• 제목/요약/키워드: three-dimensional imaging

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Unilateral C1 Lateral Mass and C2 Pedicle Screw Fixation for Atlantoaxial Instability in Rheumatoid Arthritis Patients : Comparison with the Bilateral Method

  • Paik, Seung-Chull;Chun, Hyoung-Joon;Bak, Koang Hum;Ryu, Jeil;Choi, Kyu-Sun
    • Journal of Korean Neurosurgical Society
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    • 제57권6호
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    • pp.460-464
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    • 2015
  • Objective : Bilateral C1 lateral mass and C2 pedicle screw fixation (C1LM-C2P) is an ideal technique for correcting atlantoaxial instability (AAI). However, the inevitable situation of vertebral artery injury or unfavorable bone structure may necessitate the use of unilateral C1LM-C2P. This study compares the fusion rates of the C1 lateral mass and C2 pedicle screw in the unilateral and bilateral methods. Methods : Over five years, C1LM-C2P was performed in 25 patients with AAI in our institute. Preoperative studies including cervical X-ray, three-dimensional computed tomography (CT), CT angiogram, and magnetic resonance imaging were performed. To evaluate bony fusion, measurements of the atlanto-dental interval (ADI) and CT scans were performed in the preoperative period, immediate postoperative period, and postoperatively at 1, 3, 6, and 12 months. Results : Unilateral C1LM-C2P was performed in 11 patients (44%). The need to perform unilateral C1LM-C2P was due to anomalous course of the vertebral artery in eight patients (73%) and severe degenerative arthritis in three patients (27%). The mean ADI in the bilateral group was 2.09 mm in the immediate postoperative period and 1.75 mm in 12-months postoperatively. The mean ADI in the unilateral group was 1.82 mm in the immediate postoperative period and 1.91 mm in 12-months postoperatively. Comparison of ADI measurements showed no significant differences in either group (p=0.893), and the fusion rate was 100% in both groups. Conclusion : Although bilateral C1LM-C2P is effective for AAI from a biomechanical perspective, unilateral screw fixation is a useful alternative in patients with anatomical variations.

Image-guided navigation surgery for bilateral choanal atresia with a Tessier number 3 facial cleft in an adult

  • Sung, Ji Yoon;Cho, Kyu-Sup;Bae, Yong Chan;Bae, Seong Hwan
    • 대한두개안면성형외과학회지
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    • 제21권1호
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    • pp.64-68
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    • 2020
  • The coexistence of craniofacial cleft and bilateral choanal atresia has only been reported in three cases in the literature, and only one of those cases involved a Tessier number 3 facial cleft. It is also rare for bilateral choanal atresia to be found in adulthood, with 10 previous cases reported in the literature. This report presents the case of a 19-year-old woman with a Tessier number 3 facial cleft who was diagnosed with bilateral choanal atresia in adulthood. At first, the diagnosis of bilateral choanal atresia was missed and septoplasty was performed. After septoplasty, the patient's symptoms did not improve, and an endoscopic examination revealed previously unnoticed bilateral choanal atresia. Computed tomography showed left membranous atresia and right bony atresia. The patient underwent an operation for opening and widening of the left choana with an image-guided navigation system (IGNS), which enabled accurate localization of the lesion while ensuring patient safety. Postoperatively, the patient became able to engage in nasal breathing and reported that it was easier for her to breathe, and there were no signs of restenosis at a 26-month follow-up. The patient was successfully treated with an IGNS.

돼지 하악 과두의 해면골에서 유한요소분석법으로 예측한 방향에 따른 탄성율과 3차원 골 미세지표 간의 상관관계 (The relationship between 3D bone architectural parameters and elastic moduli of three orthogonal directions predicted from finite elements analysis)

  • 박관수;이삼선;허경회;이원진;허민석;최순철
    • Imaging Science in Dentistry
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    • 제38권2호
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    • pp.81-87
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    • 2008
  • Purpose: To investigate the relationship between 3D bone architectural parameters and direction-related elastic moduli of cancellous bone of mandibular condyle. Materials and Methods: Two micro-pigs (Micro-$pig^R$, PWG Genetics Korea) were used. Each pig was about 12 months old and weighing around 44 kg. 31 cylindrical bone specimen were obtained from cancellous bone of condyles for 3D analysis and measured by micro-computed tomography. Six parameters were trabecular thickness (Tb. Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI), degree of anisotropy (DA) and 3-dimensional fractal dimension (3DFD). Elastic moduli of three orthogonal directions (superior-inferior (SI), medial-lateral (ML), andterior-posterior (AP) direction) were calculated through finite element analysis. Results: Elastic modulus of superior-inferior direction was higher than those of other directions. Elastic moduli of 3 orthogonal directions showed different correlation with 3D architectural parameters. Elastic moduli of SI and ML directions showed significant strong to moderate correlation with BV/TV, SMI and 3DFD. Conclusion: Elastic modulus of cancellous bone of pig mandibular condyle was highest in the SI direction and it was supposed that the change into plate-like structure of trabeculae was mainly affected by increase of trabeculae of SI and ML directions.

