• Title/Summary/Keyword: Cross-modality

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A comparison of functional MRI and MRSI on occipital cortex by visual stimulation (시각자극에 의한 후두엽 피질에서의 기능적 자기공명영상법과 양성자 대사물질영상의 비교)

  • Kim, T.;Suh, T.S.;Choe, B.Y.;Shinn, K.S.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.291-292
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    • 1998
  • The purpose of the study was aimed to evaluate the BOLD contrast fMRI in occipital lobe and compare this imaging with metabolite changes based on $^1H$ MRS and MRSI before and after visual stimulation. As a result, the activation map were sucessfully produced by thresholding with minimum cross-correlate value of 0.45. In MRS, NAA/Cr ratio is almost same. however, latate was elevated almost 9 times higher than before activation. Lactate metabolic images were consistent with the BOLD effect map. The BOLD contrast fMRI is not enough to detect the activation area in human brain. so, the other modality was required such as lactate metabolic map.

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Stiffness Comparison of Tissue Phantoms using Optical Coherence Elastography without a Load Cell

  • Chae, Yu-Gyeong;Park, Eun-Kee;Jeon, Min Yong;Jeon, Byeong-Hwan;Ahn, Yeh-Chan
    • Current Optics and Photonics
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    • v.1 no.1
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    • pp.17-22
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    • 2017
  • Mechanical property of tissue is closely related to diseases such as breast cancer, prostate cancer, cirrhosis of the liver, and atherosclerosis. Therefore measurement of tissue mechanical property is important for a better diagnosis. Ultrasound elastography has been developed as a diagnostic modality for a number of diseases that maps mechanical property of tissue. Optical coherence elastography (OCE) has a higher spatial resolution than ultrasound elastography. OCE, therefore, could be a great help for early diagnosis. In this study, we made tissue phantoms and measured their compressive moduli with a rheometer measuring the response to applied force. Uniaxial strain of the tissue phantom was also measured with OCE by using cross-correlation of speckles and compared with the results from the rheometer. In order to compare stiffness of tissue phantoms by OCE, the applied force should be measured in addition to the strain. We, however, did not use a load cell that directly measures the applied force for each sample. Instead, we utilized one silicone film (called as reference phantom) for all OCE measurements that indirectly indicated the amount of the applied force by deformation. Therefore, all measurements were based on displacement, which was natural and effective for image-based elastography such as OCE.

Flow Characteristics and Riverbed Change Simulation on Bridge-intensive Section (교량밀집 구간의 흐름특성과 하상변동 모의)

  • Cho, Hong Je;Jeon, Woo Yeol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.6B
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    • pp.589-598
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    • 2010
  • When the hydraulic structures, such as bridge and weir, are consecutively installed to a short section of a river with complicated cross section, analyzing the flow characteristics and the riverbed change modality of the river is very important. In the 250 m section of the Taehwa river near the Samho-bridge, which passes through Ulsan city, three bridges has been installed, and the tributary water is flowing into both up and downstream of the section. Due to these factors, when the flood occurs, the cross section of the river changes vastly by the water level change and scour. Even so, due to the fact that the Samho-bridge divides the section into two parts, the national river and the regional river, each part is being analyzed separately by the onedimensional model. In this study, the flow characteristics due to the bridge concentration and the tributary water inflow were jointly analyzed for both up and downstream by using the one-dimensional HEC-RAS model and the two-dimensional SMS model, such as RMA2. The riverbed change modality of the section was also investigated by using the SED2D model. The results showed that the water level difference between the HEC-RAS and RMA2 was 0.87 m when applied to the three consecutive bridges. The riverbed change simulation using SED2D showed that the maximum scour was 0.231 m and it occurred at the Samho-bridge, which located in the middle and has short pier distance. In conclusion, when planning the river maintenance for the regions with concentrated bridges or the sections with severe changes in cross-section and flow, estimating the flood elevation by two-dimensional model and establishing countermeasures for the scouring of the bridge are required. In addition, an integrated analysis on both the national river and the regional river is necessary.

