Application of naïve Bayesian approach in detecting reproducible fatal collision locations on freeway

Detecting high-collision-concentration locations based solely on collision frequency may produce different results compared to those considering the severities of the collisions. In particular, it can lead government agencies focusing sites with a high collision frequency while neglecting those with a lower collision frequency but a higher percentage of injury and fatal collisions. This study developed systematic ways of detecting reproducible fatal collision locations (R) using the naïve Bayes approach and a continuous risk profile (CRP) that estimates the true collision risk by filtering out random noise in the data. The posterior probability of fatal collisions being reproducible at a location is estimated by the relationship between the spatial distribution of fatal-collision locations (i.e., likelihood) and the CRP (i.e., prior probability). The proposed method can be used to detect sites with the highest proxy measure of the posterior probability (PMP) of observing R. An empirical evaluation using 5-year traffic collision data from six routes in California shows that detecting R based on the PMP outperform those based on the SPF-based approaches or random selection, regardless of various conditions and parameters of the proposed method. This method only requires traffic collision and annual traffic volume data to estimate PMP that prioritize sites being R and the PMPs can be compared across multiple routes. Therefore, it helps government agencies prioritizing sites of multiple routes where the number of fatal collisions can be reduced, thus help them to save lives with limited resources of data collection.

Radiomics analysis of contrast-enhanced CT for classification of hepatic focal lesions in colorectal cancer patients: its limitations compared to radiologists

OBJECTIVE

To evaluate diagnostic performance of a radiomics model for classifying hepatic cyst, hemangioma, and metastasis in patients with colorectal cancer (CRC) from portal-phase abdominopelvic CT images.

METHODS

This retrospective study included 502 CRC patients who underwent contrast-enhanced CT and contrast-enhanced liver MRI between January 2005 and December 2010. Portal-phase CT images of training (n = 386) and validation (n = 116) cohorts were used to develop a radiomics model for differentiating three classes of liver lesions. Among multiple handcrafted features, the feature selection was performed using ReliefF method, and random forest classifiers were used to train the selected features. Diagnostic performance of the developed model was compared with that of four radiologists. A subgroup analysis was conducted based on lesion size.

RESULTS

The radiomics model demonstrated significantly lower overall and hemangioma- and metastasis-specific polytomous discrimination index (PDI) (overall, 0.8037; hemangioma-specific, 0.6653; metastasis-specific, 0.8027) than the radiologists (overall, 0.9622-0.9680; hemangioma-specific, 0.9452-0.9630; metastasis-specific, 0.9511-0.9869). For subgroup analysis, the PDI of the radiomics model was different according to the lesion size (< 10 mm, 0.6486; ≥ 10 mm, 0.8264) while that of the radiologists was relatively maintained. For classifying metastasis from benign lesions, the radiomics model showed excellent diagnostic performance, with an accuracy of 84.36% and an AUC of 0.9426.

CONCLUSION

Albeit inferior to the radiologists, the radiomics model achieved substantial diagnostic performance when differentiating hepatic lesions from portal-phase CT images of CRC patients. This model was limited particularly to classifying hemangiomas and subcentimeter lesions.

KEY POINTS

• Albeit inferior to the radiologists, the radiomics model could differentiate cyst, hemangioma, and metastasis with substantial diagnostic performance using portal-phase CT images of colorectal cancer patients. • The radiomics model demonstrated limitations especially in classifying hemangiomas and subcentimeter liver lesions.

Adenotonsillectomy Does not Alter the Risk of Upper Airway Infections in Children

OBJECTIVE

Given the conflicting evidence regarding adenotonsillectomy and the risk of upper airway infections (UAIs), including acute pharyngitis (APT), rhinosinusitis (ARS), and otitis media (AOM), we evaluated the risk of developing UAIs following adenotonsillectomy in a childhood population.

METHODS

In this population-based follow-up study, we used data from the National Health Insurance Service-National Sample Cohort. The adenotonsillectomy group (n = 2,377) included patients aged <10 years who underwent an adenotonsillectomy. For every patient with APT (n = 2,309), ARS (n = 2,308), and AOM (n = 2,207) who had an adenotonsillectomy, four participants were randomly selected for the control groups (n = 9,204, n = 9,196, and n = 8,788, respectively) using propensity score matching. The number of postoperative hospital visits for UAIs was recorded for 1 to 9 years, and the equivalence test was used to compare the number of visits between the adenotonsillectomy and control groups.

