporal resolution in the millisecond range with techniques such as ultrafast Doppler imaging. Ultrafast Doppler imaging has become a priceless tool for neuroscience, especially for visualizing functional vascular structures and navigating the brain in real time. Yet, the quality of a Doppler image strongly depends on experimental conditions and is easily subject to artifacts and deterioration, especially with transcranial imaging, which often comes at the cost of higher noise and lower sensitivity to small blood vessels. A common solution to better visualize brain vasculature is either accumulating more information, integrating the image over several seconds or using standard filter-based enhancement techniques, which often over-smooth the image, thus failing both to preserve sharp details and to improve our perception of the vasculature. In this study we propose combining the standard Doppler accumulation process with a real-time enhancement strategy, based on deep-learning techniques, using perceptual loss (PerceptFlow). With our perceptual approach, we bypass the need for long integration times to enhance Doppler images. We applied and evaluated our proposed method on transcranial Doppler images of mouse brains, outperforming state-of-the-art filters. We found that, in comparison to standard filters such as the Gaussian filter (GF) and block-matching and 3-D filtering (BM3D), PerceptFlow was capable of reducing background noise with a significant increase in contrast and contrast-to-noise ratio, as well as better preserving details without compromising spatial resolution.


Assuntos
Aumento da Imagem , Ultrassonografia Doppler , Animais , Camundongos , Aumento da Imagem/métodos , Ultrassonografia Doppler/métodos , Distribuição Normal , Artefatos , Redes Neurais de Computação , Processamento de Imagem Assistida por Computador/métodos , Razão Sinal-Ruído
5.
Nefrologia (Engl Ed) ; 42(4): 471-480, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36460432

RESUMO

BACKGROUND AND OBJECTIVE: Fluid overload is an important factor of morbidity and mortality in hemodialysis patients. Today correct determination of dry weight (DW) remains an important issue of hemodialysis practice. Within this context, it is subjected to new method searching. The objective of this study was to calculate estimated pulmonary capillary wedge pressure (ePCWP) with Tissue Doppler Imaging (TDI) in hemodialysis patients and to evaluate its correlation with the other volume markers and to evaluate whether it can be a new method for detection of DW. MATERIALS AND METHODS: Echocardiographic, hemodynamic, and biochemical volume markers of 41 hemodialysis patients were evaluated in the pre- and post-dialysis periods. Patients were divided into two groups based on ePCWP values (Group 1 ePCWP<20mmHg, Group 2 ePCWP>20mmHg). RESULTS: In the pre-dialysis period; parameters related to volume load including ePCWP, systolic blood pressure, mean arterial pressure, pulse pressure, left atrial diameter, left atrial volume, E/é, ratio and E/Vp ratio were statistically significantly higher in Group2 compared to Group1. On the other hand, strong correlations were found between pre-dialysis ePCWP and systolic blood pressure, mean arterial pressure, pulse pressure, NT-ProBNP, left atrial diameter, E/é ratio and E/Vp ratio. CONCLUSIONS: Strong correlations found between ePCWP which was calculated with TDI and the other volume markers both in pre-dialysis and post-dialysis periods. These findings can provide a significant contribution to routine evaluating of DW in hemodialysis patients. From this aspect, the prediction of ePCWP with TDI can be a new practical and reproducible method for the determination of DW.


Assuntos
Diálise Renal , Ultrassonografia Doppler , Humanos , Pressão Propulsora Pulmonar , Peso Corporal , Pressão Sanguínea
6.
Ultrasound Q ; 38(4): 322-327, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36398886

RESUMO

ABSTRACT: In this study, we aim to evaluate Doppler ultrasound (US) and clinical features of patients with and without femoral hernia (FH) in lower extremity chronic venous insufficiency (CVI) patients.We retrospectively analyzed prospectively collected data of 1364 limbs with the CVI suspected. Femoral hernia was detected in 32 of the limbs, and the control group was formed with 32 limbs without FH. All limbs were evaluated with Valsalva maneuver and augmentation method to detect venous reflux in FH group. Venous reflux rates in the Doppler US, venous clinical severity scores (VCSSs), and clinical classes of Clinical-Etiology-Anatomy-Pathophysiology classification were compared statistically in both groups.The mean VCSS was 3.87 ± 0.74 in the FH group and 2.68 ± 0.65 in the control group, which was statistically significant ( P = 0.04). In the more severe clinical classes of Clinical-Etiology-Anatomy-Pathophysiology (C4-6), the number of limbs in the FH group was higher than in the control group (8 and 4, respectively). Doppler US examinations showed venous reflux in 22 of 32 limbs in the FH group and 19 of 32 patients in the control group, and there was a statistically significant difference ( P = 0.029). In the FH group, reflux could be shown only by augmentation method in the vast majority of limbs (16 of 22, 73%).In conclusion, VCSS and reflux rates are higher in limbs with CVI accompanied by FH. In addition, FH may cause false negative results in the evaluation of CVI. The use of augmentation method in limbs with FH can help avoid false negatives.


