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Objectives In the midst of the coronavirus disease 2019 (COVID-19) outbreak, chest X-ray (CXR) imaging is playing an important role in diagnosis and monitoring of patients with COVID-19. We propose a deep learning model for detection of COVID-19 from CXRs, as well as a tool for retrieving similar patients according to the model’s results on their CXRs. For training and evaluating our model, we collected CXRs from inpatients hospitalized in four different hospitals. Methods In this retrospective study, 1384 frontal CXRs, of COVID-19 confirmed patients imaged between March and August 2020, and 1024 matching CXRs of non-COVID patients imaged before the pandemic, were collected and used to build a deep learning classifier for detecting patients positive for COVID-19. The classifier consists of an ensemble of pre-trained deep neural networks (DNNS), specifically, ReNet34, ReNet50¸ ReNet152, and vgg16, and is enhanced by data augmentation and lung segmentation. We further implemented a nearest-neighbors algorithm that uses DNN-based image embeddings to retrieve the images most similar to a given image. Results Our model achieved accuracy of 90.3%, (95% CI: 86.3–93.7%) specificity of 90% (95% CI: 84.3–94%), and sensitivity of 90.5% (95% CI: 85–94%) on a test dataset comprising 15% (350/2326) of the original images. The AUC of the ROC curve is 0.96 (95% CI: 0.93–0.97). Conclusion We provide deep learning models, trained and evaluated on CXRs that can assist medical efforts and reduce medical staff workload in handling COVID-19. Key Points • A machine learning model was able to detect chest X-ray (CXR) images of patients tested positive for COVID-19 with accuracy and detection rate above 90%. • A tool was created for finding existing CXR images with imaging characteristics most similar to a given CXR, according to the model’s image embeddings. Supplementary Information The online version contains supplementary material available at 10.1007/s00330-021-08050-1.

Objective: While COVID-19 symptoms impact rhinology (anosmia) and laryngology (airways), two major disciplines of the otolaryngology armamentarium, the virus has seemed to spare the auditory system. A recent study, however, reported changes in otoacoustic emission (OAE) signals measured in SARS-COV-2 positive patients. We sought to assess the effect of COVID-19 infection on auditory performance in a cohort of recovered SARS-COV-2 patients and controls. To avoid a potential bias of previous audiological dysfunction not related to SARS-COV-2 infection, the study encompasses patients with normal auditory history. We hypothesized that if SARS-COV-2 infection predisposes to hearing loss, we would observe subtle and early audiometric deficits in our cohort in the form of subclinical auditory changes. Study Design: Cross-sectional study. Setting: Tertiary referral center. Patients: The Institutional Review Board approved the study and we recruited participants who had been positive for SARS-COV-2 infection, according to an Reverse Transcription Polymerase Chain Reaction (RT-PCR) test on two nasopharyngeal swabs. The patients included in this study were asymptomatic for the SARS-COV-2 infection and were evaluated following recovery, confirmed by repeated swab testing. The control group comprised healthy individuals matched for age and sex, and with a normal auditory and otologic history. Intervention(s): The eligibility to participate in this study included a normal audiogram, no previous auditory symptoms, normal otoscopy examination with an intact tympanic membrane, and bilateral tympanometry type A. None of our volunteers reported any new auditory symptoms following SARS-COV-2 infection. Ototacoustic emissions (OAE) and auditory brainstem response (ABR) measurements were used to evaluate the auditory function. Main Outcome Measure(s): OAE and ABR measurements. Results: We have found no significant differences between recovered asymptomatic SARS-COV-2 patients and controls in any of transitory evoked otoacoustic emission (TEOAE), distortion product otoacoustic emissions (DPOAE), or ABR responses. Conclusions: There is no cochlear dysfunction represented by ABR, TEOAE, and DPOAE responses in recovered COVID-19 asymptomatic patients. Retrocochlear function was also preserved as evident by the ABR responses. A long-term evaluation of a larger cohort of SARS-COV-2 patients will help to identify a possible contribution of SARS-COV-2 infection to recently published anecdotal auditory symptoms associated with COVID-19.

