• Title/Summary/Keyword: Clinical prevalence

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Research of z-axis geometric dose efficiency in multi-detector computed tomography (MDCT 장치의 z-축 기하학적 선량효율에 관한 연구)

  • Kim, You-Hyun;Kim, Moon-Chan
    • Journal of radiological science and technology
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    • v.29 no.3
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    • pp.167-175
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    • 2006
  • With the recent prevalence of helical CT and multi-slice CT, which deliver higher radiation dose than conventional CT due to overbeaming effect in X-ray exposure and interpolation technique in image reconstruction. Although multi-detector and helical CT scanner provide a variety of opportunities for patient dose reduction, the potential risk for high radiation levels in CT examination can't be overemphasized in spite of acquiring more diagnostic information. So much more concerns is necessary about dose characteristics of CT scanner, especially dose efficient design as well as dose modulation software, because dose efficiency built into the scanner's design is probably the most important aspect of successful low dose clinical performance. This study was conducted to evaluate z-axis geometric dose efficiency in single detector CT and each level multi-detector CT, as well as to compare z-axis dose efficiency with change of technical scan parameters such as focal spot size of tube, beam collimation, detector combination, scan mode, pitch size, slice width and interval. The results obtained were as follows ; 1. SDCT was most highest and 4 MDCT was most lowest in z-axis geometric dose efficiency among SDCT, 4, 8, 16, 64 slice MDCT made by GE manufacture. 2. Small focal spot was 0.67-13.62% higher than large focal spot in z-axis geometric dose efficiency at MDCT. 3. Large beam collimation was 3.13-51.52% higher than small beam collimation in z-axis geometric dose efficiency at MDCT. 4. Z-axis geometric dose efficiency was same at 4 slice MDCT in all condition and 8 slice MDCT of large beam collimation with change of detector combination, but was changed irregularly at 8 slice MDCT of small beam collimation and 16 slice MDCT in all condition with change of detector combination. 5. There was no significant difference for z-axis geometric dose efficiency between conventional scan and helical scan, and with change of pitch factor, as well as change of slice width or interval for image reconstruction. As a conclusion, for reduction of patient radiation dose delivered from CT examination we are particularly concerned with dose efficiency of equipment and have to select proper scanning parameters which increase z-axis geometric dose efficiency within the range of preserving optimum clinical information in MDCT examination.

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A Study on Findings from Simple Chest Radiographes without Any Clinical Symptoms (임상적 증상이 없는 흉부 단순X선영상 소견에 대한 분석)

  • Kim, Ham-Gyum
    • Journal of radiological science and technology
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    • v.30 no.2
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    • pp.95-104
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    • 2007
  • In this study, the analysis on findings from simple chest radiography(CXR) test with total 1,669 subjects without any special clinical symptom came to the following conclusions : 1. In terms of the general characteristics of subjects hereof, male and female group accounted for 55.2% and 44.8% respectively out of all 1,669 people. 2. Pulmonary disease cases amounted to 249 persons(14.9%) out of all subjects. 3. In the analysis on prevalence rate by age distribution, it was noted that the older age led to the more number of diseases, which was demonstrated by age 34 or younger(6.1%), age $35{\sim}39(9.7%)$, age $40{\sim}49(13.3\;%)$, and age 50 or older(30.8%). 4. In regard of pulmonary disease alone, the region of onset was represented primarily by right upper lobe, which was followed by both upper lobe and left upper lobe, respectively. 5. In terms of disease types, it was found that most cases were represented by pulmonary nodule(55.0%), which was followed by cardiomegaly(24.5%), CP angle blunting(4.8%), scoliosis(4.6%), tortuous aorta(2.8%), bronchial luminal dilatation(2.4%), and pleural thickening(2.0%). However, dextrocardia, cystic dilation of bronchus, cavitary lesion, and lung collapse accounted for relatively low rate(0.4% respectively). 6. In terms of disease types by sex, it was found that male group accounted for higher percentage of having pulmonary nodule than female group, while the latter accounted for higher percentage of having cardiomegaly, tortuous aorta and scoliosis than the former. 7. In terms of disease types by age distribution, it was noted that age 34 or younger group accounted for higher percentage of scoliosis than any other age groups, while age $40{\sim}49$ group, age $35{\sim}39$ group, and age 50 or older group represented the case of CP angle blunting, pulmonary nodule, and cardiomegaly/tortuous aorta, respectively.

