High-definition Color Research Articles

The Utility of a Novel Stacked Microvascular Imaging for Enhanced Detection of Fibrosis in Chronic Liver Diseases

Ultrasonographic imaging plays a primary role to detect fibrotic changes in patients with chronic liver disease (CLD). To enhance detectability of fibrosis in its early stage, we developed a novel stacked microvascular imaging (SMVI) that enables continuous visualization of fibrotic changes in intrahepatic vessels. SMVI was produced by accumulating 3-5 seconds of high-definition color images in tilted-scan mode. An SMVI score was devised by quantitating three hallmark vascular changes in liver fibrosis in 0-2 grades (total 0-6): narrowing, caliber irregularity, and tortuosity. To evaluate the clinical utility of the SMVI score, 469 well-defined CLD patients were enrolled and subgrouped by the stage of liver fibrosis defined based on elastography: F0-1Low, F0-1High, F2, F3, and F4. The diagnostic performance of the SMVI score was compared to conventional B-mode liver morphology score and various laboratory test markers of fibrosis. Unlike conventional microvascular imaging that relies on a single image, SMVI enabled an undisrupted view of intrahepatic vessels for easy detection of fibrotic changes. SMVI detected microvascular narrowing in 92% at stage F0-1High. While detection rates for caliber irregularity and tortuosity were low at early stages but increased proportionately in advanced stages. Multiple logistic regression analysis revealed that SMVI score was most accurate in distinguishing F0-1Low from F0-1High cases compared to B-mode or laboratory test scores. SMVI provides enhanced vascular images of liver fibrosis in CLD, especially in its early stage. The SMVI score can be used as a primary tool for determining fibrotic stages in CLD.

Osteology of the Hamadryas Baboon (Papio hamadryas).

Besides living as a free-ranging primate in the horn of Africa and the Arabian Peninsula, the hamadryas baboon has an important place in zoos and can be found in biomedical research centers worldwide. To be valuable as a non-human primate laboratory model for man, its anatomy should be portrayed in detail, allowing for the correct interpretation and translation of obtained research results. Reviewing the literature on the use of the baboon in biomedical research revealed that very limited anatomical works on this species are available. Anatomical atlases are incomplete, use archaic nomenclature and fail to provide high-definition color photographs. Therefore, the skeletons of two male hamadryas baboons were prepared by manually removing as much soft tissues as possible followed by maceration in warm water to which enzyme-containing washing powder was added. The bones were bleached with hydrogen peroxide and degreased by means of methylene chloride. Photographs of the various bones were taken, and the anatomical structures were identified using the latest version of the Nomina Anatomica Veterinaria. As such, the present article shows 31 annotated multipanel figures. The skeleton of the hamadryas baboon generally parallels the human skeleton, but some remarkable differences have been noticed. If these are taken into consideration when evaluating the results of experiments using the hamadryas baboon, justified conclusions can be drawn.

Taxonomic revision of the Neotropical genus Argentinomyia Lynch-Arribálzaga, 1891 (Diptera: Syrphidae), with description of 16 new species