Vaccine hesitancy remains a barrier to full population inoculation against highly infectious diseases. With rapid developments in a potential COVID-19 vaccine by scientists across the globe, public concerns over the safety and side effects of such a vaccine may contribute to vaccine hesitancy. We analyzed anonymous questionnaire answers regarding acceptance of a potential COVID-19 vaccine posed to healthcare workers and the general population throughout Israel with a total respondent count of 1941. Our results demonstrate higher rates of COVID-19 vaccine hesitancy among various groups: parents, nurses, and medical workers not caring for SARS-CoV-2 positive patients. Healthcare staff involved in the care of COVID-19 positive patients and individuals who consider themselves at higher risk of disease were more likely to self-report acquiescence to obtain a COVID-19 vaccine if and when it becomes available. Interventional educational campaigns targeted towards populations at risk of vaccine hesitancy, therefore, are urgently needed to combat misinformation and resultant low inoculation rates.

ObjectivePost-surgical bleeding after tonsillectomy occurs in 2–7 per cent of cases. This study examined whether heart rate and haematocrit changes are associated with the amount of bleeding.MethodIn this retrospective analytical study, data were collected from the medical charts of patients admitted with post-surgical bleeding.ResultsOver the course of 10 years, there were 218 cases of post-operative bleeding in children aged under 18 years. There was a significant increase in heart rate after the bleeding had started, and a significant decrease in both haemoglobin and haematocrit levels (p < 0.05). There was no significant correlation between the differences in haemoglobin and haematocrit and changes in heart rate.ConclusionNo correlation was found between the differences in haemoglobin and haematocrit levels and the changes in heart rate from before the surgery to after the bleeding had started. The monitoring of paediatric patients’ heart rate after tonsillectomy surgery solely for the purpose of predicting acute blood loss is therefore discouraged.

Objective Studies have demonstrated a potential correlation between low vitamin D status and both an increased risk of infection with SARS-CoV-2 and poorer clinical outcomes. This retrospective study examines if, and to what degree, a relationship exists between pre-infection serum 25-hydroxyvitamin D (25(OH)D) level and disease severity and mortality due to SARS-CoV-2. Participants The records of individuals admitted between April 7th, 2020 and February 4th, 2021 to the Galilee Medical Center (GMC) in Nahariya, Israel, with positive polymerase chain reaction (PCR) tests for SARS-CoV-2 (COVID-19) were searched for historical 25(OH)D levels measured 14 to 730 days prior to the positive PCR test. Design Patients admitted to GMC with COVID-19 were categorized according to disease severity and level of 25(OH)D. An association between pre-infection 25(OH)D levels, divided between four categories (deficient, insufficient, adequate, and high-normal), and COVID-19 severity was ascertained utilizing a multivariable regression analysis. To isolate the possible influence of the sinusoidal pattern of seasonal 25(OH)D changes throughout the year, a cosinor model was used. Results Of 1176 patients admitted, 253 had records of a 25(OH)D level prior to COVID-19 infection. A lower vitamin D status was more common in patients with the severe or critical disease (p < 0.001). Patients with vitamin D deficiency (p < 0.001). Conclusions Among hospitalized COVID-19 patients, pre-infection deficiency of vitamin D was associated with increased disease severity and mortality.

Early detection of COVID-19 is key in containing the pandemic. Disease detection and evaluation based on imaging is fast and cheap and therefore plays an important role in COVID-19 handling. COVID-19 is easier to detect in chest CT, however, it is expensive, non-portable, and difficult to dis-infect, making it unfit as a point-of-care (POC) modality. On the other hand, chest X-ray (CXR) and lung ultrasound (LUS) are widely used, yet, COVID-19 findings in these modalities are not always very clear. Here we train deep neural networks to significantly enhance the capability to detect, grade and monitor COVID-19 patients using CXRs and LUS. Collaborating with several hospitals in Israel we collect a large dataset of CXRs and use this dataset to train a neural network obtaining above 90% detection rate for COVID-19. In addition, in collaboration with ULTRa (Ultrasound Laboratory Trento, Italy) and hospitals in Italy we obtained POC ultrasound data with annotations of the severity of disease and trained a deep network for automatic severity grading.

