Echo Area Research Articles

Characteristics of lacrimal passage diseases by 80-MHz ultrasound biomicroscopy: an observational study

PurposeTo investigate the microstructure of the lacrimal canaliculus and the characteristics of lacrimal canalicular diseases by 80-MHz ultrasound biomicroscopy (UBM).MethodsThis study included 33 participants: 20 normal subjects (40 eyes), 2 patients with chronic lacrimal canaliculitis (4 eyes), 10 patients with chronic dacryocystitis (16 eyes), and 1 patient with lacrimal punctum atresia (2 eyes). All participants underwent 80-MHz UBM; disease-specific features were noted.ResultsOn 80-MHz UBM of the lacrimal canaliculi (vertical section) in normal subjects, low echo of the lacrimal canalicular lumen and high echo of the lacrimal canalicular wall were observed. The uniform low echo near the wall was the mucosal epithelium. The outermost layer of medium-to-high echo was the subepithelial elastic fibrous layer. In the horizontal section, the lumen was continuous. Two linear high echoes parallel to the canalicular wall could be observed at the center of the lacrimal canaliculus, which were sometimes attached and sometimes separated. When separated, the center of the lacrimal canaliculus was a low echo area (lumen). Lacrimal canaliculitis (vertical section) showed obvious ectasia of the lacrimal canalicular lumen, with a high echo mass shadow, which might have been calculi, and uneven thickness of the mucosal epithelium with a slightly high echo shadow. In the horizontal section, the lumen varied in size with clear boundaries of medium and high echoes. The central linear high echoes of the lumen were absent, and the echoes of the mucosal epithelium were discontinuous. In chronic dacryocystitis, the lacrimal canalicular lumen was extensively enlarged, with continuous echoes and uniform thickness of the mucosal epithelium and homogeneous patches of slightly higher echoes. Lacrimal punctum atresia indicated that the lacrimal canaliculus existed in both eyes and its structure was normal.ConclusionsThe 80-MHz UBM is a new non-invasive technique that can be used for clear visualization of the fine structure of the lacrimal canaliculus, including the mucosal epithelium and subepithelial elastic fiber layer. The use of this approach will improve understanding of the hierarchical structure of the lacrimal canaliculi and provide a comprehensive basis for diagnosis, differential diagnosis, and treatment plan in patients with lacrimal passage diseases.

Multiresolution and velocity vector average processing algorithm for wind field retrieval based on Doppler radar

A multiresolution and velocity vector average processing algorithm is proposed to retrieve the wind field. When the radar echo area is divided into many square grids with sides of 5 km, the radar radial velocities on the edges and in the center of these grids are obtained through velocity vector averaging in the grid region. In order to solve the problem of a nonuniform wind field caused by different distances from echo to radar, the wind field is retrieved with a different angular resolution, whereas the Cartesian grid resolution remains unchanged. Through comparison and research, the correctness of this retrieval method is proven. At the same time, superposition application between geographic information and radar wind field is completed. The application based on this method can provide support for gale disaster early warning. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)

Two-pulse photon echo area theorem in an optically dense medium.

We perform a theoretical and experimental study of the two-pulse photon echo area conservation law in an optically dense medium. The experimental properties of the echo signal are studied at 4K on the optical transition 3H6(1)→3H4(1) (793 nm) of Tm3+ in a YAG crystal for a wide range of pulse areas of the two incoming light pulses, up to θ 1 r o x4π and θ 2≈7π respectively, with optical depth 1.5. We analyze the experimental data by using the analytic solution of the photon echo area theorem for plane waves. We find that the transverse Gaussian spatial profile of the beam leads to an attenuation of the echo area nutation as function of θ1 and θ2. Additional spatial filtering of the photon echo beam allows to recover this nutation. The experimental data are in good agreement with the solution of photon echo pulse area theorem for weak incoming pulse areas θ 1,2≲π. However at higher pulse areas, the observations diverge from the analytic solution requiring further theoretical and experimental studies.

Richter's Hernia in a 5-mm Trocar Site

A 59-year-old woman underwent laparoscopic staging surgery for malignant uterine tumors and recovered well. However, nausea and vomiting occurred on the eighth day after operation, and her anal exhaust did not stop. A soft mass was found in the subcutaneous tissue of the left lower abdomen on physical examination. The “spring sign” was indicated on the plain film (Fig. 1A). Ultrasound suggested that the weak echo area (Figs. 1B–3) was located in the muscular layer and connected to the abdominal cavity through a “channel” with an inner diameter of about 0.7 cm.

The international collaboration of active surveillance trials for low-risk DCIS (LORIS, LORD, COMET, LORETTA).