The Neotropical flower fly genus Argentinomyia Lynch-Arribálzaga (Diptera: Syrphidae) is revised and rediagnosed. An updated key to the Neotropical genera of Bacchini and Melanostomini is provided. As a result of the ongoing systematic study of the genus, sixteen new species were discovered and described: Argentinomyia aurifacies Montoya & Thompson sp. nov. (Dominican Republic), Argentinomyia belmira Montoya & Wolff sp. nov. (Colombia), Argentinomyia humboldti Montoya & Wolff sp. nov. (Colombia and Ecuador), Argentinomyia ivani Montoya sp. nov. (Colombia), Argentinomyia jalcaensis Thompson & Montoya sp. nov. (Perú), Argentinomyia jamaicensis Montoya sp. nov. (Jamaica), Argentinomyia norrbomi Montoya sp. nov. (Brazil), Argentinomyia occidentalis Montoya & Wolff sp. nov. (Colombia), Argentinomyia plaumanni Thompson & Montoya sp. nov. (Brazil), Argentinomyia sagoti Montoya sp. nov. (Mexico), Argentinomyia serendipia Montoya sp. nov. (Colombia), Argentinomyia spinifemorata Montoya sp. nov. (Colombia), Argentinomyia taina Montoya & Thompson sp. nov. (Dominican Republic), Argentinomyia teresae Montoya sp. nov. (Colombia), Argentinomyia transversalis Montoya sp. nov. (Colombia and Bolivia) and Argentinomyia tropandeana Montoya sp. nov. (Colombia, Ecuador and Perú). Five new synonyms are proposed for four species: Melanostoma melanocerum (Williston, 1891) = Argentinomyia catabomba (Williston, 1891), Braziliana columbiana (Enderlein, 1935) = Argentinomyia fastigata (Fluke, 1945), Braziliana peruviana (Shannon, 1927), Braziliana thiemei (Enderlein, 1935) = Argentinomyia longicornis (Walker, 1836) and Rhysops funerea (Hull, 1949) = Argentinomyia nigrans (Fluke, 1945). Lectotypes are designated for the following names: Melanostoma catabombum Williston, 1891, Melanostoma crenulatum Williston, 1891, Melanostoma longicornis Williston, 1888, Melanostoma melanocerum Williston, 1891 and Pipiza longicornis Walker, 1836. Twenty-six species are redescribed and an updated key proposed for 41 out of the 47 species recognized as valid. Synonyms, descriptions, comparative diagnosis, high-definition color photographs of overall appearance, illustrations of the male genitalia as well as field photographs are provided. The known distribution ranges are mapped and the biogeographical affinity and endemism are discussed. Female genitalia are described for the first time for the genus. Argentinomyia berthae (Lima, 1946) is rediscovered and redescribed, including the designation of a neotype. The taxonomic status of Argentinomyia scitula (Williston, 1888) is considered doubtful and needs further study. Taxonomic notes are provided for Argentinomyia aenea (Willistoni, 1891) and A. huitepecensis Montoya, 2020. The high diversity, the biogeographical affinities, the noteworthy endemism patterns, new country records as well as the morphological variation evidenced in the present revision suggest that the genus is much more diverse than it appears, with many new species that undoubtedly remain to be described from unexplored areas of the Neotropics. Our study provides a thorough morphological assessment as well as the updated biogeographical distribution, which constitute a starting point to answer questions and propose hypotheses about the phylogenetic relationships, historical biogeography, diversification patterns and conservation of Argentinomyia in forthcoming contributions.

Utility of shear wave elastography and high-definition color for diagnosing carpal tunnel syndrome

ObjectiveThe diagnostic values of measuring median nerve (MN) stiffness and vascularity with shear wave elastography (SWE) and high-definition (HD) color were investigated in carpal tunnel syndrome (CTS). MethodsSeventy patients (123 wrists) with CTS and thirty-five healthy volunteers (70 wrists) were enrolled. Based on nerve conduction studies (NCS), the patients were subdivided into NCS-negative, mild-to-moderate, and severe CTS groups. MN and abductor pollicis brevis (APB) SWE and MN HD color were performed on a longitudinal plane. ResultsThe mild-to-moderate and severe CTS groups showed increased MN stiffness at the wrist and MN stiffness ratio (wrist-to forearm) compared with the control (p < 0.001). The NCS-negative CTS group showed increased MN stiffness at the wrist (p = 0.022) and MN stiffness ratio (p = 0.032) compared with the control. The severe CTS group showed increased MN stiffness at the wrist compared with the mild-to-moderate CTS group (p = 0.034). The cutoff-values in diagnosing NCS-confirmed CTS were 50.12 kPa for MN stiffness at the wrist, 1.91 for MN stiffness ratio, and grade 1 for HD color. ConclusionsSWE and HD color are good supportive tools in diagnosing and assessing severity in CTS. SignificanceSWE and HD color demonstrated that MN in CTS was associated with increased stiffness and hypervascularity.