Background Thalassemia is an inherited autosomal recessive blood disorder causing abnormal formation of hemoglobin, known as a syndrome of anemia with microcytic erythrocytes. It is the most common genetic disorder worldwide, with a high prevalence among individuals of Mediterranean descent. The state of homozygosity of the beta-globin mutated gene is known as beta-thalassemia major, and these patients require regular blood transfusions and iron chelation therapy for survival. The rapid loss of red blood cells among affected individuals activates compensatory mechanisms of excessive medullary and extramedullary hematopoiesis, leading to severe skeletal bone deformity. Case presentation We present the case of a 39-year-old Bedouin male, diagnosed with beta-thalassemia major at infancy, with diagnosed homozygosity for the intervening sequence 2-1 (guanine > adenine) mutation. Since early infancy, he started receiving blood transfusions with a gradual increase in treatment frequency through adulthood due to the severe clinical progression of the disease. He was referred to the oral and maxillofacial surgery department at Galilee Medical Center to evaluate his facial deformity in the upper jaw and treat his severe periodontal disease. The patient presented maxillary overgrowth, and severe dental deformity resulted in progressive disfigurement and difficulty chewing, swallowing, and speaking. To address the challenge of surgical treatment, we utilized the advantage of three-dimensional planning and printing technology to simulate the optimal result. Resection of maxillary bone overgrowth and insertion of custom-made subperiosteal implants were followed by rehabilitation of both jaws to the patients' satisfaction at 3-year follow-up. Conclusions The ongoing implementation of state-of-the-art technologies such as virtual reality and three-dimensional printing has become a prominent component in surgical toolsets. Comprehensive case simulation and accurate planning before surgery will improve surgical results and patient satisfaction. This approach is highly advocated when approaching a case of rare maxillofacial deformity associated with either genetic or orphan diseases.

Introduction The current corona virus disease 2019 (COVID-19) outbreak set new challenges to nearly all health plans and large health organizations worldwide, including movement restrictions, strict limitations in healthcare services, especially in the dental profession, and patient fears regarding potential infection. Telehealth can serve as an effective platform for remote connection between dental healthcare providers and patients, and can help reduce the risk of infection when social distancing is required. Objective The current study aimed to evaluate the quality of treatment provided via teledentistry, as perceived by patients using the service, as well as their willingness to use online distant medical consultation in the future. Methods Since March 2020, a new online service was implemented in the Oral Medicine Unit and Oral and Maxillofacial Surgery Department in the Galilee Medical Center, to expand the range of services beyond merely emergency treatments. Results The current study examined the quality of teledentistry services as perceived by 89 patients participating in at least one teleconsultation, and their acceptance of remote healthcare. Satisfaction rates were high in patients who received both full and partial solution to their chief complaint. Moreover, acceptance of the teledentistry platform was high, even in the older age groups. Conclusions We propose to implement teledentistry services in current and future pandemics, as well as during routine times, to strengthen our health care system with digital technologies.

Our study compares the number of postoperative complications of Syrian patients admitted to the Galilee Medical Center (GMC) over a 5-year period (May 2013–May 2018) for treatment after initial high-velocity maxillofacial injuries sustained during the Syrian civil war. Specifically, we evaluated complication rates of patients arriving “early,” within 24 h, to the GMC versus those who arrived “late,” or 14–28 days following high-velocity maxillofacial injuries. Both groups of patients received definitive surgical treatment within 48 h of admission to our hospital with a total of 60 patients included in this study. The mean age was 26 ± 8 years (range: 9–50) and all except one were male. Postoperative complications in the early group were found to be significantly higher compared to the delayed arrival group (p = 0.006). We found that unintentionally delayed treatment may have contributed to a critical revascularization period resulting in improved healing and decreased postoperative morbidity and complications. We discuss potential mechanisms for complication rate variations, including critical vascularization periods. Our study may add to a growing body of work demonstrating the potential benefit of delayed surgical treatment for high-velocity maxillofacial injuries.