Assuntos
Hérnia Femoral , Insuficiência Venosa , Humanos , Estudos Retrospectivos , Insuficiência Venosa/complicações , Insuficiência Venosa/diagnóstico por imagem , Extremidade Inferior/diagnóstico por imagem , Ultrassonografia Doppler
7.
J Am Coll Radiol ; 19(11S): S319-S328, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36436959

RESUMO

Uterine fibroids (leiomyomas or myomas) are the most common neoplasm of the uterus. Though incompletely understood, fibroid etiology is multifactorial, a combination of genetic alterations and endocrine, autocrine, environmental, and other factors such as race, age, parity, and body mass index. Black women have greater than an 80% incidence of fibroids by age 50, whereas White women have an incidence approaching 70%. Fibroid symptoms are protean, and menorrhagia is most frequent. The societal economic burden of symptomatic fibroids is large, 5.9 to 34.3 billion dollars annually. There are a variety of treatment options for women with symptomatic fibroids ranging from medical therapy to hysterectomy. Myomectomy and uterine fibroid embolization are the most common uterine sparing therapies. Pelvic ultrasound (transabdominal and transvaginal) with Doppler and MRI with and without intravenous contrast are the best imaging modalities for the initial diagnosis of fibroids, the initial treatment of known fibroids, and for surveillance or posttreatment imaging. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.


Assuntos
Leiomioma , Sociedades Médicas , Gravidez , Humanos , Feminino , Pessoa de Meia-Idade , Medicina Baseada em Evidências , Leiomioma/diagnóstico por imagem , Leiomioma/terapia , Imageamento por Ressonância Magnética/métodos , Ultrassonografia Doppler/métodos
8.
BMC Vet Res ; 18(1): 404, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36380376

RESUMO

This study aimed to correlate the pulsed wave spectral indices of the middle uterine artery at both sides with placental development in jenny within mid-late pregnancies, and establish umbilical Doppler values for different ages and different gestational months. Twenty Equus Asinus pregnant jennies 260-450 kg (average, 320 ± 10 kg) were examined from 5 to 9 months of pregnancy with different ages (4-14 years). Monthly B-mode ultrasound examination was performed on both the combined thickness of the uterus and placenta (CTUP; mm) and umbilical artery cross-sectional diameter, and Doppler mode examination was performed on both the middle uterine (MUA at right [R] and left [L] sides) and umbilical arteries to measure both Doppler indices that expressed by resistance (RI) and pulsatility indices (PI), and blood flow rate. CTUP was elevated within pregnancy time at different ages (P < 0.05). L. PI was significantly declined throughout different ages (P < 0.05), but this declining trend was not observed in L. RI. The L. blood flow rate (R; bpm) was elevated among different ages and different months (P < 0.05). Both RI and PI were significantly decreased from 5 to 9 month of gestation period in jennies (P < 0.05).. The umbilical arteries cross-sectional diameter (Umb A; mm), was elevated among different ages and different months, while both Doppler indices were declined. A positive correlation was found (between both Doppler indices of both umbilical and uterine arteries P < 0.001). There was elevated vascular perfusion in uterine and umbilical arteries associated with reduced both Doppler indices along the course of pregnancy at different ages.


