Application of Machine Learning and Deep Learning in Imaging of Ischemic Stroke

Timely analysis of imaging data is critical for diagnosis and decision-making for proper treatment strategy in the cases of ischemic stroke. Various efforts have been made to develop computer-assisted systems to improve the accuracy of stroke diagnosis and acute stroke triage. The widespread emergence of artificial intelligence technology has been integrated into the field of medicine. Artificial intelligence can play an important role in providing care to patients with stroke. In the past few decades, numerous studies have explored the use of machine learning and deep learning algorithms for application in the management of stroke. In this review, we will start with a brief introduction to machine learning and deep learning and provide clinical applications of machine learning and deep learning in various aspects of stroke management, including rapid diagnosis and improved triage, identifying large vessel occlusion, predicting time from stroke onset, automated ASPECTS (Alberta Stroke Program Early CT Score) measurement, lesion segmentation, and predicting treatment outcome. This work is focused on providing the current application of artificial intelligence techniques in the imaging of ischemic stroke, including MRI and CT.

Monitoring Radiation Doses during Diagnostic and Therapeutic Neurointerventional Procedures: Multicenter Study for Establishment of Reference Levels / 신경중재치료의학

Purpose@#To assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL). @*Materials and Methods@#Consecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution. @*Results@#Analysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group. @*Conclusion@#Various RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.

Gender and age differences in the prevalence and associated factors of metabolic syndrome among children and adolescents in South Korea

Purpose@#This study examined the prevalence of metabolic syndrome (MetS) in South Korean children and adolescents by gender and age and analyzed gender-specific factors associated with MetS. @*Methods@#This study used data on children aged 10~18 from the Korea National Health and Nutrition Examination Survey (KNHANES) from 2010 to 2015. Analyses included descriptive statistics, the independent t-test, the x2 test, and univariate logistic regression analysis (p<.050). @*Results@#The prevalence of MetS was 4.8% in boys and 3.4% in girls. The prevalence was higher in girls up to the age of 12, but higher in boys who were 13 or older. Abdominal obesity was frequent in girls, whereas low high-density lipoprotein cholesterol (HDL-C) and elevated blood pressure were more common in boys. Higher body mass index, waist-to-height ratio, waist circumference, blood pressure, triglycerides, HDL-C, perceived "fat" body shape, and weight loss efforts were associated with MetS in both genders. Increasing age, having one meal per day, and weight maintenance were associated factors unique to boys. Fasting plasma glucose, familial medical history of low HDL-C, and perceived "thin" body shape were associated factors in girls. @*Conclusion@#Gender and age differences should be considered in the risk assessment and prevention of MetS.

Pictorial Review of Mediastinal Masses with an Emphasis on Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) has become a crucial tool for evaluating mediastinal masses considering that several lesions that appear indeterminate on computed tomography and radiography can be differentiated on MRI. Using a three-compartment model to localize the mass and employing a basic knowledge of MRI, radiologists can easily diagnose mediastinal masses. Here, we review the use of MRI in evaluating mediastinal masses and present the images of various mediastinal masses categorized using the International Thymic Malignancy Interest Group’s three-compartment classification system. These masses include thymic hyperplasia, thymic cyst, pericardial cyst, thymoma, mediastinal hemangioma, lymphoma, mature teratoma, bronchogenic cyst, esophageal duplication cyst, mediastinal thyroid carcinoma originating from ectopic thyroid tissue, mediastinal liposarcoma, mediastinal pancreatic pseudocyst, neurogenic tumor, meningocele, and plasmacytoma.

Predictors of Catastrophic Outcome after Endovascular Thrombectomy in Elderly Patients with Acute Anterior Circulation Stroke

Prevalence of Menstrual Disorders according to Body Mass Index and Lifestyle Factors: The National Health Insurance Service-National Health Screening Cohort in Korea, 2009~2016

Purpose@#This study was performed to identify the prevalence of menstrual disorders in Korean women based on body mass index (BMI)and lifestyle factors, by utilizing the Korean National Health Insurance Database. @*Methods@#A retrospective observational study designwas used for the secondary data analysis. Data of women aged 15 to 49 years who were diagnosed with menstrual disorders were extractedfrom The National Health Insurance Service-National Health Screening Cohort in Korea from 2009 to 2016. The age-standardizedprevalence rate of menstrual disorders was calculated using SAS version 9.4, and a Chi-square test and Cochran-Armitage test were performed. @*Results@#In total, 2,219,445 cases were extracted from the database. The prevalence of menstrual disorders significantly increasedfrom 8.6% to 11.6% (Z=135.16, p for trend <.001) over the past eight years. In particular, it was higher in underweight womenthan in women with normal weight across all years (Z=-4.18~-14.72, p <.001). Moreover, statistically significant differences in the prevalenceof menstrual disorders were found to be associated with drinking and smoking in all years and with physical activity levels in part(p <.05~.001). @*Conclusion@#These findings present compelling evidence on the prevalence of menstrual disorders based on a national database.Since the prevalence of menstrual disorders has steadily increased and differs based on BMI and lifestyle factors, educational andclinical interventions are necessary to promote risk awareness and appropriate behavioral changes among Korean women.

