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Triangle meshes are used in many important shape-related applications including geometric modeling, animation production, system simulation, and visualization. However, these meshes are typically generated in raw form with several defects and poor-quality elements, obstructing them from practical application. Over the past decades, different surface remeshing techniques have been presented to improve these poor-quality meshes prior to the downstream utilization. A typical surface remeshing algorithm converts an input mesh into a higher quality mesh with consideration of given quality requirements as well as an acceptable approximation to the input mesh. In recent years, surface remeshing has gained significant attention from researchers and engineers, and several remeshing algorithms have been proposed. However, there has been no survey article on remeshing methods in general with a defined search strategy and article selection mechanism covering the recent approaches in surface remeshing domain with a good connection to classical approaches. In this article, we present a survey on surface remeshing techniques, classifying all collected articles in different categories and analyzing specific methods with their advantages, disadvantages, and possible future improvements. Following the systematic literature review methodology, we define step-by-step guidelines throughout the review process, including search strategy, literature inclusion/exclusion criteria, article quality assessment, and data extraction. With the aim of literature collection and classification based on data extraction, we summarized collected articles, considering the key remeshing objectives, the way the mesh quality is defined and improved, and the way their techniques are compared with other previous methods. Remeshing objectives are described by angle range control, feature preservation, error control, valence optimization, and remeshing compatibility. The metrics used in the literature for the evaluation of surface remeshing algorithms are discussed. Meshing techniques are compared with other related methods via a comprehensive table with indices of the method name, the remeshing challenge met and solved, the category the method belongs to, and the year of publication. We expect this survey to be a practical reference for surface remeshing in terms of literature classification, method analysis, and future prospects.

A 78-year female presented with the complain of per rectal fresh bleeding for 4 days. She was known to have diabetes and hypertension, 3 weeks back. She had an episode of left middle cerebral artery (MCA) stroke. After stroke, she suffered from upper limb weakness and aphasia. At the time of presentation, her vitals showed blood pressure of 118/52 mmHg, O2 saturation of 98%, temperature: 37°C, respiratory rate (RR) of 20/min, and heart rate (HR) of 90 bpm. After achieving hemodynamic stability, she was transferred to radiology department. Her presenting complain of active rectal bleeding was managed by interventional radiologist using angiographic embolisation. In this patient, it was found pooling of blood in a retrograde fashion in the sigmoid colon. Bleeding was initially believed to be coming from sigmoid arteries seen on images of CT scan and colonoscopy. However, arteriography showed that source of bleeding was from middle and inferior rectal arteries that originated from left internal iliac artery. The intervention radiology (IR) team had to put in extensive effort to locate and perform therapeutic embolisation.

Introduction The RENAL (radius, exophytic/endophytic properties, nearness of tumor to the collecting system or sinus in millimeters, anterior/posterior, location relative to polar lines) nephrometry score (RENAL-NS) has been described as a structured and quantifiable method to describe a renal tumor's relevant anatomic features as they relate to the complexity of the lesion. We aim to evaluate a tumor's RENAL-NS and to assess the reproducibility of the score among different observers. Methods This retrospective study included 49 patients diagnosed with renal cell carcinoma (RCC) who had complete computed tomography (CT) data, RENAL-NS, and histopathology results. All patients underwent renal surgery/intervention at our center between January 2008 and December 2018. The radius of the lesion, exophytic/endophytic properties, nearness to the collecting system, anterior or posterior description, and location relative to the polar lines was used to calculate the score. Tumor complexity was graded as low, intermediate, or high. Two body imaging radiologists evaluated the data independently. Results Interobserver agreement for each of the RENAL-NS parameters, respectively, and overall complexity was calculated. The total agreement was 82%, 51%, 84%, 69%, 73%, and 90%, corresponding to Kappa values of 0.72, 0.33, 0.44, 0.49, 0.58, and 0.83, respectively. The radius, nearness to the collecting system, and total complexity showed the best agreement. Exophytic properties of the lesion showed the least agreement. For cases that were discordant in terms of the final score, no major implications in surgical planning were observed. Conclusion The results of this study show that the RENAL-NS is a useful tool to assess the anatomical features of renal tumors and it is easily reproducible, even for less experienced radiologists in a developing nation.

Generation of drift waves by field-aligned shear flow of protons and oxygen ions is investigated in the presence of kappa distributed trapped electrons in upper ionosphere within auroral latitudes. Very low-frequency electrostatic waves having frequencies of the order of a few Hz observed by Freja satellite at altitude 1700 km can be either the ion acoustic waves (IAWs) or the electrostatic drift waves EDW depending up on density uniformity or non-uniformity in the region. Growth rate of drift wave increases in the presence of 0.4 percent hydrogen ions in oxygen plasma. Drift wave is coupled with the four branches of ion acoustic modes in this bi-ion plasma. In nonlinear regime, EDW and IAWs produce electrostatic solitary structures of a few meters width and their amplitude depends up on the density gradient scale length, non-thermality parameter and trapping of electrons.