RESULTS

There were no significant differences in the incidence of APT, ARS, or AOM at the margin of equivalence of difference (-0.5 < 95% confidence interval of difference < 0.5) between the two groups from postoperative year 1 to year 9. The hospital visits for these diseases gradually decreased over time in both groups. There was a significant decrease in the number of visits for APT, ARS, and AOM in the 5-9 years age group when compared with those in the <4 years age group (P < .01).

CONCLUSION

Our results suggest that adenotonsillectomy does not alter the frequency of UAIs in children.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Prevalence of Intracranial Aneurysm in Patients With Aortic Disease in Korea: A Nationwide Population-Based Study

Background Patients with aortic disease (AD) might have a higher prevalence of intracranial aneurysm (IA). The present study evaluated the prevalence of IA in patients with AD and identified potential risk factors of IA using nationwide representative cohort sample data. Methods and Results We defined AD as both aortic dissections and aortic aneurysms. This study used a nationwide representative cohort sample from the Korea National Health Insurance Service-National Sample Cohort database from 1.1million patients. Using χ² or Fisher's exact tests, the prevalence of the IA in patients with AD and potential risk factors for their concurrence were analyzed. The prevalence of IA in patients with AD was 6.8% (155/2285). The adjusted odds ratios (OR) for having concurrent IA in patients with AD was 3.809 (95% CI, 3.191-4.546; P<0.01). Patients with AD and hypertension were >19 times more likely to be affected by IA (adjusted OR, 18.679; 95% CI, 16.555-21.076; P<0.01). Patients with AD and diabetes mellitus, old age (>60 years), and male sex were >4, 3, and 2 times more likely to be affected by IA, respectively (adjusted OR, 4.291, 3.469, and 1.983, respectively; 95% CI, 3.914-4.704, 3.152-3.878, and 1.779-2.112, respectively). Subgroup analysis with socioeconomic status or disability revealed that the prevalence of IA was significantly higher in all groups. Conclusions In the current population-based study, the prevalence of IA in patients with AD was quadrupled compared with that in the general population. Early IA screening might be considered among patients with AD for appropriate management.

Coagulopathy after snake envenomation in South Korea

OBJECTIVE

This retrospective study investigated the nature and severity of venom-induced consumption coagulopathy (VICC) and determined the clotting factors involved in VICC in patients after envenomation by South Korea's snakes. Additionally, we studied the effectiveness of antivenom for the treatment of VICC after envenomation.

METHODS

Included patients were divided into three groups according to the severity of VICC (no VICC, partial VICC, and complete VICC). Data, including changes in coagulation parameters during hospitalization and clotting factors at presentation, were collected and analyzed.

RESULTS

One hundred nineteen patients who presented at our emergency department within 3 h after snake envenomation were included. VICC developed in 34 patients (27 patients with partial VICC and 7 patients with complete VICC). Two of 34 patients with VICC required blood transfusions. Five patients with complete VICC had an undetectable fibrinogen concentration at presentation. Three patients with complete VICC had an unmeasurable INR and aPTT within 24 h. The median times of the most extreme values were 10 h for INR, 12 h for aPTT, and 16 h for fibrinogen after presentation in the VICC group. The D-dimer concentration peaked at a median of 63.5 h after presentation. The activities of factors II and X were significantly reduced in the complete VICC group (factor II: 88 (84-99.3)% in the non-VICC group vs. 69 (49.5-83.5)% in the complete VICC group; factor X:94 (83-102) in the non-VICC group vs. 70 (66.5-79.8)% in the complete VICC group), while there was no difference in factor V activity at presentation. The time from bite to first antivenom administration did not correlate with the time course and most extreme concentrations for fibrinogen and D-dimer within the VICC groups.

DISCUSSION AND CONCLUSION

VICC occurs in approximately one-quarter of snakebite patients in South Korea; however, VICC itself does not appear to lead to clinical deterioration. Fibrinogen is an early diagnostic maker for complete VICC. Clotting factors II and X are involved in VICC. Future investigations should explore the mechanism of VICC from Korean snakebites and the effect of antivenom on VICC.