Objective The COVID-19 pandemic-related restrictions on the public have led to changes in occupation status and societal behavior which may be linked with adverse effects on mental health. We hypothesized that elevated personal stress induced by COVID-19 may underlie pain exacerbation among individuals with chronic myofascial pain. Methods Comprehensive myofascial pain questionnaire among 319 patients registered in our pain clinic. In total, 78 patients with TMD-associated pain responded and 113 patients with pain in other orofacial regions responded. Results Patients with chronic TMD pain reported a higher self-rated stress level, which correlated with significantly increased pain intensity, and analgesic consumption. In contrast, patients experiencing non-TMD pain did not report of any increase pain, regardless of their stress levels. Conclusion Significant correlation between self-perceived psychosocial stress levels and chronic myofascial pain exacerbation. Patients may benefit from early education and conservative intervention, and avoid uncontrolled increases in consumption of pain relief medication.

Vaccine hesitancy is a global health threat which may hinder the widespread acceptance of several COVID-19 vaccines. Following the collection of 2470 responses from an anonymous questionnaire distributed between October and November 2020 across Israel, we analyzed the responses of physicians, life science graduates (biology, virology, chemistry, etc.), and the general public to whether they would obtain a COVID-19 vaccine with particular vaccine characteristics such as vaccine country of origin, technology, side effect profile, efficacy, and other attributes. Physicians and life science graduates were least likely to accept a vaccine based on mRNA technology (30%) while the general population seemed to adopt any vaccine technology if the declared efficacy is above 90% and the country of manufacturing is the USA/UK rather than China or Russia. However, current inoculation rates in Israel far outpace our predicted rate. Our results highlight the importance of tailored vaccine educational campaigns based on population demographic details and specific vaccine concerns.

With the onset of the COVID-19 pandemic, social distancing guidelines have reshaped the way that we live our lives. Perhaps the most common and strictly adopted measure has been mask wearing. Mask wearing, whether it be cloth, surgical, or N95, has quickly become the new norm in the ongoing struggle against this pandemic and has been proven to be effective in curbing its high infection rate. There has, however, been growing opposition to these policies by a substantial part of the general population who claims that masks are ineffective and can worsen breathing. To some, the choice to use or not use a mask has morphed into a point of political contention, rather than a choice rooted in concerns for public health. This commentary attempts to investigate the validity of these claims and explore how clinicians can encourage the usage of masks despite the fears and confusion against them.

Serving ML prediction pipelines spanning multiple models and hardware accelerators is a key challenge in production machine learning. Optimally configuring these pipelines to meet tight end-to-end latency goals is complicated by the interaction between model batch size, the choice of hardware accelerator, and variation in the query arrival process.In this paper we introduce InferLine, a system which provisions and manages the individual stages of prediction pipelines to meet end-to-end tail latency constraints while minimizing cost. InferLine consists of a low-frequency combinatorial planner and a high-frequency auto-scaling tuner. The low-frequency planner leverages stage-wise profiling, discrete event simulation, and constrained combinatorial search to automatically select hardware type, replication, and batching parameters for each stage in the pipeline. The high-frequency tuner uses network calculus to auto-scale each stage to meet tail latency goals in response to changes in the query arrival process. We demonstrate that InferLine outperforms existing approaches by up to 7.6x in cost while achieving up to 34.5x lower latency SLO miss rate on realistic workloads and generalizes across state-of-the-art model serving frameworks.

