• 제목/요약/키워드: Partial resonance

검색결과 225건 처리시간 0.028초

고식적 견관절 자기공명영상에 추가적인 사각시상면 영상 이용 시 극상건 손상 검출 진단능 차이에 대한 고찰 (The Difference in Diagnostic Performance for Detection of Supraspinatus Tendon Tears by Adding Angled Oblique Sagittal Plane Image to the Routine Shoulder MRI)

  • 김지희;김현주;차장규;최득린;홍성숙;장윤우;황정화
    • Investigative Magnetic Resonance Imaging
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    • 제18권2호
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    • pp.157-166
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    • 2014
  • 목적 : 고식적 견관절 MRI 검사에 사각시상면 영상 추가 시 극상건 파열의 진단적 정확도가 증가하는지 관절경 수술 소견을 대비표준으로 삼아 알아보고자 하였다. 대상 및 방법 : 2011년 1월부터 2012년 12월까지 본원에서 견관절 MRI 검사를 하고 관절경 수술을 받은 121명의 환자를 대상으로 하였다. 두 명의 영상의학과 의사가 독립적으로 관상사면과 시상사면 영상을 이용하여 극상건 파열을 평가하고 4주후 사각시상면 영상을 추가하여 다시 판독하였다. 관절경 수술을 대비표준으로 이용하였다. 건 파열 진단의 민감도와 특이도는 McNemar test로 비교하였고 관찰자 간, 기술 간 일치도는 카파계수로 평가하였다. 결과 : 사각시상면 추가 시 고식적 견관절 MRI만 이용하였을 때 보다 극상건 전층 파열 진단의 민감도가 증가하였고, 부분 파열 진단의 민감도, 특이도, 정확도 모두 증가하였지만 통계학적으로 유의한 차이는 없었다. 관찰자간 일치도는 사각시상면을 추가하거나 하지 않았을 때 모두 높은 일치도를 보였다. 영상 소견과 관절경 수술 소견은 사각시상면 추가 시와 추가하지 않았을 때 모두 중등도의 일치도를 보였다. 결론 : 극상건의 전층 및 부분 파열 평가를 위해 고식적 MRI에 사각시상면 영상을 추가 시 기존의 영상면 만으로 평가하였을 때와 진단적 정확도에 의미 있는 차이는 없었다.

Lumbar burner and stinger syndrome in an elderly athlete

  • Wegener, Veronika;Stabler, Axel;Jansson, Volkmar;Birkenmaier, Christof;Wegener, Bernd
    • The Korean Journal of Pain
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    • 제31권1호
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    • pp.54-57
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    • 2018
  • Burner or stinger syndrome is a rare sports injury caused by direct or indirect trauma during high-speed or contact sports mainly in young athletes. It affects peripheral nerves, plexus trunks or spinal nerve roots, causing paralysis, paresthesia and pain. We report the case of a 57-year-old male athlete suffering from burner syndrome related to a lumbar nerve root. He presented with prolonged pain and partial paralysis of the right leg after a skewed landing during the long jump. He was initially misdiagnosed since the first magnet resonance imaging was normal whereas electromyography showed denervation. The insurance company refused to pay damage claims. Partial recovery was achieved by pain medication and physiotherapy. Burner syndrome is an injury of physically active individuals of any age and may appear in the cervical and lumbar area. MRI may be normal due to the lack of complete nerve transection, but electromyography typically shows pathologic results.

Cervico-Thoracic Intradural Extramedullary Lipoma

  • Jun, Young-Hoon;Kim, Se-Hoon;Kim, Sang-Dae;Lim, Dong-Jun
    • Journal of Korean Neurosurgical Society
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    • 제38권4호
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    • pp.316-319
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    • 2005
  • A 42-year-old female was admitted with an 11-month history of progressive spastic paraparesis and ataxic gait. Magnetic resonance imaging showed intraspinal space occupying lesion compressing the spinal cord posteriorly, located from C5 to T2 with iso to high signal intensity at T2-weighted images and high signal intensity at T1-weighted images. The patient underwent surgery for decompression of the affected spinal cord because of the progressive neurological deficit. At surgery, the lesion was intradural extramedullary lipoma composed with mature adipose tissue. Partial tumor removal to decompress the neural structures and laminoplasty to avoid postoperative instability and deformity were performed. Postoperatively, she demonstrated improvement in paraparesis and was able to walk without assistance. Though attempts to decrease the size of or even to totally remove a lipoma are not required to achieve satisfactory results and carry considerable risks of surgical morbidity, a careful and limited decompression of the affected spinal cord through a partial removal of the tumor and laminoplasty could result in a significant neurological improvement.

