• Korean Journal of Radiology
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• v.25 no.2
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• pp.189-198
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• 2024

Objective: To investigate the prognostic utility of radiomics features extracted from ¹⁸F-fluorodeoxyglucose (FDG) PET/CT combined with clinical factors and metabolic parameters in predicting progression-free survival (PFS) and overall survival (OS) in individuals diagnosed with extranodal nasal-type NK/T cell lymphoma (ENKTCL). Materials and Methods: A total of 126 adults with ENKTCL who underwent ¹⁸F-FDG PET/CT examination before treatment were retrospectively included and randomly divided into training (n = 88) and validation cohorts (n = 38) at a ratio of 7:3. Least absolute shrinkage and selection operation Cox regression analysis was used to select the best radiomics features and calculate each patient's radiomics scores (RadPFS and RadOS). Kaplan-Meier curve and Log-rank test were used to compare survival between patient groups risk-stratified by the radiomics scores. Various models to predict PFS and OS were constructed, including clinical, metabolic, clinical + metabolic, and clinical + metabolic + radiomics models. The discriminative ability of each model was evaluated using Harrell's C index. The performance of each model in predicting PFS and OS for 1-, 3-, and 5-years was evaluated using the time-dependent receiver operating characteristic (ROC) curve. Results: Kaplan-Meier curve analysis demonstrated that the radiomics scores effectively identified high- and low-risk patients (all P < 0.05). Multivariable Cox analysis showed that the Ann Arbor stage, maximum standardized uptake value (SUVmax), and RadPFS were independent risk factors associated with PFS. Further, β2-microglobulin, Eastern Cooperative Oncology Group performance status score, SUVmax, and RadOS were independent risk factors for OS. The clinical + metabolic + radiomics model exhibited the greatest discriminative ability for both PFS (Harrell's C-index: 0.805 in the validation cohort) and OS (Harrell's C-index: 0.833 in the validation cohort). The time-dependent ROC analysis indicated that the clinical + metabolic + radiomics model had the best predictive performance. Conclusion: The PET/CT-based clinical + metabolic + radiomics model can enhance prognostication among patients with ENKTCL and may be a non-invasive and efficient risk stratification tool for clinical practice.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.4
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• pp.17-34
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• 2023

Camera trapping has been used as a non-invasive survey method that minimizes anthropogenic disturbance to ecosystems. Nevertheless, it is labor-intensive and time-consuming, requiring researchers to quantify species and populations. In this study, we aimed to improve the preprocessing of camera trapping data by utilizing an object detection algorithm. Wildlife monitoring using unmanned sensor cameras was conducted in a forested urban forest and a green space on a university campus in Cheonan City, Chungcheongnam-do, Korea. The collected camera trapping data were classified by a researcher to identify the occurrence of species. The data was then used to test the performance of the YOLO-X object detection algorithm for wildlife detection. The camera trapping resulted in 10,500 images of the urban forest and 51,974 images of green spaces on campus. Out of the total 62,474 images, 52,993 images (84.82%) were found to be false positives, while 9,481 images (15.18%) were found to contain wildlife. As a result of wildlife monitoring, 19 species of birds, 5 species of mammals, and 1 species of reptile were observed within the study area. In addition, there were statistically significant differences in the frequency of occurrence of the following species according to the type of urban greenery: Parus varius(t = -3.035, p < 0.01), Parus major(t = 2.112, p < 0.05), Passer montanus(t = 2.112, p < 0.05), Paradoxornis webbianus(t = 2.112, p < 0.05), Turdus hortulorum(t = -4.026, p < 0.001), and Sitta europaea(t = -2.189, p < 0.05). The detection performance of the YOLO-X model for wildlife occurrence was analyzed, and it successfully classified 94.2% of the camera trapping data. In particular, the number of true positive predictions was 7,809 images and the number of false negative predictions was 51,044 images. In this study, the object detection algorithm YOLO-X model was used to detect the presence of wildlife in the camera trapping data. In this study, the YOLO-X model was used with a filter activated to detect 10 specific animal taxa out of the 80 classes trained on the COCO dataset, without any additional training. In future studies, it is necessary to create and apply training data for key occurrence species to make the model suitable for wildlife monitoring.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.385-392
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• 2023