Prediction of age and sex from paranasal sinus images using a deep learning network

This study was conducted to develop a convolutional neural network (CNN)-based model to predict the sex and age of patients by identifying unique unknown features from paranasal sinus (PNS) X-ray images.We employed a retrospective study design and used anonymized patient imaging data. Two CNN models, adopting ResNet-152 and DenseNet-169 architectures, were trained to predict sex and age groups (20-39, 40-59, 60+ years). The area under the curve (AUC), algorithm accuracy, sensitivity, and specificity were assessed. Class-activation map (CAM) was used to detect deterministic areas. A total of 4160 PNS X-ray images were collected from 4160 patients. The PNS X-ray images of patients aged ≥20 years were retrieved from the picture archiving and communication database system of our institution. The classification performances in predicting the sex (male vs female) and 3 age groups (20-39, 40-59, 60+ years) for each established CNN model were evaluated.For sex prediction, ResNet-152 performed slightly better (accuracy = 98.0%, sensitivity = 96.9%, specificity = 98.7%, and AUC = 0.939) than DenseNet-169. CAM indicated that maxillary sinuses (males) and ethmoid sinuses (females) were major factors in identifying sex. Meanwhile, for age prediction, the DenseNet-169 model was slightly more accurate in predicting age groups (77.6 ± 1.5% vs 76.3 ± 1.1%). CAM suggested that the maxillary sinus and the periodontal area were primary factors in identifying age groups.Our deep learning model could predict sex and age based on PNS X-ray images. Therefore, it can assist in reducing the risk of patient misidentification in clinics.

Association of Behçet disease with psoriasis and psoriatic arthritis

Behçet disease (BD) is a debilitating multi-systemic vasculitis with a litany of muco-cutaneous manifestations and potentially lethal complications. Meanwhile, psoriasis (PSO) is a cutaneous and systemic inflammatory disorder marked by hyperplastic epidermis and silvery scales, which may be accompanied by a distinct form of arthropathy called psoriatic arthritis (PsA). While the clinical pictures of these two are quite different, they feature some important similarities, most of which may stem from the autoinflammatory components of BD and PSO. Therefore, the aim of this study was to investigate the prospective link between BD and cutaneous and articular manifestations of psoriasis. BD, PSO, and PsA cohorts were extracted using the National Health Insurance Service of Korea database. Using χ² tests, prevalence of PSO and PsA with respect to BD status was analysed. Relative to non-BD individuals, those with personal history of BD were nearly three times more likely to be diagnosed with PSO. The adjusted odds ratio (aOR) was 2.36 [95% confidence interval (CI), 1.91–2.93, p < 0.001]. Elevated PSO risk was more pronounced in the male BD cohort (aOR = 1.19, 95% CI 1.16–1.23, p < 0.001). In age-group sub-analysis, individuals over 65 years with PSO were one and a half times more likely to be affected with BD, relative to those under 65. The adjusted OR for the older group was 1.51 (95% CI 1.43–1.59, p < 0.001). BD individuals with “healthy” body weight were significantly less likely to be affected by PSO (aOR = 0.59, 95% CI 0.57–0.62, p < 0.001). On the other hand, there was a correlation between BMI and the risk of BD, with the “moderately obese (30–35 kg/m²)” group having an aOR of 1.24 (95% CI 1.12–1.38, p < 0.001). BD patients were also twice more likely to be associated with PsA (aOR = 2.19, 95% CI 1.42–3.38, p < 0.001). However, in contrast to the case of psoriatic disease itself, females were exposed to a greater risk of developing BD compared to the male PsA cohort (aOR = 2.02, 95% CI 1.88–2.16, p < 0.001). As with PSO, older BD patients were exposed to a significantly higher risk of developing PsA (aOR = 3.13, 95% CI 2.90–3.40, p < 0.001). Behçet disease may place an individual at a significantly increased risk of psoriasis, and still greater hazard of being affected with psoriatic arthritis. This added risk was pronounced in the male cohort, and tended to impact senile population, and this phenomenon may be related with the relatively poor prognosis of BD in males and PSO in older patients.

Association Between Burning Mouth Syndrome and the Development of Depression, Anxiety, Dementia, and Parkinson Disease

Importance

Burning mouth syndrome is a chronic oral pain disorder that is characterized by a generalized or localized burning sensation without the presence of any specific mucosal lesions. It remains unclear, however, whether burning mouth syndrome is associated with the development of psychoneurological conditions among patients with the syndrome.