TPS603 Background: Retrospective data suggest breast cancer-specific survival rates with versus without surgery in patients with low-grade ductal carcinoma in situ (DCIS) are similar. Some DCIS patients have a low likelihood of progression to invasive cancer, but predicting who is at risk has not been established. Thus, treatment with a well-balanced risk / benefit ratio has not been achieved. Four active surveillance clinical trials for low risk DCIS have commenced in the United Kingdom (LORIS), Europe (LORD), United States (COMET), and Japan (LORETTA). We aim to examine the effectiveness & safety of active surveillance compared with surgical based treatment approaches for low-risk DCIS patients. Methods: Non surgical approaches are of the two types; active surveillance (AS) alone and AS + endocrine therapy (ET). In the randomized trials LORIS and LORD, the study arms are AS only, but while ET is an option in COMET, ET is mandatory in the single arm trial LORETTA. COMET and LORETTA have broader inclusion criteria as compared to LORIS and LORD. In COMET, comedo necrosis is eligible. In LORETTA, findings other than calcification on mammography (MMG) are also eligible (e.g. low echo area on breast ultrasound). Leaders of the four trials hold regular meetings to foster international DCIS trials collaboration to share information. LORIS Clinical trial information: ISRCTN27544579, LORD Clinical trial information: NCT02492607, COMET Clinical trial information: NCT02926911, LORETTA Clinical trial information: UMIN000028298 [JCOG1505]. Clinical trial information: UMIN000028298, NCT02492607, NCT02926911, ISRCTN27544579. [Table: see text]

Calibration of an X-band commercial radar and reflectivity measurements in suburban areas

Calibrating a radar system, i.e., establishing a precise relationship between the radar observable (the power level of the received signal) and the radar cross section (RCS, the equivalent echoing area) of the object, or surface, of interest is not a trivial task. Concerning radar observables, in this work, we are mostly interested in land clutter (bare soil and soil with vegetation of different types) and manmade objects such as buildings, lampposts, and tankers. Our aim is to calibrate a simple, lightweight X-band radar to create a map of the land clutter of a suburban and rural area, using the one around Tor Vergata University, Rome. In the frame of the vast literature on measurement and modeling of land clutter (see, for instance, the classical works in [1]–[3]), this article aims to contribute a practical methodology based on a movable, lightweight, small, and cheap marine radar and its calibration. Live results are also analyzed; they are related to RCS measurements in a typical suburban area, i.e., the one around Tor Vergata University, within the border of the Roma town district and close to the town districts of Frascati and Monteporzio Catone in the Castelli Romani area. University buildings, residential buildings, streets, highways, car-parking areas with different coatings, large and medium lampposts, bare soil, and soil with grass and trees, all in a radius of a few kilometers, make this area interesting as far as land clutter characterization is concerned. The main aims of such clutter characterization are the design and the optimal siting of X-band surveillance radars for various purposes, including the surveillance of airports (surface movements radar and apron control) and the surveillance of urban and suburban areas for detection of unauthorized drones. In all of these radar applications, a map of the clutter levels for each radar position is a useful tool.

Assessment of rectal feces storage condition by a point-of-care pocket-size ultrasound device for healthy adult subjects: A preliminary study

The aim of this study was to assess rectal feces storage condition by a pocket-size ultrasonography (PUS) in healthy adults so as to define normal rectal defecation desire. Participants were first assessed rectum by PUS imaging immediately after defecation desire (pre-defecation). Nurses checked the amount and quality of the participants' feces using King's Stool Chart and Bristol stool scale. Finally, PUS was performed for defecation with no defecation desire (post-defecation). Pre-defecation PUS detected high echo area in all patients. All of the post-defecation PUS did not detect high echo area (perfectly no recognizable high echo area in 54.5%, high echo line in 36.4%, and low echo of entire circumference in 9.1% of the patients). Average diameter of rectal crescent was 4.22 ± 0.8 cm. Bristol Stool Scale 1 or 2 (indicating hard stool) of pre-defecation PUS indicated high echo area and acoustic shadow in 100% of the patients. This study showed that healthy adult with defecation desire had high average rectal echo area of 4.0 cm in diameter. PUS may be able to define the rectum diameter for defecation desire of elderly people. PUS is capable of assessing fecal retention of the rectum for point-of-care examinations in home care.

