• 전기의세계
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• v.31 no.7
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• pp.486-491
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• 1982

초음파 영상장비는 군사장비로 부터 사용하기 시작하여 어군탐지기등 수산업에도 응용되었고, 1970년 이후 반도체기술의 획기적인 발전으로 의료장비로써의 초음파 영상장비가 개발되어 급속히 보급되고 있어서 X-ray장비와 함께 진단용장비로써 위치가 확고히 되어 가고 있다. 대부분의 의료기관에서는 뇌, 심장, 간, 신장등과 같은 인체기관의 진단에 초음파 영상장비를 사용하고 있는데. 특히 X-ray 장비와 달리 인체에 hazard를 주지 않기 때문에 어린이, 임산부의 진단에 유용하게 사용된다. 그러므로 초음파 영상기술은 임상의학에서 중요한 역할을 하게 되었으며 이 분야는 앞으로 연구개발될 부분이 많이 남아있다. 본 원고에서는 초음파 영상 장비의 주종을 이루고 있는 B-스캔장비에 대한 원리, 구성 및 종류에 대해서 설명하고자 한다.

• Childhood Kidney Diseases
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• v.6 no.2
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• pp.218-226
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• 2002

Purpose: The purpose of this study is to assess the ability of power Doppler sonography in the detection of acute pyelonephritis. Materials and Methods: We performed gray scale sonography, power Doppler sonography, and $^{Tc-99m}DMSA$ scintigraphy of the kidney in 80 patients with symptoms suggesting upper urinary tract infection. All imaging studies were obtained within 4 days. On $^{Tc-99m}DMSA$ scintigraphy, decreased radioactivity or photopenic lesions were considered indicative of acute pyelonephritis. Triangular areas of decreased perfusion identified on power Doppler sonography were considered as parenchymal lesions of acute pyelonephritis. The results of gray scale sonography and power Doppler sonography were retrospectively analysed and compared with those of $^{Tc-99m}DMSA$ scintigraphy which was given as the standards of reference. Results: For 40(85%) of the 47 patients with scintigraphy-proven acute pyelonephritis, power Doppler sonography diagnosed this condition on the correct side. The acute pyelonephritis which was not revealed by power Doppler sonography was observed in seven patients. Also, in three patients, false-positive indication of pyelonephritis was given by power Doppler sonography. Gray scale sonography showed positive findings in 23(49%) of 47 patients with positive findings on scintigraphy. Conclusion: Power Doppler sonography seems to be less sensitive than $^{Tc-99m}DMSA$ DMSA scintigraphy but significantly more sensitive than gray scale sonography for the detection of acute pyelonephritis in children. Power Doppler sonography shows promise as a noninvasive means of assessing renal cortical perfusion in children with clinically suspected acute pyelonephritis.

• Childhood Kidney Diseases
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• v.2 no.2
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• pp.161-168
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• 1998

Purpose : Lots of congenital anomalies of urinary tract including hydronephrosis are detected in fetus and neworn by popular use of prenatal ultrasonography. But there are little data available in Korea about natural course of hydronephrosis diagnosed antenatally by ultrasonography. So we intended to help management of these patients by analizing the follow up data of the neonates with hydronephrosis diagnosed antenatally. Methods : We evaluated 22 patients with neonatal hydronephrosis(33 renal units) who were diagnosed prenatally and confirmed postnatally. Especially patients with suspected ureteropelvic junction obstruction were followed regulary with renal ultrasonography and diuretic renography for 8-24 months. Results : 1) The etiologies of neonatal hydronephrosis diagnosed prenatally were suspected ureteropelvic junction obstruction($69.9\%$), vesicoureteral reflux($15.1\%$), primary megaureter($3.0\%$), double ureter with ureterocele($3.0\%$), ureteral stricture($3.0\%$), multicystic dysplastic kidney(3.0$\%$), and ureterovesical junction obstruction(3.0$\%$). 2) The follow up results of 23 renal units of suspected ureteropelvic junction obsruction: Except 4 renal units with palpable abdominal mass, of the remained 19 renal units, 14 units($73.6\%$) were improved spontaneously, 3 units($15.7\%$) remained stable, only2 units($10.5\%$) were aggravated. Conclusion : We concluded that in most cases of hydronephrosis there is no need for immediate surgery, and that nonoperative approach, using serial ultrasonography and diuretic renogram, is safe management of neonatal hydronephrosis diagnosed anteratally.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.556-558
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• 2019