Objective

To evaluate the risk of developing psychoneurological conditions, including depression, anxiety, dementia, and Parkinson disease, in patients with burning mouth syndrome.

Design, Setting, and Participants

This retrospective population-based cohort study was conducted using a nationwide representative cohort sample from the Korean National Health Insurance Service-National Sample Cohort, which consists of data from approximately 1 million patients in South Korea. The study included 586 patients with burning mouth syndrome (patient group) and 1172 individuals without burning mouth syndrome (comparison group). The patient group included all patients who received inpatient and outpatient care for an initial diagnosis of burning mouth syndrome between January 1, 2002, and December 31, 2012. The comparison group was selected (2 individuals without burning mouth syndrome for each patient with burning mouth syndrome) using propensity score matching for sex, age, location of residence, household income level, and comorbidities. Data were collected and analyzed from January 1, 2002, to December 31, 2013.

Main Outcomes and Measures

Death and the incidence of psychopathological diseases. Affective disorder events that occurred among participants during the follow-up period were investigated using survival analysis, a log-rank test, and Cox proportional hazards regression models to estimate the incidence rates, survival rates, and hazard ratios, respectively, of participants who developed psychoneurological conditions.

Results

Of 1758 total participants, 1086 (61.8%) were female; 701 participants (39.9%) were younger than 45 years, 667 (37.9%) were aged 45 to 64 years, and 390 (22.2%) were older than 64 years. The overall incidence of depression and anxiety was higher in patients with burning mouth syndrome (n = 586; 30.8 incidents and 44.2 incidents per 1000 person-years, respectively) than in individuals without burning mouth syndrome (n = 1172; 11.7 incidents and 19.0 incidents per 1000 person-years, respectively). The results also indicated a similar incidence of dementia and Parkinson disease between the patient group (6.5 incidents and 2.5 incidents per 1000 person-years, respectively) and the comparison group (4.9 incidents and 1.7 incidents per 1000 person-years, respectively). After adjusting for sociodemographic factors (age, location of residence, household income level, and comorbidities), the adjusted hazard ratios for the development of depression and anxiety among patients with burning mouth syndrome were 2.77 (95% CI, 2.22-3.45) and 2.42 (95% CI, 2.02-2.90), respectively. However, no association was found between burning mouth syndrome and the risk of developing dementia and Parkinson disease.

Conclusions and Relevance

Results of this observational study suggest that burning mouth syndrome is associated with increases in the incidence of depression and anxiety but not in the incidence of dementia and Parkinson disease among patients with the syndrome. Clinicians should be aware of this association and be prepared to make referrals to appropriate mental health care professionals.

Effect of obstructive sleep apnea on immunity in cases of chronic rhinosinusitis with nasal polyp

Objective

Chronic rhinosinusitis (CRS) with nasal polyp (wNP) is a more severe inflammatory form of CRS that often coexists with obstructive sleep apnea (OSA). However, little is known the relationship between OSA and immunologic profile on patients with CRSwNP. We aimed to investigate the immune profile of patients with CRSwNP according to OSA severity.

Methods

This study included 63 patients with CRSwNP and nine control subjects. Protein levels of inflammatory mediators were determined using multiplex immunoassay. All patients underwent standard polysomnography.

Results

We found that, in patients with eosinophilic CRSwNP (ECRSwNP), IL-6 and CXCL-1 (type 1 immune-related markers) were upregulated in cases of moderate-to-severe OSA. Additionally, IL-4, IL-13, CCL-11, CCL-24 (type 2 immune-related markers), and IL-17A (type 3 immune-related marker) were increased in patients with moderate-to-severe OSA. Though there were no significant differences in type 1, 2, or 3 immune-related markers among patients with non-eosinophilic CRSwNP (NECRSwNP) according to the severity of OSA, TGF--β expression was increased in those with moderate-to-severe OSA. Furthermore, in ECRSwNP with moderate-to-severe OSA, associations were detected between serum markers and some upregulated inflammatory markers.

Conclusion

Our findings revealed that OSA may increase the heterogeneity of immune profiles (types 1, 2, and 3) in patients with ECRSwNP but not in those with NECRSwNP.