Assuntos
Equidae , Artérias Umbilicais , Feminino , Gravidez , Animais , Artérias Umbilicais/diagnóstico por imagem , Artérias Umbilicais/fisiologia , Placenta/diagnóstico por imagem , Ultrassonografia Pré-Natal/veterinária , Velocidade do Fluxo Sanguíneo , Ultrassonografia Doppler/veterinária , Útero/diagnóstico por imagem , Hemodinâmica , Envelhecimento , Perfusão/veterinária
9.
Clin. transl. oncol. (Print) ; 24(11): 2200-2209, noviembre 2022.
Artigo em Inglês | IBECS | ID: ibc-210148

RESUMO

The purpose of this study is to explore the application value of CDFI and SMI combined with serological markers in distinguishing benign and malignant thyroid nodules.MethodA total of 192 patients with thyroid nodules admitted to our hospital from July 2019 to December 2020 were selected as subjects. Color Doppler blood flow imaging (CDFI) and supermicro blood flow imaging (SMI) methods are used to detect the blood flow of patients and the levels of serum thyroglobulin antibody (TgAb), thyroid peroxidase antibody (TPOAb), and thyroid stimulating hormone (TSH). The receiver operating characteristic curve (ROC curve) was used to observe the sensitivity and specificity of serological markers for distinguishing benign and malignant thyroid nodules, and combined with CDFI and SMI to observe the sensitivity and specificity for distinguishing benign and malignant thyroid nodules.ResultsThe levels of TgAb, TPOAb and TSH in benign thyroid nodules were lower than those of the malignant group, and the difference was statistically significant (P < 0.01). There was no statistically significant difference between benign and malignant thyroid nodules in the presence or absence of the capsule and the presence or absence of vocal halo (P > 0.05), while the differences in the nodule morphology, boundary, internal echo and internal calcification were statistically significant (P < 0.01).ConclusionCDFI and SMI combined with serological index detection have higher value in the differential diagnosis of thyroid cancer, which can significantly improve the sensitivity and specificity of differential diagnosis. (AU)


Assuntos
Humanos , Biomarcadores , Iodeto Peroxidase , Tireoglobulina , Neoplasias da Glândula Tireoide/diagnóstico , Nódulo da Glândula Tireoide/diagnóstico , Ultrassonografia Doppler/métodos , Sensibilidade e Especificidade , Tireotropina
10.
BMC Surg ; 22(1): 396, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36401253

RESUMO

BACKGROUND: In earlobe reconstruction, it is a challenging task to find a simple one-stage technique that is applicable to the variable configurations of defects and that results in a longstanding naturally appearing earlobe. METHODS: In this article, we present a perforator-based flap design for earlobe reconstruction with preoperative perforator detection by pencil doppler to ensure the maximum vascularity of the used flap. Thirty cases of earlobe reconstruction were performed in the Department of Plastic and Reconstructive Surgery at Tanta University in the period from July 2015 to July 2019 using the technique described in this article. RESULTS: None of our cases developed necrosis of the flaps. The mean result for the aesthetic evaluation of our cases was 4.7 and the mean patient satisfaction was 4.8 where the maximum score was 5. CONCLUSION: freestyle perforator flap with preoperative doppler perforator detection is a safe and reliable method of earlobe reconstruction.


Assuntos
Pavilhão Auricular , Retalho Perfurante , Humanos , Pavilhão Auricular/cirurgia , Ultrassonografia Doppler , Necrose
11.
Sensors (Basel) ; 22(22)2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36433527

RESUMO

To address the dangerous driving behaviors prevalent among current car drivers, it is necessary to provide real-time, accurate warning and correction of driver's driving behaviors in a small, movable, and enclosed space. In this paper, we propose a method for detecting dangerous behaviors based on frequency-modulated continuous-wave radar (mm-DSF). The highly packaged millimeter-wave radar chip has good in-vehicle emotion recognition capability. The acquired millimeter-wave differential frequency signal is Fourier-transformed to obtain the intermediate frequency signal. The physiological decomposition of the local micro-Doppler feature spectrum of the target action is then used as the eigenvalue. Matrix signal intensity and clutter filtering are performed by analyzing the signal echo model of the input channel. The signal classification is based on the estimation and variety of the feature vectors of the target key actions using a modified and optimized level fusion method of the SlowFast dual-channel network. Nine typical risky driving behaviors were set up by the Dula Hazard Questionnaire and TEIQue-SF, and the accuracy of the classification results of the self-built dataset was analyzed to verify the high robustness of the method. The recognition accuracy of this method increased by 1.97% compared with the traditional method.