Calibration and location analysis of a heterogeneous binocular stereo vision system.

In the dairy farming industry, we can obtain the temperature, color, and location information of dairy cows by patrol inspection robot so as to monitor the health status and abnormal behaviors of dairy cows. We build and calibrate a heterogeneous binocular stereo vision (HBSV) system comprising a high-definition color camera and infrared thermal camera and mount it on a patrol inspection robot. First, based on the traditional chessboard, an easy-to-make calibration board for the HBSV system is designed. Second, an accurate locating and sorting algorithm for the calibration points of the calibration board is designed. Then, the cameras are calibrated and the HBSV system is stereo-calibrated. Finally, target locating is achieved based on the above calibration results and Yolo target detection technology. In this paper, several experiments are carried out from many aspects. The target locating average error of HBSV system is 3.11%, which satisfies the needs of the dairy farming environment. The video's FPS captured by using HBSV is 7.3, which is 78% higher than that by using binocular stereo vision system and infrared thermal camera. The results show that the HBSV system has application value to a certain degree.

A global non-invasive methodology for the phenotyping of potato under water deficit conditions using imaging, physiological and molecular tools

BackgroundDrought is a major consequence of global heating that has negative impacts on agriculture. Potato is a drought-sensitive crop; tuber growth and dry matter content may both be impacted. Moreover, water deficit can induce physiological disorders such as glassy tubers and internal rust spots. The response of potato plants to drought is complex and can be affected by cultivar type, climatic and soil conditions, and the point at which water stress occurs during growth. The characterization of adaptive responses in plants presents a major phenotyping challenge. There is therefore a demand for the development of non-invasive analytical techniques to improve phenotyping.ResultsThis project aimed to take advantage of innovative approaches in MRI, phenotyping and molecular biology to evaluate the effects of water stress on potato plants during growth. Plants were cultivated in pots under different water conditions. A control group of plants were cultivated under optimal water uptake conditions. Other groups were cultivated under mild and severe water deficiency conditions (40 and 20% of field capacity, respectively) applied at different tuber growth phases (initiation, filling). Water stress was evaluated by monitoring soil water potential. Two fully-equipped imaging cabinets were set up to characterize plant morphology using high definition color cameras (top and side views) and to measure plant stress using RGB cameras. The response of potato plants to water stress depended on the intensity and duration of the stress. Three-dimensional morphological images of the underground organs of potato plants in pots were recorded using a 1.5 T MRI scanner. A significant difference in growth kinetics was observed at the early growth stages between the control and stressed plants. Quantitative PCR analysis was carried out at molecular level on the expression patterns of selected drought-responsive genes. Variations in stress levels were seen to modulate ABA and drought-responsive ABA-dependent and ABA-independent genes.ConclusionsThis methodology, when applied to the phenotyping of potato under water deficit conditions, provides a quantitative analysis of leaves and tubers properties at microstructural and molecular levels. The approaches thus developed could therefore be effective in the multi-scale characterization of plant response to water stress, from organ development to gene expression.

Neuromuscular ultrasound (NMUS) O-NU001. Feasibility of shear wave elastography and high definition color in evaluation of carpal tunnel syndrome