Predictors of a Favorable Outcome after Emergent Carotid Artery Stenting in Acute Anterior Circulation Stroke Patients

Purpose@#This study aimed to identify independent predictors of favorable outcomes associated with emergent carotid artery stenting (CAS) in patients with acute anterior circulation stroke. @*Materials and Methods@#This study included 93 patients with acute stroke who underwent emergent CAS to treat stenoocclusive lesions in the cervical internal carotid artery (ICA) within 6 hours of the onset of the associated symptoms. Data were compared between patients with and without favorable outcomes. The independent predictors of a favorable outcome were determined via logistic regression analysis (modified Rankin Scale 0–2 at 90 days). @*Results@#Intracranial tandem occlusion was noted in 81.7% of patients (76/93) among which (76/93), 55 of whom underwent intracranial recanalization therapy. Intracranial reperfusion was successful in 74.2% (69/93) and favorable outcomes were noted in 51.6% of patients (48/93). The mortality rate was 6.5% (6/93). In logistic regression analysis, diffusion-weighted imaging-Alberta Stroke Program Early CT Score [odds ratio (OR), 1.487; 95% confidence interval (CI), 1.018–2.173, p = 0.04], successful reperfusion (OR, 5.199; 95% CI, 1.566–17.265, p = 0.007), and parenchymal hemorrhage (OR, 0.042; 95% CI, 0.003–0.522, p = 0.014) were independently associated with a favorable outcome. @*Conclusion@#Baseline infarct size, reperfusion status, and parenchymal hemorrhage were independent predictors of favorable outcomes after emergent CAS to treat stenoocclusive lesions in the cervical ICA in patients with acute anterior circulation stroke.

Reliability and Validity of the Brief Schema Questionnaire for Adult / 신경정신의학

OBJECTIVES: The aim of this study was to develop a brief schema questionnaire for adults (BSQ-A) and investigate its validity and reliability. METHODS: A 36-item questionnaire was developed or selected by six psychiatrists. The questionnaire was administered to 209 subjects in Seoul and Gyeonggi area. The construct validity was investigated by performing principal component analysis, and the reliability was assessed in terms of the internal consistency using Cronbach's alpha. RESULTS: The principal component analysis revealed 18 factors underlying 18 early maladaptive schemas (EMSs). These 18 factors accounted for 87.488% of the common variance. The Cronbach's alpha was high, indicating that the reliability of the questionnaire was satisfactory. Every schema showed a positive correlation with most psychological measures. CONCLUSION: The results indicate that the BSQ-A is a reliable and valid scale for assessing EMSs. Although there are many limitations, the present study is expected to form the basis of future research.

Reliability and Validity of the Mental Health Questionnaire for Adult / 신경정신의학

OBJECTIVES: The aim of this study was to develop a Mental Health Questionnaire for Adults (MHQ-A) and investigate its validity and reliability. METHODS: A 73-item questionnaire was developed or selected by seven psychiatrists and a clinical psychologist. The questionnaire was administered to 351 subjects in Seoul and Gyeonggi area. The construct validity was investigated by performing principal component analysis, and the reliability was assessed in terms of the internal consistency using Cronbach's alpha. RESULTS: Principal component analysis revealed 15 factors underlying the psychiatric disorder and symptom category. Taken together, these 15 factors accounted for 64.023% of the common variance. Cronbach's alpha was high, indicating that the reliability of the questionnaire was satisfactory. Every category showed a positive correlation with most psychological measures. CONCLUSION: These results indicate that the MHQ-A is a reliable and valid scale for assessing psychiatric disorders. Although there were many limitations, the present study has significance as the basis of future research.

