Image Definition Research Articles

Varifocal liquid microlens in scaffold microstructures under electrothermal actuation

Liquid microlens (LML) has attracted wide attention due to their miniaturization, uniformities and easy integration in adaptive optical systems. However, optical aberration and simple varifocal imaging are still critical challenges for the broader application of LML. Inspired by the easy deformation of droplets trapped by micropillars, LML in scaffold microstructures are proposed. In this paper, we present a simple, low-cost and effective approach to fabricate LML in scaffold microstructures. Our LML consists of glycerol droplets trapped in hydrophobic NOA71 scaffold microstructures, which are imprinted onto an ITO glass substrate to enable electrothermal control of the LML imaging characteristics. The electrothermal control allows changing the shape of the LML spherical surface, thus making it possible to tune their focus, decrease their imaging aberration, and improve their imaging definition. The electrothermal actuator is obtained by applying a DC power with a voltage of 8.4 V and a current of 0.39 A onto the ITO glass. It is found that the imaging aberration of LML reduced by 6 times of initial state and the imaging definition of LML increased by 2.8 times of initial state on the DC power for 2 min. Thus, the LML in scaffold microstructures demonstrates the potential of the adjustable imaging performance in the development of integrated dynamical tunable optical devices.

Cavernous sinus haemangioma: systematic review and pooled analysis relating to a rare skull base pathology

Cavernous sinus haemangiomas (CSHs) are rare malformations of the microcirculation arising from the cavernous sinus. A systematic review and pooled data analysis of the associated clinical features, diagnostic modalities, management, and outcomes for CSHs was done. In total, 68 articles (338 cases) were eligible for analysis based on our selection criteria. The primary outcome measures were the occurrence of (i) and (ii) symptom resolution/improvement. Categorical outcome variables were assessed by binary logistic regression at 5% significance level. With headaches (39.9%) and diplopia (36.5%) as the most common presenting symptoms reported, dynamic contrast-enhanced MRI was the most commonly used diagnostic modality and was the most definitive pre-treatment imaging modality for diagnosing CSH with a sensitivity of 89.5%. The majority of CSHs were managed with radiosurgery (47.9% of cases), 37.9% by surgical resection alone, and 14.2% by a combination of both. Compared to patients that were treated with surgical resection only, those treated solely with radiosurgery had a 100% decrease in the odds of developing post-treatment complications (adjusted OR: 0.00, 95% CI: 0.00-0.002, p < 0.001), with a 5.03 times greater odds of symptom resolution/improvement (adjusted OR: 5.03, 95% CI: 1.89-13.4, p = 0.001). Patients that underwent combined therapy had a 79% reduction in risk of developing post-treatment complications (adjusted OR: 0.21, 95% CI: 0.06-0.68, p = 0.01), with no statistically significant difference in the odds of symptom resolution/improvement, compared to those that had surgery only. In conclusion, radiosurgery offered the best outcomes with regards to symptom resolution/improvement and post-treatment complications in patients with CSH.

The Influence of Curriculum on the Concept of Function: An Empirical Study of Pre-Service Teachers

This article reports on the understanding of the function concept by pre-service mathematics teachers from two countries (Germany and Croatia). We focused on investigating students’ concept definition and concept image of the function in relation to their curriculum experiences. Data were collected using a questionnaire in the form of open-ended questions followed by interviews. The results indicate that the curriculum has a great influence on the development of the concept definition and concept image. The curriculum strongly influenced the theoretical background of the function concept and thus the gap between the formal and the personal definition of function. Later and more intensive work with the formal definition of function led to a better development of the function concept in general. The curriculum also had an influence on the range of the concept image developed by the pre-service mathematics teachers, with no proportional dependence in relation to the better developed understanding of the concept of function.