Wandering spleen is a rare entity that results from the absence or maldevelopment of the ligaments that support the spleen in its normal location. As a result, the spleen is hypermobile and may be predisposed to hilar torsion and subsequent infarction, making it a potentially fatal abdominal emergency. We present a case of a 36-year-old Afghan female who presented with an acute abdomen, and was radiologically and surgically confirmed to have a wandering spleen with torsion and complete infarction. Knowledge of this condition and its radiological findings can play a crucial role in making a correct and timely diagnosis.

Background: This study, therefore aims to assess the frequency and the factorscontributing to the needle stick injuries among health care workers of a tertiary care privatehospital of Lahore. Setting: Shalamar Hospital Lahore, Pakistan a tertiary care private institution.Period: July and August 2015. Study Design: Cross-sectional study. Methods: A modifiedstructured pre-tested questionnaire containing both open and close-ended questions wasadministered to 160 study participants. The selected candidates were thoroughly briefed aboutthe study and informed consent was obtained. Confidentiality and anonymity of the participantswas maintained. Data entry was done on SPSS version 20 for Microsoft Windows. Results: Theresponse rate was 97%. Among all respondents (n=122), almost 41% (n= 63) were medicaldoctors and 34% (n= 53) were nursing staff. A small proportion of 4% (n= 6) belonged to thedental surgical background as well. Of all the surveyed participants, 45% (n=69) had eversuffered from needle stick/ sharps injury during their medical job and career, whereas, 34%(n=53) had suffered from a needle stick injury during the last year. Nearly 63% (n=47) reportedthat the cause of injury was accidental, 16% (n=25) acknowledged lack of awareness, 7%(n=10) acknowledged improper equipment and 4% (n=6) accused lack of training as the majorcause of needle stick injuries. A hefty 34% (n=53) believed that there existed no protocols in theinstitution regarding needle stick injuries, while another 50% (n=78) stated that they were notaware of the hospital protocols regarding needle stick injuries if there existed any. A disturbing34% (n=53) assume that they should recap the needles after using them. There was a strongstatistical association p

Educational institutions demand cost-effective and simple-to-use augmented reality systems. ARToolKit, an open-source computer tracking library for the creation of augmented reality applications that overlay virtual imagery on the real world, is such a system. It uses a simple camera and black-and-white markers printed on paper. However, due to inter-marker confusion, if the marker distinctions are not ensured, the markers are often miss-recognized. This paper presents an ARToolKit-based Interactive Writing Board (IWB) with a simple mechanism for designing confusion-free marker libraries. The board is used for teaching single characters of Arabic/Urdu to primary level students. It uses a simple ARToolKit marker for the recognition of each character. After marker recognition, the IWB displays the corresponding image, helping students with character understanding and pronunciation. Experimental results reveal that the system improves students&rsquo, motivation and learning skills.

We present a case of a young female who had large bilateral pulmonary artery aneurysms and was found to have infective endocarditis on echocardiography. Endovascular treatment was sought; however, was not possible due to severe sepsis and other associated complications. Subsequent serial imaging revealed the rapid enlargement of one of the aneurysms and possible rupture which proved to be fatal. Although pulmonary artery aneurysms are a rare vascular anomaly, they are seen in a wide variety of conditions, such as congenital heart disease, infection, trauma, pulmonary hypertension, cystic medial necrosis, and generalized vasculitis. This case highlights the consequences of mycotic aneurysms and emphasizes the importance of prompt diagnosis. Early angioembolization and/or surgical repair is often essential to avoid death from rupture of the aneurysm.

The emergence in computing and the latest hardware technologies realized the use of natural interaction with computers. Gesture-based interaction is one of the prominent fields of natural interactions. The recognition and application of hand gestures in virtual environments (VEs) need extensive calculations due to the complexities involved, which directly affect the performance and realism of interaction. In this paper, we propose a new interaction technique that uses single fingertip-based gestures for interaction with VEs. The objective of the study is to minimize the computational cost, increase performance, and improve usability. The interaction involves navigation, selection, translation, and release of objects. For this purpose, we propose a low-cost camera-based system that uses a colored fingertip for the fastest and accurate recognition of gestures. We also implemented the proposed interaction technique using the Leap Motion controller. We present a comparative analysis of the proposed system with the Leap Motion controller for gesture recognition and operation. A VE was developed for experimental purposes. Moreover, we conducted a comprehensive analysis of two different recognition setups including video camera and the Leap Motion sensor. The key parameters for analysis were task accuracy, interaction volume, update rate, and spatial distortion of accuracy. We used the Standard Usability Scale (SUS) for system usability analysis. The experiments revealed that camera implementation was found with good performance, less spatial distortion of accuracy, and large interaction volume as compared to the Leap Motion sensor. We also found the proposed interaction technique highly usable in terms of user satisfaction, user-friendliness, learning, and consistency.

