• 제목/요약/키워드: resistive index

검색결과 25건 처리시간 0.021초

색채 및 펄스 도플러 초음파를 이용한 경부 림프절의 양성과 악성의 감별 (Differentiation of Malignant and Benign Cervical Lymph Nodes with Color and Pulsed Doppler Ultrasonography)

  • 이강대;이봉희;이윤우;이환호;안경모;이영수
    • 대한두경부종양학회지
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    • 제17권1호
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    • pp.19-25
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    • 2001
  • Objectives: The clinical efficacy of the color and pulsed Doppler ultrasound with spectral waveform analysis for differentiation of malignant from benign cervical lymphadenopathy was prospectively evaluated in cervical lymphadenopathy. Materials and Methods: Color and pulsed Doppler ultrasound examination was prospectively performed in 32 cervical lymph nodes in 28 patients. These 10 nodes from 10 patients were malignant and 22 nodes from 18 patients were benign, proved by operation, biopsy, and follow-up examination. Another 12 lymph nodes from 12 normal volunteers were evaluated as control group. The peak systolic velocity (PSV), minimal diastolic velocity (MDV) , and resistive indexes (RI) of arterial flows within the 32 lymph nodes were assessed to differentiate the malignant from benign nodes with pulsed Doppler ultrasonography. The results were qualitified with one-way ANOVA and Bonferroni method of multiple comparison. Results: The mean values of PSV of malignant, benign, and control nodes were 38.2(10.1-134)cm/sec, 23.3(9-38.5) cm/sec and 11.8(6.7-18.1) cm/sec, respectively. The mean values of MDV of them were 0.9(-7.5-10.7)cm/sec, 9.7(2.9-18.6)cm/sec and 6.5(3.7-9.3)cm/sec, respectively. However, there was no statistical significance in differentiation of malignant from benign nodes with PSV and MDV. The mean values of RI of malignant, benign, and control nodes were 0.99(0.80-1.30), 0.59(0.46-0.77) and 0.45(0.38-0.50), respectively. RI value of 0.8 is suggestive value for discrimination of malignant from benign lymphadenopathy during examination of color Doppler ultrasound of cervical lymphadenopathy. Conclusion: Color and pulsed Doppler ultrasound examination with spectral waveform analysis may be quite helpful in the differentiation between benign and malignant alterations of cervical lymph nodes.

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자장감쇠법을 이용한 $(Bi,Pb)_2Sr_2Ca_2Cu_3O_x$/Ag 초전도선재의 접합저항 측정 (Measurement of Joint Resistance of $(Bi,Pb)_2Sr_2Ca_2Cu_3O_x$/Ag Superconducting Tape by Field decay Technique)

  • 김정호;이승묵;주진호
    • Progress in Superconductivity
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    • 제14권1호
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    • pp.1-10
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    • 2012
  • We fabricated a closed coils by using resistive-joint method and the joint resistance of the coils were estimated by field decay technique in liquid nitrogen. We used the Runge-kutta method for the numerical analysis to calculate the decay properties. The closed coil was wound by $(Bi,Pb)_2Sr_2Ca_2Cu_3O_x$/Ag tape. Both ends the tape were overlapped and soldered to each other. The current was induced in a closed coils by external magnetic flux density. Its decay characteristic was observed by means of measuring the magnetic flux density generated by induced current at the center of the closed coil with hall sensor. The joint resistance was calculated as the ratio of the inductance of the loop to the time constants. The joint resistances were evaluated as a function of critical current of loop, contact length, sweep time, and external magnetic flux density in a contact length of 7 cm. It was observed that joint resistance was dependent on contact length of a closed coil, but independent of critical current, sweep time, and external magnetic flux density. The joint resistance was measured to be higher for a standard four-probe method, compared with that for the field decay technique. This implies that noise of measurement in a standard four-probe method is larger than that of field decay technique. It was estimated that joint resistance was $8.0{\times}10^{-9}{\Omega}$ to $11.4{\times}10^{-9}{\Omega}$ for coils of contact length for 7 cm. It was found that 40Pb/60Sn solder are unsuitable for persistent mode.

Descending Aorta Blood Flow Characteristics before the Development of Necrotizing Enterocolitis in Preterm Neonates