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The Etiology and Clinical Features of Acute Osteoarthritis in Children; 2003-2009 (최근 6년간 소아청소년기 급성 화농성 골관절염의 원인균과 임상 양상; 2003-2009)

  • Choi, Jin Hyoung;Choe, Young June;Hong, Ki Bae;Lee, Jina;Yoo, Won Joon;Kim, Han Soo;Park, Moon Seok;Cho, Tae Joon;Chung, Chin Youb;Lee, Hoan Jong;Choi, In Ho;Choi, Eun Hwa
    • Pediatric Infection and Vaccine
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    • v.18 no.1
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    • pp.31-39
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    • 2011
  • Purpose : This study was performed for the purpose of finding causative organisms and clinical features of septic arthritis or acute osteomyelitis in children. Methods : The study involved a retrospective review of the medical records of 63 microbiologically confirmed cases of acute pyogenic arthritis and osteomyelitis. All of the cases were brought about by community-associated infections and managed at the Seoul National University Children's Hospital or Seoul National University Bundang Hospital from June 2003 to July 2009. Results : The median age of all cases was 60 months and there were 35 males and 28 females. Major involved joints included the hip joint (15 cases), knee joint (7 cases), shoulder joint (4 cases), and elbow joint (4 cases). Also, major involved bones included the femur (20 cases), tibia (13 cases), humerus (7 cases), and radius (7 cases). Staphylococcus aureus was the most commonly identified causative organism, accounting for 49 cases (77.8%). Of the 49 isolates of S. aureus, methicillin-resistant S. aureus (MRSA) accounted for 8 cases (16.3%). Group B streptococcus spp. (GBS) and Salmonella spp. accounted for 3 cases, respectively. Nafcillin or cefazolin was often prescribed as an initial empirical antibiotic. There were 9 cases that were managed by a regimen that included vancomycin as the first choice. Fifty four cases (85.7%) recovered without any complications. Methicillin-sensitive S. aureus (MSSA), responsible for 41 cases, caused chronic complications in 3 cases. Of 8 cases caused by MRSA, 1 case showed chronic complication. There were no fatal cases. Conclusion : S. aureus remains the most common organism causing acute pyogenic arthritis and osteomyelitis of childhood acquired in the community. The high prevalence of methicillin resistance among S. aureus should be considered carefully in the selection of initial empirical antibiotics.

Association of Diagnostic Criteria and Autoantibodies with Juvenile Dermatomyositis in Newly Diagnosed Children (소아기 피부근염의 진단 기준과 자가항체의 진단적 의의)

  • Shin, Kyung Sue;Kim, Joong Gon
    • Clinical and Experimental Pediatrics
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    • v.46 no.9
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    • pp.898-902
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    • 2003
  • Purpose : To determine the clinical association of diagnostic criteria and the prevalence of autoantibodies in newly diagnosed children with juvenile dermatomyositis(JDM). Methods : Thirty-two children with JDM were identified at Seoul National University Children's Hospital from March 1985 to March 1999 by retrospective review. The diagnosis of JDM was based on the criteria proposed by Bohan and Peter. We investigated for the presence of several autoantibodies: antinuclear(ANA), double-stranded DNA, anti-Sm, anti-ribonucleoprotein(RNP), anti-SSA/ SSB, anti-Jo1, anti-Scl-70 antibodies and rheumatoid factor(RF). Results : Sex ratio and age at diagnosis were similar to data published in other studies. All the newly diagnosed children with JDM had a typical rash(100%) and proximal muscle weakness(100%); 17(53%) had muscle pain or tenderness; 10(31%) calcinosis; eight(25%) dysphagia; eight(25%) arthritis, and seven(22%) fever. Muscle enzymes were elevated in 90% of the patients. Of the 27 patients who had an electromyogram, 20(70%) had diagnostic results. Sixteen(70%) of biopsied patients had appropriated results for JDM. Patients were negative for all autoantibodies except ANA and RF. ANA and RF were detected in 47% and 7% of the patients respectively. Conclusion : Although the sensitivity of the criteria proposed by Bohan and Peter is superior, each of these criteria has possible confounding factors. Additional criteria may be needed for early diagnosis of JDM. Based on our findings of autoantibodies in JDM, we do not recommend routine testing for autoantibodies in children with typical JDM.