Metaplastic breast carcinoma: an overview of the radio-pathologic features in retrospective cohort tertiary hospital

BackgroundMetaplastic breast carcinoma (MBC) is a rare type of breast carcinoma. It accounts for 0.2–1% of all invasive breast carcinoma. The aim of this study is to investigate the radiological features of this tumor and correlate them with the pathological findings.ResultsOf the 22 patients with pathology-proven metaplastic cancers, 18 patients (81.82%) presented with a palpable mass. The majority of the mammogram findings were masses with irregular shapes (n = 12, 63.16%) and indistinct margins (n = 11, 57.89%). Similarly, the majority of the ultrasound studies showed masses with irregular shapes (n = 16, 72.73%) and indistinct margins (n = 8, 36.36%). Most of the echopatterns were complex or with heterogeneous textures, each presented in eight cases (36.36%). More than half of the cases had a posterior acoustic enhancement (n = 12, 54.55%). Most of the cases tested negative for estrogen receptors, progesterone receptors and HER2 protein, and they were high-grade tumors with a high proliferative index (Ki-67%) of > 15%.ConclusionMBC is a rare and distinct aggressive breast cancer with no definite characteristic imaging compared to other breast cancer. It shows a mass with irregular shape and indistinct margins in both mammogram and ultrasound. Additionally, it reveals posterior acoustic enhancement and rarely contains microcalcifications. The correlation with the pathological findings is crucial for the diagnosis and subsequent appropriate treatment.

Imaging of neuroendocrine neoplasms of the male GU tract.

Male genitourinary neuroendocrine neoplasms (GU-NENs) are rare, without any definite imaging characteristics. The WHO classified neuroendocrine neoplasms in the 2016 classification of the tumors of the urinary tract and genital organs along with other GU tumors; however, no pathologic grading system is available as published for gastroenteropancreatic neuroendocrine neoplasms. Often a multimodality approach using cross-sectional imaging techniques, such as molecular imaging and histopathology are implemented to arrive at the diagnosis. This article provides a review of the pathology and imaging features of the male GU-NENs.

Preliminary experience with 3D digital image microscope system on the treatment of varicocele.

The three-dimension digital image microscope system (3D-DIM) with a better ergonomic design and equipment characteristics can contribute to the achievement of good results during microsurgery. In this study, the safety and efficiency of 3D-DIM assisted varicocelectomy was evaluated. From July 2019 to November 2019, fifteen cases with varicocele (20 sides of varicocele in total) were included, seven cases underwent 3D-DIM-assisted modified microsurgical subinguinal varicocelectomy, and eight cases underwent modified microsurgical subinguinal varicocelectomy under standard operating microscope (SOM). The mean operative time of 3D-DIM group (67±12.3min) was a little longer than that of SOM group (55±12.9min) (p<0.05). There was no significant difference between the two groups in the number of internal spermatic arteries, internal spermatic vein, lymphatics, gubernacular vein, external spermatic vein and post-operation complications. The 3D-DIM showed a significant difference in image definition for nurse (p<0.01) and in doctor-nurse cooperation (p<0.05) over SOM. The 3D-DIM with better ergonomic design and image definition can be applied to perform microsurgical subinguinal varicocelectomy, and could improve the surgeon's fatigue and doctor-nurse cooperation. We believe that the 3D-DIM would be widely used in the field of male infertility microsurgery in the near future.

353 The Rise of the Exoscope

Abstract Introduction An exoscope is a next generation HD telescope video monitoring system used to perform microsurgeries that is now a formidable rival to the existing operating microscope in neurosurgery. While the microscope revolutionised neurosurgery with its advent in 1957, the exoscope allows surgeons to operate utilising high-definition images enhancing the field of vision and focus. The exoscope opens new avenues with regards to ergonomics, teaching in theatre and enhances the surgeon’s experience. Method We will do a literature review on available literature on the use of exoscope in neurosurgery with regards to the operating microscope. Both qualitative and quantitative data will be reviewed. Personal experience of Neurosurgeons in our unit will also be reviewed using questionnaires. Results The exoscope has many benefits when compared to the operating microscope where it surpasses its predecessor in many ways. 15 studies were reviewed where the exoscope was compared to the operating microscope which concluded the exoscope equal or superior in many aspects such as teaching, ergonomics, image definition and being user friendly. There were some pitfalls of the exoscope reported such as the image being in 2D which limited the surgeon’s stereoscopic vision and the costs involved. Conclusions The exoscope is a revolutionary advent in neurosurgery and may soon make the operating microscope obsolete but there is still room for improvement.

