Objective: Brain computed tomography (CT) scans are often performed to determine the cause of dizziness in emergency departments (EDs). This study examined the usefulness of brain CT in diagnosing dizziness. Methods: This retrospective study examined the medical records of patients aged 18 years or older who visited a single emergency medical center with dizziness from January 1, 2023, to December 31, 2023. The patients’ demographic information, symptoms, and brain CT results were collected. Univariate and multivariate logistic regression were performed. Results: A total of 1,428 patients were enrolled. Among them, 45 patients had positive findings on brain CT. In the group of patients with a previous history of cerebrovascular accident (CVA), the proportion of positive brain CT results was higher than in those without a history of CVA (P<0.01). The group with one or more underlying diseases was statistically significant (P=0.02). In patients with nystagmus, the rate of positive brain CT findings was low, but the difference from patients without nystagmus was not statistically significant (0.9%, P=0.05). In patients who had one or more abnormal neurological exam findings, multivariate logistic regression analysis showed that the presence of neurologic exam finding (odds ratio [OR], 3.04; 95% confidence interval [CI], 1.65-5.75; P<0.01), and the presence of nystagmus (OR, 0.12; 95% CI, 0.03-0.55; P<0.01) were associated with positive findings on brain CT. Conclusion Brain CT has limited diagnostic value in patients with dizziness presenting to the emergency room. This imaging modality should be performed in limited situations where central-type vertigo is suspected. Even in these cases, other diagnostic modalities such as MRI should be considered.

In patients with type 2 diabetes mellitus (T2DM), diabetic kidney disease (DKD) is diagnosed based on clinical features. A kidney biopsy is used only in selected cases. This study aimed to reconsider the role of a biopsy in predicting renal outcomes. Methods: Clinical and laboratory parameters and renal biopsy results were obtained from 237 patients with T2DM who underwent renal biopsies at Soonchunhyang University Cheonan Hospital between January 2000 and March 2020 and were analyzed. Results: Of 237 diabetic patients, 29.1% had DKD only, 61.6% had non-DKD (NDKD), and 9.3% had DKD with coexisting NDKD (DKD/NDKD). Of the patients with DKD alone, 43.5% progressed to end-stage kidney disease (ESKD), while 15.8% of NDKD patients and 36.4% of DKD/NDKD patients progressed to ESKD (p < 0.001). In the DKD-alone group, pathologic features like ≥50% global sclerosis (p < 0.001), tubular atrophy (p < 0.001), interstitial fibrosis (p < 0.001), interstitial inflammation (p < 0.001), and the presence of hyalinosis (p = 0.03) were related to worse renal outcomes. The Cox regression model showed a higher risk of progression to ESKD in the DKD/NDKD group compared to the DKD-alone group (hazard ratio [HR], 2.73; p = 0.032), ≥50% global sclerosis (HR, 3.88; p < 0.001), and the degree of mesangial expansion (moderate: HR, 2.45; p = 0.045 and severe: HR, 6.22; p < 0.001). Conclusion: In patients with T2DM, a kidney biopsy can help in identifying patients with NDKD for appropriate treatment, and it has predictive value.

Background: Cardiovascular disease is life-threatening yet preventable for patients with type 2 diabetes mellitus (T2DM). Because each patient with T2DM has a different risk of developing cardiovascular complications, the accurate stratification of cardiovascular risk is critical. In this study, we proposed cardiovascular risk engines based on machine-learning algorithms for newly diagnosed T2DM patients in Korea. Methods: To develop the machine-learning-based cardiovascular disease engines, we retrospectively analyzed 26,166 newly diagnosed T2DM patients who visited Seoul St. Mary’s Hospital between July 2009 and April 2019. To accurately measure diabetes-related cardiovascular events, we designed a buffer (1 year), an observation (1 year), and an outcome period (5 years). The entire dataset was split into training and testing sets in an 8:2 ratio, and this procedure was repeated 100 times. The area under the receiver operating characteristic curve (AUROC) was calculated by 10-fold cross-validation on the training dataset. Results: The machine-learning-based risk engines (AUROC XGBoost=0.781±0.014 and AUROC gated recurrent unit [GRU]-ordinary differential equation [ODE]-Bayes=0.812±0.016) outperformed the conventional regression-based model (AUROC=0.723± 0.036). Conclusion GRU-ODE-Bayes-based cardiovascular risk engine is highly accurate, easily applicable, and can provide valuable information for the individualized treatment of Korean patients with newly diagnosed T2DM.