Prevalence of CTX-M-type Extended-Spectrum $\beta$-Lactamases Producing Escherichia coli and Klebsieilla pneumoniae Isolates in General Hospitals in 2005 (임상에서 분리된 CTX-M형 Extended-Spectrum $\beta$-Lactamases를 생산하는 Escherichia coli와 Klebsiella pneumoniae의 유행)

  • Kim, Yun-Tae;Kim, Tae-Un
    • Microbiology and Biotechnology Letters
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    • v.34 no.4
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    • pp.342-351
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    • 2006
  • The aim of this study was to survey susceptibilities of Escherichia coli and Klebsiella pneumoniae isolates against cefotaxime and to determine the prevalences of CTX-M type extended-spectrum $\beta$-lactamases (ESBLs) producing E. coli and K. pneumoniae in Korea. During the period of February to July, 2005, 153 E. coli and 52 K. neumoniae isolates were collected from 2 hospitals in Busan. Antimicrobial susceptibilities to cefotaxime were tested by the disk diffusion method. ESBL production of E. coli and K. pneumoniae was determined by the double disk synergy test. MICs of $\beta$-lactam antibiotics were determined by the agar dilution method. Blac$_{CTX-M}$ genes of the organism were detected by PCR. Among 153 isolates of E. coli and 52 isolates of K. neumoniae, 27 (17.6%) and 25 (48.0%) were intermediate or resistant to cefotaxime, respectively. Twenty-three (15.0%) isolates out of 153 E. coli and 13 (25.0%) out of 52 K. neumoniae isolates showed positive results for ESBL by the double disk synergy test. Twenty isolates out of 23 ESBL producing E. coli and 12 out of 13 ESBL producing K. neumoniae isolates harbored biacTx-M gene,11 of ESBL producing E. coli and 12 of ESBL producing K. neuinoniae isolates harbored bla$_{CTX-M}$ gene, 11 of the ESBL producing E. coli and 2 of ESBL producing K. neumoniae isolates harbored bla$_{TEM}$ gene, and 1 of the ESBL producing E. coli and 12 of ESBL producing K. neumoniae isolates harbored bla$_{SHV}$ gene. E. coli and K. neumoniae isolates producing CTX-M-type ESBLs were not uncommon in Korea. It is thought that continuous survey are necessary for inspecting the spread and novel variants of CTX-M-type ESBL genes. Further me]'e investigation and research on ESBL producing strains are needed in order to prevent the spread of resistant bacteria.

Diagnostic Significance of Cholesterol in Pleural Effusion (흉막액내 Cholesterol치 측정의 진단적 의의)

  • Yeo, Dong-Seung;Lee, Dong-Il;Lee, Soo-Keol;Moon, Chang-Hyung;Park, Soon-Kew;Shin, Young-Kee
    • Tuberculosis and Respiratory Diseases
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    • v.39 no.3
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    • pp.248-254
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    • 1992
  • Background: Pleural effusion is one of the most common clinical problems in pulmonology because of high prevalence of pulmonary tuberculosis and bronchogenic carcinoma in Korea. The differential diagnosis between pleural transudate and exudate is very important, but it is very difficult in some cases. Methods: In order to assess the clinical usefulness of cholesterol levels for the differential diagnosis of pleural transudate and exudate, we measured pleural fluid cholesterol levels by enzymatic method in 45 patients who were admitted due to pleural effusion. Results: The mean cholesterol level of transudate was $33.1{\pm}12.9\;mg%$, tuberculous exudate was $97.3{\pm}28.2\;mg%$ and malignant exudate was $97.3{\pm}28.2mg%$. When the cut-off value of pleural cholesterol level was 60 mg%, one case (6.7%) of tuberculous exudate and two cases (13.3%) of malignant exudate were incorrectly classified, but all cases of transudate were classified correctly. When the cut-off value of pleural/serum cholesterol ratio was 0.3, one case (6.7%) of transudate and two cases (13.3%) of malignant exudate were incorrectly classified, but all cases of tuberculous exudate were classified correctly. When the cut-off value of pleural cholesterol level to differentiate pleural transudate from exudate was 60 mg%, sensitivity was 90% and specificity was 100%. When the cut-off value of pleural/serum cholesterol level to differentiate pleural transudate form exuidate was 0.3, sensitivity was 93% and specifiity was 93%. Conclusions: From the above results, it can be concluded that measurement of pleural fluid cholesterol levels is useful for the differential diagnosis between pleural transudate and exudate.