Caroli's disease is a fibrocystic liver disease. Autosomal recessive disorder is characterized by congenital multiple dilatation of the bile duct. Computerized tomography, magnetic resonance imaging, cholangiography and ultrasound are among the methods for diagnosing caroli disease. Computerized tomography is essential for detecting and distinguishing fibroplastic liver disease and is useful for determining intrahepatic bile duct dilatation. However, awareness of the possible side effects of using contrast mediums is necessary. A typical method of magnetic resonance cholangiography is used for magnetic resonance imaging. A non-invasive examination can reduce the pain of the patient, and the anatomical structure of the bile pancreatic duct and the presence or absence of lesions can be easily and quickly observed. Biliary contrast is an effective diagnostic method that can directly visualize various cystic dilatations throughout the enlarged bile duct. However, since this procedure is also an invasive procedure, it is recommended not for diagnosis but for treatment purposes. Ultrasonography can confirm similar findings to computerized tomography. The hepatic artery root is difficult to prove with conventional grayscale ultrasound. However, it is of clinical value in that it can not only describe dilated bile ducts with vascular roots in the tube but also easily identify color Doppler signals in the tube. With the development of video diagnostics, early diagnosis has become possible through computerized tomography, magnetic resonance imaging, cholangiography, and ultrasound. In order to further contribute to the development of video diagnostics so that long-term prognosis can be improved after treatment through early diagnosis, we examined what aspects of each test's caroli disease appear.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.566-574
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• 2022

Heavy metals are one of the dangerous pollutants that threaten urban biodiversity due to their accumulation over a long period without being decomposed in vivo. Accordingly, there is a need for biological monitoring to compare accumulation concentrations in living organisms according to the degree of heavy metal exposure to evaluate heavy metal contamination in the air in urban areas. This study aims to examine the possibility of using nesting materials as heavy metal monitoring samples and determine the effects of heavy metals on Paridae. We installed 54 artificial nest boxes in the research areas that included campus green spaces (14), urban forests (11), and urban parks (29) on a university campus in Cheonan City, Chungcheongnam Province. The birds' use rate of artificial nest boxes was 11/14 (78.57%) in campus green spaces, 8/11 (72.72%) in urban forests, and 6/29 (20.68%) in urban parks. Moss materials were collected from collected nests, and the heavy metal accumulation characteristics of each type of urban green space and the effects of heavy metals on the success of fledging of Paridae were compared through heavy metal analysis. The analysis showed that the average concentrations of zinc and lead were 228.08±209.62 ㎍/dry g and 17.67 ± 6.72 ㎍/dry g, respectively. There was no significant difference in zinc concentration for each type of urban green space (Kruskal-Wallis test, p-value=0.28), but lead concentration showed a significant difference (Kruskal-Wallis test, p<0.05^*). Of the 21 Paridae, nests analyzed for heavy metals, fledging of birds was observed in 11 nests (52.38%). Fledging of birds observed in each urban green space type was 7 campus green spaces (77.78%), 6 in urban forests (85.71%), and 1 in urban park (20%), mainly in urban forests and green spaces on campus. Heavy metal concentrations were compared to check the effect of heavy metal accumulation on the successful fledging of Paridae, but there was no statistically significant difference (Zn: W=44, p-value=0.74, Pb: t=0.64676, df =7.2422, p-value=0.54). This study is a basic study using the nesting materials of Paridae as heavy metal monitoring samples, and it is determined that it can be used as basic data for non-invasive biological monitoring.

• Sleep Medicine and Psychophysiology
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• v.19 no.1
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• pp.27-34
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• 2012

Objectives: The analysis of heart rate variability (HRV) is a useful non-invasive tool to investigate the autonomic nerve function. Previous studies on the relationship between HRV and depression have been reported controversial results. Similarly, the correlation between the serum lipids and depression is debatable. The purpose of this study is to examine the relationship between heart rate variability, lipid profile and depression. Methods: A total of 42 patients with major depressive disorder (MDD) and 32 age and sex-matched normal subjects who had no previous history of major medical and mental illnesses were recruited for this study. A structured-interview was used to assess the general characteristics and psychiatric illness. HRV measures were assessed by time-domain and frequency-domain analyses. Psychological symptoms were measured using the Hamilton rating scale for anxiety (HAM-A), Hamilton rating scale for depression (HAM-D). In addition, the evaluation for lipid profile was performed by blood test. Results: In serum lipid profile test, MDD group showed higher cholesterol ($197.68{\pm}42.94$ mg/dL vs. $176.85{\pm}34.68$ mg/dL, p=0.044), TG ($139.45{\pm}92.54$ mg/dL vs. $91.4{\pm}65.68$ mg/dL, p=0.018), LDL ($130.03{\pm}33.18$ vs. $106.62{\pm}27.08$, p=0.004) level than normal control group. In HRV time domain analyses, the standard deviation of the NN interval (SDNN) was decreased in MDD group than normal control group, but was not significant ($32.82{\pm}14.33$ ms vs. $40.36{\pm}21.40$ms, p=0.078). ApEn (Approximate Entrophy) was significantly increased in MDD group than normal control group ($1.13{\pm}0.11$ vs. $0.91{\pm}0.18$, p<0.001). ApEn was correlated with LDL level (r=0.277, p=0.028), HAM-D scores (r=0.534, p<0.001) and HAM-A scores (r=0.470, p<0.001). Conclusions: MDD patients showed increased ApEn, one of the HRV measurement. And this ApEn was correlated with LDL, HAM-D and HAM-A scores. In this study, the analysis of ApEn would be a useful test of MDD.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.21-25
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• 2005