Introduction . Diagnosis of carpal tunnel syndrome (CTS) is based on clinical findings and electrodiagnostic tests (EDT). However, EDT has high false negative rates, and the results often do not reflect the severity of symptoms. The aim of this study is to investigate the value of shear wave elastography (SWE) and high definition (HD) color in diagnosis and evaluation of symptom severity in CTS. Methods . The study prospectively enrolled 39 wrists from 23 patients with EDT-confirmed CTS, 15 wrists from 12 patients who have CTS symptoms without EDT abnormality and 28 wrists from 14 healthy volunteers. Cross-sectional area (CSA) and longitudinal diameter of median nerve were measured. SWE of median nerve at the wrist and midforearm were performed, and the ratio between them was calculated. SWE of abductor pollicis brevis (APB) and abductor digiti minimi (ADM) were also measured and the ratio was obtained. HD color was conducted in the longitudinal plane at carpal tunnel. Results . The CSA of the median nerve at the carpal inlet and longitudinal diameter were significantly larger for the EDT-confirmed CTS group compared to control group (13.21[11.28,17.23] vs 7.98[6.53,8.94]; p < 0.001, 2.77[2.41,3.08] vs 2.07[1.79,2.24]; p < 0.001). It also had significantly higher median nerve elasticity ratio (2.59[1.77,4.09] vs 1.61[1.32,1.94]; p = 0.007). HD color showed significantly higher grades in the former group (p = 0.004). In ROC analysis, a 1.97 cut-off value on SWE ratio revealed sensitivity, specificity, PPV, NPV of 74.4%, 78.6%, 82.9%, 68.8%, respectively (AUC: 0.796[0.687,0.905]). Inter-rater reliability was excellent for SWE measurements (ICC: 0.908(0.761,0.967)). There was no significant correlation of CSA, elasticity and HD color grade with clinical symptom scores. In comparison between the group of CTS patients without EDT abnormality and control group, the former had significantly larger CSA in carpal inlet and elasticity ratio (9.61[7.21,11.55] vs 7.98[6.53,8.94]; p = 0.011, 2.59[0.94,4.65] vs 1.61[1.32,1.94]; p = 0.009). Conclusion . SWE and HD color are helpful supportive tools in diagnosing CTS, especially in patients who have typical CTS symptoms but normal results in EDT.

First-trimester fetal heart evaluation: time to move forward.

First-trimester fetal heart evaluation: time to move forward.

Prenatal diagnosis of major aortopulmonary collateral arteries (MAPCA) in fetuses with pulmonary atresia with ventricular septal defect and agenesis of ductus arteriosus

Objective The aim of this study was to describe the prenatal diagnosis of Major Aortopulmonary Collateral Arteries (MAPCAs), and to present a systematic ultrasound method for evaluating lung vascularity in fetuses with pulmonary atresia with ventricular septal defect (PAVSD) and agenesis of ductus arteriosus (DA). Method This retrospective study evaluated fetuses diagnosed with PAVSD with agenesis of DA, for the presence of the MAPCAs anomaly. Fetal pulmonary vasculature was investigated by 2D and 4D Spatio Temporal Image Correlation (STIC) technology using High Definition Color Doppler. Results Over a 10 year period, six fetuses were diagnosed with MAPCAs. Prenatal diagnosis was made between 17 w 6 d and 28 w 4 d in five fetuses, with the sixth diagnosed at 37 w 6 d. All six had PAVSD with agenesis DA, four exhibited pulmonic atresia without any arterial outflow, while two fetuses presented with absent left pulmonary artery, and a miniscule right pulmonary artery. In five cases, the parents elected to terminate the pregnancy and the last, although born alive, did not survive an attempt at restorative surgery and died at the age of 5 months. Postnatal CT angiography imaging of this case revealed the subclavian origin of the MAPCAs. Chromosomal micro array analysis of the amniotic fluid revealed that five of the six fetuses were normal and one was lost to follow up. Conclusion MAPCAs should be investigated in cases of PAVSD with agenesis DA. A meticulous ultrasound evaluation using 2D and 4D STIC can permit the prenatal diagnosis of this anomaly and provide the parents with the opportunity for prenatal consultation.

Normal Fetal Umbilical, Portal, and Hepatic Venous System: Four-dimensional STIC Rendering.

Online supplemental material is available for this article.