기존 초음파 지방간 분석은 Hepatorenal sonographic index(HI)를 사용하여 지방간을 진단하여 왔다. 이러한 HI 기법에서는 Hepato(간)과 Renal(신장), 두 부분의 영상데이터를 비교 활용하였다면, 본 논문에서는 신장의 영상데이터만을 이용하여, 이의 통계적 특징 벡터만을 활용하여 지방간을 진단을 함으로서 기존의 HI기반 분석대비 편리성과 정확도를 개선코자 Kidney Index(KI) 기반의 분석 기법을 제안한다. 본 논문에서 제안된 KI는 정상간과 지방간을 가진 실제 환자의 초음파 사진(정상간, 지방간 각 30명)을 학습 데이터를 구성하고, 이들 데이터군으로부터 특징 벡터들을 선별하여 머신러닝 기법 중 서포트 벡터 머신(Support Vector Machine)을 통해 학습시켜, 제안된 알고리즘의 유효성을 입증하였다.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.161-169
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• 2008

Since measuring the size of kidney with sonography becomes an important index for diagnosis, treatment, and prognostic prediction in kidney disease, the accurate measurement and evaluation on this are clinically very important. Accordingly, the purpose of this study was to increase reproducibility and objectivity in measuring the size of kidney by enumerating factors that have an impact for measurement. It targeted 44 adults in Korea at the age of 21-27. It measured in order for both kidneys to be seen most largely while changing a subject-examiner's position in a state of fasting for 8 hours and a transducer's approaching direction. It compared a size of kidney by measuring, respectively, with the same method in 30 minutes and in 1 hour after drinking water in 700-1,000cc. In case of the lateral approach scan in decubitus position, the average length of the kidney both to the right and the left and the deviation of measurement to be the largest. In NPO(None Per Oral) state, the average length in the right kidney was 10.19cm, and the average length in the left kidney was 10.33cm. In 60 minutes after taking moisture, the average length in the right kidney was 10.94cm, and the average length in the left kidney was 11.13cm. In comparing the average length of the kidney in NPO state and its average length in 60 minutes after taking moisture, the size swelled by 7.3% for the length in the right kidney and by 7.7% in the left, thereby having been indicated to be statistically significant(P<0.003). The measurement in a size of kidney by using ultrasound may be measured differently depending on a patient's state of taking moisture and a transducer's approaching direction. It is thought that when the measurement in a size of kidney is especially important clinically, the intake and intake time in moisture need to be considered and that measuring with the posterior approach in prone position is a good method aiming to increase reproducibility in measuring length of the kidney.

• Childhood Kidney Diseases
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• v.5 no.1
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• pp.30-35
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• 2001

Purpose : To evaluate tile frequency of urinary tract anomalies in male neonates less than 3 months old who presented with urinary tract infection(UTI) and to evaluate a appropriate imaging approach after first UTI. Materials and methods : During a period of 5 years from March 1994 to February 1999, 65 male infants less than 3months old(range: 4-92 days, mean: 43 days) with UTI were evaluated. Ultrasound(US) and Voiding cystourethrogram(VCUG) were done in 60 patients. Due to refusal and technological problem, 5 patients were missed. 99mTc-dimercaptosuccinic acid renal scan (99mTc-DMSA renal scan) was recommended to most patients but performed in 40 patients. Renal scan was performed at least 3 months later after urinary tract infection. Results : Urinary tract anomalies were found in 26 of 65 infants. Twenty-six had vesicoureteral reflux(VUR), two had both VUR and double ureter, two had both U and posterior urethral valve. In patients with VUR, eight had renal scar or renal atrophies. In case of renal scar or atrophy, grades of VUR were III or above. Conclusion : We suggest that US and VCUG should be routinely performed in infants(<3months)with first UTI. 99mTc-DMSA renal scan should be performed only when renal parenchymal damage was observed in US and VUR grade III or above in VCUG. (J. Korean Soc Pediatr Nephrol 5 : 30- 5, 2001)

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.57-64
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• 1999