Assuntos
Condução de Veículo , Comportamento Perigoso , Condução de Veículo/psicologia , Radar , Ultrassonografia Doppler , Inquéritos e Questionários
12.
Sensors (Basel) ; 22(21)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36366046

RESUMO

Coherent plane wave compounding (CPWC) reconstructs transmit focusing by coherently summing several low-resolution plane-wave (PW) images from different transmit angles to improve its image resolution and quality. The high frame rate of CPWC imaging enables a much larger number of Doppler ensembles such that the Doppler estimation of blood flow becomes more reliable. Due to the unfocused PW transmission, however, one major limitation of the Doppler estimation in CPWC imaging is the relatively low signal-to-noise ratio (SNR). Conventionally, the Doppler power is estimated by a zero-lag autocorrelation which reduces the noise variance, but not the noise level. A higher-lag autocorrelation method such as the first-lag (R(1)) power Doppler image has been developed to take advantage of the signal coherence in the temporal direction for suppressing uncorrelated random noises. In this paper, we propose a novel Temporal Multiply-and-Sum (TMAS) power Doppler detection method to further improve the noise suppression of the higher-lag method by modulating the signal coherence among the temporal correlation pairs in the higher-lag autocorrelation with a tunable pt value. Unlike the adaptive beamforming methods which demand for either receive-channel-domain or transmit-domain processing to exploit the spatial coherence of the blood flow signal, the proposed TMAS power Doppler can share the routine beamforming architecture with CPWC imaging. The simulated results show that when it is compared to the original R(1) counterpart, the TMAS power Doppler image with the pt value of 2.5 significantly improves the SNR by 8 dB for the cross-view flow velocity within the Nyquist rate. The TMAS power Doppler, however, suffers from the signal decorrelation of the blood flow, and thus, it relies on not only the pt value and the flow velocity, but also the flow direction relative to the geometry of acoustic beam. The experimental results in the flow phantom and in vivo dataset also agree with the simulations.


Assuntos
Angiografia , Ultrassonografia Doppler , Razão Sinal-Ruído , Ultrassonografia/métodos , Ultrassonografia Doppler/métodos , Imagens de Fantasmas , Processamento de Imagem Assistida por Computador/métodos
13.
Sensors (Basel) ; 22(21)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36366107

RESUMO

Doppler-radar-based continuous human motion recognition recently has attracted extensive attention, which is a favorable choice for privacy and personal security. Existing results of continuous human motion recognition (CHMR) using mmWave FMCW Radar are not considered the continuous human motion with the high similarity problem. In this paper, we proposed a new CHMR algorithm with the consideration of the high similarity (HS) problem, called as CHMR-HS, by using the modified Transformer-based learning model. As far as we know, this is the first result in the literature to investigate the continuous HMR with the high similarity. To obtain the clear FMCW radar images, the background and target signals of the detected human are separated through the background denoising and the target extraction algorithms. To investigate the effects of the spectral-temporal multi-features with different dimensions, Doppler, range, and angle signatures are extracted as the 2D features and range-Doppler-time and range-angle-time signatures are extracted as the 3D features. The 2D/3D features are trained into the adjusted Transformer-encoder model to distinguish the difference of the high-similarity human motions. The conventional Transformer-decoder model is also re-designed to be Transformer-sequential-decoder model such that Transformer-sequential-decoder model can successfully recognize the continuous human motions with the high similarity. The experimental results show that the accuracy of our proposed CHMR-HS scheme are 95.2% and 94.5% if using 3D and 2D features, the simulation results also illustrates that our CHMR-HS scheme has advantages over existing CHMR schemes.


Assuntos
Radar , Processamento de Sinais Assistido por Computador , Humanos , Movimento (Física) , Algoritmos , Ultrassonografia Doppler
14.
Glob Health Sci Pract ; 10(3)2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-36332066

