• Korean Journal of Radiology
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• v.23 no.4
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• pp.466-478
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• 2022

Objective: ¹⁸F-fluorodeoxyglucose (FDG) PET/CT is often used for detecting malignancy in patients with newly diagnosed hemophagocytic lymphohistiocytosis (HLH), with acceptable sensitivity but relatively low specificity. The aim of this study was to improve the diagnostic ability of ¹⁸F-FDG PET/CT in identifying malignancy in patients with HLH by combining ¹⁸F-FDG PET/CT and clinical parameters. Materials and Methods: Ninety-seven patients (age ≥ 14 years) with secondary HLH were retrospectively reviewed and divided into the derivation (n = 71) and validation (n = 26) cohorts according to admission time. In the derivation cohort, 22 patients had malignancy-associated HLH (M-HLH) and 49 patients had non-malignancy-associated HLH (NM-HLH). Data on pretreatment ¹⁸F-FDG PET/CT and laboratory results were collected. The variables were analyzed using the Mann-Whitney U test or Pearson's chi-square test, and a nomogram for predicting M-HLH was constructed using multivariable binary logistic regression. The predictors were also ranked using decision-tree analysis. The nomogram and decision tree were validated in the validation cohort (10 patients with M-HLH and 16 patients with NM-HLH). Results: The ratio of the maximal standardized uptake value (SUVmax) of the lymph nodes to that of the mediastinum, the ratio of the SUVmax of bone lesions or bone marrow to that of the mediastinum, and age were selected for constructing the model. The nomogram showed good performance in predicting M-HLH in the validation cohort, with an area under the receiver operating characteristic curve of 0.875 (95% confidence interval, 0.686-0.971). At an appropriate cutoff value, the sensitivity and specificity for identifying M-HLH were 90% (9/10) and 68.8% (11/16), respectively. The decision tree integrating the same variables showed 70% (7/10) sensitivity and 93.8% (15/16) specificity for identifying M-HLH. In comparison, visual analysis of ¹⁸F-FDG PET/CT images demonstrated 100% (10/10) sensitivity and 12.5% (2/16) specificity. Conclusion: ¹⁸F-FDG PET/CT may be a practical technique for identifying M-HLH. The model constructed using ¹⁸F-FDG PET/CT features and age was able to detect malignancy with better accuracy than visual analysis of ¹⁸F-FDG PET/CT images.

• Korean Journal of Radiology
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• v.23 no.12
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• pp.1241-1250
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• 2022

Objective: To conduct a simulation study to determine whether artificial intelligence (AI)-aided mammography reading can reduce unnecessary recalls while maintaining cancer detection ability in women recalled after mammography screening. Materials and Methods: A retrospective reader study was performed by screening mammographies of 793 women (mean age ± standard deviation, 50 ± 9 years) recalled to obtain supplemental mammographic views regarding screening mammography-detected abnormalities between January 2016 and December 2019 at two screening centers. Initial screening mammography examinations were interpreted by three dedicated breast radiologists sequentially, case by case, with and without AI aid, in a single session. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and recall rate for breast cancer diagnosis were obtained and compared between the two reading modes. Results: Fifty-four mammograms with cancer (35 invasive cancers and 19 ductal carcinomas in situ) and 739 mammograms with benign or negative findings were included. The reader-averaged AUC improved after AI aid, from 0.79 (95% confidence interval [CI], 0.74-0.85) to 0.89 (95% CI, 0.85-0.94) (p < 0.001). The reader-averaged specificities before and after AI aid were 41.9% (95% CI, 39.3%-44.5%) and 53.9% (95% CI, 50.9%-56.9%), respectively (p < 0.001). The reader-averaged sensitivity was not statistically different between AI-unaided and AI-aided readings: 89.5% (95% CI, 83.1%-95.9%) vs. 92.6% (95% CI, 86.2%-99.0%) (p = 0.053), although the sensitivities of the least experienced radiologists before and after AI aid were 79.6% (43 of 54 [95% CI, 66.5%-89.4%]) and 90.7% (49 of 54 [95% CI, 79.7%-96.9%]), respectively (p = 0.031). With AI aid, the reader-averaged recall rate decreased by from 60.4% (95% CI, 57.8%-62.9%) to 49.5% (95% CI, 46.5%-52.4%) (p < 0.001). Conclusion: AI-aided reading reduced the number of recalls and improved the diagnostic performance in our simulation using women initially recalled for supplemental mammographic views after mammography screening.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1146-1153
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• 2024