Clinical Study on East-West Combination Treatment in Joint Disorders (관절.류마티스 질환의 한.양방 협진에 관한 임상적 고찰)

  • Shin, Ye-Jji;Kim, Chan-Young;Kwon, Na-Hyoun;Kwon, Sin-Ae;Lee, Jung-Woo;Koh, Hyung-Kyun;Woo, Hyun-Su;Park, Dong-Suk;Baek, Yong-Hyeon
    • Journal of Acupuncture Research
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    • v.26 no.6
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    • pp.121-132
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    • 2009
  • Objectives : To evaluate the current status of East-West combination treatment in joint disorders. Methods : The medical records of patients who visited the Joints & Rheumatism Center at the Kyung Hee East-West Neo Medical Center from April 2006 to June 2009 were evaluated. The general characteristics of patients who underwent combination treatment, trend in number of cross-system referrals, and disorders and involved body regions of patients referred to the Eastern medical hospital from the Western medical hospital were initially assessed. 6 major disorders were found from the initial scanning. The trend in number of cross-hospital referrals, number of visits to the Eastern medical hospital, current status of combination treatment, treatment modality, and reason for cross-system referral was evaluated. Results : 1. 1510 patients were referred from the Eastern medical hospital to the Western medical hospital, and 1065 patients were referred from the Western medical hospital to the Eastern medical hospital. First visit patients reached a peak at the second quarter of 2007 and fourth quarter of 2006 respectively, and have steadily decreased from then on. Referrals of female patients were twice as common as male patient referrals. Patients in their sixth or seventh decade of life were most commonly referred, and more outpatients were referred compared to inpatients. 2. Patients with knee joint disorders were most commonly referred from the Western medical hospital to the Eastern medical hospital, followed by hip, shoulder, ankle, wrist, and elbow joint disorders. The most common disorders for each of the above regions in referred patients were knee osteoarthritis, avascular necrosis of the hip, adhesive capsulitis, and ankle strain and sprain. The generalized disorders rheumatoid arthritis and ankylosing spondylitis followed. 3. Patients referred to the Eastern hospital received approximately 3 to 10 Eastern medical treatment sessions. 45 percent remained on constant combination treatment, and 98 percent of referred patients received acupuncture treatment. Conclusions : In regard to the number of patients and duration of combination treatment, combination treatment was successfully performed for knee osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis, while it was not so for avascular necrosis of the hip, adhesive capsulitis, and ankle strain and sprain. Further research on this subject is required.

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Accuracy of Magnetic Resonance Imaging in Pretreatment Lymph Node Assessment for Gynecological Malignancies

  • Sufian, Saira Naz;Masroor, Imrana;Mirza, Waseem;Hussain, Zainab;Hafeez, Saima;Sajjad, Zafar
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4705-4709
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    • 2014
  • Objective: To determine the accuracy of magnetic resonance imaging (MRI) in detection of metastasis in pelvic and para-aortic lymph nodes from different gynecological malignancies. Materials and Methods: This retrospective cross sectional analytic study was conducted at the Department of Diagnostic Radiology, Aga Khan University Hospital Karachi Pakistan from January 2011 to December 2012. A sample of 48 women, age range between 20-79 years, fulfilling inclusion criteria were included. All patients had histopathologically proven gynecological malignancies in the cervix, endometrium or ovary and presented for a pretreatment MRI to our radiology department. Results: MRI was 100% sensitive and had a 100% positive predictive value to detect lymph node metastasis in lymph nodes with spiculated margins and 100% sensitive with a 75% positive predictive value to detect lymph node metastasis in a lymph node with lobulated margins. The sensitivity and positive predictive value of MRI to detect heterogeneous nodal enhancement were 100% and 75% respectively. Conclusions: Our study results reinforce that MRI should be used as a modality of choice in the pretreatment assessment of lymph nodes in proven gynaecological malignancies in order to determine the line of patientmanagement, distinguishing surgical from non-surgical cases.

Analysis of the Importance of Sacroiliac Joint Fractures as a Prognostic Factor of the Patients with Pelvic Fractures