In the midst of the coronavirus disease 2019 (COVID-19) outbreak, chest X-ray (CXR) imaging is playing an important role in the diagnosis and monitoring of patients with COVID-19. Machine learning solutions have been shown to be useful for X-ray analysis and classification in a range of medical contexts. The purpose of this study is to create and evaluate a machine learning model for diagnosis of COVID-19, and to provide a tool for searching for similar patients according to their X-ray scans. In this retrospective study, a classifier was built using a pre-trained deep learning model (ReNet50) and enhanced by data augmentation and lung segmentation to detect COVID-19 in frontal CXR images collected between January 2018 and July 2020 in four hospitals in Israel. A nearest-neighbors algorithm was implemented based on the network results that identifies the images most similar to a given image. The model was evaluated using accuracy, sensitivity, area under the curve (AUC) of receiver operating characteristic (ROC) curve and of the precision-recall (P-R) curve. The dataset sourced for this study includes 2362 CXRs, balanced for positive and negative COVID-19, from 1384 patients (63 +/- 18 years, 552 men). Our model achieved 89.7% (314/350) accuracy and 87.1% (156/179) sensitivity in classification of COVID-19 on a test dataset comprising 15% (350 of 2326) of the original data, with AUC of ROC 0.95 and AUC of the P-R curve 0.94. For each image we retrieve images with the most similar DNN-based image embeddings; these can be used to compare with previous cases., Elisha Goldstein, Daphna Keidar, and Daniel Yaron have made an equal contribution and are equal first authors, listed alphabetically

Many government websites and mobile content are inaccessible for people with vision, hearing, and cognitive disabilities. The COVID-19 pandemic highlighted these disparities when health authority website information, critical in providing resources for curbing the spread of the virus, remained inaccessible for disabled populations. The Web Content Accessibility Guidelines provide comparatively universally accepted guidelines for website accessibility. We utilized these parameters to examine the number of countries with or without accessible health authority websites. The resulting data indicate a dearth of countries with websites accessible for persons with disabilities. Methods of information dissemination must take into consideration individuals with disabilities, particularly in times of global health crises.

Background: Over 3200 Syrian patients were admitted and treated at Galilee Medical Center (GMC) over a five-year period (May 2013 - May 2018) since the beginning of the Syrian civil war in 2011. This study compares the number of postoperative complications of patients admitted to the GMC immediately after injury or two to three weeks after initial high-velocity maxillofacial injuries and the potential mechanisms for the variation in complication rates. We describe our experiences, strategies, and resultant treatment approach.Methods: Retrospective case studies in which the incidence of complications including infection, rejection of hardware, bone or soft tissue grafts, tissue dehiscence, oroantral fistula formation, excessive scarring, and unplanned return to the operating theater were investigated. Patients arriving at the GMC within 24 hours following maxillofacial injury were considered “early” while patients arriving to the GMC within 14-28 days following initial trauma without treatment prior to arrival were considered “late” or “delayed.” Both groups of patients received definitive surgical treatment within 48 hours of admission to our hospital. Results: Sixty patients suffering from "high-velocity" maxillofacial Syrian civil war-related battlefield injuries were included in this study. The mean age was 26±8 years (range: 9-50) and all except one were male. Post-operative complications in the early group were found to be significantly higher compared to the delayed group (p = 0.006).Conclusions: We discovered that the delayed group of patients, characterized by progressive neovascularization of injured tissue, had better surgical success from rich blood supply that enhances tissue survival. Sustained tissue perfusion to the tissue supports efficient systemic antibiotic delivery, a favorable condition in lowering infection rate and complication. We found that the unintendedly delayed treatment contributed to a critical revascularization period resulting in improved healing and decreased postoperative morbidity and complications.

Infrastructure-as-a-Service (IaaS) cloud providers hide available interfaces for virtual machine (VM) placement and migration, CPU capping, memory ballooning, page sharing, and I/O throttling, limiting the ways in which applications can optimally configure resources or respond to dynamically shifting workloads. Given these interfaces, applications could migrate VMs in response to diurnal workloads or changing prices, adjust resources in response to load changes, and so on. This article proposes a new abstraction that we call a Library Cloud and that allows users to customize the diverse available cloud resources to best serve their applications. We built a prototype of a Library Cloud that we call the Supercloud . The Supercloud encapsulates applications in a virtual cloud under users’ full control and can incorporate one or more availability zones within a cloud provider or across different providers. The Supercloud provides virtual machine, storage, and networking complete with a full set of management operations, allowing applications to optimize performance. In this article, we demonstrate various innovations enabled by the Library Cloud.