Optic Nerve Choristoma Mimicking a Neurenteric Cyst

Optic nerve choristomas are rare entities in which a developmental focus of histologically normal tissue is abnormally located within or along a segment of the optic nerve. Although benign, choristomas may demonstrate slow growth, ultimately resulting in visual field deficits due to compression of the adjacent nerve in the few cases reported in the anterior fossa. Choristomas may have cystic components, though this has not been described in such lesions along the optic nerve. Here, a predominantly cystic optic nerve choristoma is described, with radiologic features mimicking those of an anterior cranial fossa neurenteric cyst. The case highlights the radiology-pathology correlates of choristomas and reviews the surgical approach and management of patients with such lesions.

Evaluation and comparison of the indoor air quality in different areas of the hospital

The levels of indoor air pollutants are increasing. However, the indoor air quality of only operating rooms, intensive care units, and radiology departments is usually monitored in hospitals. Hence, we aimed to evaluate the indoor air quality of an otorhinolaryngology outpatient clinic and compare air quality indices among different areas in a hospital.We prospectively measured indoor air quality using air quality sensors in different areas of a hospital from February 1, 2019 to January 31, 2020. Carbon dioxide (CO2), total volatile organic compounds (VOCs), particulate matter with diameter of <2.5 μm (PM2.5), and nitrogen dioxide concentrations were measured in the otorhinolaryngology clinic, orthopedic clinic, and reception area. The intervention efficacy was compared between otorhinolaryngology clinics employing and not employing air-cleaners.The overall concentrations of CO2, VOCs, and PM2.5 in the otorhinolaryngology clinic were significantly higher than those in the orthopedic clinic or reception area. The indoor air quality was the worst in winter. The intervention effect was observed only in PM2.5 concentrations in otorhinolaryngology clinics employing an air-cleaner.Medical practitioners and patients are frequently exposed to ambient indoor air pollution in otorhinolaryngology clinics. Hence, health-related strategies to protect against ambient indoor air pollution in otorhinolaryngology clinics are warranted.

Spatiotemporal filtering method for detecting kinematic waves in a connected environment

Backward-moving kinematic waves (KWs) (e.g., stop-and-go traffic conditions and a shock wave) cause unsafe driving conditions, decreases in the capacities of freeways, and increased travel time. In this paper, a sequential filtering method is proposed to detect KWs using data collected in a connected environment, which can aid in developing a traffic control strategy for connected vehicles to stop or dampen the propagation of these KWs. The proposed method filters out random fluctuation in the data using ensemble empirical mode decomposition that considers the spectral features of KWs. Then, the spatial movements of KWs are considered using cross-correlation to identify potential candidate KWs. Asynchronous changes in the denoised flow and speed are used to evaluate candidate KWs using logistic regression to identify the KWs from localized reductions in speed that are not propagated upstream. The findings from an empirical evaluation of the proposed method showed strong promise for detecting KWs using data in a connected environment, even at 30% of the market penetration rates. This paper also addresses how data resolution of the connected environment affects the performance in detecting KWs.

Effects of speed humps on vehicle speed and pedestrian crashes in South Korea

INTRODUCTION

Speeding is a crucial risk factor for pedestrian safety because it shortens reaction time while increasing the impact force in collisions. Various types of traffic calming measures to prevent speeding have been devised. A speed hump-a raised bump installed in the pavement-has been widely used for this purpose.

METHOD

To evaluate the effectiveness of speed humps, the speed profiles of vehicles passing speed humps were analyzed along with pedestrian crash records near speed humps.

RESULTS

The speed profiles showed that vehicles gradually diminished their speeds starting 30 m ahead of speed humps and, immediately after passing the humps, accelerated to regain their original speeds within a distance of 30 m. This speed reduction effect is substantial on both local and major roads: 18.4% and 24.0% reduction in speeds, respectively. The analysis of pedestrian crash records revealed that, inside the zones of speed reduction effect near speed humps (i.e., ±30 m from speed humps), fewer pedestrian crashes per roadway distance occurred and pedestrian injuries were less severe, compared with events outside the effect zones. This safety improvement was greater on major roads than local roads. Practical Applications: This work finds that the speed reductions that occurred near speed humps were gradual and influential ±30 m from their locations, suggesting that the hump installations should be close enough to the pedestrian crossings. It is noteworthy that, albeit that speed humps are more prevalent on local roads, the benefits of speed reduction effects from speed humps were more pronounced on major roads than on local roads. Therefore, speed humps on major roads can be considered a more effective measure for pedestrian safety.