Operando Observation of Zinc Negative Electrode Using Confocal Optical System and X-Ray Diffraction

Alkaline secondary batteries using zinc negative electrodes are attractive candidates for large-scale energy storage systems since they potentially satisfy low cost, high safety standard and high energy density. However, the short cycle life of the zinc electrodes hinders their practical applications. To overcome this problem, it is necessary to understand the degradation mechanism. In this work, we applied the combination of operando confocal optical system and operando x-ray diffraction (XRD) to alkaline zinc electrode systems to investigate the mechanism of the degradation from the physical and the chemical points of view. Operando confocal optical system is a confocal-optics-based microscopy system that enables acquisition of all-in-focus high definition color image on uneven surface by vertical scanning of observation surface. It also enables time-resolved observation of morphological and color change of electrodes during charge-discharge cycle by periodical scanning. We previously applied this to lithium-ion battery systems and successfully visualized local reaction distribution.[1] Since the morphological change and the local reaction distribution mainly cause the degradation of zinc electrode[2], the operando confocal optical system possibly supplies important information about the degradation mechanism. On the other hand, it is difficult to analyze the chemical properties with the optical system. To compensate the chemical aspect, we also carried out operando XRD. Nakata et al. applied operando synchrotron XRD to zinc electrode systems and successfully quantified ZnO and Zn phases.[2] In this work, we expanded synchrotron XRD into laboratory XRD, which has higher versatility and higher availability.The optical measurements and the XRD were separately employed with a confocal optical system (ECCS, Lasertec) and XRD system (SmartLab, Rigaku), respectively, but the same electrochemical cell and operating conditions were applied. The electrochemical cell consists of ZnO composite electrode filled in Cu foam (working electrode), Hg|HgO electrode (reference electrode), Zn wire (counter electrode), poly(propylene) film (observation window) and 1.0 and 4.0 mol dm–3 KOH solutions saturated (sat’d) with ZnO (electrolyte solution).Figure (a), (b) shows parts of operando confocal optical images and operando XRD patterns of the cross-section of the ZnO composite electrodes in 1.0 and 4.0 mol dm–3 KOH solutions sat’d with ZnO. Zn deposited to form clusters at around the Cu current collectors at the charge in 4.0 mol dm–3 KOH sat’d with ZnO while relatively uniform Zn deposition was observed at the charge in 1.0 mol dm–3 KOH sat’d with ZnO. The diffraction pattern of ZnO was hardly observed after the discharge in 4.0 mol dm–3 KOH sat’d with ZnO. In contrast, ZnO110 peak was clearly observed and bluish blacked deposition was uniformly observed in the optical image after the discharge in 1.0 mol dm–3 KOH sat’d with ZnO. Charge-discharge measurements using three-electrode full-cells with Ni(OH)2 counter electrodes showed that the ZnO composite electrode in 1.0 mol dm–3 KOH exhibited about 4 times longer cycle life than that in 4.0 mol dm–3 KOH. These results indicated that higher solubility of [Zn(OH)4]2– in 4.0 mol dm–3 KOH caused local deposition of Zn and ZnO followed by the degradation due to the shape change.

The Plant Health Monitoring System of the EDEN ISS Space Greenhouse in Antarctica During the 2018 Experiment Phase.

The EDEN ISS project has the objective to test key technologies and processes for higher plant cultivation with a focus on their application to long duration spaceflight. A mobile plant production facility was designed and constructed by an international consortium and deployed to the German Antarctic Neumayer Station III. Future astronaut crews, even if well-trained and provided with detailed procedures, cannot be expected to have the competencies needed to deal with all situations that will arise during a mission. Future space crews, as they are today, will be supported by expert backrooms on the ground. For future space-based greenhouses, monitoring the crops and the plant growth system increases system reliability and decreases the crew time required to maintain them. The EDEN ISS greenhouse incorporates a Plant Health Monitoring System to provide remote support for plant status assessment and early detection of plant stress or disease. The EDEN ISS greenhouse has the capability to automatically capture and distribute images from its suite of 32 high-definition color cameras. Collected images are transferred over a satellite link to the EDEN ISS Mission Control Center in Bremen and to project participants worldwide. Upon reception, automatic processing software analyzes the images for anomalies, evaluates crop performance, and predicts the days remaining until harvest of each crop tray. If anomalies or sub-optimal performance is detected, the image analysis system generates automatic warnings to the agronomist team who then discuss, communicate, or implement countermeasure options. A select number of Dual Wavelength Spectral Imagers have also been integrated into the facility for plant health monitoring to detect potential plant stress before it can be seen on the images taken by the high-definition color cameras. These imagers and processing approaches are derived from traditional space-based imaging techniques but permit new discoveries to be made in a facility like the EDEN ISS greenhouse in which, essentially, every photon of input and output can be controlled and studied. This paper presents a description of the EDEN ISS Plant Health Monitoring System, basic image analyses, and a summary of the results from the initial year of Antarctic operations.

