• Journal of the Korean Society of Radiology
• /
• 제81권6호
• /
• pp.1412-1423
• /
• 2020

Purpose Some patients with neonatal seizures show diffuse, symmetric diffusion-restricted lesions in the cerebral white matter. The aim of this study was to describe clinical and imaging findings of patients with neonatal seizures who had diffuse, symmetric diffusion-restricted lesions without any structural or metabolic etiology. Materials and Methods A total of 56 neonates aged less than 1 week underwent brain magnetic resonance imaging (MRI) for evaluation of seizures from November 2008 to February 2017. After excluding 43 patients, 13 patients showed diffuse white matter abnormality on diffusion-weighted imaging. Initial and follow-up clinical and MRI findings were analyzed retrospectively. Results All 13 patients were born at full term. Among the ten patients who underwent a stool test for viruses, six were positive for rotavirus and one for astrovirus. MRI revealed diffuse, symmetric diffusion-restricted lesions distributed along the cerebral white matter, thalami, and midbrain variably. Conclusion Diffuse, symmetric diffusion-restricted lesions involving the cerebral white matter can be seen in patients with neonatal seizures without any structural or metabolic etiology. Rotavirus is commonly but not exclusively detected in these patients. Nevertheless, viral infection-associated encephalopathy should be considered for patients with characteristic clinical and MRI findings.

• Clinical and Experimental Pediatrics
• /
• 제52권3호
• /
• pp.289-294
• /
• 2009

Purpose : To assess the usefulness of magnetic resonance imaging (MRI), karyotyping, brainstem auditory evoked potential (BAEP), electroencephalogram (EEG), tandem mass screening test, and newborn metabolic screening test in children with language delay for diagnosing underlying diseases. Methods : From January 2000 to June 2007, a retrospective chart review was performed for 122 children with language delay who visited the Child Neurology Clinic at Yeungnam University Hospital and who underwent neuropsychologic tests and other diagnostic evaluations for underlying diseases. They were grouped into phenomenological diagnostic categories, and test results were analyzed according to the underlying diseases. Results : Of 122 patients, 47 (38.5%) had mental retardation, 40 (32.8%) had developmental language disorders, 23 (18.9 %) had borderline IQ, and 12 (9.8%) had autism spectrum disorder. In 26 (21.3%) cases, the causes or relevant clinical findings to explain language delay were found. Eight (10.4%) of 77 MRIs, 6 (8.0%) of 75 EEGs, and 4 (5%) of 80 BAEPs showed abnormal results. Results directly attributed to diagnosing underlying diseases were 2 hearing defects in BAEPs and 1 bilateral perisylvian cortical dysplasia in MRIs. No abnormal results were found in karyotyping, tandem mass screening tests, and new-born screening tests. Conclusion : Commonly used tests to diagnose the cause of language delay are not very effective and should only be used selectively, according to patient characteristics. However, despite the low diagnostic yields from these tests, because many patients show abnormal results, these tests are useful when conducted in complete evaluation.

• The korean journal of orthodontics
• /
• 제33권3호
• /
• pp.211-222
• /
• 2003

The purpose of this study was to determine whether there is an association between disk displacement of the Temporomandibular Joint (TMJ) and dentofacial asymmetry In orthodontic patients. The subjects consisted of 60 female orthodontic patients between the ages of 18 and 38 years (mean age 23.3 years) who had visited the Department of Orthodontics at Seoul National University Dental Hospital from January 2000 to April 2002. On the basis of magnetic resonance imaging (MRI) of their bilateral TMJs, the subjects were divided Into four groups'. bilateral normal group (twenty-one persons); disk displacement of right TMJ group (six persons); disk displacement of left TMJ group (nine persons); and disk displacement of both TMJs group (twenty-four persons) Postero-anterior (PA) cephalograms and diagnostic models which had been taken before orthodontic treatment were measured. In the linear measurements, a line connecting the right and left Latero-Orbitale (Lo) represented the horizontal reference line (H). The vertical reference line (V) was constructed as a line bisecting and running perpendicular to H. One-way analysis of variance (ANOVA) was used to test whether the mean values of measurements between groups were significantly different. In addition, Bonferronil's multiple comparison test was performed at a level of 0.05. The results were as follows; 1 In the diagnostic model analysis, the overjet, nght molar relationship, and left molar relationship were significantly different among the four groups. 2. In the PA cephalometric analysis, differences in the right and left vertical position of the lower first molar and Ag were significantly dissimilar among the four groups. 3. If the disk displacement of TMJ was present on one side, the ipsilateral ramus was shorter, resulting in asymmetry in the vertical position of Ag. This study indicated that dentofacial asymmetry might be related to the disk displacement of TMJ.