Generating spatially entangled itinerant photons with waveguide quantum electrodynamics

Realizing a fully connected network of quantum processors requires the ability to distribute quantum entanglement. For distant processing nodes, this can be achieved by generating, routing, and capturing spatially entangled itinerant photons. In this work, we demonstrate the deterministic generation of such photons using superconducting transmon qubits that are directly coupled to a waveguide. In particular, we generate two-photon N00N states and show that the state and spatial entanglement of the emitted photons are tunable via the qubit frequencies. Using quadrature amplitude detection, we reconstruct the moments and correlations of the photonic modes and demonstrate state preparation fidelities of 84%. Our results provide a path toward realizing quantum communication and teleportation protocols using itinerant photons generated by quantum interference within a waveguide quantum electrodynamics architecture.

Safety of Consecutive Bilateral Decubitus Digital Subtraction Myelography in Patients with Spontaneous Intracranial Hypotension and Occult CSF Leak

BACKGROUND AND PURPOSE

Digital subtraction myelography performed with the patient in the lateral decubitus position has the potential for increased sensitivity over prone-position myelography in the detection of spinal CSF-venous fistulas, a well-established cause of spontaneous intracranial hypotension. We report on the safety of performing routine, consecutive-day right and left lateral decubitus digital subtraction myelography in these patients.

MATERIALS AND METHODS

In this retrospective case series, all patients undergoing consecutive-day lateral decubitus digital subtraction myelography for suspected spinal CSF leak between September 2018 and September 2019 were identified. Chart review was performed to identify any immediate or delayed adverse effects associated with the procedures. Procedural parameters were also analyzed due to inherent variations associated with the positive-pressure myelography technique that was used.

RESULTS

A total of 60 patients underwent 68 pairs of consecutive-day lateral decubitus digital subtraction myelographic examinations during the study period. No major adverse effects were recorded. Various minor adverse effects were observed, including pain requiring analgesics (27.2%), nausea/vomiting requiring antiemetics (8.1%), and transient neurologic effects such as syncope, vertigo, altered mental status, and autonomic dysfunction (5.1%). Minor transient neurologic effects were correlated with increasing volumes of intrathecal saline injectate used for thecal sac prepressurization.

CONCLUSIONS

In patients with spontaneous intracranial hypotension and suspected spontaneous spinal CSF leak, consecutive-day lateral decubitus digital subtraction myelography demonstrates an acceptable risk profile without evidence of neurotoxic effects from cumulative intrathecal contrast doses. Higher intrathecal saline injectate volumes may correlate with an increased incidence of minor transient periprocedural neurologic effects.

Multiple membership multilevel model to estimate intersection crashes

Numerous studies have developed intersection crash prediction models to identify crash hotspots and evaluate safety countermeasures. These studies largely considered only micro-level crash contributing factors such as traffic volume, traffic signals, etc. Some recent studies, however, have attempted to include macro-level crash contributing factors, such as population per zone, to predict the number of crashes at intersections. As many intersections are located between multiple zones and thus affected by factors from the multiple zones, the inclusion of macro-level factors requires boundary problems to be resolved. In this study, we introduce an advanced multilevel model, the multiple membership multilevel model (MMMM), for intersection crash analysis. Our objective was to reduce heterogeneity issues between zones in crash prediction model while avoiding misspecification of the model structure. We used five years of intersection crash data (2009-2013) for the City of Regina, Saskatchewan, Canada and identified micro- and macro-level factors that most affected intersection crashes. We compared the fitting performance of the MMMM with that of two existing models, a traditional single model (SM) and a conventional multilevel model (CMM). The MMMM outperformed the SM and CMM in terms of fitting capability. We found that the MMMM avoided both the underestimation of macro-level variance and the type I statistical error that tend to occur when the crash data are analyzed using a SM or CMM. Statistically significant micro-level and macro-level crash contributing factors in Regina included major roadway AADT, four legs, traffic signals, speed, young drivers, and different types of land use.