Human pluripotent stem cells (hPSCs) such as human embryonic stem cells (hESCs), induced pluripotent stem cells, and somatic cell nuclear transfer (SCNT)-hESCs can permanently self-renew while maintaining their capacity to differentiate into any type of somatic cells, thereby serving as an important cell source for cell therapy. However, there are persistent challenges in the application of hPSCs in clinical trials, where one of the most significant is graft rejection by the patient immune system in response to human leukocyte antigen (HLA) mismatch when transplants are obtained from an allogeneic (non-self) cell source. Homozygous SCNT-hESCs (homo-SCNT-hESCs) were used to simplify the clinical application and to reduce HLA mismatch. Here, we present a xeno-free protocol that confirms the efficient generation of neural precursor cells in hPSCs and also the differentiation of dopaminergic neurons. Additionally, there was no difference when comparing the HLA expression patterns of hESC, homo-SCNT-hESCs and hetero-SCNT-hESCs. We propose that there are no differences in the differentiation capacity and HLA expression among hPSCs that can be cultured in vitro. Thus, it is expected that homo-SCNT-hESCs will possess a wider range of applications when transplanted with neural precursor cells in the context of clinical trials.

Magnetic resonance angiography (MRA) plays an important role in accurate diagnosis and appropriate treatment planning for patients with arterial disease. Contrastenhanced (CE) MRA is fast and robust, offering hemodynamic information of arterial flow, but involves the risk of a side effect called nephrogenic systemic fibrosis. Various non-contrast-enhanced (NCE) MRA techniques have been developed by utilizing the fact that arterial blood is moving fast compared to background tissues.NCE MRA is completely free of any safety issues, but has different drawbacks for various approaches. This review article describes basic principles of CE and NCE MRA techniques with a focus on how to generate angiographic image contrast from a pulse sequence perspective. Advantages, pitfalls, and key applications are also discussed for each MRA method.

OBJECTIVE: To demonstrate that human visual illusion can contribute to sub-endocardial dark rim artifact in contrast-enhanced myocardial perfusion magnetic resonance images.MATERIALS AND METHODS: Numerical phantoms were generated to simulate the first-passage of contrast agent in the heart, and rendered in conventional gray scale as well as in color scale with reduced luminance variation. Cardiac perfusion images were acquired from two healthy volunteers, and were displayed by the same gray and color scales used in the numerical study. Before and after k-space windowing, the left ventricle (LV)-myocardium boarders were analyzed visually and quantitatively through intensity profiles perpendicular the boarders.RESULTS: k-space windowing yielded monotonically decreasing signal intensity near the LV-myocardium boarder in the phantom images, as confirmed by negative finite difference values near the board ranging −1.07 to −0.14. However, the dark band still appears, which is perceived by visual illusion. Dark rim is perceived in the in-vivo images after k-space windowing that removed the quantitative signal dip, suggesting that the perceived dark rim is a visual illusion. The perceived dark rim is stronger at peak LV enhancement than the peak myocardial enhancement, due to the larger intensity difference between LV and myocardium. In both numerical phantom and in-vivo images, the illusory dark band is not visible in the color map due to reduced luminance variation.CONCLUSION: Visual illusion is another potential cause of dark rim artifact in contrast-enhanced myocardial perfusion MRI as demonstrated by illusory rim perceived in the absence of quantitative intensity undershoot.

OBJECTIVES: To develop a simple algorithm for prescreening of obstructive sleep apnea (OSA) on the basis of respiratorysounds recorded during polysomnography during all sleep stages between sleep onset and offset. METHODS: Patients who underwent attended, in-laboratory, full-night polysomnography were included. For all patients, audiorecordings were performed with an air-conduction microphone during polysomnography. Analyses included allsleep stages (i.e., N1, N2, N3, rapid eye movement, and waking). After noise reduction preprocessing, data were segmentedinto 5-s windows and sound features were extracted. Prediction models were established and validated with10-fold cross-validation by using simple logistic regression. Binary classifications were separately conducted for threedifferent threshold criteria at apnea hypopnea index (AHI) of 5, 15, or 30. Prediction model characteristics, includingaccuracy, sensitivity, specificity, positive predictive value (precision), negative predictive value, and area under thecurve (AUC) of the receiver operating characteristic were computed. RESULTS: A total of 116 subjects were included; their mean age, body mass index, and AHI were 50.4 years, 25.5 kg/m2, and23.0/hr, respectively. A total of 508 sound features were extracted from respiratory sounds recorded throughoutsleep. Accuracies of binary classifiers at AHIs of 5, 15, and 30 were 82.7%, 84.4%, and 85.3%, respectively. Predictionperformances for the classifiers at AHIs of 5, 15, and 30 were AUC, 0.83, 0.901, and 0.91; sensitivity, 87.5%,81.6%, and 60%; and specificity, 67.8%, 87.5%, and 94.1%. Respective precision values of the classifiers were89.5%, 87.5%, and 78.2% for AHIs of 5, 15, and 30. CONCLUSION: This study showed that our binary classifier predicted patients with AHI of ≥15 with sensitivity and specificityof >80% by using respiratory sounds during sleep. Since our prediction model included all sleep stage data, algorithmsbased on respiratory sounds may have a high value for prescreening OSA with mobile devices.
Apnea ; Area Under Curve ; Body Mass Index ; Classification ; Humans ; Logistic Models ; Machine Learning ; Noise ; Polysomnography ; Respiratory Sounds ; ROC Curve ; Sensitivity and Specificity ; Sleep Apnea, Obstructive ; Sleep Stages ; Sleep, REM