Abnormal formation of otoconia, the biominerals of the inner ear, results in balance disorders. The inertial mass of otoconia activates the underlying mechanosensory hair cells in response to change in head position primarily during linear and rotational acceleration. Otoconia associate exclusively with the two gravity receptors, the utricle and saccule. The cristae sensory epithelium is associated with an extracellular gelatinous matrix known as cupula, equivalent to otoconia. During head rotation, the inertia of endolymphatic fluids within the semicircular canals deflect the cupula of the corresponding crista and activates the underlying mechanosensory hair cells. It is believed that detached free floating otoconia particles travel ectopically to the semicircular canal and cristae and are the culprit for benign paroxysmal positional vertigo (BPPV). The Slc26a4 mouse mutant harbors a missense mutation in pendrin. This mutation leads to impaired transport activity of pendrin and to defects in otoconia composition and distribution. All Slc26a4(loop/loop) homozygous mutant mice are profoundly deaf but show inconsistent vestibular deficiency. A panel of behavioral tests was utilized in order to generate a scoring method for vestibular function. A pathological finding of displaced otoconia was identified consistently in the inner ears of mutant mice with severe vestibular dysfunction. In this work, we present a mouse model with a genetic predisposition for ectopic otoconia with a clinical correlation to BPPV. This unique mouse model can serve as a platform for further investigation of BPPV pathophysiology, and for developing novel treatment approaches in a live animal model.

"Cloud-native" container platforms, such as Kubernetes, have become an integral part of production cloud environments. One of the principles in designing cloud-native applications is called Single Concern Principle, which suggests that each container should handle a single responsibility well. In this paper, we propose X-Containers as a new security paradigm for isolating single-concerned cloud-native containers. Each container is run with a Library OS (LibOS) that supports multi-processing for concurrency and compatibility. A minimal exokernel ensures strong isolation with small kernel attack surface. We show an implementation of the X-Containers architecture that leverages Xen paravirtualization (PV) to turn Linux kernel into a LibOS. Doing so results in a highly efficient LibOS platform that does not require hardware-assisted virtualization, improves inter-container isolation, and supports binary compatibility and multi-processing. By eliminating some security barriers such as seccomp and Meltdown patch, X-Containers have up to 27X higher raw system call throughput compared to Docker containers, while also achieving competitive or superior performance on various benchmarks compared to recent container platforms such as Google's gVisor and Intel's Clear Containers.

The currently accepted treatment for idiopathic sudden sensorineural hearing loss (ISSHL) is systemic steroids as first-line and intratympanic steroids as salvage therapy. Intratympanic (IT) treatment is applied worldwide in many different ways with no universally accepted protocol.To present the current disparity in ISSHL management and to discuss the necessity for establishing a common national protocol.In 2014 we conducted a national survey by sending questionnaires on ISSHL management to otologists in every otolaryngology department in the country.The majority of otolaryngology departments (56%) admit patients with sudden sensorineural hearing. Almost two-thirds (61%) of departments recommend supplementary initial treatment in addition to systemic steroids. None of the medical centers offer intratympanic steroid treatment as primary therapy, but 94% offer this treatment as a salvage therapy. Fewer than half the medical centers (44%) consider the maximal period for intratympanic therapy to be 4 weeks since hearing loss appears. Almost half (48%) the departments use intratympanic steroids once every 5-7 days, usually in an ambulatory setting. Almost half (44%) the medical centers tend to use not more than four courses of IT steroids. In 44% of departments an audiogram is performed at the beginning and at the end of the intratympanic course.Our results demonstrate a variability among Israeli medical centers in many aspects of intratympanic treatment. We believe this reinforces the need for a comparative international study in order to establish a standard protocol.

Introduction Deep vein thrombosis of the upper-extremity (ueDVT) is often caused by trauma to the subclavian vein, central venous line and hypercoagulation disorders. Case Report We present a case of a ueDVT due to retrosternal goiter compressing the right brachiocephalic vein. Low molecular weight heparin was initiated subcutaneously and fluid was aspirated from the thyroid cyst causing an immediate improvement. Cytology detected no malignancy. At eight-month follow-up, the patient showed complete resolution of her symptoms. Discussion In general, the optimal treatment should include removal of the compressing thyroid. In co-morbid patients and a dominant thyroidal cyst, thyroid aspiration may be sufficient.