Time to Resolution of Inadvertent Subdural Contrast Injection during a Myelogram: When Can the Study Be Reattempted?

BACKGROUND AND PURPOSE

Inadvertent subdural contrast injections can occur during any myelogram. Currently, there are no guidelines defining when residual subdural iodinated contrast will be cleared and no longer interfere with subsequent procedure and imaging. We investigated the time to resolution of subdural contrast using a 2-day lateral decubitus digital subtraction myelogram and associated CT myelogram data in patients undergoing evaluation for spontaneous intracranial hypotension.

MATERIALS AND METHODS

Retrospective review of 63 patients with lateral decubitus digital subtraction myelograms from September 4, 2018, to October 1, 2019, was performed. Patients with 2-day lateral decubitus digital subtraction myelograms on 2 consecutive days, with or without a same-day CT myelogram on day 1 and with a same-day CT myelogram on day 2, were included. Patients with next-day CT covering at least the abdomen and pelvis after either-day injection were also included. In cases of subdural injection, next-day CT scans were evaluated for residual subdural contrast.

RESULTS

Of 49 included patients, 5 had subdural injection on day 1, with the second-day CT myelogram available for review. One of these 5 patients had subdural injections on 2 different days and subsequently had chest/abdomen/pelvis CTA a day after the second subdural injection. In all 6 cases of subdural injections, there was complete resolution of subdural contrast on the next-day CT, with the shortest time to resolution of approximately 20.5 hours (range, 20.5-28.5 hours).

CONCLUSIONS

Our study suggests that resolution of inadvertently injected subdural contrast occurs within 1 day, and the myelogram can be reattempted as early as the next day.

Exophytic Lumbar Vertebral Body Mass in an Adult with Back Pain

Chordomas are rare primary bone malignancies derived from notochord remnants. The tumors often are slow-growing and often present with indolent, nonspecific symptoms. Nevertheless, chordomas are locally aggressive and highly prone to local recurrence, necessitating precise planning before biopsy and/or surgical resection. Familiarity with the imaging features of chordomas is, therefore, essential. This case highlights the typical imaging and pathologic features of a spinal chordoma as well as the surgical approach and the patient's subsequent outcome.

Big Data Analysis of Sports and Physical Activities among Korean Adolescents

The Korean government (Ministry of Culture, Sports and Tourism, Ministry of Health and Welfare, and Ministry of Education) has framed policies and conducted many projects to encourage adolescents to be more physically active. Despite these efforts, the participation rate of physical activity in Korean adolescents keeps decreasing. Thus, the purpose of this study was to analyze the perception of sports and physical activity in Korean adolescents through big data analysis of the last 10 years and to provide research data and statistical direction with regard to sports and physical activity participation in Korean adolescents. For data collection, data from 1 January 2010 to 31 December 2019 were collected from Naver (NAVER Corp., Seongnam, Korea), Daum (Kakao Corp., Jeju, Korea), and Google (Alphabet Inc., Mountain View, CA, USA), which are the most widely used search engines in Korea, using TEXTOM 4.0 (The Imc Inc., Daegu, Korea), a big data collection and analysis solution. Keywords such as “adolescent + sports + physical activity” were used. TEXTOM 4.0 can generate various collection lists at once using keywords. Collected data were processed through text mining (frequency analysis, term frequency–inverse document frequency analysis) and social network analysis (SNA) (degree centrality, convergence of iterated correlations analysis) by using TEXTOM 4.0 and UCINET 6 social network analysis software (Analytic Technologies Corp., Lexington, KY, USA). A total of 9278 big data (10.36 MB) were analyzed. Frequency analysis of the top 50 terms through text mining showed exercise (872), mind (851), health (824), program (782), and burden (744) in a descending order. Term frequency–inverse document frequency analysis revealed exercise (2108.070), health (1961.843), program (1928.765), mind (1861.837), and burden (1722.687) in a descending order. SNA showed that the terms with the greatest degree of centrality were exercise (0.02857), program (0.02406), mind (0.02079), health (0.02062), and activity (0.01872) in a descending order. Convergence of the iterated correlations analysis indicated five clusters: exercise and health, child to adult, sociocultural development, therapy, and program. However, female gender, sports for all, stress, and wholesome did not have a high enough correlation to form one cluster. Thus, this study provides basic data and statistical direction to increase the rate of physical activity participation in Korean adolescents by drawing significant implications based on terms and clusters through bid data analysis.