Wykorzystanie wizerunku pacjenta przez lekarza. Zdjęcia przed i po zabiegu

Abstract The aim of this publication is to discuss theoretical issues related to the dissemination of the so-called before and after photos presenting an image of a patient. The paper will discuss the definition of the patient's image, as well as characterise the permission for dissemination of the patient's image, with particular emphasis on its unclear legal construction. Practice shows that the image of a patient may be disseminated for advertising purposes. As a rule, the purpose of dissemination of "before and after" photographs will be self-promotion of the doctor, consisting in encouraging potential patients to use a given service. However, such photo-reporting may have prohibited features of advertising.

Research on Autofocus Recognition of the LAMOST Fiber View Camera System Under Front and Back Illumination

In the closed-loop detection system of the LAMOST, the lens of the fiber view camera system must focus the end of the optical fiber to accurately acquire the fiber position. It is difficult to evaluate the fibers image with a very small proportion of the image with the traditional autofocus algorithm, whether it is recognition of the front illuminated by the fiber ceramic ferrules, or the light-emitting spot of the fibers in the black background, that is, the recognition of the back illumination of the fibers. In this paper, we propose an autofocus determination method for the LAMOST closed-loop control under front and back illumination conditions. Under the condition of front illumination, to greatly reduce the calculation time, the system first pre-recognizes the focusing target through the Faster R-CNN and then uses an optimized contrast algorithm to evaluate the image definition of the corrected focusing target ROI. Then, the algorithm is compared with Tenengrad gradient and Laplacian gradient calculations using the Sobel operator and Laplacian operator in OpenCV. The results show that this method takes only one-ninth of the time required by the other methods to obtain the same accuracy. Under the condition of back illumination, we use the average number and average brightness of spot pixels as the evaluation basis of image sharpness. This method can complete the evaluation of image sharpness in the process of spot recognition and provide initial data for the subsequent detection for closed-loop control. The focus accuracy of the camera is of great significance for thousand-fiber metrology, which will have an important influence on the accuracy of astronomical observations. These focusing methods not only play an important role in the closed-loop control of the LAMOST but also apply to the focusing of closed-loop detection systems of other multi-target optical fiber spectral astronomical telescopes.

Corporate image as a high-order construct in hospitality

PurposeThe purpose of this paper is to empirically investigate the corporate image as a high-order construct in the hospitality industry. Therefore, it includes an important part of all the agents that contribute to the formation of this corporate image: the clients, the employees and the hotel management.Design/methodology/approachIn order to better conceptualize and understand the dimensions of corporate image in the hospitality industry, a theoretical systematization and analysis of the literature on corporate image definitions and validated scales to date are presented. The primary research is based on a questionnaire survey that emerged from the theoretical model. The collected data were tested using confirmatory factor analysis and covariance-based structural equation modelling (CB-SEM).FindingsResults indicate that corporate image is a high-order construct that includes the dimensions of symbols from servicescape, employees' behaviour, perception of the organization, perception of the management, perception of the service and perception of the hotel.Research limitations/implicationsThe application of this paper will enable new research in the corporate marketing literature, while the presented multidimensional approach will support future empirical research on corporate image in hospitality.Originality/valueThe paper contributes to theory by conceptualizing the corporate image as high-order construct. It provides evidence of corporate image multidimensionality, comprising six dimensions. Moreover, the findings provide an insight for practitioners to better understand how to manage hotel image.

Acute pancreatitis associated with gangrenous cholecystitis in the absence of definitive laboratory or imaging evidence: Case report and literature review

Gangrenous cholecystitis (GC) is the most severe form of cholecystitis and is associated with acute pancreatitis. Once GC diagnosis is established, urgent cholecystectomy is recommended. The preoperative diagnosis is challenging, and clinical judgment can be critical. We report a case of GC with acute pancreatitis diagnosed in the absence of definite laboratory or imaging evidence. Keywords: gangrenous cholecystitis; acute pancreatitis; diagnosis; clinical judgment. Abbreviations: GC: Gangrenous cholecystitis; CT: computed tomography

Magnetic Resonance Imaging as a Prognostic Disability Marker in Clinically Isolated Syndrome and Multiple Sclerosis: A Systematic Review and Meta-Analysis.