The increasing economic losses associated with growth retardation caused by Enterocytozoon hepatopenaei (EHP), a microsporidian parasite infecting penaeid shrimp, require effective monitoring. The internal transcribed spacer (ITS)-1 region, the non-coding region of ribosomal clusters between 18S and 5.8S rRNA genes, is widely used in phylogenetic studies due to its high variability. In this study, the ITS-1 region sequence (~600-bp) of EHP was first identified, and primers for a polymerase chain reaction (PCR) assay targeting that sequence were designed. A newly developed nested-PCR method successfully detected the EHP in various shrimp (Penaeus vannamei and P. monodon) and related samples, including water and feces collected from Indonesia, Thailand, South Korea, India, and Malaysia. The primers did not cross-react with other hosts and pathogens, and this PCR assay is more sensitive than existing PCR detection methods targeting the small subunit ribosomal RNA (SSU rRNA) and spore wall protein (SWP) genes. Phylogenetic analysis based on the ITS-1 sequences indicated that the Indonesian strain was distinct (86.2% nucleotide sequence identity) from other strains collected from Thailand and South Korea, and also showed the internal diversity among Thailand (N = 7, divided into four branches) and South Korean (N = 5, divided into two branches) samples. The results revealed the ability of the ITS-1 region to determine the genetic diversity of EHP from different geographical origins.

• Journal of radiological science and technology
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• v.32 no.1
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• pp.95-99
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• 2009

The purpose of this research is to seek SPAIR's reversal time (TI) which satisfies two conditions ; maintaining the suppression ability of fat tissue and simultaneously minimizing the inhomogeneity of fat tissue in T2 high-speed spin echo 3.0T magnetic resonance image (MRI) of the brain, and to compare SPAIR with STIR which is fat-suppression technique. The reversal times (TI) of SPAIR protocol are set to 1/2, 1/3, 1/6 and 1/12 of SPAIR TR (420 msec), namely 210 msec (8 people), 140 msec (26 people), 70 msec (26 people) and 35 msec (18 people) and STIR TI is set with 250 msec (26 people). With these parameter sets, we acquired the axis direction 104 images of the brain. In ROI ($50\;mm^2$) of output image, signal intensities of the fatty tissue, the muscular tissue, and the background were measured and the CNRs of fatty tissue and the muscular tissue were calculated. The inhomogeneity of the fatty tissue is SD/mean, where SD is the standard deviation and 'mean' is a average fatty tissue signal. Consequently, SPAIR TI is determined on either 1/3 or 1/6 of TR (420 ms) ; 140 ms or 70 ms. Because the difference of statistics in fat-suppression ability and inhomogeneity of fatty tissue is very small (p < 0.001), Selecting 140 ms seems to be better choice for the image quality. Meanwhile, Comparing SPAIR (TI : 140 ms) with STIR, the fat-suppression is not able to be considered statistically (p < 0.252), but the image quality is able to be considered statistically (p < 0.01). In conclusion, SPAIR is better than STIR in the image quality.