This retrospective case review describes a subset of 5 patients with necrotizing otitis externa (NOE) with a refractory disease course who underwent surgery as part of their management plan between 2008 and 2013. Surgery promoted the cure of 4 of the 5 patients, and a fungal pathogen was recovered in 4 of 5 surgical samples. We conclude that surgery may be a necessary diagnostic and treatment adjunct in selective cases of NOE, especially in patients with a refractory disease course or with a suspected fungal etiology.

This study proposes nine success factors for enterprise-wide e-learning. These factors were derived from the literature, interviews with e-learning project leaders, and analysis. Twelve semistructured interviews were conducted and analyzed in order to find out the best success factors to implement e-learning. These factors are divided into two categories: “must-have” factors and “nice-to-have” factors. The must-have factors include: useful and easy to use e-learning tools, marketing, management support, the right organizational culture, and the existence of a real need for the organization. The “nice to have” factors include: time to learn, support, mandatory learning, and incentives. Based on the research conclusions, a checklist of e-learning success factors is provided. A special addendum includes looking at the factors in downturn times, their relative importance and nature.

Silver nitrate is sometimes used as a means of chemical cauterization for control of minor bleeding and management of hypergranulation tissue following bedside head and neck procedures. There are only few reports available on the imaging appearance of silver nitrate and its potential to mimic a foreign body. We report a case of a patient presenting with dysphagia, odynophagia, and fever following dental work who had a peritonsillar incision and drainage for treatment of a deep neck space infection. During the procedure, silver nitrate was applied to halt the bleeding. Patient was subsequently transferred to another institution. Since the patient was not showing significant clinical improvement on antibiotic therapy, a computed tomography (CT) scan was performed demonstrating a hyperdense structure lodged in the pharyngeal mucosal space in the oropharynx and soft palate that was mistaken for a foreign body such as bone. Silver nitrate can have density similar to bone but does not have the normal architecture of bone with cortex and marrow on CT. Familiarity with the appearance of silver nitrate on CT, lack of bone architecture, and proper documentation and communication of the use of silver nitrate to the consultant radiologist and medical personnel could help avoid misdiagnosis and potentially unnecessary surgical exploration.

Background The aim of this study is to prospectively review the role of sentinel lymph node (SLN) biopsy in the management of well differentiated thyroid carcinoma (WDTC), and to determine the efficacy of intraoperative frozen section analysis at detecting SLN metastasis and central compartment involvement. Methods The SLN biopsy protocol using 1% methylene blue was performed in 300 patients undergoing thyroidectomy for WDTC. A limited pretracheal central compartment neck dissection (CCND) was performed on all patients. Lymph nodes staining blue were considered as SLN’s. Both frozen and permanent section analyses were performed. Results SLN’s with metastasis were found in 14.3% (43/300) of cases. Of this, 11% (33/300) were positive on intraoperative frozen section analysis. Frozen section results failed in predicting central compartment involvement in 15 cases (5%) whereas central neck compartment involvement was missed in 5 cases (1.7%) when based on permanent section results. On frozen section analysis, the sensitivity, specificity, positive predictive value and negative predictive value (95% CI) of our SLN biopsy technique aiming to remove all disease from the central compartment was 68.8% (53.6-80.9), 100% (98.1-100), 100% (87.0-100) and 94.4% (90.7-96.7) respectively with P Conclusion This data series demonstrates that patients with WDTC have positive SLN’s in 14.3% of cases. Moreover, when the SLN’s are negative for metastasis on frozen section, the central compartment was disease-free in 94.4% of cases. Finally, this study shows that 23.3% of positive SLN’s were false negatives on intraoperative frozen section. According to this data, SLN involvement is an accurate predictor of central compartment metastasis, however surgeons should use caution when relying on intraoperative frozen section to determine whether to perform a CCND.