• Journal of radiological science and technology
• /
• 제39권1호
• /
• pp.51-57
• /
• 2016

Acoustic noise during magnetic resonance imaging (MRI) is the main source for patient discomfort. we report our preliminary experience with this technique in neuroimaging with regard to subjective and objective noise levels and image quality. 60 patients(29 males, 31 females, average age of 60.1) underwent routine brain MRI with 3.0 Tesla (MAGNETOM Tim Trio; Siemens, Germany) system and 12-channel head coil. Q-$T_2$ and $T_2$ sequence were performed. Measurement of sound pressure levels (SPL) and heart rate on Q-$T_2$ and $T_2$ was performed respectively. Quantitative analysis was carried out by measuring the SNR, CNR, and SIR values of Q-$T_2$, $T_2$ and a statistical analysis was performed using independent sample T-test. Qualitative analysis was evaluated by the eyes for the overall quality image of Q-$T_2$ and $T_2$. A 5-point evaluation scale was used, including excellent(5), good(4), fair(3), poor(2), and unacceptable(1). The average noise and peak noise decreased by $15dB_A$ and $10dB_A$ on $T_2$ and Q-$T_2$ test. Also, the average value of heartbeat rate was lower in Q-$T_2$ for 120 seconds in each test, but there was no statistical significance. The quantitative analysis showed that there was no significant difference between CNR and SIR, and there was a significant difference (p<0.05) as SNR had a lower average value on Q-$T_2$. According to the qualitative analysis, the overall quality image of 59 case $T_2$ and Q-$T_2$ was evaluated as excellent at 5 points, and 1 case was evaluated as good at 4 points due to a motion artifact. Q-$T_2$ is a promising technique for acoustic noise reduction and improved patient comfort.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• 제13권11호
• /
• pp.5299-5304
• /
• 2012

MRI signals are significantly reduced by the magnetic field inhomogenity result from human body itself being consisted of various materials like air, fat, muscle, bone and blood vessels. In this study we used silicon which is tissue equivalent to compensate wound body shapes. Objects were eight adults who do not have any special symptoms. Feet were scanned because of their complicated structures and consequently signal reduction occurs a lot. Thirty images were acquired from the middle of arcus pedis longitudinalis including five distal phalanges parallel to the line connecting metatarsal bone and phalanges. SNR data from bones and soft tissues were compared before and after sticking silion between toes and paired t test was performed. It was came out that SNR data from bone and soft tissue were both significantly higher after applying silicon on both T1 and T2 weighted images and it was statistically meaningful having positive corelation. As a result, this study dramatically increases SNR without affecting object by increasing the object volume inside the surface coil.

• Health Policy and Management
• /
• 제25권1호
• /
• pp.40-52
• /
• 2015

Background: The purpose of this study was to analyze the increase in Grade of Nursing Management Fee of medical institutions and establish a reasonable government policy by examining which factors affect the increase of nurse staffing. Methods: Analyzing data collected from the Health Insurance Review & Assessment Service resource management department with targets of 1,104 medical institutions. The study period was 5 years from June 30, 2008 to June 30, 2013. SAS ver. 9.2 (SAS Institute Inc., Cary, NC, USA) was used for statistical analysis. The data was analyzed by a chi-square test and also conducted muiltivariate logistic regression analyses for variables of basic characteristics, human resource characteristics, and material resources. Results: Adjusted odds ratio (AOR) of the rise in Grade of Nursing Management Fee among other hospitals compared to hospitals owned by government or universities was 0.264. The AOR in hospitals established after November 2006 compared to those before June 1995 was 2.383. The AOR in Gangwon, Chungcheng South, and Jeolla South Provinces compared to Seoul was 0.084, 0.036, and 0.194, respectively. The AOR in hospitals with more than 6.75 specialists per 100 beds compared to those with less than 6.75 specialists per 100 beds was 7.514. The AOR in hospitals with more than 17.48 nurse per 100 beds compared to those with less than 17.48 nurse per 100 beds was 3.300. The AOR in hospitals with 50% to 75% bed utilization, 75% to 90% bed utilization and more than 90% bed utilization compared to those with less than 50% bed utilization was 5.428, 9.884, and 10.699, respectively. The AOR in hospitals with one magnetic resonance imaging (MRI) and more than two MRI compared to those with no MRI was 2.018 and 2.942, respectively. Conclusion: This result has showed policies to induce the rise in Grade of Nursing Management Fee among old hospitals and the incentive system for local medical institutions are needed. Also we need to develop a governmental policy for medium-small hospitals with low operation rate of beds and insufficient medical personnel and number of equipment in hospitals.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XII)
• /
• pp.40-44
• /
• 2003