Automated Segmentation of the Lateral Ventricle Based on Graph Cuts Algorithm and Morphological Operations

  • Park, Seongbeom;Yoon, Uicheul
    • 대한의용생체공학회:의공학회지
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    • 제38권2호
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    • pp.82-88
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    • 2017
  • Enlargement of the lateral ventricles have been identified as a surrogate marker of neurological disorders. Quantitative measure of the lateral ventricle from MRI would enable earlier and more accurate clinical diagnosis in monitoring disease progression. Even though it requires an automated or semi-automated segmentation method for objective quantification, it is difficult to define lateral ventricles due to insufficient contrast and brightness of structural imaging. In this study, we proposed a fully automated lateral ventricle segmentation method based on a graph cuts algorithm combined with atlas-based segmentation and connected component labeling. Initially, initial seeds for graph cuts were defined by atlas-based segmentation (ATS). They were adjusted by partial volume images in order to provide accurate a priori information on graph cuts. A graph cuts algorithm is to finds a global minimum of energy with minimum cut/maximum flow algorithm function on graph. In addition, connected component labeling used to remove false ventricle regions. The proposed method was validated with the well-known tools using the dice similarity index, recall and precision values. The proposed method was significantly higher dice similarity index ($0.860{\pm}0.036$, p < 0.001) and recall ($0.833{\pm}0.037$, p < 0.001) compared with other tools. Therefore, the proposed method yielded a robust and reliable segmentation result.

양측 견관절을 침범한 거울 병변 -머리 위의 작업을 하는 근로자 대상 관절경적 연구 (Bilateral Shoulder Involvement with Mirror Image Lesion -An Arthroscopic Study in Overhead Workers)

  • 문영래;이철갑;김종식
    • Clinics in Shoulder and Elbow
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    • 제9권1호
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    • pp.68-72
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    • 2006
  • Purpose: To demonstrate arthroscopically the presence of bilateral shoulder "mirror lesions" due to overhead work. Materials and Methods: A cross-sectional study was performed in a historical cohort of 10 male tire plant workers who underwent MRI studies of both shoulders. Bilateral intraarticular shoulder pathology was diagnosed by magnetic resonance imaging and confirmed by arthroscopy. "Mirror lesions" were defined as similar pathology between an individual patient's two shoulders. Results: We report on ten patients who had bilateral "mirror lesions." The most common mirror lesions were tears of the rotator cuff. Most patients (7 of 10) had more than one mirror lesion in their shoulders. There were two bilateral full thickness tears involving the supraspinatus and infraspinatus, four bilateral partial thickness supraspinatus tears, six bilateral partial or upper corner lesion complete subscapularis tears, and one bilateral complete supraspinatus tear. Conclusion: Occupational overhead work with simultaneous use of both arms is associated with bilateral shoulder lesions verified by arthroscopy. By demonstrating the work-related bilateral shoulder involvement, this study suggests an etiopathogenesis for these lesions and provides rational for developing worksite prevention strategies.

Differentiation of Roots of Glycyrrhiza Species by 1H Nuclear Magnetic Resonance Spectroscopy and Multivariate Statistical Analysis

  • Yang, Seung-Ok;Hyun, Sun-Hee;Kim, So-Hyun;Kim, Hee-Su;Lee, Jae-Hwi;Whang, Wan-Kyun;Lee, Min-Won;Choi, Hyung-Kyoon
    • Bulletin of the Korean Chemical Society
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    • 제31권4호
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    • pp.825-828
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    • 2010
  • To classify Glycyrrhiza species, samples of different species were analyzed by $^1H$ NMR-based metabolomics technique. Partial least squares discriminant analysis (PLS-DA) was used as the multivariate statistical analysis of the 1H NMR data sets. There was a clear separation between various Glycyrrhiza species in the PLS-DA derived score plots. The PLS-DA model was validated, and the key metabolites contributing to the separation in the score plots of various Glycyrrhiza species were lactic acid, alanine, arginine, proline, malic acid, asparagine, choline, glycine, glucose, sucrose, 4-hydroxy-phenylacetic acid, and formic acid. The compounds present at relatively high levels were glucose, and 4-hydroxyphenylacetic acid in G. glabra; lactic acid, alanine, and proline in G. inflata; and arginine, malic acid, and sucrose in G. uralensis. This is the first study to perform the global metabolomic profiling and differentiation of Glycyrrhiza species using $^1H$ NMR and multivariate statistical analysis.

