• Title/Summary/Keyword: Lateral resolution

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Stereotactic Mesencephalotomy for Cancer - Related Facial Pain

  • Kim, Deok-Ryeong;Lee, Sang-Won;Son, Byung-Chul
    • Journal of Korean Neurosurgical Society
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    • v.56 no.1
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    • pp.71-74
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    • 2014
  • Cancer-related facial pain refractory to pharmacologic management or nondestructive means is a major indication for destructive pain surgery. Stereotactic mesencephalotomy can be a valuable procedure in the management of cancer pain involving the upper extremities or the face, with the assistance of magnetic resonance imaging (MRI) and electrophysiologic mapping. A 72-year-old man presented with a 3-year history of intractable left-sided facial pain. When pharmacologic and nondestructive measures failed to provide pain alleviation, he was reexamined and diagnosed with inoperable hard palate cancer with intracranial extension. During the concurrent chemoradiation treatment, his cancer-related facial pain was aggravated and became medically intractable. After careful consideration, MRI-based stereotactic mesencephalotomy was performed at a point 5 mm behind the posterior commissure, 6 mm lateral to and 5 mm below the intercommissural plane using a 2-mm electrode, with the temperature of the electrode raised to $80^{\circ}C$ for 60 seconds. Up until now, the pain has been relatively well-controlled by intermittent intraventricular morphine injection and oral opioids, with the pain level remaining at visual analogue scale 4 or 5. Stereotactic mesencephalotomy with the use of high-resolution MRI and electrophysiologic localization is a valuable procedure in patients with cancer-related facial pain.

Single Shot Epidural Injection for Cervical and Lumbosaccral Radiculopathies: A Preliminary Study

  • Nawani, Digambar Prasad;Agrawal, Sanjay;Asthana, Veena
    • The Korean Journal of Pain
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    • v.23 no.4
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    • pp.254-257
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    • 2010
  • Background: Epidural steroid injection is an established treatment modality for intervertebral disc prolapse to radiculopathy. In cases where two levels of radiculopathy are present, two separate injections are warranted. Herein, we present our experience of management of such cases with a single epidural injection of local anaesthetic, tramadol and methylprednisolone, and table tilt for management of both radiculopathies. Methods: 50 patients of either sex aged between 35-65 years presenting with features of cervical and lumbar radiculopathic pain were included and were subjected to single lumbar epidural injection of local anaesthetic, tramadol and methylprednisolone, in the lateral position. The table was then tilted in the trendelberg position with a tilt of 25 degrees, and patients were maintained for 10 minuted before being turned supine. All patients were administered 3 such injections with an interval of 2 weeks between subsequent injections, and pain relief was assessed with a visual analogue scale. Immediate complications after the block were assessed. Results: Immediate and post procedural complications observed were nausea and vomiting (20%), painful injection site (4%), hypotension (10%) and high block (4%). Pain relief was assessed after the three injections by three grades: 37 (74%) had complete resolution of symptoms; 18% had partial relief and 8% did not benefit from the procedure. Conclusions: This technique may be used as an alternative technique for pain relief in patients with unilateral cervical and lumbar radiculopathies.

Structure of Ni and NiO Nanoparticles Observed by X-ray Coherent Diffraction Imaging

  • Kim, Chan;Kim, Yoon-Hee;Hamh, Sun-Young;Son, Jun-Gon;Khakurel, Krishna Prasad;Iqbal, Mazhar;Noh, Do-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.542-543
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    • 2012
  • Coherent diffraction imaging (CDI) method using hard x-ray at 5.46 keV was applied to study assembly of Ni and Ni oxide nano structures formed on a Si3N4 membrane. Density distribution of Ni nano-particles was obtained quantitatively with about 15 nm lateral resolution by reconstructing images from the speckle diffraction pattern. In addition, reconstructed images of nickel oxide particles indicated that Ni atoms diffuse out during the oxidation process leaving pores inside the nickel oxide crust. Furthermore, we recognize that really weak phase object, less than 5 nm thickness of Ni residues, can be reconstructed due to the reference particles. We achieved quantitative information of nanometer sized materials and demonstrate the effect of reference particles by using hard x-ray coherent diffractive imaging method.