Soil-borne infectious disease including Pythium aphanidermatum and Rhizoctonia solani causes severe damage to plants, such as cucumber. This soil-borne infectious disease was not controlled effectively by chemical pesticide. Since these diseases spread through the soil, chemical agents are usually ineffective. Instead, biological control, including antagonistic microbe can be used as a preferred control method. An efficient method was developed to select an antagonistic strain to be used as a biological control agent strain. In this new method, surface tension reduction potential of an isolate was included in the ‘decision factor’ in addition to the other factors, such as growth rate, and pathogen inhibition rate. Considering these 3 decision factors by a statistical method, an isolate from soil was selected and was identified as Bacillus sp. GB16. In the pot test, this strain showed the best performance among the isolated strains. The lowest disease incidence rate and fastest seed growth was observed when Bacillus sp. GB16 was used. Therefore this strain was considered as plant growth promoting rhizobacteria (PGPR). The action of surface tension reducing component was deduced as the enhancement of wetting, spreading, and residing of antagonistic strain in the rhizosphere. This result showed that new selection method was significantly effective in selecting the best antagonistic strain for biological control of soil-borne infectious plant pathogen. The antifungal substances against P. aphanidermatum and R. solani were partially purified from the culture filtrates of Bacillus sp. GB16. In this study, lipopeptide possessing antifungal activity was isolated from Bacillus sp. GB16 cultures by various purification procedures and was identified as a surfactin-like lipopeptide based on the Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), high performance liquid chromatography mass spectroscopy (HPLC-MS), and quadrupole time-of-flight (Q-TOF) ESI-MS/MS data. The lipopeptide, named GB16-BS, completely inhibited the growth of Pythium aphanidermatum, Rhizoctonia solani, Penicillium sp., and Botrytis cineria at concentrations of 10 and 50 mg/L, respectively. A novel method to prevent the foaming and to provide oxygen was developed. During the production of surface active agent, such as lipopeptide (surfactin), large amount of foam was produced by aeration. This resulted in the carryover of cells to the outside of the fermentor, which leads to the significant loss of cells. Instead of using cell-toxic antifoaming agents, low amount of hydrogen peroxide was added. Catalase produced by cells converted hydrogen peroxide into oxygen and water. Also addition of corn oil as an oxygen vector as well as antifoaming agent was attempted. In addition, Ca-stearate, a metal soap, was added to enhance the antifoam activity of com oil. These methods could prevent the foaming significantly and maintained high dissolved oxygen in spite of lower aeration and agitation. Using these methods, high cell density, could be achieved with increased lipopeptide productivity. In conclusion to produce an effective biological control agent for soil-borne infectious disease, following strategies were attempted i) effective screening of antagonist by including surface tension as an important decision factor ii) identification of antifungal compound produced from the isolated strain iii) novel oxygenation by $H_2O_2-catalase$ with vegetable oil for antifungal lipopeptide production.