Exploring the Value of Bedside Craniocerebral Ultrasound in the Dynamic Observation of Neonatal Subependymal Hemorrhage

Background: The purpose of this study is to investigate the ultrasonic performance of bedside brain ultrasound in the observation of subependymal hemorrhages (SEH) in newborns and provide evidence for clinical prevention and treatment of hemorrhage. 152 cases of newborns diagnosed as SEH were examined and followed up regularly, and their ultrasonographic features were analyzed. As a result, the craniocerebral ultrasound found strong and slightly strong echo in the anterior horn of the lateral ventricle and the thalamic caudate nucleus region, which did not affect the lateral ventricle. In the early stage of hemorrhage, the lesions showed a high echo and the border was slightly blurred. The echo gradually increased and the boundaries became clear at the stable period. During the absorption period, the center of the lesion was low echogenic and the edge was still hyper echoic, and gradually formed a poorly sound, separated thick cyst cavity. Subsequently, there was no echo area in the center of the lesion, and eventually the lumen was formed under the subependymal hemorrhage. Post discharge follow-up showed that 6 cases (3.95% 6/152), 75 cases (49.34% 75/152), 37 cases (24.34% 37/152), 13 cases (8.55% 13/152) had their cyst cavity disappeared after their hemorrhage in 1 months and 2 months, 3 months and 6 months. The patients with their lesions basically absorbed within 6 months accounted for 86.18% (131/152). Conclusion: Intracranial ultrasound has the advantage of early diagnosis of SEH, and it can be used to observe the patient's bedside examination, to observe the change of the course of the disease dynamically, to evaluate the blood transfer, to effectively guide the clinical medication and evaluate the prognosis.

Echoing landscapes: Echolocation and the placement of rock art in the Central Mediterranean

Many societies give special importance to places where echoes are generated, and often these places receive special treatment including the production of rock paintings in them. The identification of the exact places where echoes come from, or echolocation, is an ability only shared by a few individuals in each community. Unfortunately for archaeologists, however, their activity leaves no trace in the archaeological record. In this article we propose that the Ambisonics technique, a method developed in the field of acoustical physics, can be applied to identify the likely use of echolocation among societies for which no ethnographic information remains, such as most of those who lived in prehistoric Europe. A description of how this method has been applied in two case studies, the rock art landscapes of Baume Brune (Vaucluse, France) and Valle d’Ividoro (Puglia, Italy), is provided. In these two echoing areas only a few shelters were chosen to be painted with Schematic art, leaving around them many others undecorated. In the description of the fieldwork phase of the test, issues related to the sound source, the sound recorder, and spherical camera and how the Impulse Response (IR) measurement was made are discussed. The processed results indicate that there was a positive relationship between sound-reflecting surfaces and the location of rock art. This leads us to propose that in both areas there is a strong probability of echolocation having been employed by Neolithic people to select the shelters in which to produce rock art. The results obtained in our study also have wider implications in our understanding of how prehistoric peoples perceived the landscape in which they lived in, understood not only on the basis of tangible elements but, perhaps more importantly, because of intangible aspects such as sound and, in particular, echoes.

Photon echo area theorem for optically dense media

The McCall–Hahn area theorem for a photon echo in an optically dense medium is generalized in light of an absorption line consisting of several spectrally unresolved optical transitions and characterized by symmetrical form. Certain theoretical results are compared to experimental data obtained for a photon echo in a Tm3+:Y3Al5O12 crystal.

Etiology and clinical manifestations of hepatic space-occupying lesions

Hepatic space-occupying lesions refer to the lesions which are located in the abnormal echo area or density area of the liver parenchyma, have the appearance of nodule or mass, occupy a certain space, and may cause pressure, displacement, or invasion of adjacent liver tissue and vessels, as determined by imaging examination. Hepatic space-occupying lesions have various causes, as well as similarities and differences in clinical manifestations. An understanding of the etiology and clinical manifestations of hepatic space-occupying lesions helps with their diagnosis and differential diagnosis and the development of targeted therapeutic regimens to improve prognosis. This article introduces related issues, in order to help clinical physicians to expand their thoughts in diagnosis and treatment.

Construction and Application of Extreme Rainstorm Probability Prediction Based on Radar Echo Base Data