Spontaneous Intracranial Hypotension: Atypical Radiologic Appearances, Imaging Mimickers, and Clinical Look-Alikes

Spontaneous intracranial hypotension is a condition characterized by low CSF volume secondary to leakage through a dural defect with no identifiable cause. Patients classically present with orthostatic headaches, but this symptom is not specific to spontaneous intracranial hypotension, and initial misdiagnosis is common. The most prominent features of spontaneous intracranial hypotension on intracranial MR imaging include "brain sag" and diffuse pachymeningeal enhancement, but these characteristics can be seen in several other conditions. Understanding the clinical and imaging features of spontaneous intracranial hypotension and its mimickers will lead to more prompt and accurate diagnoses. Here we discuss conditions that mimic the radiologic and clinical presentation of spontaneous intracranial hypotension as well as other disorders that CSF leaks can imitate.

Cluster Analysis of Inhalant Allergens in South Korea: A Computational Model of Allergic Sensitization

Objectives.

Sensitization to specific inhalant allergens is a major risk factor for the development of atopic diseases, which impose a major socioeconomic burden and significantly diminish quality of life. However, patterns of inhalant allergic sensitization have yet to be precisely described. Therefore, to enhance the understanding of aeroallergens, we performed a cluster analysis of inhalant allergic sensitization using a computational model.

Methods.

Skin prick data were collected from 7,504 individuals. A positive skin prick response was defined as an allergen-to-histamine wheal ratio ≥1. To identify the clustering of inhalant allergic sensitization, we performed computational analysis using the four-parameter unified-Richards model.

Results.

Hierarchical cluster analysis grouped inhalant allergens into three clusters based on the Davies-Bouldin index (0.528): cluster 1 (Dermatophagoides pteronyssinus and Dermatophagoides farinae), cluster 2 (mugwort, cockroach, oak, birch, cat, and dog), and cluster 3 (Alternaria tenus, ragweed, Candida albicans, Kentucky grass, and meadow grass). Computational modeling revealed that each allergen cluster had a different trajectory over the lifespan. Cluster 1 showed a high level (>50%) of sensitization at an early age (before 19 years), followed by a sharp decrease in sensitization. Cluster 2 showed a moderate level (10%–20%) of sensitization before 29 years of age, followed by a steady decrease in sensitization. However, cluster 3 revealed a low level (<10%) of sensitization at all ages.

Conclusion.

Computational modeling suggests that allergic sensitization consists of three clusters with distinct patterns at different ages. The results of this study will be helpful to allergists in managing patients with atopic diseases.

Characterizing osmolyte chemical class hierarchies and functional group requirements for thermal stabilization of proteins

Osmolytes are naturally occurring organic compounds that protect cellular proteins and other macromolecules against various forms of stress including temperature extremes. While biological studies have correlated the accumulation of certain classes of osmolytes with specific forms of stress, including thermal stress, it remains unclear whether or not these observations reflect an intrinsic chemical class hierarchy amongst the osmolytes with respect to effects on protein stability. In addition, very little is known in regards to the molecular elements of the osmolytes themselves that are essential for their functions. In this study, we use differential scanning fluorimetry to quantify the thermal stabilizing effects of members from each of the three main classes of protecting osmolytes on two model protein systems, C-reactive protein and tumor necrosis factor alpha. Our data reveals the absence of a strict chemical class hierarchy amongst the osmolytes with respect to protein thermal stabilization, and indicates differential responses of these proteins to certain osmolytes. In the second part of this investigation we dissected the molecular elements of amino acid osmolytes required for thermal stabilization of myoglobin and C-reactive protein. We show that the complete amino acid zwitterion is required for thermal stabilization of myoglobin, whereas removal of the osmolyte amino group does not diminish stabilizing effects on C-reactive protein. These disparate responses of proteins to osmolytes and other small molecules are consistent with previous observations that osmolyte effects on protein stability are protein-specific. Moreover, the data reported in this study support the view that osmolyte effects cannot be fully explained by considering only the solvent accessibility of the polypeptide backbone in the native and denatured states, and corroborate the need for more complex models that take into account the entire protein fabric.