Rock lithological classification by hyperspectral, range 3D and color images

Mine operations in the future will require automatic rock characterization at many different stages, since it can be used to supervise and optimize various processes in the laboratory as well as at the mine locations for planning and exploitation. Different methods for classifying rocks based on image analysis have been proposed in the past. In this paper, we report the use of hyperspectral sensors in the classification of rock lithology. The lithology provides information about the chemical composition of the rock, and its physical properties. According to our literature review, this is the first time hyperspectral sensors have been employed in rock type classification. Additionally, it is the first time the use of three different technologies in rock type classification has been reported: hyperspectral sensors, laser range and a color camera. We use two hyperspectral sensors, one has sensibility within the visible and near-infrared range of 400–1000 nm, and the second has sensibility within the short-wavelength infrared range of 900–2500 nm. The range and high definition color images are used to perform accurate segmentation of the rock samples. Images are tessellated into sub-images in which various features from the three sensor types are extracted. In a first stage, the sub-images are classified by using a support-vector machine (SVM) classifier with the extracted features as inputs. In a second stage, the rock segmentation is used to perform a voting process among all the sub-images of each rock and improve the classification. The method was tested using a database with 13 lithologies from a copper mine in Chile. The results show that lithological classification performance obtained by using hyperspectral images greatly exceeds the performance of the color and range images. The achieved classification performance was 98.62% using sub-image classification and 99.95% using a voting process among sub-images. The number of features was also reduced by using the CMIM (Conditional Mutual Information Maximization) feature selection method, achieving a performance of over 99% with using only 3% of the total number of features.

Look—Do you see the noise leaking through that ceiling?

Oftentimes, acousticians must convey complex, three-dimensional, acoustical phenomena that occur within and between rooms in buildings to architects, interior designers and other visually oriented people. The message can be lost during translation from quantitative acoustics metrics and their acronyms to the design and intersection of actual building elements such as walls and ceilings. The current phase of the Optimized Acoustics Research Program focuses on turning sound absorption and sound isolation performance visual by using color mapping. Much like a thermal imaging camera shows differences in surface temperatures, a sound intensity probe is being used to produce high definition color sound mapping of noise transmitting through acoustical ceiling systems and sound reflecting off or being absorbed by surfaces with different absorption coefficients. This measurement method helps to bridge the gap between the technical, quantitative side of acoustics and the visual side of design in an impactful and memorable way.

Evaluation of the Four-dimensional “Spatiotemporal Image Correlation” Technology with High-definition Color Doppler as Third Step for Preoperative Differential Diagnosis of Ovarian Tumors: A Prospective Study

Evaluation of the Four-dimensional “Spatiotemporal Image Correlation” Technology with High-definition Color Doppler as Third Step for Preoperative Differential Diagnosis of Ovarian Tumors: A Prospective Study

Compression Efficiency of High Dynamic Range and Wide Color Gamut Pixel’s Representation