• Journal of Sasang Constitutional Medicine
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• v.12 no.1
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• pp.173-185
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• 2000

1. The purpose of study The purpose of study is The New Sasang Constitution Questionnaire to improve clinical right, as the person takes off uncomfortable to must use both Questionnaire of Sasang Constitution Classification II (QSCC) and Questionnaire of Sasang Classification(I) 2. The method of study I made the judgmental equation, increasing ability of judgment to give thinking importance among each subject about a Clinical study of judgment and the method of using, I investigated which Equation is better by a Clinical Study of the judgment. I made Equation, 9 and examine the Accuracy rate of the judgment through patients, student of University formal peoples and peoples taking the drugs 304 member totally. 3. The result of study I made 9 Equation of the judgment. The Equation of the judgment(I-2) is the highest ability of the judgment, the diagnostic accuracy is 60.53% about Soeum, 52.78% about Taeum, 48.39 about Soyang.

• Korean Journal of Biological Psychiatry
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• v.13 no.2
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• pp.70-81
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• 2006

Objective : The purpose of this study was to investigate the differences of the cognitive performance, emotional and behavioral problems among the attention-deficit/hyperactivity disorder(ADHD) groups that show the difference between visual and auditory attention. Method : Using 'ADHD Diagnostic System(ADS)', visual attention and auditory attention of 98 children diagnosed as ADHD were measured. According to the omission and commission error of ADS, they were divided into three groups ; 1) the group whose each visual omission and commission error scores were higher than each auditory omission and commission error scores(VV group), 2) the group whose each auditory omission and commission error scores were higher than each visual omission and commission error scores(AA group), 3) the group that was the rest of VV and AA group(M group). And the results of both the subscales of Korean Educational Development Institute-Wechsler Intelligence Scale for Children(KEDI-WISC) and the subscales of Korean Child Behavior Checklist(K-CBCL) among three groups were compared. Finally, the correlation between the visual omission, visual commission, auditory omission, auditory commission error and the results of KEDI-WISC, K-CBCL were investigated. Results : The results were as follows ; 1) In 98 ADHD children, the number of VV group(N=56) was higher than that of AA (N=10) and M group (N=32). 2) All mean scores of the subscales of KEDI-WISC of VV group were higher than those of M and AA group. The score of verbal IQ(p=.039) of VV group was significantly higher than that of AA group and the scores of block design(p=.015), Kaufman's factor 2(p=.045), performance IQ(p=.004) were significantly higher than those of M group. The score of full IQ(p=.004) were significantly higher than that of M and AA group. 3) The mean scores of all K-CBCL subscales of VV group were higher than those of M and AA group, except the score of Somatic complaint subscale. The score of Social subscale(p=.041) of VV group was significantly higher than that of AA group. The score of Withdrawn subscale(p=.021) of AA group was significantly higher than that of VV group. 4) There were no significant correlation between the scores of visual omission/commission error and those of each subscale of KEDI-WISC. But, there were many significant correlations between the scores of auditory omission/commission error and those of each subscale of KEDI-WISC. 5) There were significant correlation between the score of the visual omission error and that of Thought problem subscale(r=.205, p=.043) of K-CBCL. There were significant correlation between the scores of the auditory omission error and those of Social subscale(r=-.319, p=.001), Social problems subscale(r=.206, p=.042), Thought problem subscale(r=.235, p=.021). Finally, there were significant correlation between the scores of auditory commission error and those of Social subscale(r=-.241, p=.017), Thought problem subscale(r=.235, p=.020). Conclusion : The ADHD children whose auditory attention ability were higher than visual attention ability had relatively better cognitive performance and less emotional/behavioral problems than the others. The more comprehensive experiment will be needed about the cognitive performance, emotion and behavior problems of the ADHD children showing the difference between visual and auditory attention.

• The Korean Journal of Nuclear Medicine
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• v.34 no.5
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• pp.393-402
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• 2000