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Simultaneous Multiple Transmit Focusing Using Orthogonal Weighted Linear FM Chirp (가중된 직교 선형 FM신호를 이용한 송신 동시 다중 빔집속 기반의 초음파 영상 기법)

  • 정영관;송태경
    • Proceedings of the IEEK Conference
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    • 2001.06d
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    • pp.155-158
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    • 2001
  • A new method for simultaneous multiple transmit focusing using orthogonal weighted FM chirp is proposed. Weighted chirp signals focused at different depths are transmitted at the same time. These chirp signals are mutually orthogonal in the approximate sense that the autocorrelation function of each signal has a narrow mainlobe width and low sidelobe levels, and the crosscorrellation function of any pair of the signals has smaller values than the sidelobe levels of each autocorrelation function. This means that each weighted chirp signal can be separately compressed into a short pulse, focused individually and combined with other focused beams to form a frame of image. Theoretically, any two chirp signals defined in two nonoverlapped frequency bands are mutually orthogonal. In the present work, however, a fractional overlap of adjacent frequency bands, by up to 25%, were permitted to design more chirp signals within a given transducer bandwidth. The crosscorrelation values due to the frequency overlap could be reduced by alternating the direction of frequency sweep of the adjacent chirp signals. The simulation results show that this method can improve the lateral resolution of image without sacrifice in the frame rate compared with the conventional pulse system.

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3-D Reconstruction of Human Face Using the Derivative Moiré Topography

  • Bae, Yoon Jae;Ha, Byeong Wan;Park, Ji An;Cho, Choon Sik
    • Journal of the Optical Society of Korea
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    • v.18 no.5
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    • pp.500-506
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    • 2014
  • A new 3-D reconstruction algorithm for the human face is proposed using the derivative Moir$\acute{e}$ topography which ensures fast and robust reconstruction even for rough surfaces. The Moir$\acute{e}$ interference fringe pattern is initially obtained through the projection Moir$\acute{e}$ topography based on phase shifting, and then differentiated to provide a full unwrapped phase map for a human face. $2{\pi}$ ambiguity, which has been a chronically unsolved problem with Moir$\acute{e}$ topography, is successfully surmounted by differentiating the Moir$\acute{e}$ fringe patterns both in x- and y-directions when the object is located in the x-y plane. A real human face is used for verifying the proposed derivative Moir$\acute{e}$ topography. A human face of 4 different phase-shifted images taken in the fixed plane is almost fully reconstructed in 3-D format in 0.1 mm lateral resolution.

Study of Human Tactile Sensing Characteristics Using Tactile Display System (질감 제시 장치를 이용한 촉감인지 특성 연구)

  • Son Seung-Woo;Kyung Ki-Uk;Yang Gi-Hun;Kwon Dong-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.5
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    • pp.451-456
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    • 2005
  • This paper describes three kinds of experiments and analysis of their results related to human tactile sensitivity using an integrated tactile display system. The device can provide vibration, normal pressure and lateral slip/stretch which are important physical quantities to sense texture. We have tried to find out the efficient method of stimulating, limitation of surface discrimination by kinesthetic farce feedback and the effectiveness of the combination of kinesthetic force and tactile feedback. Seven kinds of different stimulating methods were carried out and they are single or combination of the kinesthetic force, normal static pressure, vibration, active/passive shear and moving wave. Both prototype specimen and stimulus using tactile display were provided to all examinees and they were allowed to answer the most similar sample. The experimental results show that static pressure is proper stimulus for the display of micro shape of the surface and vibrating stimulus is more effective for the display of fine surface. And the sensitivities of active touch and passive touch are compared. Since kinesthetic force feedback is appropriate to display shape and stiffness of an object, but roughness display has a limitation of resolution, the concurrent providing methods of kinesthetic and tactile feedback are applied to simulate physical properties during touching an object.

Permanent Ground Deformation induced by Christchurch Earthquake and Estimation of Underground Water Pipeline Performance in New Zealand (뉴질랜드 크라이스트처어치 지진에 의해 발생된 영구지반변형과 매설된 상수도관 성능평가)

  • Jeon, Sang-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4201-4207
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    • 2015
  • In this study, the performance of underground water pipeline system affected by earthquakes is examined by using data acquired after MW 6.2 February 22, 2011 earthquake in Christchurch, NZ. Water pipeline repair rates, expressed as repairs/km, for different types of pipe are evaluated inside the areas of which liquefaction induced by permanent ground deformation was observed and assessed relative to differential settlement and lateral ground strain, calculated from high resolution LiDAR data acquired before and after each seismic event. The earthquake performance of underground water pipeline systems associated with permanent ground deformation is summarized in this paper. The results show that highly ductile polyethylene water pipelines has a high earthquake performance.