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Clinical Characteristics of Pneumococcal Bacteremia in Adults : The Effect of Penicillin Resistance on the Mortality of Patients with Pneumococcal Bacteremia (폐렴구균 균혈증에서 폐렴구균의 페니실린 내성 여부가 사망률에 미치는 영향)

  • HwangBo, Bin;Yoon, Ho-Il;Lee, Sang-Min;Choi, Seung-Ho;Park, Gye-Young;Yoo, Chul-Gyu;Lee, Choon-Taek;Kim, Young-Whan;Han, Sung-Koo;Min, Kyung-Up;Kim, You-Young;Shim, Young-Soo
    • Tuberculosis and Respiratory Diseases
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    • v.47 no.2
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    • pp.184-194
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    • 1999
  • Backgrounds : The advent of penicillin has led to the marked reduction in the mortality from pneumococcal bacteremia, however, the mortality is still relatively high in this post-antibiotic era. Actually the prevalence of infection due to penicillin-resistant penumococci is increasing worldwide, and it is especially high in Korea due to irrelevant use of antibiotics. So, the high mortality of pneumococcal sepsis might be related to the emergence of penicillin-resistant strains, however, many other antibiotics, which eradicate pneumococci effectively, are available in these days. This has led us to suspect the role of penicillin-resistance in the high mortality rate. In this study, we evaluated the effect of penicillin resistance on the mortality of patients with penumococcal bacte remia. Methods: The study population consisted of 50 adult patients with penumococcal bacteremia who were admitted between Jan, 1990 and July, 1997. Medical records were analyzed retrospectively. Results: Most of the patients (96%) had underlying diseases. The most common local disease associated with pneumococcal bacteremia was pneumonia (42%), which was followed by spontaneous bacterial peritonitis (14%), cholangitis (10%), meningitis (8%), liver abscess (4%), pharyngotonsillitis (4%), sinusitis (2%) and cellulitis (2%). While the overall case-fatality rate in this study was 24%, it was higher when peumococcal bacteremia was associated with pneumonia (42%) or meningitis (50%). The rate of penicillin resistance was 40%, which was increased rapidly from 1991. The rate of penicillin resistance was significantly higher in patients with the history of recent antibiotics use and hospitalization within 3 months respectively. The clinical manifestations, that is, age, severity of underlying diseases, nosocomial infection, associated local diseases, and the presence of shock or acute renal failure were not statistically different between the patients with penicillin-resistant and -sensitive pneumococcal bacteremia. The mortality of patients infected with penicillin-resistant pneumococci was not statistically different from those with penicillin-sensitive pneumococcal bacteremia. Conclusion: Penicillin resistance is not associated with high mortality in adult patients with pneumococcal bacteremia. As the overall mortality is high, active penumococcal vaccination is recommended in patients with high risk of infection.

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Clinical Characteristics of Tuberculosis in North Korean Refugees (북한이탈주민에서의 결핵의 임상적 고찰)

  • Choi, Chang-Min;Jeong, Woo-Kyoung;Kang, Cheol-In;Kim, Doh-Hyung;Kim, Young-Keun;Heo, Sang-Taek;Kim, Hee-Jin
    • Tuberculosis and Respiratory Diseases
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    • v.60 no.3
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    • pp.285-289
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    • 2006
  • Background : North Korea's economic and public health problems began in the early 1990s as a result of the gradual loss of economic support from its communist allies, combined with an inordinate number of natural disasters. The decline in public health has increased the incidence of tuberculosis in North Koreans and refugees. This study investigated tuberculosis situation in North Korean refugees in order to prepare for the future impact of tuberculosis control in Korea. Material and Methods : From 2001 to 2005, tuberculosis patients among North Korean refugees who were diagnosed before or after arriving in South Korea, based on the official records of OO hospital, were enrolled in this study. The demographic and clinical data of the cases were evaluated retrospectively. Results : A total of 42 TB cases were reviewed during the study period. Of these, 37 (88.1%) cases were pulmonary TB. based on the cases identified among the number of North Korean refugees' arriving each year, the annual incidence of pulmonary TB were 900 per 100,000 in 2004, 700 in 2003, The number of smear-positive patients was 20 (47.6%) and the number of culture-positive patients was 18 (42.9%). Of the M. tuberculosis isolates, 2 cases were found to be susceptible to all anti-TB drugs available, 4 were resistant to isoniazid, and 3 were multi-drug resistant. Conclusion : The prevalence of pulmonary TB in North Korean Refugees is high. In addition, North Korean refugees suffer from more severe tuberculosis in bacteriological and radiological aspects.