Purpose: Tc-99m-MIBI (MIBI) and Tc-99m-Tetrofosmin (TF) are commonly used for scintimammog (SMM). We compared the diagnostic ability of SMM using Tc-99m-MIBI and Tc-99m-TF for the diagnosis of breast mass. Materials and Methods: The study subjects were comprised of 123 breast lesior 86 normal breasts of 114 patients who underwent SMM. Bilateral prone images and anterior supine images obtained at 5 minutes and 1 or 3 hours after intravenous injection of 740 MBq of either MIBI or TF. of tumors were not significantly different between the MIBI and TF groups. First, two observers read the SMM without clinical information (1st interpretation), then read again with information about location (2nd interpretation). Sensitivity and specificity of each radiopharmaceutical for the diagnosis of cancer were evaluated in terms of image acquisition time, tumor size, and location. Results: The SMM a good agreement between two observers for 1st and 2nd interpretation, except for TF SMM at 3 hr. first interpretation, the sensitivities at 5 min, 1 hr, and 3 hr were not significantly different between MIBI TF SMM (81.6%, 80.0%, 60.9% in MIBI vs. 88.9%, 80.6%, 42.9% in TF), although the sensitivities of images were significantly lower than 5 min images in both MIBI and TF SMM. The specificity of TF at was superior to that of MIBI (81.5%, 90.0%, 82.9% in MIBI vs. 96.7%, 100%, 90.0% in TF, p<0.01 MIBI TF at 5 min). For the second interpretation with information of mass location, the sensitivities at 3 hr were significantly lower than 5 min images (86.8%, 86.7%, 78.3% in MIBI vs. 88.9%, 93.5%, 57.1% between MIBI and TF SMM. However, there was no significant difference in the specificity (60.0%, 75.0% for MIBI vs. 86.7%, 100%, 100% for TF). MIBI and TF SMM showed lower sensitivities for the with less than 1 cm than tumors with more than 1 cm. However, the location of tumors did not sensitivity and specificity between MIBI and TF SMM. Conclusion: The ability for the differential of breast tumor is similar between MIBI and TF SMM, and delayed image is not necessary. TF may be than MIBI considering the specificity of SMM without clinical information and labeling convenience.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.96-101
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• 2012

Purpose: Glomerular filtration rate is an important index for assessment of renal function, early discovery of renal disease, and progress observation of chronic renal disease patients. In the present study, the objective is to conduct a comparative analysis of differences between Gates and Modified Gates method in dynamic renal scintigraphy based on MDRD (Modification of Diet Renal Disease) formula using blood collection. Materials and Methods: Renal scintigraphy was performed for 45 patients who visited our hospital between November 2010 and August 2011. For 20 patients of those tested, glomerular filtration rates from Gates method and MDRD formula using AGUS equipment, were compared. For the other 20 patients, glomerular filtration rates from Modified Gates method and MDRD formula using INFINIA equipment. Finally, Gates and Modified Gates method were compared for 5 patients who indicated no change in glomerular filtration rates from MDRD formula during progress observation. Results: Glomerular filtration rates from both Gates and Modified Gates method showed a high correlation with those from MDRD formula ($p$<0.01, r=0.903, r=0.867), with a paired difference mean for Gates method of $2.05{\pm}2.54mL/min/1.73m$, and that for Modified Gates method of $25.2{\pm}3.71mL/min/1.73m$. Finally, the values for Gates method and those for Modified Gates method showed a high correlation for the five patients ($p$<0.05, r=0.949), with a paired difference mean of $20.4{\pm}8.84mL/min/1.73m$. Conclusion: Glomerular filtration rates from Gates method, Modified Gates method and MDRD formula showed mutually high correlations. If the tests are performed with recognition for the correlations between Gates and Modified Gates method used in a dynamic renal scintigraphy, then an accurate assessment of renal function is considered possible with an improved diagnostic ability.

• Clinical and Experimental Pediatrics
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• v.46 no.8
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• pp.758-762
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• 2003