Molecular surface mesh generation is a prerequisite for using the boundary element method (BEM) and finite element method (FEM) in implicit-solvent modeling. Molecular surface meshes typically have small angles, redundant vertices, and low-quality elements. In the implicit-solvent modeling of biomolecular systems it is usually required to improve the mesh quality and eliminate low-quality elements. Existing methods often fail to efficiently remove low-quality elements, especially in complex molecular meshes. In this paper, we propose a mesh refinement method that smooths the meshes, eliminates invalid regions in a cut-and-fill strategy, and improves the minimal angle. We compared our method with four different state-of-the-art methods and found that our method showed a significant improvement over state-of-the-art methods in minimal angle, aspect ratio, and other meshing quality measurements. In addition, our method showed satisfactory results in terms of the ratio of regular vertices and the preservation of area and volume.

Objective Our aim was to review the results of pelvic arterial embolization (PAE) performed in the interventional radiology suite. Method The data of all patients in whom pelvic angioembolization was performed was collected from July 2011 to June 2017. Procedures were performed by an experienced interventional radiologist. The clinical and laboratory data, as well as the outcome data, were obtained from the medical records of our hospital. The following parameters were collected for each patient, including the age, gender, presenting symptoms, site of bleeding, catheters used for embolization, material used for embolization, previous computed tomography (CT) scan and/or focused assessment with sonography for trauma (FAST) ultrasound, average hemoglobin before the procedure, and patient clinical status on discharge. Result A total of 37 patients underwent pelvic angiography for acute hemorrhage at our institution. They had contrast blush, active extravasation, or abnormal vascularity from the branches of the internal iliac artery and underwent therapeutic transcatheter embolization. A total of 29 patients (78.3%) were male and 8 (21.7%) were female. The average age was 30.0 years (range: 6-90 year). Of these, 16 patients (43.2%) presented with road traffic accidents (RTAs), six with gunshot injuries (16.2%), six with iatrogenic injuries (16.2%), four with a history of a fall (10.8%), two with bomb blast injuries (5.4%), one with a history of a glass injury (2.7%), one had a history of a roof falling on her during an earthquake, and one patient had a pelvic pseudoaneurysm secondary to an abscess. The type of embolic material used for embolization included coils in 16 patients, polyvinyl alcohol (PVA) particles were used in eight patients, both PVA particles and coils were used in 11 patients, and glue was used in one patient. All were successfully embolized. Thirty-four were discharged while three patients expired during the course of hospital stay due to other coexisting morbidities. Conclusion The management of pelvic injuries has always been a topic of debate, with multiple methods reported to date but growing evidence supports the use of pelvic arterial embolization in hemorrhagic pelvic injuries. The formulation of a standardized protocol is the need of the day.

International audience; Fiducial markers are images or landmarks placed in real environment, typically used for pose estimation and camera tracking. Reliable fiducials are strongly desired for many augmented reality (AR) applications, but currently there is no systematic method to design highly reliable fiducials. In this paper, we present fiducial marker optimizer (FMO), a tool to optimize the design attributes of ARToolKit markers, including black to white (B:W) ratio, edge sharpness, and information complexity, and to reduce inter-marker confusion. For these operations, the FMO provides a user friendly interface at the front-end and specialized image processing algorithms at the back-end. We tested manually designed markers and FMO optimized markers in ARToolKit and found that the latter were more robust. The FMO will be used for designing highly reliable fiducials in easy to use fashion. It will improve the application's performance, where it is used.

To ascertain the accuracy and reliability of tablet as an imaging console for detection of radiological signs of acute appendicitis [on focused appendiceal computed tomography (FACT)] using Picture Archiving and Communication System (PACS) workstation as reference standard. From January, 2014 to June, 2015, 225 patients underwent FACT at our institution. These scans were blindly re-interpreted by an independent consultant radiologist, first on PACS workstation and, two weeks later, on tablet. Scans were interpreted for the presence of radiological signs of acute appendicitis. Accuracy of tablet was calculated using PACS as reference standard. Kappa (κ) statistics were calculated as a measure of reliability. Of 225 patients, 99 had radiological evidence of acute appendicitis on PACS workstation. Tablet was 100% accurate in detecting radiological signs of acute appendicitis. Appendicoliths, free fluid, lymphadenopathy, phlegmon/abscess, and perforation were identified on PACS in 90, 43, 39, 10, and 12 scans, respectively. There was excellent agreement between tablet and PACS for detection of appendicolith (к = 0.924), phlegmon/abscess (к = 0.904), free fluid (к = 0.863), lymphadenopathy (к = 0.879), and perforation (к = 0.904). Tablet computer, as an imaging console, was highly reliable and was as accurate as PACS workstation for the radiological diagnosis of acute appendicitis.