Purpose: $^{14}C$-urea breath test (UBT) is a non-invasive and reliable method for the diagnosis of Helicobacter pylori (HP) infection. In this study, we evaluated the diagnostic performance of a new and rapid $^{14}C$-UBT (Heliprobe method), which was equipped with $Geiger-M\ddot{u}ller$ counter and compared the results with those obtained by using the conventional method. Materials and Methods: Forty-nine patients with dyspepsia underwent gastroduodenoscopy and $^{14}C$-UBT. A 37 KBq $^{14}C$-urea capsule was administered to patients and breath samples were collected. In Heliprobe method, patients exhaled into a Hellprobe BreathCard for 10 min. And then the activities of the BreathCard were countered using Heliprobe analyzer. In the conventional method, results were countered using liquid scintillation counter. During gastroduodenoscopy, 18 of 49 patients were underwent biopsies. According to these histologic results, we evaluated the diagnostic performance of two different methods and compared them. Also we evaluated the concordant and disconcordant rates between them. Results: In all 49 patients, concordant rate of both conventional and Heliprobe methods was 98% (48/49) and the discordant rate was 2% (1/49). Thirteen of 18 patients to whom biopsies were applied, were found to be HP positive on histologic results. And both Heliprobe method and conventional method classified 13 of 13 HP-positive patients and 5 of 5 HP-negative patients correctly (sensitivity 100%, specificity 100%, accuracy 100%). Conclusion: The Heliprobe method demonstrated the same diagnostic performance compared with the conventional method and was a simpler and more rapid technique.

• Childhood Kidney Diseases
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• v.11 no.1
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• pp.59-64
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• 2007

Purpose : Suprapubic aspiration(SPA) has been considered the "gold standard" for obtaining urine in non-toilet trained infants. Ultrasound(US)-guided SPA improves the success rate of the procedure and reduces the complications. However, many physicians perceive SPA as invasive and prefer the use of urethral catheterization (Ucat). We compared the success rate, complications and accuracy of US-guided SPA and Ucat. Methods : 121 infants who visited Ewha Womans University Mokdong Hospital with suspected urinary tract infection(UTI) were investigated. For the first study, the study infants were randomly assigned to either the US-guided SPA(n=32) or Ucat(n=32) groups. The success rate and complications of both procedures were compared. For the second study, US-guided SPA and Ucat were performed simultaneously(n=57). The accuracy of urethral catheterization was subsequently analyzed. The criteria for success was defined as the collection of more than 0.5 mL of urine. UTI was diagnosed by the presence of uropathogens over 105 colony-forming units (CFU)/mL. Results : The overall success rate of the US-guided SPA was 96.9%(71.9% in first attempts, 25.0% in second attempts) which was not significantly different compared to 96.9%(90.6% in first attempts, 6.3% in second attempts) in the Ucat(P>0.05) group. The aspirated urine volume was $7.4{\pm}3.7mL$ in the US-guided SPA group, which was not significantly different to $4.5{\pm}2.6mL$ in the Ucat(P>0.05) group. The accuracy of Ucat in comparison to the US guided SPA was low with sensitivity 59.5%, specificity 86.6%, false-positive rate 13.3% and false-negative rate 40.5%. Conclusion : US-guided SPA should be encouraged as the best method to collect the urine in non-toilet trained infants with UTI.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.14 no.2
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• pp.141-147
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• 2011

Purpose: Ultrasonography (US) is widely used as a screening test in patients with abdominal pain (AP). We investigated the usefulness of US by a pediatrician in children with AP. Methods: We retrospectively analysed the medical records of children with AP who undertook US from December, 2008 to July, 2010. Results: A total of 628 patients (325 male, 303 female) were enrolled in this study. The mean age of patients was $8.08{\pm}4.61$ years. Duration of AP was acute in 427 and chronic in 201 patients. Localization of AP was diffuse (36.9%), periumbilical (24.4%), epigastric (21.0%), and right lower quadrant (8.1%). On the examination, there were no abnormal findings in 327 patients (52.1%). Abnormal ultrasonographic findings were mesenteric lymphadenitis (27.1%), intestinal mural thickening (10.0%), intussusception (3.0%), appendicitis (2.6%), choledochal cyst (1.6%), and pancreatitis (0.3%). We performed additional imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) in 39 patients who showed obscure findings on the US. In 33 patients (84.6%), the same results were obtained from CT or MRI. Two cases of appendicitis, one case of pancreatitis and one case of Henoch-Sh$\ddot{o}$nlein purpura were diagnosed by the CT examination. However, there were two cases of appendicitis diagnosed by US thathad no evidence of appendicitis on the CT. Diagnostic accuracy of initial US in children with abdominal pain was 99.4%. Conclusion: US by a pediatrician as a screening test in children with AP provides a rapid and accurate diagnostic indication and has non-invasive and radiation-free advantages.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1577-1584
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• 2002