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시공 분할방식을 이용한 다시점 삼차원 디스플레이 시스템의 설계 (Designing a kmultiview 3D display system based on a spatiotemporal multiplexing)

  • 손정영;김재순;전호인
    • 한국광학회지
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    • 제9권6호
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    • pp.368-372
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    • 1998
  • 2개의 시분할 8시점 영상 채널을 공간적으로 시역을 결합시킴에 의해 16시점 3차원 영상 시스템을 설계했다. 각각의 8시점 채널을 빛의 3원색(빨강, 초록 그리고 파랑)에 대응하는 빛을 발산하는 3개의 CRT들을 한 개의 채널로 결합해주는 이색 빔 분할기(dichroic beam splitter)로 이루어져 있고 각각의 CRT는 8시점의 영상을 시간분할 방식에 의해 표시하며, 각 채널별 영상은 투사광학계를 통과하여 1$\times$0.8$m^2$ 크기의 홀로그래픽 스크린에 투영된다. 이 시스템을 위한 최적 투사광학계를 설계하기 위해 시스템에 적용 가능한 3개의 서로 다른 투사광학계에 대해 그 특성을 광학 설계 프로그램인“ DEMOS ”를 사용하여 시험했다. 설계 시스템의 최적 투사광학계는 각 채널별 영상을 양면 반사경(two-folded mirror)에 의해 결합하여 16개의 띠형 액정 셔터로 구성된 한 개의 LCD 셔터를 통해 투사용 대물렌즈로 입사시키는 구조를 가지는 것이 최적임을 보였다. 단 이 구조에서 셔터는 투사용 대물렌즈의 입력개구(entrance pupil)에 위치해야하며, 양면 반사경의 접혀진 선은 이 셔터의 중심과 맞닿아 대칭이 되도록 위치해야 한다.

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간정격 및 간승격 자침이 정상 성인의 맥파에 미치는 영향 비교 연구 (The Effects of Sa-am Acupuncture on Radial Pulse in Healthy Human Subjects: A Comparative Study of Liver Tonifying and Sedating)

  • 육동일;전주현;김영일;김정호
    • Journal of Acupuncture Research
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    • 제32권2호
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    • pp.169-185
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    • 2015
  • Objectives : The purpose of this study is to find the effects of Sa-am liver tonifying and sedating acupuncture on radial pulse. Methods : Sixty healthy people were divided into a liver tonifying acupuncture(LTA) group, liver sedating acupuncture(LSA) group, and control group. The LTA group and LSA group received acupuncture for 20 minutes with a supine position. The Control group took a rest without receiving acupuncture. Radial pulse was measured by three dimensional pulse imaging system(DMP-3000) at four different time points (before, right after, 30 minutes after, and 60 minutes after acupuncture). We compared the three groups and figure out determined the parameters which significantly changed after acupuncture treatment. Results : 1. Pulse period, T1/T, T4/T, (T-T4)/T, T4/(T-T4), T5/T significantly changed after acupuncture. 2. H4, pulse area, systolic pulse area, diastolic pulse area, radial augmentation index(RAI), and pulse power volume / min significantly changed after acupuncture. 3. Frequency of Fourier components, ratio of frequencies of Fourier components, magnitude of Fourier components, and ratio of magnitudes of Fourier components significantly changed after acupuncture. Conclusions : LTA and LSA have an effect on the radial pulse parameters. Further studies on radial pulse change using Sa-Am acupuncture are needed.

Inter- and Intra-Observer Variability of the Volume of Cervical Ossification of the Posterior Longitudinal Ligament Using Medical Image Processing Software