  • Ju, Yeon-Uk;Cho, Jun-Min;Kim, Nam-Ryeol;Lee, Kyung-Bum;Kim, Jin-Kak;Oh, Jong-Keon
    • Journal of Trauma and Injury
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    • v.31 no.1
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    • pp.6-11
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    • 2018
  • Purpose: The diagnosis of pelvic fractures pattern has become to be essential in the decision making of treatment modality and reducing morbidity and mortality in multiple trauma patients. Sacroiliac joint (SIJ) disruption can cause life-threatening massive arterial bleeding. This study aimed to determine a method of predicting the prognosis and treatment direction with pelvis X-ray alone in the emergency room. We investigated whether SIJ disruption can be used alone as a poor prognostic factor. Methods: We analyzed the medical records and radiologic examination results of 167 patients with pelvic fractures from January 1, 2015 to December 31, 2016 retrospectively. Patients with pathologic fractures, thoraco-abdominal bleeding, and acetabulum fractures and pediatric patients (n=63) were excluded. Factors related to the clinical manifestations and treatments, such as transfusion and surgery, were statistically compared. Results: The cross-sectional analysis showed that there was no correlation between SIJ injury and sex; there were statistically significant relationships between occurrences of shock, conjoined fractures, transfusion, and surgeries. The hospitalization period and partial thromboplastin time and prothrombin time values increased. The logistic regression analysis showed that when an SIJ injury occurred, blood transfusion and hypotension possibilities increased. Conclusions: When pelvic fractures occur near the SIJ, blood transfusion and shock possibilities increase. Physicians must be aware of the high severity and poor prognosis of such fractures when these are diagnosed in the emergency room. And furthermore, the physician has to predict and prepare the intensive care and multidisciplinary approaches.

Complications after Senning Operation for TGA with and Wothout VSD (대혈관전위증에서 Senning수술후 합병증에 관한 임상적 고찰)

  • 안재호
    • Journal of Chest Surgery
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    • v.26 no.8
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    • pp.595-603
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    • 1993
  • We analysed 60 consecutive patients who got Senning operation for transposition of the great arteries [TGA] with or without ventricular septal defects [VSD]. There were 41 simple TGA [group I] and 19 TGA with VSD [Group II], the operative mortality was 20 % [in group I 4.9 %, group II 52.6 %]. Among the survivors [n=48], the mean follow-up period was 7 years [range, 1 year to 13.5 years] and the actuarial survival rate at 13 years were 95 % in group I and 42 % in group II. Preoperative high left ventricular pressure and high pulmonary arterial pressure affected the surviving [p<0.01]. There occurred various type of arrhythmia like junctional rhythm, first degree atrioventricular [AV] block, sick sinus syndrome and complete AV block, and we inserted 2 permanent pacemakers for these patients. The incidence of arrhythmia were 28.2 % [11/39] in group I and 55.6 % [5/9] in group II, and the actuarial freedom from arrhythmia at 13 years after operation was 66 % [71 % in group I, 44 % in group II]. Increased aortic cross clamping time had affected the development of arrhythmia [p<0.05] which meant the complexity of the operation. The total incidence of left ventricular outflow tract obstruction [LVOTO] was 31.3 % [15/48], but only 3 patients [6.25 %] showed the significant gradient requiring reoperation. The pulmonary venous pathway obstruction [PVO] were found in 3 patients, all in group I, and among them only one required the reoperation. The estimated freedom from PVO was 89 % at 13 years [87 % in group I, 100 % in group II], but we couldn`t find any significant systemic venous obstruction in our series. There occurred 27.1 % [13/48] mild degree tricuspid valve regurgitation without necessary surgical correction. We experienced 14.6 % [7/48] reoperation rate: 3 residual VSD, 3 LVOTO, 1 PVO, 3 atrial baffle leakage. For this high incidence of complication rate after Senning operation and high mortality in TGA with VSD, We do not use this kind of surgical modality any more and do the Jatene operation for all the TGA patients since several years ago.

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Value of Ultrasonography in the Diagnosis of Carpal Tunnel Syndrome : Correlation with Electrophysiological Abnormalities and Clinical Severity