Ultra-high definition (UHD) is currently being deployed in video distribution pipelines for improved quality of experience. This new recommendation not only improves spatial and temporal resolution, but also the quality and accuracy of pixels using wide color gamut (WCG) and high dynamic range (HDR) technologies. Indeed, HDR video technology aims at conveying the full range of perceptible shadow and highlight details with enough different tonal levels to prevent loss of visual information, while WCG increases the amount of visible color that can be represented. However, these technologies require different standard digital pixel representations than the ones currently employed in high definition (HD) television. While the impact of increasing spatial and temporal resolution (i.e., increase of resolution and frame rate) on compression efficiency has already been assessed, it is not clear how new pixel representations would affect the compression performance. In this paper, we discuss the differences between HD color pixel representation and the newly standardized representations developed to meet the requirements introduced by WCG and HDR. Moreover we explain why existing HD pixel representations are sub-efficient for encoding HDR and WCG pixels. We also perform a statistical analysis of pixel distribution in real images to explain how pixel’s representation influences compression efficiency. Results show that by tailoring a pixel representation upon the range of luminance and color values accessible in content and displays, bandwidth savings can be achieved while increasing the quality of delivered content. We conclude this paper by discussing the shortcomings of the color pixel representation recommended for the UHD television standards and provide guidelines to create a more efficient one.

(Development of Contemporary Technical Formulations in Art Painting)

(Development of Contemporary Technical Formulations in Art Painting)

The Calibration of Kinect Camera Based on ARtoolkit

To deal with mutual occlusion of the virtual and real objects in the augmented reality scene, their depth values should be compared by using ARtoolkit and Kinect application programming interfaces (APIs). To improve the accuracy of the experiment, it has given up the existing default camera parameters file in ARtoolkit, and calibrated the Kinect camera to generate its own parameters data file. And different from the existing Kinect camera calibration methods, it abandoned the method of using the open NI SDK or extra high definition color camera as an intermediate bridge. Experimental results show this method has achieved a high accuracy and the validity by verifying in ARtoolkit.

Monter une histoire, montrer l’Histoire, table ronde sur le film documentaire historique

Seven film directors – Mehran Tamadon, David Korn-Brzoza, Jean-Gabriel Périot, Frédéric Gonseth, Stéphane Goël, Daniel Wyss et Alex Mayenfisch – discussed the four key-steps in historic documentary film production. Their seven points of view diverged on why and how films should and can portray History. From the roundtable brilliantly moderated by Anaïs Kien, producer for La Fabrique de l’Histoire at France Culture radio station, there emerged a variety of film-making practices – from purists of audiovisual archives to illusionists of high definition colour movies.

Variation of safety indices during in the learning curve for color Doppler assessment of the fetal heart at 11+0 to 13+6 weeks' gestation.

The aim of our study was to analyze the variation of acoustic output, as expressed by the thermal (TI) and mechanical index (MI), during the learning curve for a fetal heart scan at 11-13 gestational weeks, with the introduction of a new ultrasound system. This was a prospective, observational study on 303 normal fetuses. The fetal heart was examined transabdominally using B-Mode and high definition (HD) color Doppler to obtain standard parameters: four-chamber, outflow tracts and three-vessel-trachea views. Data were analyzed in groups of 20 consecutive examinations and the percentage of successful examinations was calculated. TI and MI were retrieved from HD color Doppler examinations of the fetal heart and from pulsed-wave Doppler assessment of the tricuspid flow and ductus venosus. MI values from the color Doppler examination of the fetal heart showed a continuous decrease (0.81 to 0.75, p<0.001), along the learning phase. TI and MI indices from pulsed-wave Doppler evaluation of the tricuspid flow increased at the beginning of the learning phase and stabilized afterwards (0.34 to 0.36, p<0.05 and 0.37 to 0.4, p<0.001, respectively). TI from color Doppler exam of the heart and indices from ductus venosus assessment were very constant and did not change along the studied periods. The length of Doppler examination of the heart increased after about 80 cases by 25%, to a mean of 4 minutes (p<0.05). Safety indices from Doppler evaluation of the fetal heart and tricuspid flow vary during the learning curve for fetal heart assessment. Also, the occurrence of constant values suggests the potential for their supplementary active reduction. For a better adaptation to a new ultrasound technology, the sonographer should scan the fetal heart longer in the first trimester and follow displayed safety indices along the first 80 cases.