RESUMO

Identifying the high-risk fetus in the low-risk pregnant mother (LRM) is a neglected area of research. Fetal growth restriction (FGR) is a major cause of stillbirths, especially in low- and middle-income countries (LMICs). FGR is very poorly detected particularly in healthy pregnant women classified as low risk. Umbiflow is an inexpensive continuous-wave Doppler ultrasound (CWDU) apparatus that is suitable for use by low-level health care providers for screening low-risk pregnant populations. It can easily detect umbilical artery blood flow in the cord, which correlates well with placental function, and poor placental function correlates well with FGR.Use of CWDU to screen an LMIC population of more than 7,000 LRMs has demonstrated a high prevalence of abnormal umbilical artery flow of 13%, and absent end-diastolic flow, which is associated with end-stage placental disease, was found in 1.2%. This is 10 times higher than previously reported in high-income countries. Screening with CWDU together with a standard protocol managing those pregnancies with abnormal placental blood flow resulted in a 43% reduction in stillbirths (risk ratio: 0.57; 95% confidence interval=0.29, 0.85) in this LRM population. Further, follow-up of infants who had abnormal umbilical artery blood flow showed that these infants had significantly less fat-free mass at ages 6 weeks, 10 weeks, 14 weeks, and 6 months, than those with normal umbilical artery blood flow (P<.015), confirming that CWDU was able to detect true FGR.Thus, screening with CWDU can detect the fetus at risk of stillbirth, and infants likely to have suboptimal growth and development postnatally. Screening with CWDU in LRMs opens the door to a step change in preventing stillbirths in LMICs.


Assuntos
Natimorto , Ultrassonografia Pré-Natal , Gravidez , Feminino , Humanos , Recém-Nascido , Natimorto/epidemiologia , Placenta/irrigação sanguínea , Placenta/diagnóstico por imagem , Mães , Ultrassonografia Doppler/métodos , Feto/irrigação sanguínea , Retardo do Crescimento Fetal/diagnóstico por imagem , Fatores de Risco
15.
Pediatr Int ; 64(1): e15341, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36331222

RESUMO

BACKGROUND: Precordial Doppler ultrasound technology can be used to confirm correct peripheral intravenous access in children. Changes in precordial Doppler sound from the baseline after injecting normal saline are detected using a correct peripheral intravenous access. However, the location of the precordial Doppler probe has been inconsistent in previous studies. Our study aimed to determine whether the right or left parasternal border is the optimal location for precordial Doppler probe placement. METHODS: This single-center, prospective interventional study was conducted between July 2021 and January 2022 and included children aged 1-6 years. The Doppler probe was placed under general anesthesia at the most audible site on the right and left parasternal borders of patients. Baseline heartbeat was recorded by the Doppler for 10 s on the right and left parasternal borders. After randomizing the order of the recorded data, two blinded raters separately listened to the data and decided the audibility of the sounds. RESULTS: A total of 77 patients were enrolled in the study. The proportion of the audible baseline heartbeat was significantly higher on the left parasternal borders than on the right by both rater 1 (96.1%, 22.1%, p < 0.001) and rater 2 (96.1%, 27.3%, p < 0.001). Regarding inter-rater reproducibility, Cohen's kappa statistics for the left and right parasternal borders were significant (0.65 and 0.79, both p < 0.001). CONCLUSIONS: The baseline heartbeat was more audible on the left parasternal border than on the right parasternal border with acceptably high interrater reproducibility. This is inconsistent with the interpretations of previous reports.


Assuntos
Ultrassonografia Doppler , Criança , Humanos , Estudos Prospectivos , Reprodutibilidade dos Testes , Ultrassonografia
16.
Acta Obstet Gynecol Scand ; 101(12): 1431-1439, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36214456

RESUMO

INTRODUCTION: The aim of this survey was to evaluate the current practice in respect of diagnosis and management of fetal growth restriction among obstetricians in different countries. MATERIAL AND METHODS: An e-questionnaire was sent via REDCap with "click thru" links in emails and newsletters to obstetric practitioners in different countries and settings with different levels of expertise. Clinical scenarios in early and late fetal growth restriction were given, followed by structured questions/response pairings. RESULTS: A total of 275 participants replied to the survey with 87% of responses complete. Participants were obstetrician/gynecologists (54%; 148/275) and fetal medicine specialists (43%; 117/275), and the majority practiced in a tertiary teaching hospital (56%; 153/275). Delphi consensus criteria for fetal growth restriction diagnosis were used by 81% of participants (223/275) and 82% (225/274) included a drop in fetal growth velocity in their diagnostic criteria for late fetal growth restriction. For early fetal growth restriction, TRUFFLE criteria were used for fetal monitoring and delivery timing by 81% (223/275). For late fetal growth restriction, indices of cerebral blood flow redistribution were used by 99% (250/252), most commonly cerebroplacental ratio (54%, 134/250). Delivery timing was informed by cerebral blood flow redistribution in 72% (176/244), used from ≥32 weeks of gestation. Maternal biomarkers and hemodynamics, as additional tools in the context of early-onset fetal growth restriction (≤32 weeks of gestation), were used by 22% (51/232) and 46% (106/230), respectively. CONCLUSIONS: The diagnosis and management of fetal growth restriction are fairly homogeneous among different countries and levels of practice, particularly for early fetal growth restriction. Indices of cerebral flow distribution are widely used in the diagnosis and management of late fetal growth restriction, whereas maternal biomarkers and hemodynamics are less frequently assessed but more so in early rather than late fetal growth restriction. Further standardization is needed for the definition of cerebral blood flow redistribution.