• Journal of Gifted/Talented Education
• /
• 제15권2호
• /
• pp.101-125
• /
• 2005

We applied functional magnetic resonance imaging (fMRI) techniques to examine whether general intelligence (g) could be assessed using a neurobiological signal of the brain. Participants were students in a national science academy and several local high schools. They were administered diverse intelligence (RAPM and WAIS) and creativity tests (TTCT-figural and TTCT-verbal). Forty of them were scanned using fMRI while performing complex and simple g tasks. In brain regions of greater blood flow in complex compared with simple g tasks, the gifted group with an exceptional g level was not significantly different from the average group with an ordinary g level: both of them activated the lateral prefrontal, anterior cingulate, posterior parietal cortices. However, the activation levels of the gifted group were greater than those of the average group, particularly in the posterior parietal cortex. Correlation analysis showed that the activity of the posterior parietal cortex has the highest correlation ($(r=0.73{\sim}0.74)$) with individual g levels and other regions also have moderate correlation ($(r=0.53{\sim}0.66)$). On the other hand, two-sample t test showed a striking contrast in intelligence tests scores between the gifted and the average group, whereas it did not show in creativity tests scores. These results suggest that it is within the bounds of possibility that a neurobiological signal of the brain is used in the assessment of the gifted and also suggest that creativity has to be given a great deal of weight on the assessment of the gifted.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• 제15권2호
• /
• pp.122-127
• /
• 2004

Background and Objectives : Many studies have described and analyzed singer's formant and it has been shown that the epilaryngeal tube in the human airway is responsible for vocal ring, or the singer's formant. A similar phenomenon produced by trained singers in their speech led some authors to examine the speaker's ring. This study was designed to analyze the speaking voice of the singers and speaker's ring. Baterials and Methods : Ten tenors, fifteen baritones, fifteen sopranos and ten mezzo sopranos attending the music college, department of vocal music were chosen for this study. Fifteen male and fifteen female untrained normal speakers were chosen for control group. Each subject was asked to produce a sample of a sustained spoken vowel /ah/ sound for at least five seconds and read sentence 'Kaeul'. The sound data was analyzed using the Fast Fourier Transform(FFT) - based power spectrum, Long term average(LTA) power spectrum using the FFT algorithm of the Computerized Speech Lab(CSL, Kay elemetrics, Model 4300B, USA). Statistical analysis was performed using the Mann-Whitney test of the Statistical Package for Social Sciences(SPSS). Results : For LTA Power spectrum of/ah/ sound, a significant increase was seen in the 2,500-3,500Hz region(p<0.01) in four trained singer group compared with untrained speaker group, and a significant increase in the 9,000-10,000Hz region(p<0.01) in soparano group. Similarly, in sentence 'Kaeul', there was a significant increase in energy in the tenor, baritone, mezzo soprano group compared with the untrained speaker group in the 2,500-3,500Hz region(p<0.01), and a significant increase in all frequency region(p<0.01) in the soprano group. Conclusions : The LTA power spectrum suggests that trained singers group show more energy concentration in the 'singer's formant' region in the speaking voice, and authors believe this region to be the 'speaker's ring'. Further research is needed on the effect of singing training on the resonance of the speaking voice.

• Journal of radiological science and technology
• /
• 제38권2호
• /
• pp.115-120
• /
• 2015

To study the differences of focal liver lesion image detection at 3 minute, 10 minute and 15 minute time points on gadoxetic acid (GA)'s enhanced MR imaging with a flip angle (FA) of $30^{\circ}$ compared with a $11^{\circ}$. The subjects were 69 patients evaluated with GA enhanced MR imaging with 3.0T MR scanner. The patients are total 35(23 men and 7 women at the mean age of 60.4 years), hepatocellular carcinoma(23) and metastsis(12) except for normal, cyst and hemangioma. After GA was injected, FA $11^{\circ}$ and $30^{\circ}$ images were obtained at 3 minute, 10 minute and 15 minute time points respectively. After quantitative and qualitative assessment of each image was done, statistical analysis was performed by using the independent sample T-test. From both quantitative and qualitative assessment of 3 minute and 10 minute MR images after the injection of GA, FA $30^{\circ}$ images was found to be superior than FA $11^{\circ}$, but there were no statistical significance. However, at 15 minute time point, Statistically significant FA $30^{\circ}$ image(p<0.05) was better than FA $11^{\circ}$ therefore, the FA $30^{\circ}$ improves the focal liver lesion detection. FA $30^{\circ}$ of MR image can detect liver lesion more sensitively than the existing $FA11^{\circ}$ image after GA contrast enhancement at 15 minute time point.