To date, there are no definite imaging predictors for long-term disability in multiple sclerosis (MS). Magnetic resonance imaging (MRI) is the key prognostic tool for MS, primarily at the early stage of the disease. Recent findings showed that white matter lesion (WML) counts and volumes could predict long-term disability for MS. However, the prognostic value of MRI in the early stage of the disease and its link to long-term physical disability have not been assessed systematically and quantitatively. A meta-analysis was conducted using studies from four databases to assess whether MS lesion counts and volumes at baseline MRI scans could predict long-term disability, assessed by the expanded disability status scale (EDSS). Fifteen studies were eligible for the qualitative analysis and three studies for meta-analysis. T2 brain lesion counts and volumes after the disease onset were associated with disability progression after 10 years. Four or more lesions at baseline showed a highly significant association with EDSS 3 and EDSS 6, with a pooled OR of 4.10 and 4.3, respectively. The risk increased when more than 10 lesions were present. This review and meta-analysis confirmed that lesion counts and volumes could be associated with disability and might offer additional valid guidance in treatment decision making. Future work is essential to determine whether these prognostic markers have high predictive potential.

Efficacy of 3D dynamic image analysis for characterising the morphology of natural sands

Two-dimensional (2D) dynamic image analysis (DIA) is gaining acceptance in geotechnical engineering research. Three-dimensional (3D) DIA extracts features from 8–12 projections of a particle and thus it is believed to verge on the true particle morphology. DIA is fast, efficient and convenient for characterising thousands of particles quickly; nevertheless, it captures shapes that are fundamentally different from the 3D morphologies reconstructed using micro-computed tomography (μCT). In DIA, particle features are interpreted using external images of a particle, which fail to account for differences in imaging perspectives. In addition, 2D and 3D shape descriptors are influenced by differences in dimensionality projection owing to variations in definition, dimensionality and perspectives of the particle images employed, which causes them to differ from their 3D counterparts. In this study, the sand particle size and shape descriptors obtained using both DIA and μCT are compared for three natural sands having wide granulometries. Three-dimensional DIA offers significant advantages in terms of efficiency, while providing adequate representation of Feret dimensions, sphericity and convexity. However, the study demonstrates that 3D roundness is difficult to characterise using DIA and that shape measurements of complex irregular calcareous sands obtained from 3D DIA are not comparable to those obtained using μCT.

Methodology for Interactive Labeling of Patched Asphalt Pavement Images Based on U-Net Convolutional Neural Network

Image recognition based on deep learning generally demands a huge sample size for training, for which the image labeling becomes inevitably laborious and time-consuming. In the case of evaluating the pavement quality condition, many pavement distress patching images would need manual screening and labeling, meanwhile the subjectivity of the labeling personnel would greatly affect the accuracy of image labeling. In this study, in order for an accurate and efficient recognition of the pavement patching images, an interactive labeling method is proposed based on the U-Net convolutional neural network, using active learning combined with reverse and correction labeling. According to the calculation results in this paper, the sample size required by the interactive labeling is about half of the traditional labeling method for the same recognition precision. Meanwhile, the accuracy of interactive labeling method based on the mean intersection over union (mean_IOU) index is 6% higher than that of the traditional method using the same sample size and training epochs. In addition, the accuracy analysis of the noise and boundary of the prediction results shows that this method eliminates 92% of the noise in the predictions (the proportion of noise is reduced from 13.85% to 1.06%), and the image definition is improved by 14.1% in terms of the boundary gray area ratio. The interactive labeling is considered as a significantly valuable approach, as it reduces the sample size in each epoch of active learning, greatly alleviates the demand for manpower, and improves learning efficiency and accuracy.

Endoscope FOV Autonomous Tracking Method for Robot-Assisted Surgery Considering Pose Control, Hand–Eye Coordination, and Image Definition

In laparoscopic surgeries, intelligent assisted endoscope-holding robots (AEHRs) with traditional servo control have limited performance due to the lack of endoscopic attitude control, hand-eye coordination, and image definition. This paper proposes an endoscope field-of-view (FOV) autonomous tracking method for robot-assisted surgery (RAS) considering pose (i.e., position and attitude) control, hand-eye coordination and image definition, it can realize that the AEHR system can safely, stably and quickly track the movement of surgical instruments. Firstly, the general framework of the intelligent tracking system with robot-assisted endoscope-holding is constructed according to the clinical needs and shortcomings of traditional research. Secondly, the kinematic model and remote center of motion (RCM) constraint equations of AEHRs are established. Then, surgical instrument tips are segmented and localized using the deep learning method (DLM), and further, a surgical FOV intelligent adjustment control model with multiple indexes is developed. Finally, an experimental system based on the hybrid of AEHRs and speech interaction is built. The simulation and experimental results demonstrate that the proposed method can achieve fast, accurate, and effective instrument tips tracking (ITT), reduce hand-eye incoordination, and improve the safety and stability of FOV intelligent adjustment.