Assuntos
Retardo do Crescimento Fetal , Artérias Umbilicais , Gravidez , Feminino , Humanos , Retardo do Crescimento Fetal/diagnóstico , Retardo do Crescimento Fetal/terapia , Artérias Umbilicais/diagnóstico por imagem , Ultrassonografia Pré-Natal , Inquéritos e Questionários , Biomarcadores , Ultrassonografia Doppler , Idade Gestacional
19.
IEEE Trans Ultrason Ferroelectr Freq Control ; 69(12): 3317-3326, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36315529

RESUMO

Accurate quantification of cardiac valve regurgitation jets is fundamental for guiding treatment. Cardiac ultrasound is the preferred diagnostic tool, but current methods for measuring the regurgitant volume (RVol) are limited by low accuracy and high interobserver variability. Following recent research, quantitative estimators of orifice size and RVol based on high frame rate 3-D ultrasound have been proposed, but measurement accuracy is limited by the wide point spread function (PSF) relative to the orifice size. The aim of this article was to investigate the use of deep learning to estimate both the orifice size and the RVol. A simulation model was developed to simulate the power-Doppler images of blood flow through orifices with different geometries. A convolutional neural network (CNN) was trained on 30 000 image pairs. The network was used to reconstruct orifices from power-Doppler data, which facilitated estimators for regurgitant orifice areas and flow volumes. We demonstrate that the network improves orifice shape reconstruction, as well as the accuracy of orifice area and flow volume estimation, compared with a previous approach based on thresholding of the power-Doppler signal (THD), and compared with spatially invariant deconvolution (DC). Our approach reduces the area estimation error on simulations: (THD: 13.2 ± 9.9 mm2, DC: 12.8 ± 15.8 mm2, and ours: 3.5 ± 3.2 mm2). In a phantom experiment, our approach reduces both area estimation error (THD: 10.4 ± 8.4 mm2, DC: 10.98 ± 8.17, and ours: 9.9 ± 6.0 mm2) and flow rate estimation error (THD: 20.3 ± 9.9 ml/s, DC: 18.14 ± 13.01 ml/s, and ours: 7.1 ± 10.6 ml/s). We also demonstrate in vivo feasibility for six patients with aortic insufficiency, compared with standard echocardiography and magnetic resonance references.


Assuntos
Insuficiência da Valva Aórtica , Aprendizado Profundo , Ultrassonografia Doppler , Humanos , Velocidade do Fluxo Sanguíneo/fisiologia , Ecocardiografia , Hemodinâmica , Ultrassonografia , Imageamento Tridimensional
20.
IEEE Trans Ultrason Ferroelectr Freq Control ; 69(12): 3243-3254, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36191097

RESUMO

Power-Doppler ultrasonic (PD-US) imaging is sensitive to echoes from blood cell motion in the microvasculature but generally nonspecific because of difficulties with filtering nonblood-echo sources. We are studying the potential for using PD-US imaging for routine assessments of peripheral blood perfusion without contrast media. The strategy developed is based on an experimentally verified computational model of tissue perfusion that simulates typical in vivo conditions. The model considers directed and diffuse blood perfusion states in a field of moving clutter and noise. A spatial registration method is applied to minimize tissue motion prior to clutter and noise filtering. The results show that in-plane clutter motion is effectively minimized. While out-of-plane motion remains a strong source of clutter-filter leakage, those registration errors are readily minimized by straightforward modification of scanning techniques and spatial averaging.


Assuntos
Processamento de Sinais Assistido por Computador , Ultrassonografia Doppler , Velocidade do Fluxo Sanguíneo , Ultrassonografia Doppler/métodos , Ultrassonografia/métodos , Perfusão , Imagens de Fantasmas
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