Purpose : Our examination was designed to determine the diagnostic properties of the cutoff point for the prediction of bacteremia in febrile children less than 3 years of age. Cutoff point is the value that simultaneously maximizes both sensitivity and specificity. Methods : We conducted a retrospective study of febrile children, less than 3 years of age, who clinically have no identifiable source of fever. Peripheral blood leukocyte count(WBC), absolute neutrophil count(ANC), erythrocyte sedimentation rate(ESR) and C-reactive protein(CRP) were measured at the same time. All patients received blood culture, urine culture and/or CSF culture. Bacterial infection was defined as single pathogen isolated from the CSF or blood or a urinary tract infection (UTI). Patients were dichotomized into two groups : those with bacterial infection and no bacterial infection. We analyzed the characteristics of the children in the two groups. Results : Seventy-one patients(44 males; 27 females) were enrolled in the study. Twenty patients (28%) had a serious bacterial infection(twelve urinary tract infection, five bacteremia, three meningitis) and fifty-one(72%) had no serious bacterial infection. WBC, ESR and CRP were significantly different between the two groups(P<0.05). The cutoff point of WBC, ESR and CRP were $20,000/mm^3$, 30 mm/hr and 3.0 mg/dL, respectively. The sensitivity and specificity of each cutoff point were WBC(75%, 75%), ESR(79%, 68%) and CRP(83%, 77%), respectively. Conclusion : These data show the ability of predictors to identify febrile children less than 3 years of age with bacterial infection. Febrile children who reach the cutoff point must be treated intensively and those who do not reach the cutoff point can be carefully managed without administering antimicrobial agents.

• Journal of Gastric Cancer
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• v.3 no.3
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• pp.122-127
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• 2003

Purpose: The incidence rate and the mortality rate of gastric cancer have decreased in developed countries over the last several decades. On the other hand, they remain high in far eastern countries such as Korea, Japan, China and in many developing countries. The cure of patients with gastric carcinomas can be achieved mostly through complete surgical resection, but most gastric cancer patients are in advanced stages when diagnosed and have poor prognoses. therefore, the development of an effective systemic therapy is essential for far advanced gastric cancer patients. Until recently, the most commonly used combination chemotherapy was based on 5-flurouracil or cisplatin, but the results were not satisfactory, so recently etoposide, adriamycin and cisplatin (EAP-II) combination chemotherapy was introduced in patients with advanced gastric cancer. Early studies showed a high response rate and the ability to convert unresectable cases to resectable ones, but later studies couldn't duplicate the result. the purpose of this study was to evaluate the relative efficacy & toxicity of EAP-II chemotherapy and ELF chemotherapy which is based on 5-flurouracil. Materials and Methods: Between July 1992 and July 2002, sixty-five patients with inoperable advanced gastric cancer were enrolled for this study. Thirty-seven patient received EAP-II chemotherapy:etoposide (20 mg/$m^{2}$ IV for $1\∼5 days$), adriamycin (20 mg/$m^{2}$ IV for $1\∼5 days$) and cisplatin (20 mg/$m^{2}$ IV for $1\∼5 days$) and Twenty-eight patients receieved ELF chemotherapy : etoposide (100 mg/$m^{2}$ IV for $1\∼3 days$), leucovorin (20 mg/$m^{2}$ IV for $1\∼5 days$) and 5-FU (500 mg/$m^{2}$ IV for $1\∼5 days$). Each treatment schedule for each group was repeated every four weeks: EAP-II means 3.4 cycles per patient..ELF means 4.1 cycles per patient Results: Total respones rates were $5.4\%$ in the ELF group and $3.6\%$ in the EAP group (P-value>0.05). The median times to progression were 144 days in the ELF group and 92 days in the EAP-II group (P-value<0.05), and themedian overall survival times were 189 days in the ELF group and 139 days in the EAP-II group (P-value>0.05). The difference in the survival curves for the two regimens was not statistically significant. Non-hematologic toxicitis & hematologic toxicitis were more frequently observed for the EAP-II regimen. Anemia: $27.6\%$ in ELF vs $54\%$ in EAP-II; Leukopenia: $8.5\%$ in ELF vs $19\%$ in EAP-II; nausea & vomiting: $45.9\%$ in ELF vs $67.8\%$ in EAP-II. Conclusion: EAP-II regimen is not superior to ELF regimen in the tratment of inoperable advanced gastric cancer (J Korean Gastric Cancer Assoc 2003;3:122-127)