  • Kim, Kyung Min;Kim, Hyo Sup;Yoon, Ji Hong;Lee, Eun-Jung;Yum, Sook Kyung;Moon, Cheong-Jun;Youn, Young-Ah;Kwun, Yoo Jin;Lee, Jae Young;Sung, In Kyung
    • Neonatal Medicine
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    • 제25권2호
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    • pp.78-84
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    • 2018
  • Purpose: To investigate the hemodynamic risk factors for necrotizing enterocolitis (NEC), we analyzed the characteristics of descending aorta (DA) blood flow in preterm neonates, who later developed NEC. Methods: This was an observational case-control study on 53 preterm neonates at a tertiary referral center. Clinical and echocardiographic data were collected from 23 preterm neonates with NEC (NEC group), and compared with those of 30 preterm neonates without NEC (control group). Echocardiography was done at a median (interquartile range) of 5 (3-9) days after birth and 2 (1-2.5) days before the diagnosis of NEC. Results: Basic clinical characteristics including gestational age, birth weight, Apgar score, breast feeding status, use of umbilical catheters, and mode of invasive ventilator care were similar between the groups. Compared with the control group, the lowest diastolic velocity of DA was significantly decreased, whereas the diastolic reverse flow and the ratio of diastolic reverse to systolic forward flows were significantly increased in the NEC group. In addition, the resistive index (RI) of DA was significantly increased in the NEC group and showed a positive association with the development of NEC. Multivariate logistic regression analysis showed that increasing RI of DA was an independent risk factor for the development of NEC (P=0.008). Conclusion: Significant changes in DA flow characteristics including decreased diastolic velocity and increased diastolic reverse flow along with increased peripheral vascular resistance were observed before the development of NEC in preterm neonates. These findings may help clinicians stratify in advance neonates at a risk of developing NEC and may help improve outcomes in these neonates.

개에서 신장의 허혈-재관류 손상에 대한관류-흡인의 감소효과 (Amelioration Effects of Irrigation-Aspiration on Renal Ischemia-Reperfusion Injury in Canine Model)

  • 이재일;손화영;정성목;김명철
    • 한국임상수의학회지
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    • 제25권4호
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    • pp.257-262
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    • 2008
  • 신장의 허혈-재관류 손상은 수술하는 동안 부득이하게 발생하는 허혈-재관류 손상에 대한 이식조직의 내성에 따라 이식된 장기의 생존력이 달려있기 때문에 임상적으로 아주 중요하다. 본 연구의 목적은 신장 혈관을 차단하여 유발한 허혈-재관류 모델에서 관류-흡인의 효과를 알아보고자 실시하였다. 신기능과 항산화 효소를 검사하기 위해 혈액 샘플을 채취하였고 신장내 동맥의 혈류저항을 측정하였다. 14일째 신장을 절제하여 조직검사를 실시하였다. 신기능(Cr, BUN)은 처치군에 비해 비처치군에서 유의성 있는 상승을 보였다. 신장내 혈류 저항은 두 그룹 사이에 유의성이 없었다. 항산화 효소 활성은 대조군에 비해 비처치군에서 유의성 있는 감소를 보였으나, 처치군에서는 대조군과 유의성이 없었다. 조직검사 결과에서도 처치군이 비처치군에 비해 적은 조직손상을 보였다. 이러한 결과는 관류-흡인 과정이 신장의 허혈-재관류 손상을 감소시키는데 유용한 단계임을 시사한다.

뒤통수밑근 이완기법과 병행된 고주파 심부투열이 만성 긴장성 두통 환자들의 압통과 목 가동성 및 기능장애에 미치는 영향 (Effects of High-frequency Diathermy Integrated into Suboccipital Release on Tenderness and Neck Mobility and Disability in People with Chronic Tension-type Headache)

  • 이형렬;심재훈;오덕원
    • 한국전문물리치료학회지
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    • 제24권2호
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    • pp.37-47
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    • 2017
  • Background: Active trigger points (TrPs) of the suboccipital muscles greatly contribute to the occurrence of chronic tension-type headache, with increased sensitivity of TrPs and facilitated referred pain. Objects: This study aimed to investigate whether the integration of high-frequency diathermy into suboccipital release is more beneficial than the use of suboccipital release alone. Methods: Thirty subjects were assigned to either experimental group-1 (EG-1) to undergo suboccipital release combined with high-frequency diathermy (frequency: 0.3 MHz, and electrode type: resistive electronic transfer), or EG-2 to undergo suboccipital release alone, or the control group (CG) with no intervention, with 10 subjects in each group. The assessment tools included the headache impact test 6 (HIT-6), perceived level of tenderness, neck disability index, and neck mobility. Intervention was performed for 10 minutes, twice per week, for 4 weeks, and measurements were performed before and after the interventions. Results: The between-group comparison of the post-test values and changes between pretest and post-test showed significant differences for all parameters at p<.05, except for the left-to-right lateral bending range. In the post hoc test, EG-1 showed significant differences for the parameters in comparison with the CG, while no significant differences in the perceived tenderness level, on both temporal regions, were found between EG-2 and CG. Furthermore, the HIT-6 score and perceived tenderness level, in the right temporal region, showed significant differences between EG-1 and EG-2. In the within-group comparison, EG-1 and EG-2 appeared to be significantly different between pretest and post-test (p<.05), except for the perceived tenderness level in the right temporal region, with significance for the EG-1 group only (p<.05). Conclusion: These findings suggest that the suboccipital release technique may be advantageous to improve headache, tenderness, and neck function and mobility, with more favorable effects with the incorporation of high-frequency diathermy.