Choroid plexus tumors are uncommon brain tumors that primarily occur in children. Most of these tumors originate from the intraventricular area, and the most common clinicalpresentation is increased intracranial pressure. Dissemination through the cerebrospinal fluid space is the inevitable natural course of the disease. Here, we present 2 rare cases of adult choroid plexus carcinoma (CPC), each with distinct clinical presentation and progression. The first case was a 40-year-old male who presented with multiple intraventricular masses. After surgical biopsy, radiation and intrathecal chemotherapy failed to elicit any response. The patient progressed with spinal cord dissemination and expired 1 year later. The second case presented with visual disturbance, and brain MRI revealed a large ovoid juxtaventricular mass with peritumoral edema. This 49-year-old female patient underwent craniotomy for what was thought to be a high-grade glioma; however, the mass was connected to the choroid plexus at the operative field. Her pathology specimen was diagnosed as CPC, and adjuvant systemic chemotherapy was administered. She has now been free of recurrence for 10 months. The description of the presentation and progression of these rare adult-onset CPC provides insight for the diagnosis and treatment of other rare instances of choroid plexus tumors.
Adult ; Biopsy ; Brain ; Brain Neoplasms ; Cerebrospinal Fluid ; Child ; Choroid Plexus Neoplasms ; Choroid Plexus ; Choroid ; Craniotomy ; Diagnosis ; Drug Therapy ; Edema ; Female ; Fourth Ventricle ; Glioma ; Humans ; Intracranial Pressure ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Pathology ; Recurrence ; Spinal Cord

PURPOSE: To develop a two-dimensional (2D) image-based respiratory motion correction technique for free-breathing coronary magnetic resonance angiography (MRA). MATERIALS AND METHODS: The proposed respiratory navigator obtained aliased a 2D sagittal image from under-sampled k-space data and utilized motion correlation between the aliased images. The proposed navigator was incorporated into the conventional coronary MRA sequence including the diaphragm navigator and tested in three healthy subjects. RESULTS: The delineation of major coronary arteries was significantly improved using the proposed 2D motion correction (S/I and A/P) compared to one-dimensional (S/I) correction using the conventional diaphragm navigator. CONCLUSION: The 2D image-based respiratory navigator was proposed for free-breathing coronary angiography and showed the potential for improving respiratory motion correction compared to the conventional 1D correction.
Coronary Angiography ; Coronary Vessels ; Diaphragm ; Healthy Volunteers ; Magnetic Resonance Angiography

BACKGROUND/AIMS: Treatment of coronary in-stent restenosis (ISR) is still associated with a high incidence of recurrence. We aimed to compare the efficacy and safety of drug-eluting balloons (DEB) for the treatment of ISR as compared with conventional balloon angioplasty (BA) and drug-eluting stents (DES). METHODS: Between January 2006 and May 2012 a total of 177 patients (188 lesions, 64.1 ± 11.7 years old) who underwent percutaneous coronary intervention for ISR were retrospectively enrolled. Clinical outcomes were compared between patients treated with DEB (n = 58, 32.8%), conventional BA (n = 65, 36.7%), or DES (n = 54, 30.5%). The primary end point was a major adverse cardiac event (MACE), defined as a composite of cardiac death, myocardial infarction, and target lesion revascularization(TLR). RESULTS: Baseline characteristics were not different except for a history of previous MI, which was more frequent in patients treated by conventional BA or DES than in patients treated by DEB (40.0% vs. 48.1% vs. 17.2%, respectively, p = 0.002). The total incidences of MACEs were 10.7%, 7.4%, and 15.4% in patients treated by DEB, DES, or conventional BA, respectively (p > 0.05). TLR was more frequent in patients treated by conventional BA than in patients treated by DEB or DES, but this was not statistically significant (10.8% vs. 6.9% vs. 3.7%, p > 0.05 between all group pairs, respectively). CONCLUSIONS: This study showed that percutaneous coronary intervention using DEB might be a feasible alternative to conventional BA or DES implantation for treatment of coronary ISR. Further large-scaled, randomized study assessing long-term clinical and angiographic outcomes will be needed.
Angioplasty, Balloon* ; Coronary Restenosis ; Death ; Drug-Eluting Stents* ; Humans ; Incidence ; Myocardial Infarction ; Percutaneous Coronary Intervention ; Recurrence ; Retrospective Studies