Purpose : Airway inflammation is considered to be a characteristic feature of asthma, and eosinophils are recognized as the most important inflammatory cells. This study aims to assess the importance of blood eosinophil count and serum eosinophil cationic protein(ECP) levels as a noninvasive marker of bronchial hyperresponsiveness(BHR) in children with suspected asthma. Methods : This study used data from 87 subjects with asthma-like symptoms(6-18 years old). The $FEV_1$ and provocative concentration producing a 20% fall in $FEV_1(PC_{20})$ on methacholin inhalation challenge test were measured. Four groups were classified based on $PC_{20}$[Group I : <2 mg/mL; Group II : 2-8 mg/mL; Group III : 8-18 mg/mL; Group IV : (18 mg/mL], and blood eosinophil count and serum ECP levels were analyzed. In addition, subjects were classified based on the cutoff value of $PC_{20}$(BHR positive group : <18 mg/mL; BHR negative group : (18 mg/mL). Then blood eosinophil count and serum ECP level were compared between these two groups. Results : Likelihood ratio test for trends revealed a significant association between the blood eosinophil count or serum ECP level, and the degree of BHR as measured by methacholine $PC_{20}$. Blood eosinophil count or serum ECP level was significantly higher in the BHR(+) group than in the BHR(-) group. Blood eosinophil count had a positive correlation with serum ECP level. Conclusion : Blood eosinophil count and serum ECP level may be a useful non-invasive clinical marker of BHR in subjects with suspected asthma. This supports the hypothesis that BHR in asthma is a consequence of airway eosinophilic inflammation.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.31-36
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• 2013

Purpose: Measure gastric emptying time (GET: Gastric Emptying Time) is a non-invasive and quantitative evaluation methods, mainly by endoscopic or radiological examination confirmed no mechanical obstruction in patients with symptoms of congestion is checked. Such tests are not common gastric emptying time measured esophageal cancer patients (who underwent esophagectomy) patients after surgery for gastric emptying time was measured test. And the period of time for more than one year after the gastric emptying time measurement was performed. By comparing the two kinds of tests in the chest cavity after surgery as the evaluation of gastrointestinal function tests evaluate the usefulness of GET, and will evaluate the characteristics of the image. Materials and Methods: 93 patients who underwent esophagectomy with gastric emptying time measurement of subject tests immediately after surgery and after 1 year or longer were twice. Preparation of the patient before the test is more than 12 hours of overnight fasting is important, in addition to the medicine or to stop smoking, and diabetes insulin injections should be early in the morning is ideal to test. Generally labeled with $^{99m}Tc-DTPA$ resin which is used to make steamed egg, seaweed and fermented milk with a high viscosity after eating, three hours in the standing position was measured. Evaluation of gastric emptying curves on the way intragastric radioactivity level by 50% the time (half-time [T1/2]) was calculated, based on the half-life was divided into three steps: over 180 minutes was defined as delayed gastric emptying, within 180minutes was defined as intermediate gastric emptying and when all the radioisotopes were dumped into the jejunum as soon as swallowed, was defined as rapid gastric emptying. Results: Gastric emptying time of a typical images stomach of antrum and fundus additional images appear stronger over time move on to the small intestine. but esophageal cancer who underwent esophagectomy side of the thoracic cavity showed a strong image. Immediately after surgery, the half-time (T1/2) of rapid gastric emptying appeared to 12.9%, intermediate gastric emptying appeared to 52.7%, delay gastric emptying appeared to 34.4%. After more than a year the results of the half-life after surgery, 67% of rapid gastric emptying to intermediate gastric emptying was changed, 69% of delay gastric emptying to intermediate gastric emptying changed. Intermediate gastric emptying worse in patients rapid gastric emptying and the delay gastric emptying is 24% in the case. Conclusion: Esophagectomy for esophageal cancer who underwent half-time measurement test (T1/2) rapid gastric emptying and delay gastric emptying are the result of the comparison over time, changes were observed intermediate gastric emptying. Mainly seeing of gastric emptying time measurement in the esophagus instead of thoracic cavity to check the evaluation of gastrointestinal function can be useful even means. And segmentation criteria and narrow time interval of checking if more accurate information and analysis of the clinical diagnosis and evaluation seems to be done.