Analysis of the Change in Seropositive Rate of the Epstein-Barr Virus in Koreans: A Single-Center Study (한국인의 Epstein-Barr Virus 항체 양성률 변화양상에 대한 분석: 단일기관 연구)

  • Kim, Su Kyung;Choi, Joon-Sik;Kim, Dongsub;Kang, Cheol-In;Chung, Doo Ryeon;Peck, Kyong Ran;Kang, Eun-Suk;Kim, Yae-Jean
    • Pediatric Infection and Vaccine
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    • v.27 no.2
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    • pp.117-126
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    • 2020
  • Purpose: Epstein-Barr virus (EBV) infection is related to infectious mononucleosis or nasopharyngeal cancer, and its epidemiology may change according to the socioeconomic development of communities. This study aimed to evaluate the recent epidemiology of EBV seropositive rate in Korea. Methods: We retrospectively reviewed EBV serology test results obtained from a part of clinical care at Samsung Medical Center, Seoul, South Korea, from January 2000 to December 2017. Results: The EBV seropositive rate in 26,527 subjects during the study period was 81.0% (21,485/26,527): 44.4% (2,716/6,122) in subjects aged 0-9 years, 75.8% (2,077/2,739) in those aged 10-19 years, and 94.5% (16,692/17,666) in those aged ≥20 years. The EBV seropositive rate decreased from 89.4% (8,592/9,616) in 2000-2008 to 76.2% (12,893/16,911) in 2009-2017 (P<0.001). Especially, the EBV seropositive rate in subjects aged 0-19 years significantly decreased from 2000-2008 to 2009-2017 (0-9 years, 62.8% [1,172/1,866] in 2000-2008 and 36.3% [1,544/4,256] in 2009-2017; 10-19 years, 83.8% [745/858] in 2000-2008 and 70.8% (1,332/1,881) in 2009-2017) (P<0.001). Conclusions: The EBV seropositive rate in children has decreased in the last 20 years. As the age of patients with primary EBV infection increased, there is a need for interest in clinical manifestation, such as infectious mononucleosis, in adolescents and young adults.

Clinical Usefulness of Ambulatory Blood Pressure Monitoring in Children and Adolescents (소아 및 청소년에서 24시간 활동 혈압 측정의 임상적 유용성)

  • Hwang, Young-Ju;Park, Hyo-Jung;Yang, Eun-Ae;Cho, Min-Hyun;Ko, Cheol-Woo;Yang, Dong-Heon;Hwang, Hyun-Hee
    • Childhood Kidney Diseases
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    • v.15 no.2
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    • pp.154-162
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    • 2011
  • Purpose: With increasing prevalence of hypertension (HTN) in children and adolescent, pediatricians have become more interested in blood pressure (BP) measurements. The ambulatory blood pressure monitoring (ABPM) is known to be useful to differentiate true HTN and white coat HTN. The object of this study is to assess the clinical usefulness of ABPM in Korean children and adolescents. Methods: A retrospective review of 51 patients in Kyungpook National University Hospital from January 2002 to February 2010 was done. All patients were 6-18 years old and underwent ABPM. We calculated the mean value of ABP, BP load, nocturnal dip and compared the results with the patients' diagnosis and characteristics. Results: The mean age of the 51 patients was $17.8{\pm}1.8$ years and 19 children were obese. 37 patients (72.5%) were truly hypertensive and 1 patient was diagnosed as masked HTN and 7 children (14%) as white coat HTN. The rest of the patients were normotensive. Among patients with white coat HTN, 5 were in a prehypertensive state. Mean systolic and diastolic BP load of patients with true HTN were significantly higher than non-hypertensive children (P<0.001). Although the nocturnal dip of all patients were below 10%, there was no statistical significance. The obese patients showed higher systolic and diastolic BP. Their systolic and diastolic BP load were significantly higher than non-obese patients (P<0.001). Conclusion: ABPM in children and adolescents seems to be a valuable tool in the assessment of white coat HTN and in the confirmation of true HTN. A considerable number of white coat HTN patients are revealed to be in a prehypertensive state and need close follow-up.