Based on a statistical relation betw een local Radar echo intensity base data and local heavy rainfall,to find the upstream echo areas that will move to the local raining region in next hour by the regional Lucas-Kanade optical flow method. Meanw hile to analyze the echo features at every scan surface,so that to learn the raining system stretching altitude. By analysis of the temporal and spatial characteristics of dynamic echo areas in current hour with information at scan surfaces every 10 minutes,to build the relation betw een Radar echo intensity features and local rainfall,then applied it on a predicting method of improved rainfall extreme probability,thus to construct forecast and warning index of extreme rainfall return period in next hour. The results will provide the technique support and professional reference for emergency schemes and strategy and tactics. The whole scheme is based on the Doppler radar echo intensity base data at scanning surfaces and the hourly precipitation data of Jianhu weather station during June,July,August in 2006-2011. Jianhu station is within the scanning area of the radar located at Yancheng. The echo dynamic upstream of the local heavy rainfall system is determined by the regional Lucas-Kanade optical flow method. The statistical probability correlation is calculated betw een echo intensity classification and precipitation series in day and night by Peirson III and Generalized Pareto Distribution methods. The probability characteristics of return period of graded extreme rainfall and the local extreme rainfall under the echo types are also calculated,then the statistic index is constructed betw een the radar echo dynamic features including the trend of evolution and the probability of local extreme rainfall in next hour,the index correlation and its test all get to 70%. The index can predict the probabilities of different grade extreme rainfall in return period at local place. It is an optimization method of radar dynamic statistics for now casting and warning of the extreme rainstorm in next hour.

Analyzing a Heavy Rainfall Process Based on Dual-Doppler Radar and Lightning Data

In order tofurther understand the application of Doppler radar data in mesoscale weather system as well as thedynamical structureof precipitationsystem,a large-scaledand more accurate inversion resultis aimed to get,basing on the new ly-proposed fuzzy logical algorithm of cloud classification and the two-step variational method which is applied to dual-Doppler radar. The data come from Dual-Doppler Radar' s(S-band) observation in Hefei and Fuyang,Anhui province. A heavy rainfall processoccurred in Anhui Province on 7 ~ 10 June in 2010 is analyzed by utilizing vertical accumulative total liquid water content(VIL),rainfalland distribution of lightning. The results show that this persistentrainfall is associated with the wind fieldsw hichcantains a convergence in low er layers and a divergence in higher layers,a cyclonic wind rotation and a wind shear line. This rainfall process which is based on stratiformis show n to be a hybridcumuluscloudprecipitation. Besides,the stratiform lightning is few during this rainfall and mainly focuses on the negative ground flashes. The heavy rain occurred20 minutes or so after lightning. The value of VIL in this heavy rainfall is small,which is less than 3 kg ·m-2.There are strong relationships among cloudclassification,the area of rain,VIL and Radar's echo.

Design and Implementation of Radar Cross-Section Models on a Virtex-6 FPGA

The simulation of radar cross-section (RCS) models in FPGA is illustrated. The models adopted are the Swerling ones. Radar cross-section (RCS) which is also termed as echo area gives the amount of scattered power from a target towards the radar. This paper elucidates the simulation of RCS to represent the specified targets under different conditions, namely, aspect angle and frequency. This model is used for the performance evaluation of radar. RCS models have been developed for various targets like simple objects to complex objects like aircrafts, missiles, tanks, and so forth. First, the model was developed in MATLAB real time simulation environment and after successful verification, the same was implemented in FPGA. Xilinx ISE software was used for VHDL coding. This simulation model was used for the testing of a radar system. The results were compared with MATLAB simulations and FPGA based timing diagrams and RTL synthesis. The paper illustrates the simulation of various target radar cross-section (RCS) models. These models are simulated in MATLAB and in FPGA, with the aim of implementing them efficiently on a radar system. This method can be generalized to apply to objects of arbitrary geometry for the two configurations of transmitter and receiver in the same as well as different locations.

Recognition of hail and rainstorm based on the radar reflectivity image features

Based on radar reflectivity image features, an automatic recognition method is proposed to identify the hail and rainstorm. We extract the image features of hail echo areas and rainstorm echo areas from radar reflectivity images. By analyzing both the differences in single feature between hail and rainstorm and the classified complementarity among different features, we determine the effective image features, including the intensity and texture features, to identify the hail and rainstorm. The hail and rainstorm objective recognition model can be established through the data mining of the extracted sample features and sounding data by using the Rough Set Theory. Through the test and identification of the 362 test samples, the hit ratio of hail reaches 93.29% and the hit ratio of rainstorm reaches 89.07%. The false alarm ratios of hail and rainstorms can be also at a low level. Compared with those from the PUP system, the experimental results from the present system show that it has a good effect to identify and classify hail and rainstorm by using the radar reflectivity image features.