Neural Mechanism of Second Language Processing in Korean-English Bilingual Children

PURPOSE@#To evaluate the neural mechanism of second language processing in Korean-English bilingual children using functional MRI (fMRI).@*MATERIALS AND METHODS@#The study was conducted on 20 Korean elementary school children who were learning English as a foreign language. fMRI was performed during short-passage comprehension tasks in Korean and English languages. We analyzed which brain areas were activated according to the language, English proficiency, and task difficulty.@*RESULTS@#Higher activities were observed in the dorsolateral prefrontal cortex, supplementary motor area, precentral gyrus, left basal ganglia, and left temporoparietal and occipital lobes during English comprehension than during Korean comprehension. The low English proficiency group showed higher activities than the high English proficiency group in the frontotemporal cortex, including the prefrontal cortex. Higher activities were observed in the right inferior frontal gyrus and right temporoparietal lobe during the English comprehension task of intermediate difficulty compared to that of low difficulty. However, the brain activities significantly decreased while performing a high-difficulty English task.@*CONCLUSION@#Brain activities significantly increased during English comprehension in the lower English proficiency group while performing an intermediate-difficulty task. However, brain activation decreased when the task difficulty exceeded the moderate comprehension level. These results suggest that a proper level of education is important to learn a second language.

Current Opinion on Endovascular Therapy for Emergent Large Vessel Occlusion Due to Underlying Intracranial Atherosclerotic Stenosis

For recanalization of emergent large vessel occlusions (ELVOs), endovascular therapy (EVT) using newer devices, such as a stent retriever and large-bore catheter, has shown better patient outcomes compared with intravenous recombinant tissue plasminogen activator only. Intracranial atherosclerotic stenosis (ICAS) is a major cause of acute ischemic stroke, the incidence of which is rising worldwide. Thus, it is not rare to encounter underlying ICAS during EVT procedures, particularly in Asian countries. ELVO due to underlying ICAS is often related to EVT procedure failure or complications, which can lead to poor functional recovery. However, information regarding EVT for this type of stroke is lacking because large clinical trials have been largely based on Western populations. In this review, we discuss the unique pathologic basis of ELVO with underlying ICAS, which may complicate EVT procedures. Moreover, we review EVT data for patients with ELVO due to underlying ICAS and suggest an optimal endovascular recanalization strategy based on the existing literature. Finally, we present future perspectives on this subject.

Analysis of Clinical Manifestations and Laboratory Findings in Children with Influenza B-Associated Myositis: A Single Center Study / 가정의학회지

BACKGROUND: Influenza-associated myositis (IAM) is a rare and poorly recognized complication of influenza infection in children, and is characterized by acute onset of severe pain in the lower extremities and a refusal to ambulate walk. We sought to understand the association between IAM and influenza B infection and to investigate its clinical and laboratory characteristics in affected children. METHODS: Influenza B-associated myositis (IBAM) cases diagnosed in the pediatrics department of Wonkwang University Hospital from January 2010 and March 2016 were analyzed retrospectively. RESULTS: Medical records of affected children were examined, and clinical characteristics and laboratory findings were recorded. Of the 536 children diagnosed with influenza B infection, 47 children complained of bilateral calf pain with or without gait disturbance. All children exhibited elevated serum aspartate aminotransferase (AST) level. The median serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels, reportedly elevated in myositis, were 2,597 IU/L and 678 IU/L, respectively. While the immunofluorescence test results were negative for some patients, the polymerase chain reaction test results indicated influenza B infection in all 47 children. At the time of hospital discharge, the patients' symptoms had resolved, and their CK levels had improved. CONCLUSION: IBAM was generally benign and short, and although the blood AST, CK, and LDH levels were markedly high, the erythrocyte sedimentation rate and C-reactive protein levels were normal. Further, the duration of IBAM symptoms correlated with the duration of fever. The IBAM-associated clinical and laboratory findings are highly characteristic and may allow its rapid diagnosis during the influenza season.

A Case of Mesenteric Cyst in a 4-Year-Old Child with Acute Abdominal Pain / 대한소아소화기영양학회지

Mesenteric cysts are rare intra-abdominal lesions occurring during childhood, which were first described in 1507. Cases of mesenteric cysts have been continuously reported, but these cases were very small in number. They are often asymptomatic and incidentally found while patients are undergoing work-up or receiving treatment for other conditions such as appendicitis, small-bowel obstruction, or diverticulitis; however, patients may still have lower abdominal pain and symptoms that are frequently associated with other abdominal conditions. The symptoms are variable and non-specific, including pain (82%), nausea and vomiting (45%), constipation (27%), and diarrhea (6%). An abdominal mass may be palpable in up to 61% of patients. We are to report the clinical course and literature of a child with mesenteric cysts who complained of acute abdominal pain, distension, and vomiting and were surgically treated after being diagnosed with mesenteric cysts based on radiological examination.