  • Kim, Min-Kyu;Jeon, Hong-Jun;Park, Se-Hyuck;Park, Dong-Sik;Nam, Hee-Seung
    • Journal of Korean Neurosurgical Society
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    • v.55 no.2
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    • pp.78-82
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    • 2014
  • Objective : To investigate a diagnostic value of ultrasonography in carpal tunnel syndrome (CTS) patients and to evaluate a correlation of sonographic measurements with the degree of electrodiagnostic abnormalities and clinical severity. Methods : Two-hundred-forty-six symptomatic hands in 135 patients and 30 asymptomatic hands in 19 healthy individuals as control group were included. In ultrasonographic study, we measured the cross-sectional area (CSA) and flattening ratio (FR) of the median nerve at the pisiform as well as palmar bowing (PB) of the flexor retinaculum. Sensitivity and specificity of ultrasonographic measurements were evaluated and ultrasonographic data from the symptomatic and control hands were compared to the grade of electrodiagnostic and clinical severity. Results : The mean CSA was $13.7{\pm}4.2mm^2$ in symptomatic hands and $7.9{\pm}1.3mm^2$ in asymptomatic hands. The mean FR was $4.2{\pm}1.0$ in symptomatic hands and $3.4{\pm}0.4$ in asymptomatic hands. The mean PB was $3.5{\pm}0.5$ mm in symptomatic hands and $2.6{\pm}0.3$ mm in asymptomatic hands. Statistical analysis showed differences of the mean CSA, FR and PB between groups were significant. A cut-off value of $10mm^2$ for the mean CSA was found to be the upper limit for normal value. Both the mean CSA and PB are correlated with the grade of electrophysiological abnormalities and clinical severity, respectively. Conclusion : Ultrasographic measurement of the CSA and PB is helpful to diagnose CTS as a non-invasive and an alternative modality for the evaluation of CTS. In addition, ultrasonography also provides a reliable correlation with the grade of electrodiagnostic abnormalities and clinical severity.

Role of Ultrasound in Characterization of Ovarian Masses

  • Hafeez, Saima;Sufian, Saira;Beg, Madiha;Hadi, Quratulain;Jamil, Yasir;Masroor, Imrana
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.603-606
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    • 2013
  • Background: Ovarian cancer is the second most common malignancy in Pakistani women, accounting for 4% of all cancers in the female population. The aim of this study was to determine sensitivity, specificity, positive and negative predictive values and 95% confidence intervals for ultrasound in characterization of ovarian masses in patients presenting at public and private tertiary care hospitals in Karachi, Pakistan. Materials and Methods: We adopted a cross-sectional analytical study design to retrospectively collect data from January 2009-11 from medical records of two tertiary care hospitals. Using a non-probability purposive sampling technique, we recruited a sample of 86 women aged between 15 and 85 years fulfilling inclusion criteria with histopathologically proven ovarian masses presenting for an ultrasound examination in our radiology departments. Results: Our retrospective data depicted sensitivity and specificity of ultrasound to be 90.7%, 95%CI (0.77, 0.97) and 91.4%, 95%CI (0.76, 0.98) respectively. Positive predictive value was 93%, 95%CI (0.79, 0.98) and negative predictive value was 89%, 95%CI (0.73, 0.96). A total of 78 ovarian masses were detected, out of which 42 were malignant and 36 were benign. Conclusions: Results of our study further reinforce the conclusion that ultrasound should be used as an initial modality of choice in the workup of every woman suspected of having an ovarian mass. It not only results in decreasing the mortality but also avoids unnecessary surgical interventions.

Three dimensional finite element analysis of the stress distribution around the mandibular posterior implant during non-working movement according to the amount of cantilever

  • Park, Ji-Man;Kim, Hyun-Joo;Park, Eun-Jin;Kim, Myung-Rae;Kim, Sun-Jong
    • The Journal of Advanced Prosthodontics
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    • v.6 no.5
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    • pp.361-371
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    • 2014
  • PURPOSE. In case of large horizontal discrepancy of alveolar ridge due to severe resorption, cantilevered crown is usually an unavoidable treatment modality. The purpose of this study was to evaluate the clinical criteria for the placement of the aforementioned implant crown. MATERIALS AND METHODS. The mandible model with 2 mm thick cortical bone and cancellous bone was fabricated from CT cross-section image. An external connection type implant was installed and cantilevered crowns with increasing offset of 3, 4, 5, 6, and 7 mm were connected. Vertical load and $30^{\circ}$ oblique load of 300 N was applied and stress around bone and implant component was analyzed. A total of 14 cases were modeled and finite element analysis was performed using COSMOS Works (Solid works Inc, USA). RESULTS. As for the location of the vertical load, the maximum stress generated on the lingual side of the implant became larger according to the increase of offset distance. When the oblique load was applied at $30^{\circ}$, the maximum stress was generated on the buccal side and its magnitude gradually decreased as the distance of the offset load increased to 5 mm. After that point, the magnitude of implant component's stress increased gradually. CONCLUSION. The results of this study suggest that for the patient with atrophied alveolar ridge following the loss of molar teeth, von-Mises stress on implant components was the lowest under the $30^{\circ}$ oblique load at the 5 mm offset point. Further studies for the various crown height and numbers of occusal points are needed to generalize the conclusion of present study.