Application of narrow band imaging in early screening of colorectal cancer

To explore the clinical application value of narrow band imaging (NBI) in the early screening of colorectal cancer. 200 patients were selected as the research objects, and were divided into test group and control group by the randomization method, within 100 cases in each group. The patients in the test group were examined by NBI, while the patients in the control group were examined by ordinary endoscopy, and then the lesion detection rate, image definition and pathological examination results of the two groups were compared. After the patients in the test group received NBI examination, the lesion detection rate, image definition and lesion detection coincidence rate were significantly higher than those of the control group, and the comparative difference between the two groups was statistically significant (P < 0.05). NBI examination of colorectal mucosa can clearly show the pit pattern and the morphological structure of capillaries of the early colorectal cancer and its precancerous lesions, thus effectively improving the diagnosis rate of early colorectal cancer and its precancerous lesions, playing a good clinical application value in the early screening of colorectal cancer, and guiding the later treatment, so it is suitable for clinical promotion.

Consensus guidelines on the role of cholangioscopy to diagnose indeterminate biliary stricture.

Indeterminate strictures pose a therapeutic dilemma. In recent years, cholangioscopy has evolved and the availability of cholangioscopy has increased. However, the position of cholangioscopy in the diagnostic algorithm to diagnose malignancy have not been well established. We aim to develop a consensus statement regarding the clinical role of cholangioscopy in the diagnosis of indeterminate biliary strictures. The international experts reviewed the evidence and modified the statements using a three-step modified Delphi method. Each statement achieves consensus when it has at least 80% agreement. Nine final statements were formulated. An indeterminate biliary stricture is defined as that of uncertain etiology under imaging or tissue diagnosis. When available, cholangioscopic assessment and guided biopsy during the first round of ERCP may reduce the need to perform multiple procedures. Cholangioscopy are helpful in diagnosing malignant biliary strictures by both direct visualization and targeted biopsy. The absence of disease progression for at least 6 months is supportive of non-malignant etiology. Direct per-oral cholangioscopy provides the largest accessory channel, better image definition, with image enhancement but is technically demanding. Image enhancement during cholangioscopy may increase the diagnostic sensitivity of visual impression of malignant biliary strictures. Cholangioscopic imaging characteristics including tumor vessels, papillary projection, nodular or polypoid mass, and infiltrative lesions are highly suggestive for neoplastic/malignant biliary disease. The risk of cholangioscopy related cholangitis is higher than in standard ERCP, necessitating prophylactic antibiotics and ensuring adequate biliary drainage. Per-oral cholangioscopy may not be the modality of choice in the evaluation of distal biliary strictures due to inherent technical difficulties. Evidence supports that cholangioscopy has an adjunct role to abdominal imaging and ERCP tissue acquisition in order to evaluate and diagnose indeterminate biliary strictures.

Evaluation of Nursing Effects of Pelvic Floor Muscle Rehabilitation Exercise on Gastrointestinal Tract Rectal Cancer Patients Receiving Anus-preserving Operation by Intelligent Algorithm-based Magnetic Resonance Imaging.

Based on magnetic resonance imaging (MRI) technology under artificial intelligence algorithm, the postoperative nursing effects of pelvic floor muscle rehabilitation exercise on gastrointestinal tract rectal cancer (RC) patients were investigated. A total of 88 patients receiving RC anus-preserving surgery in hospital were selected. The included patients were divided randomly into the experimental group (44 cases) and the control group (44 cases). Patients in the control group engaged in Kegel motion, while patients in the experimental group underwent self-designed comprehensive pelvic floor training. Anorectum function rating scale and quality of life questionnaire for colorectal cancer (EORTC QLQ-CR29) were utilized to compare and analyze anus functions and living quality of patients in the two groups. Besides, all patients in two groups received MRI examinations, and images were processed by a convolutional neural network (CNN) algorithm. The results showed that in MRI images, there were significant signal differences between lesion tissues and normal tissues. After being processed by an artificial intelligence algorithm, the definition of MRI images was remarkably enhanced with clearer lesion edges. The quality of images was also significantly improved. Besides, the comparison of anus functions of patients in two groups showed that the differences demonstrated statistical meaning after the intervention (P < 0.05). In conclusion, artificial intelligence algorithm-based MRI and comprehensive pelvic floor muscle exercise showed significant application prospects and values in the recovery of patients' intestinal functions after RC anus-preserving surgery.