고주파 부분방전(HFPD)측정용 하이브리드 센서 개발에 관한 연구 (A development of the Hybrid Sensor for the detection of the High Frequency Partial Discharge(HFPD))

  • 김지홍;구자윤;김정태
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.173-175
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    • 2002
  • In general, CT and Shunt have been traditionally used as a sensor for detecting the partial discharges in order to diagnose the present insulation state of the electric power apparatus. The former is very convenient for the practical application since it is not only non-contact method but its frequency bandwidth and resonance frequency could be designed for its specific application. However, it has been proved to have poor linearity and low sensitivity. For the latter, even though it is an ideal sensor, noise from the power source and the ground could flow into the system. Furthermore, the surge current could be easily come into the measuring systems giving rise to a severe breakdown. In this respect, a hybrid sensor has been designed and fabricated in order to overcome the shortcoming of these two types of sensors. For this purpose, the experimental comparison with commercialized products has been also carried out. In this concept of the hybrid sensor, two different impedances could provide the passage of the signals. In this way, the discrimination of the noise could be accomplished very effectively with high ratio of signal over noise(S/N) under the little influence from the external noises and the breakdown.

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Extracardiac Conduit Fontan Operation and Right Ventricular Exclusion Procedure for Right Ventricle Failure after Repair of Partial Atrioventricular Septal Defect

  • Yang, Chan Kyu;Jang, Woo Sung;Choi, Eun-Suk;Cho, Sungkyu;Choi, Kwangho;Nam, Jinhae;Kim, Woong-Han
    • Journal of Chest Surgery
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    • 제47권3호
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    • pp.275-279
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    • 2014
  • A 13-year-old girl, who had undergone the total correction of partial atrioventricular septal defect at the age of 4 years, was admitted with severe tricuspid regurgitation in echocardiography. She had received one-and-a-half ventricle repair during follow-up. Her right ventricle showed global akinesia, and the ejection fraction of the left ventricle was 25% with paradoxical interventricular septal motion. We performed right ventricular exclusion adjunct to the Fontan procedure. She is doing well two years after the operation without complications.

Desmopressin responding female nephrogenic diabetes insipidus: a case report

  • Juyeon Lee;Hae Il Cheong;Jung Won Lee;Ki Soo Pai
    • Childhood Kidney Diseases
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    • 제26권2호
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    • pp.107-110
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    • 2022
  • Nephrogenic diabetes insipidus, decreased ability to concentrate urine, with production of large amounts of urine, is caused by the refractory response of renal tubules to the action of antidiuretic hormone. This rare disorder, known as X-linked nephrogenic diabetes insipidus, is caused by a mutation in the AVPR2 gene. Because it is hereditary, most patients are male. This report highlights a case of nephrogenic diabetes insipidus in a 3-year 5-month-old female; upon presentation to the hospital, her symptoms included frequent urinationand consumptionof a significant amount ofwater,which had begun2 years ago. The results of blood tests showed increased levels of serum antidiuretic hormone, and sellar magnetic resonance imaging showed no abnormality. The results of the water restriction test and the desmopressin administration test confirmed the diagnosis of nephrogenic diabetes insipidus showing a partial response to desmopressin. The results of genetic testing indicated the presence of an AVPR2 mutation, a heterozygous missense mutation (p.Val88Met), suggesting inheritance of X-linked nephrogenic diabetes insipidus. This report describes a significant case of symptomaticX-linked nephrogenic diabetes insipidus in a female patient who showed a partial response to desmopressin.

SF6 가스중의 공진주파수에 따른 신호특성 (Characteristic as a Resonance Frequency of $SF_6$ Gas)

  • 이용희;이현동;박정남;신양섭;박장수;서정민
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 C
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    • pp.1867-1869
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    • 2003
  • In this paper, chamber(Circuit breaker compartment of C-GIS) made of stainless steel with 4 mm width is used. Artificial defect was made on enclosure or HV conductor of chamber and $SF_6$ gas was injected into it according to pressure. In this experiment, Acoustic emission sensors of different types was used to compare sensitivity to detect acoustic signal occurred by Partial discharge(PD) of according to types and resonance frequency in $SF_6$ gas atmosphere. Sensors used in tests was R6I, R15I and 2/4/6 Pre-Amplifier connected with R6IU without pre. amp. In case of R6IU, gain was adjusted with 40 dB like other sensors and operated by differential mode. Post amplifier(post. amp) and band pass filter(BPF) were developed Gain of post. amp. is 60 dB and BPF has band width of $50{\sim}300$ kHz. Also, envelope circuit developed reduces frequency of AE sensor. As a result, in $SF_6$ atmosphere, R6IU and R6I had resonance frequency of 60 Hz was better than R15I. Also, R6IU was better than R6I because of type property of pre.amp. had differential mode.

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