Diagnosis of occult posterior scleral rupture with B-scan ocular ultrasonography

Objective To assess the value of the B-scan ocular ultrasonography in patients with no ocular surface wounds and suggestive of posterior scleral rupture.Methods Thirty-six eyes of 36 patients suggestive of posterior scleral rupture were examined with B-scan to observe the images of posterior segment of eyeball and retrobulbar contents.Results In 36 cases,the major radiographic signs included vitreous hemorrhage(36 eyes,100％),hemorrhagic choroidal detachment (29 eyes,80.56％),retinal detachment (13 eyes,36.11％).The images of 8 eyes with occult posterior scleral rupture diagnosed by B-scan ocular ultrasonography showed the changes of globe contour,interruption of occular ring,or the uneven low echo area in middle peripheral eyeball.The occult posterior scleral ruptures in these 8 eyes were confirmed by surgeries or pathological examinations.Conclusion For patients diagnosed as severe ocular contusion,who present with large subconjunctival hemorrhage,no wounds in cornea or sclera,especially with low intraocular pressure,B-scan ocular ultrasonography is necessary to detect occult posterior scleral rupture to avoid delaying the optimal surgical timing. Key words: B-scan ultrasonography ; Rupture,posterior scleral

Оценка точности современных компьютерных программ для вычисления эффективной поверхности рассеяния объектов

Оценка точности современных компьютерных программ для вычисления эффективной поверхности рассеяния объектов

PTU-095 Liver Lesions on Ultrasonography: is it Cancer or not?

IntroductionThe ultimate goal of the United Kingdom Cancer plan is to ‘offer patients a maximum one month wait from an urgent referral for suspected cancer to the beginning of treatment’.The...

X-밴드 이중편파레이더에서 관측된 채프에코의 특성

채프에코는 기상레이더 영상에서 강수에코로 자주 오인된다. 본 연구에서는 채프에코를 효과적으로 제거하기 위하여 국립기상연구소 X-밴드 이중편파레이더에서 관측한 자료를 활용하여 채프에코의 반사도와 각각의 이중편파변수의 관계성을 분석하였다. 특히 본 연구는 채프에코 사례의 입체관측자료 영상에서 채프에코가 발생한 영역만을 선별하여 이중편파변수 자료들을 수집하였다. 전반적으로 이중편파변수(반사도, 차등반사도, 교차상관계수, 차등반사도 표준편차와 비차등위상차)에 대해 채프에코의 변수 값이 강수에코보다 넓은 범위를 차지하며, 채프 섬유의 공간적 배치는 레이더빔에 대해 수평적으로 놓여있는 경향이 나타났다. 일부 강수에코의 교차상관계수는 0.8 이하의 값을 갖고 있기 때문에 채프에코 값과 상당한 중첩이 나타났다. 일반적으로 교차상관계수는 강수에코와 채프에코를 효과적으로 분리하는데 좋은 변수로 고려되고 있지만, 이 연구는 교차상관계수만을 이용하여 채프에코를 제거할 경우에 일부 강수에코가 제거될 가능성이 있음을 시사한다. To effectively remove chaff echoes, which are often misidentified as precipitation echoes on weather radars, this study examines the relationship between the radar reflectivity and each of dual polarimetric parameters. The dual polarimetric parameters are collected only for the echo areas identified as chaff echoes on the NIMR X-band dual polarization radar. Overall, the polarimetric parameters (i.e., reflectivity, differential reflectivity, cross correlation coefficient, standard deviation of differential reflectivity and specific differential phase) for chaff echoes have a wider range of values than those for precipitation echoes and the chaff filaments tend to be horizontally oriented to radar beams. There appears to be a considerable overlap in the cross correlation coefficient range of chaff and precipitation echoes since some precipitation echoes have cross correlation coefficient lower than 0.8. Therefore, although the cross correlation coefficient is known to be a good variable in identifying and separating chaff echoes from precipitation echoes, it is suggested that additional care should be taken when using the cross correlation coefficient solely in removing chaff echoes.

Ground-based Salt Seeding in Tamil Nadu State, South Inida, 1973-1977

A long series of ground-based salt seeding experiments in north India during the southwest monsoonseasons (June-September) of 1957-66 showed significant increases of about 20 percent in rainfall on seeded days (Ramana Murty and Biswas, 1968). In September of 1974, salt seeding from aircraft on isolated maritime warm cumulus clouds within 50 km off the coast at Bombay(18 15’N, 72v 49’D, II m ASL) was followed by increases in radar echo area coverage in the vertical and in echo intensity (Chatterjee et al., 1978). seek similar results in a different area, a randomized salt-seeding experiment, using a single ground-based generator, was conducted in 1973 and 1975-77 just west of Madras, on the Bengal coast 1,000 km southeast of Bombay. There in the state of Tamil Nadu, South India, the main rainy season is during the northeast monsoon(Oct-Dec), whereas in most parts of India, about 75 percent of the annual rainfall is received during the southwest monsoon(Ananthakrishnan, 1977).