Reperfusion Injury-Related Intramyocardial Hemorrhage

Myocardial reperfusion injury is defined as the death of cardiomyocytes as a direct result of one or more events initiated by reperfusion. These events could be inflammation, oxidative stress, calcium overload, neurohumoral activation, cytotoxicity of anaerobic metabolites, etc. Intramyocardial hemorrhage as a consequence of ischemia–reperfusion injury during acute myocardial infarction and subsequently is frequent and portends worse prognosis. Animal studies have demonstrated that intramyocardial hemorrhage does not occur with ST-elevation myocardial infarction unless myocardium is reperfused with blood. Magnetic resonance imaging is the technique of choice for its detection but has limited availability in emergencies and is expensive. Echocardiography can be used for indirect myocardial tissue characterization. Echocardiography coupled with myocardial contrast imaging is increasingly being used for detecting hemorrhage in infarcted segments. In the presence of wall motion abnormality, increased segmental echogenicity, significantly increased wall thickness underlying hypermobile endocardium, and neocavitations within the myocardium are the characteristic features. Occasionally, extensive wall splitting and formation of pseudotumor due to large hematoma are the striking features of intramyocardial hemorrhage. Intramyocardial hemorrhage in acute myocardial infarction can occur during early phase, following reperfusion and during remodeling process. There is no definite echocardiographic imaging method to assess reperfusion hemorrhage in vivo, but signal-void cavity-like or cystic appearance within the myocardium in the setting of myocardial infarction is highly suggestive. Detecting hypointense area of hemorrhage could be complicated by low-intensity echoes emanating from the normal myocardium. Echocardiography should be performed in every patient before and after reperfusion therapy and serially till discharge. There are no studies comparing the diagnostic yield of echocardiography compared to magnetic resonance imaging. Those with obvious myocardial hematoma need special attention with regard to antiremodeling agents, dual antiplatelet therapy, and possibly surgery. A majority of patients with significant intramural hemorrhage end up having reduced left ventricular function, adverse remodeling, true or pseudo-aneurysms, and even heart failure although spontaneous resorption has also been reported.

Emergency brain imaging findings in children with first afebril convulsion

Convulsion is the most common neurological disease seen in childhood and constitutes 4-10% of all neurological diseases and 2% of the admissions to child emergency rooms. While the primary purpose of performing emergency neuroimaging in a child presenting with the first afebrile convulsion is to investigate intracranial pathologies that may require urgent intervention. The cranial imaging to be performed for this purpose are transfontanellar ultrasonography, computed tomography, and magnetic resonance imaging. We aimed to evaluate the necessity, the contribution to diagnosis, and the effect of treatment of magnetic resonance imaging that was performed in the emergency rooms. Patients who were admitted to the pediatric emergency room for a one-year complaint of their first afebrile convulsion and performed brain magnetic resonance imaging in the pediatric emergency room within the first 24 hours of hospital admission were evaluated retrospectively. A statistically significant correlation was found between the abnormal magnetic resonance imaging and abnormal physical examination of the patients (p&lt;0.001). By the brain magnetic resonance imaging findings acute changes were made in the treatment of 7 cases (1.3%) There was no statistically significant relationship between the magnetic resonance imaging abnormality and emergency seizures. We determined that it would be more appropriate to perform magnetic resonance imaging in outpatient clinics in cases where transportation can be provided early, in cases above 6 years of age without risk factors, and have a normal examination. Nonetheless, higher magnetic resonance imaging rates lead to lower computed tomography rates and ıts beneficial for pediatric patients in limiting radiation and providing definitive structural imaging for seizures.