Feature extraction of time series data on functional near-infrared spectroscopy and comparison of deep learning performance for classifying patients with Alzheimer's-related mild cognitive impairment: a post-hoc analysis of a diagnostic interventional trial

OBJECTIVE

This study aimed to define a method of classifying patients with mild cognitive impairment caused by Alzheimer's disease by the retrieval of functional near-infrared spectroscopy (fNIRS) signal characteristics obtained during olfactory stimulation and the validation of deep learning findings.

PATIENTS AND METHODS

Participants were recruited for the study from March 02 and August 30, 2021. A total of 78 participants met the criteria for categorization. The Mini-Mental State Examination and the Seoul Neuropsychological Scale were used to distinguish between patients with mild Alzheimer's disease-related cognitive impairment and healthy controls. fNIRS data received during olfactory stimulation were used to create 1,680 time-series sample values. A total of 150 indices with a p-value ≤ 0.1 were used as deep learning features to construct the result values for 120 models accounting for all conceivable combinations of data ratios.

RESULTS

For this trial, 78 participants were recruited for the original intervention trial. The average accuracy of the 120 deep-learning models for classifying patients with Alzheimer's-related mild cognitive impairment ranged from 0.78 to 0.90. Sensitivity ranged from 0.88 to 0.96 for the 120 models, while specificity ranged from 0.86 to 0.94. The F1 scores ranged from 0.74 to 0.88. At 0.78 to 0.90, the precision and recall were equivalent.

CONCLUSIONS

This trial using a deep-learning model found that the representative value extracted from the time series data of each channel could distinguish between healthy people and patients with mild cognitive impairment caused by Alzheimer's disease.

Ethnic and sex differences in the distributions of body mass index and waist circumference among adults: a binationally representative study in South Korea and the United States

OBJECTIVE

The ethnic and sex differences in the distributions of body mass index (BMI) and waist circumference (WC) among adults are largely unknown. Therefore, we aimed to investigate the percentiles of BMI and WC in groups divided according to age, sex, and ethnicity.

PATIENTS AND METHODS

We conducted a population-based binational study of adults aged ≥20 years based on data from two sources: US National Health and Nutrition Examination Survey (2015 to 2020) and Korea National Health and Nutrition Examination Survey (2016 to 2019).

RESULTS

Weight, height, and WC were measured in 13,144 American adults and 30,191 Korean adults. Overall, BMI increased at younger ages and decreased at older ages, which indicates a reversed U-shaped relationship, and differed in terms of age, sex, and ethnicity. Women in the other Hispanic, non-Hispanic white, non-Hispanic black, and "other ethnic groups" showed a common BMI peak at ages 50-54 years. The patterns of WC distribution were similar to those of BMI distribution.

CONCLUSIONS

In this binational representative study, we found varied distributions of ethnic and sex differences in BMI and WC. Considering the differences in these distributions may help improve individual and personalized treatment strategies.

17-year trends of body mass index, overweight, and obesity among adolescents from 2005 to 2021, including the COVID-19 pandemic: a Korean national representative study

OBJECTIVE

There is a lack of pediatric studies that have analyzed trends in mean body mass index (BMI) and the prevalence of obesity and overweight over a period that includes the mid-stage of the COVID-19 pandemic. Thus, we aimed to investigate trends in BMI, overweight, and obesity among Korean adolescents from 2005 to 2021, including the COVID-19 pandemic.

SUBJECTS AND METHODS

We used data from the Korea Youth Risk Behavior Web-based Survey (KYRBS), which is nationally representative of South Korea. The study included middle- and high-school students between the ages of 12 and 18. We examined trends in mean BMI and prevalence of obesity and/or overweight during the COVID-19 pandemic and compared these to those of pre-pandemic trends in each subgroup by gender, grade, and residential region.

RESULTS

Data from 1,111,300 adolescents (mean age: 15.04 years) were analyzed. The estimated weighted mean BMI was 20.48 kg/m2 (95% CI, 20.46-20.51) between 2005 and 2007, and this was 21.61 kg/m2 (95% CI, 21.54-21.68) in 2021. The prevalence of overweight and obesity was 13.1% (95% CI, 12.9-13.3%) between 2005 and 2007 and 23.4% (95% CI, 22.8-24.0%) in 2021. The mean BMI and prevalence of obesity and overweight have gradually increased over the past 17 years; however, the extent of change in mean BMI and in the prevalence of obesity and overweight during the pandemic was distinctly less than before. The 17-year trends in the mean BMI, obesity, and overweight exhibited a considerable rise from 2005 to 2021; however, the slope during the COVID-19 pandemic (2020-2021) was significantly less prominent than in the pre-pandemic (2005-2019).

CONCLUSIONS

These findings enable us to comprehend long-term trends in the mean BMI of Korean adolescents and further emphasize the need for practical prevention measures against youth obesity and overweight.

Beyond the Chief Complaint: Our Patients' Worries

Fourth-year medical students at the University of Colorado School of Medicine distributed cards to patients in the emergency department asking, "What Worries You Most?" The patients' responses provided insight about their most pressing concerns, often unrelated to their "chief complaints."

Extrapulmonary small-cell carcinoma of the liver

A 53-year-old man was admitted to our hospital for the evaluation of a mass (13 x 10 cm) in the left lobe of the liver seen by imaging studies. On subsequent biopsy of the mass, the lesion was histologically diagnosed as malignant small round-cell tumor, consistent with metastatic small-cell carcinoma. Segment IV segmentectomy was performed. On pathological examination, the mass showed a yellowish-gray granular appearance with multifocal hemorrhage and necrosis. The phenotypes shown by immunohistochemistry revealed characteristic patterns of small-cell carcinoma (neuron-specific enolase [NSE]+, synaptophysin+, c-Kit+, cluster designation [CD]56+, epithelial membrane antigen [EMA]+, cytokeratin [CK]7-). High resolution-computed tomography (HRCT) revealed inactive pulmonary tuberculosis with small calcified tuberculoma in the right upper lobe. Sputum cytology was negative for malignancy. The postoperative course was uneventful, and platinum-based chemotherapy (cisplatin, etoposide) was initiated.

The University of California, Irvine experience with tomotherapy using the Peacock system

Our institutional experience using the Peacock system for intensity-modulated radiation therapy (IMRT) is summarized. Over 100 patients were treated using this system, which is fitted to a Clinac 600C linac. Both cranial and extracranial lesions have been treated using this modality. Immobilization is achieved either with the Talon system for cranial sites or an Aquaplast cast. Target volumes up to 500 cm3 have been treated. Multiple lesions (up to 3) were treated in one setup. The range of dose/fractionation schemes used was 15 Gy/1 fx (radiosurgical treatment) - 80 Gy/40 fx. Dose validation studies were carried out using film and ion chamber dosimetry in a specially designed phantom. Optimal dose distributions were attainable using inverse treatment planning for IMRT delivery. These were found to encompass the target volumes accurately using dose validation phantom studies. Immobilization methods used were accurate to within 1 mm, as evidenced by daily portal films. IMRT using the Peacock system offers the advantage of delivery of conformal therapy to high doses safely and accurately. This provides the opportunity for dose escalation studies, retreatment of previously treated tumors, as well as treating multiple targets in one setup. The system may be fitted to a conventional linac without major modifications.