A Case of Mesenteric Cyst in a 4-Year-Old Child with Acute Abdominal Pain / 대한소아소화기영양학회지

Mesenteric cysts are rare intra-abdominal lesions occurring during childhood, which were first described in 1507. Cases of mesenteric cysts have been continuously reported, but these cases were very small in number. They are often asymptomatic and incidentally found while patients are undergoing work-up or receiving treatment for other conditions such as appendicitis, small-bowel obstruction, or diverticulitis; however, patients may still have lower abdominal pain and symptoms that are frequently associated with other abdominal conditions. The symptoms are variable and non-specific, including pain (82%), nausea and vomiting (45%), constipation (27%), and diarrhea (6%). An abdominal mass may be palpable in up to 61% of patients. We are to report the clinical course and literature of a child with mesenteric cysts who complained of acute abdominal pain, distension, and vomiting and were surgically treated after being diagnosed with mesenteric cysts based on radiological examination.

A Mild Form of COG5 Defect Showing Early-Childhood-Onset Friedreich's-Ataxia-Like Phenotypes with Isolated Cerebellar Atrophy

Progressive cerebellar ataxias are rare diseases during childhood, especially under 6 years of age. In a single family, three affected siblings exhibited Friedreich's-ataxia-like phenotypes before 2 years of age. They had progressive cerebellar atrophy, intellectual disability, and scoliosis. Although their phenotypes were similar to those observed in patients with autosomal recessive cerebellar ataxias, other phenotypes (e.g., seizure, movement disorders, ophthalmologic disturbance, cardiomyopathy, and cutaneous disorders) were not noted in this family. Whole-exome sequencing of the family members revealed one potential heterozygous mutation (c.1209delG, NM_181733.2; p.Met403IlefsX3, NP_859422.2) of the gene encoding conserved oligomeric Golgi complex subunit 5 (COG5). The heterozygous deletion at the fifth base in exon 12 of COG5 caused a frameshift and premature stop. Western blotting of COG5 proteins in the skin tissues from an affected proband showed a significantly decreased level of full length COG5 and smaller, aberrant COG5 proteins. We reported a milder form of COG5 defect showing Friedreich's-ataxia-like phenotypes without hypotonia, microcephaly, and short stature that were observed in most patients with COG5 defect.

Predictive Factors for Good Outcome and Mortality After Stent-Retriever Thrombectomy in Patients With Acute Anterior Circulation Stroke / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: Predictive factors associated with stent-retriever thrombectomy for patients with acute anterior circulation stroke remain to be elucidated. This study aimed to investigate clinical and procedural factors predictive of good outcome and mortality after stent-retriever thrombectomy in a large cohort of patients with acute anterior circulation stroke. METHODS: We analyzed clinical and procedural data in 335 patients with acute anterior circulation stroke treated with stent-retriever thrombectomy. A good outcome was defined as a modified Rankin Scale score of 0 to 2 at 3 months. The associations between clinical, imaging, and procedural factors and good outcome and mortality, respectively, were evaluated using logistic regression analysis. RESULTS: Using multivariate analysis, age (odds ratio [OR], 0.965; 95% confidence interval [CI], 0.944-0.986; P=0.001), successful revascularization (OR, 4.658; 95% CI, 2.240-9.689; P<0.001), parenchymal hemorrhage (OR, 0.150; 95% CI, 0.049-0.460; P=0.001), and baseline NIHSS score (OR, 0.908; 95% CI, 0.855-0.965; P=0.002) were independent predictors of good outcome. Independent predictors of mortality were age (OR, 1.043; 95% CI, 1.002-1.086; P=0.041), successful revascularization (OR, 0.171; 95% CI, 0.079-0.370; P<0.001), parenchymal hemorrhage (OR, 2.961; 95% CI, 1.059-8.276; P=0.038), and a history of previous stroke/TIA (OR, 3.124; 95% CI, 1.340-7.281; P=0.008). CONCLUSIONS: Age, revascularization status, and parenchymal hemorrhage are independent predictors of both good outcome and mortality after stent retriever thrombectomy for acute anterior circulation stroke. In addition, NIHSS score on admission is independently associated with good outcome, whereas a history of previous stroke is independently associated with mortality.

A Randomized Comparison of Remifentanil Target-Controlled Infusion Versus Dexmedetomidine Single-Dose Administration: A Better Method for Smooth Recovery From General Sevoflurane Anesthesia.