Purpose: The purpose of this study was to evaluate the accuracy of Tc-99m DTPA diuretic renal scans in children with dilated upper urinary tract. Materials and Methods: We reviewed diuretic renal scans of 14 pediatric patients (age range: 3 days to 4 years) with unilateral hydronephrosis diagnosed by ultrasonography. Diuretic renal scan was done using Tc-99m DTPA and standardized protocol. In 3 neonates, diuretic renal scans were performed within 1 week and 3-7 months after birth. Results: Six patients required Pyeloplasty and eight were managed conservatively. All 6 patients requiring Pyeloplasty were diagnosed as having ureteropelvic junction obstruction in the diuretic renal scan. In these 6 patients, post-operative renal scans at 3-12 months after surgery were converted to nonobstructive pattern in 5 and a nonfunctioning pattern in 1. In 3 patients who underwent diuretic renal scan within 1 week after birth, nonobstructive patterns of initial scan were converted to obstructive patterns in the follow-up scan. However, all patients with nonobstructive diuretic renal scans performed after the neonatal period did well on serial ultrasonography and showed favorable clinical outcome without progression to obstruction. Conclusion: Tc-99m DTPA diuretic renal scan with standardized protocol is useful in assessing suspected ureteropelvic junction obstruction in children as an initial diagnostic or post-operative follow-up modality. Nonobstructive or indeterminate scan results in the neonatal period requires follow-up scan to monitor development of the obstructive pattern.

• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.495-502
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• 2020

Kidney stones are a common disease with an annual prevalence of about 30,000 people in Korea, and are deeply related to an increase in chronic kidney disease, high blood pressure, coronary artery disease, metabolic syndrome, type 2 diabetes, hyperlipidemia, and abdominal obesity. Therefore, in this study, 135 examinees who visited a general hospital in Dalseong-gun from May 2019 to June 2020 for a medical examination were examined. The relationship between kidney stones and factors related to obesity and metabolic syndrome were found in abdominal ultrasound. I tried to find out the relevance. As a result of the study, the risk of kidney stones in the abnormal group was increased by 4.255 times compared to the normal group in total cholesterol factor, and the risk of kidney stones in the abnormal group was increased by 2.072 times compared to the normal group in the low-density lipoprotein cholesterol factor. Total cholesterol factor and low-density lipoprotein cholesterol It was found that the factor affects the prevalence of kidney stones and metabolic syndrome. Since the risk of kidney stones is related to total cholesterol and low-density lipoprotein cholesterol factors, active attention should be paid to preventive purposes through health check-ups.

• The Korean Journal of Nuclear Medicine
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• v.36 no.4
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• pp.271-276
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• 2002

Purpose: To measure reliable glomerular filtration rate by using the representative values of transplanted renal depths, which are measured with ultrasonography. Materials and Methods: We included 54 patients (26 men, 28 women), with having both renal scintigraphy and ultrasonography after renal transplantation. We measured GFR with Gates' method using the renal depth measured by ultrasonography, and median and mean ones in each patient. We compared GFR derived from ultrasonography-measured renal depth with GFR derived from median and mean renal depths. The correlation coefficients were obtained among GFR derived from ultrasonography-measured renal depths, median and mean renal depths under linear regression analysis. We determined whether GFR derived from median or mean renal depth could substitute GFR derived from ultrasonography-measured renal depth with Bland-Altman method. We analyze the expected errors of the GFR using representative renal depth in terms of age, sex, weight, height, creatinine value, and body surface. Results: The transplanted renal depths range from 3.20 cm to 5.96 cm. The mean value and standard deviation of renal depths measured by ultrasonography are $4.09{\pm}0.65cm$ in men, and $4.24{\pm}0.78cm$ in women. The median value of renal depths measured by ultrasonography is 4.36 cm in men and 4.14 cm in women. The GFR derived from median renal depth is more consistent with GFR derived from ultrasonography-measured renal depth than GFR derived from mean renal depth. Differences of GFR derived from median and ultrasonography-measured renal depth are not significantly different in the groups classified with creatinine value, age, sex, height, weight and body surface. Conclusion: When median value is adapted as a representative renal depth, we could obtain reliable GFR in transplanted kidney simply.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.291-298
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• 2016

The aim of the study was to investigate the diagnostic value of the color Doppler twinkling artifact in disease of urinary system. The intensity of twinkling artifact(TA) with color Doppler was classified into 3 levels, 0(non-TA) to 3(distinct TA). In the in vitro study, acorn jelly with various materials on top was examined using color Doppler at B-mode sonography in a water bath for TA. 31 patients with diagnosis of urinary calculi(renal stones 16, urinary stones 15) based on B-mode sonography were studied in vivo for TA. The materials with rough surfaces such as salt, screw and cubics at B-mode sonography with color Doppler contributed to causing TA. At B-mode sonography without color Doppler 37% of renal stones and 60% of ureter stones were detected. but at B-mode sonography with color Doppler TA was demonstrated for all cases. Superficial roughness of materials affected occurrence of TA at B-mode sonography with color Doppler. Therefore, TA at B-mode sonography without color Doppler could play a role in confident diagnosis of the disease of urinary system.