Anatomical study of divergences in facial artery endings

  • Yasser Ayish Alharbi
    • Anatomy and Cell Biology
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    • v.56 no.2
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    • pp.211-218
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    • 2023
  • Despite several studies focusing on the facial arteries variable courses, the findings have significantly differed. The divergent findings have made it increasingly challenging to establish consistent correlations. Thus, as a vital artery, the facial artery is prone to numerous variations, which makes the identification of the variations vital to clinical practice, particularly for the orofacial and rhinoplastic surgery, and the increasingly selective chemotherapy procedures. The present research uses angiography images for analysis in studying the bilateral facial artery variations noted in patients undergoing carotid angiography for the evaluation of congenital anomalies, cerebral vascular malformations, and intra-arterial procedures. Conventional angiography was used, as it is a vital assessment tool that helps in the assessment of variations in the facial arteries and is suitable in evaluating smaller vascular anatomy, due to the perfect spatial resolution and portrayal of vascular anatomy. Thus, rather than normal ending of the facial artery as an angular artery, the study disclosed that in certain instances, the artery termination took the form of a superior labial artery with a small lateral nasal artery branch located closer to the midline compared to the normal cases. Also, the study has disclosed a conspicuous pre-masseteric branch with small branches originating from the infraorbital artery and providing potential compensation for the facial artery's shortness. Regardless of the infrequency of such variations, it is vital that they are considered during the performance of any facial surgical procedure.

Evaluation on Organ Dose and Image Quality of Lumbar Spine Radiography Using Glass Dosimeter (유리선량계를 이용한 요추검사의 장기선량 및 영상의 평가)

  • Kim, Jae-Kyeom;Kim, Jeong-Koo
    • Journal of radiological science and technology
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    • v.39 no.1
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    • pp.1-11
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    • 2016
  • The purpose of this study was to provide resources for medical exposure reduction through evaluation of organ dose and image resolution for lumbar spine around according to the size of the collimator in DR system. The size of the collimator were varied from $8^{\prime\prime}{\times}17^{\prime\prime}$ to $14^{\prime\prime}{\times}17^{\prime\prime}$ by 1" in AP and lateral projection for the lumbar spine radiography with RANDO phantom. The organ dose measured for liver, stomach, pancreas, kidney and gonad by the glass dosimeter. The image resolution was analyzed using the Image J program. The organ dose of around lumbar spine were reduced as the size of the collimator is decreased in AP projection. There were no significant changes decreasing rate whenever the size of the collimator were reduced 1" in the gonad. The organ dose showed higher on liver and kidney near the surface in lateral projection. There were decreasing rate of less than 5% in liver and kidney, but decreasing rate was 24.34% in the gonad whenever the size of the collimator were reduced 1". Organ dose difference for internal and external of collimator measured $549.8{\mu}Gy$ in the liver and $264.6{\mu}Gy$ in the stomach. There were no significant changes organ dose difference that measured $1,135.1{\mu}Gy$ in the gonad. Image Quality made no difference because SNR and PSNR were over than 30 dB when the collimator size is less than $9^{\prime\prime}{\times}17^{\prime\prime}$ on AP projection and $10^{\prime\prime}{\times}17^{\prime\prime}$ on lateral projection. Therefore, we are considered that the recommendations criterion for control of collimator were suggested in order to reduce unnecessary X-ray exposure and to obtain good image quality because lumbar spine radiography contains a lot of peripheral organs rather than other area radiography.

Simultaneous Multiple Transmit Focusing Method with Orthogonal Chirp Signal for Ultrasound Imaging System (초음파 영상 장치에서 직교 쳐프 신호를 이용한 동시 다중 송신집속 기법)

  • 정영관;송태경
    • Journal of Biomedical Engineering Research
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    • v.23 no.1
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    • pp.49-60
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    • 2002
  • Receive dynamic focusing with an array transducer can provide near optimum resolution only in the vicinity of transmit focal depth. A customary method to increase the depth of field is to combine several beams with different focal depths, with an accompanying decrease in the frame rate. In this Paper. we Present a simultaneous multiple transmit focusing method in which chirp signals focused at different depths are transmitted at the same time. These chirp signals are mutually orthogonal in a sense that the autocorrelation function of each signal has a narrow mainlobe width and low sidelobe levels. and the crossorelation function of any Pair of the signals has values smaller than the sidelobe levels of each autocorrelation function. This means that each chirp signal can be separated from the combined received signals and compressed into a short pulse. which is then individually focused on a separate receive beamformer. Next. the individually focused beams are combined to form a frame of image. Theoretically, any two chirp signals defined over two nonoverlapped frequency bands are mutually orthogonal In the present work. however, a tractional overlap of adjacent frequency bands is permitted to design more chirp signals within a given transducer bandwidth. The elevation of the rosscorrelation values due to the frequency overlap could be reduced by alternating the direction of frequency sweep of the adjacent chirp signals We also observe that the Proposed method provides better images when the low frequency chirp is focused at a near Point and the high frequency chirp at a far point along the depth. better lateral resolution is obtained at the far field with reasonable SNR due to the SNR gain in Pulse compression Imaging .