Remifentanil target-controlled infusion and dexmedetomidine single-dose administration are known to reduce airway response and hemodynamic stimulation during anesthetic recovery. We compared the effects of 2 drugs on the prevention of cough during emergence. We enrolled 70 female patients aged 20-60 years with American Society of Anesthesiologists (ASA) I-II who underwent general anesthesia for elective thyroidectomy. The patients were randomly assigned to remifentanil (group R) or dexmedetomidine (group D). Anesthesia was maintained with sevoflurane and effect-site target-controlled infusion of remifentanil. In group D, remifentanil was discontinued, and dexmedetomidine 0.5 µg/kg was given 10 minutes before the end of surgery. In group R, remifentanil target-controlled infusion at an effective-site concentration of 2.0 ng/mL was maintained during emergence until extubation. The cough grade, hemodynamic values, respiration, and other recovery profiles were evaluated during the periextubation period. The proportion of patients with no cough or just a single cough during extubation was significantly higher in group R than in group D (96.8% vs. 55.9%). The change of mean arterial pressure and heart rate were not significantly different during extubation in both groups. Respiratory rate and the incidence of residual sedation after extubation were lower in group R. There were no desaturation events and no differences in time to extubation or duration of postanesthesia care unit stay in both groups. Remifentanil target-controlled infusion reduces emergence cough from general anesthesia more effectively than single-dose dexmedetomidine. However, a single-dose of dexmedetomidine has the effect with respect to respiratory and hemodynamic stability during emergence.

Correlation between Tissue Oxygen Saturation and Global Oxygenation Parameters in Emergency Patients: A Pilot Clinical Study

PURPOSE: Near-infrared spectroscopy (NIRS) can noninvasively assess changes in tissue oxygen saturation (StO₂). The primary concern of the current study is to determine whether StO₂ can be used as a surrogate for global oxygenation parameters such as central venous oxygen saturation (ScvO₂), lactic acid, and base deficit (BD) in patients presenting to the emergency department (ED). METHODS: This was a prospective, observational study in patients requiring central venous catheter placement, admitted to the ED with complaints classified as infectious and non-infectious etiology. The NIRS sensor (15 mm probe) was applied on the thenar eminence for at least 3 minutes and ScvO₂, arterial lactic acid, and BD were measured during insertion of a central venous catheter. Data were analyzed using a simple correlation and Bland-Altman plot. RESULTS: A total of 120 patients were enrolled in the study and further classified as an infection (n=39) and a noninfection (n=81) group. Lactic acid BD showed significant correlation with StO₂ in total and in non-infection patients but the degree of correlation was weak and these correlations were not observed in infection patients. Approximately 94% of the difference between StO₂ and ScvO₂ was placed within limit of agreement but there was a risk that StO₂ may overestimate ScvO₂ when ScvO₂ becomes lower. When patients were assigned to two groups according to laboratory results (lactic acid 4.0 mmol/L; BD > 3.0 mmol/L; ScvO₂> 65% or 75%), no significant difference in StO₂ was observed between the two groups. CONCLUSION: In ED patients suspected of having systemic hypoperfusion, StO₂ showed a weak correlation with lactic acid and BD in non-infection patients and no correlation in infection patients. In addition, as ScvO₂ decreased, the difference between StO₂ and ScvO₂ showed a tendency to increase, and StO₂ was much higher than ScvO₂ at low ScvO₂ level. Therefore, before using StO₂ as surrogate for ScvO₂, lactic acid and BD in critically ill patients presenting to the ED, further investigation should be conducted to overcome the limitations of NIRS addressed in this study.

Successful Cross-circulation Stent-Retriever Embolectomy Through Posterior Communicating Artery for Acute MCA Occlusion by Using Trevo XP ProVue / 신경중재치료의학

Acute ischemic stroke due to embolic occlusion of the middle cerebral artery (MCA) in patients with chronic ipsilateral internal carotid artery (ICA) occlusion is quite rare. Several previous reports demonstrated that intra-arterial (IA) thrombolytic therapy or aspiration thrombectomy using the cross-circulation technique via an alternative collateral pathway is feasible in acute stroke patients with an unfavorable direct route to the occluded sites. However, stent-retriever embolectomy via the cross-circulation approach has not been reported in the literature. The present paper reports the first case of successful stent-retriever embolectomy for acute MCA occlusion via the patent posterior communicating artery (PComA) by using Trevo XP ProVue stent-retriever in a patient with acute MCA stroke and chronic occlusion at the origin site of the ipsilateral ICA.