  • Shin, Dong Ah;Ji, Gyu Yeul;Oh, Chang Hyun;Kim, Keung Nyun;Yoon, Do Heum;Shin, Hyunchul
    • Journal of Korean Neurosurgical Society
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    • 제60권4호
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    • pp.441-447
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    • 2017
  • Objective : Computed tomography (CT)-based method of three dimensional (3D) analysis ($MIMICS^{(R)}$, Materialise, Leuven, Belgium) is reported as very useful software for evaluation of OPLL, but its reliability and reproducibility are obscure. This study was conducted to evaluate the accuracy of $MIMICS^{(R)}$ system, and inter- and intra-observer reliability in the measurement of OPLL. Methods : Three neurosurgeons independently analyzed the randomly selected 10 OPLL cases with medical image processing software ($MIMICS^{(R)}$) which create 3D model with Digital Imaging and Communication in Medicine (DICOM) data from CT images after brief explanation was given to examiners before the image construction steps. To assess the reliability of inter- and intra-examiner intraclass correlation coefficient (ICC), 3 examiners measured 4 parameters (volume, length, width, and length) in 10 cases 2 times with 1-week interval. Results : The inter-examiner ICCs among 3 examiners were 0.996 (95% confidence interval [CI], 0.987-0.999) for volume measurement, 0.973 (95% CI, 0.907-0.978) for thickness, 0.969 (95% CI, 0.895-0.993) for width, and 0.995 (95% CI, 0.983-0.999) for length. The intra-examiner ICCs were 0.994 (range, 0.991-0.996) for volume, 0.996 (range, 0.944-0.998) for length, 0.930 (range, 0.873-0.947) for width, and 0.987 (range, 0.985-0.995) for length. Conclusion : The medical image processing software ($MIMICS^{(R)}$) provided detailed quantification OPLL volume with minimal error of inter- and intra-observer reliability in the measurement of OPLL.

Photoacoustic lymphangiography before and after lymphaticovenular anastomosis

  • Oh, Anna;Kajita, Hiroki;Matoba, Eri;Okabe, Keisuke;Sakuma, Hisashi;Imanishi, Nobuaki;Takatsume, Yoshifumi;Kono, Hikaru;Asao, Yasufumi;Yagi, Takayuki;Aiso, Sadakazu;Kishi, Kazuo
    • Archives of Plastic Surgery
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    • 제48권3호
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    • pp.323-328
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    • 2021
  • Background Lymphaticovenular anastomosis (LVA) is a minimally invasive surgical procedure used to treat lymphedema. Volumetric measurements and quality-of-life assessments are often performed to assess the effectiveness of LVA, but there is no method that provides information regarding postoperative morphological changes in lymphatic vessels and veins after LVA. Photoacoustic lymphangiography (PAL) is an optical imaging technique that visualizes the distribution of light-absorbing molecules, such as hemoglobin or indocyanine green (ICG), and provides three-dimensional images of superficial lymphatic vessels and the venous system simultaneously. In this study, we performed PAL in lymphedema patients before and after LVA and compared the images to evaluate the effect of LVA. Methods PAL was performed using the PAI-05 system in three patients (one man, two women) with lymphedema, including one primary case and two secondary cases, before LVA. ICG fluorescence lymphography was performed in all cases before PAL. Follow-up PAL was performed between 5 days and 5 months after LVA. Results PAL enabled the simultaneous visualization of clear lymphatic vessels that could not be accurately seen with ICG fluorescence lymphography and veins. We were also able to observe and analyze morphological changes such as the width and the number of lymphatic vessels and veins during the follow-up PAL after LVA. Conclusions By comparing preoperative and postoperative PAL images, it was possible to analyze the morphological changes in lymphatic vessels and veins that occurred after LVA. Our study suggests that PAL would be useful when assessing the effect of LVA surgery.

대학생의 배가로근과 뭇갈래근 두께와 척추정렬간의 상관관계 (Correlations between the Muscle Thickness of the Transverse Abdominis and the Multifidus Muscle with Spinal Alignment in College Students)

  • 임재헌
    • PNF and Movement
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    • 제12권4호
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    • pp.243-248
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    • 2014
  • Purpose: The transverse abdominis and themultifidus muscle are located in the core. They surround one's trunk and help in body stabilization. Specifically, they control spine articulation to maintain posture and balance. Therefore, weakened deep muscle in the trunk may cause spinal malalignment. This study aims to compare the correlation between the thickness of the transverse abdominis and the multifidus muscle and the spine alignment among college students in their 20s. Methods: This study measured the thickness of the transverse abdominis and the multifidus muscle of 42 healthy college students in their 20s using ultrasonic waves. The thickness of the muscle was measured for the length of the cross-section except for fascia. The thickness of the left and right muscles was measured, and the mean value was calculated. As the thickness of the transverse abdominis can increase because of pressure during exhalation, it was measured at the last moment of exhalation. Spinal alignment was measured by the kyphosis angle, lordosis angle, pelvic tilt, trunk inclination, lateral deviation, trunk imbalance, and surface rotation using Formetric III, which is a three-dimensional imaging equipment. They were measured for three times, and the mean values were calculated. The general characteristics of the subjects were analyzed using descriptive statistics. The correlations between each factor were analyzed using Pearson's correlation analysis. Results: The transverse abdominis showed asignificant correlation with trunk inclination (p<.05). The multifidus muscle showed a significant positive correlation with pelvic tilt and a negative correlation with surface rotation (p<.05). Conclusion: The thickness of transverse abdominis and the multifidus muscle appears to influence spinal alignment. Specifically, the multifidus muscle, which plays an important role on the sagittal plane, influences surface rotation, thus making it an important muscle for scoliosis patients. Therefore, a strengthening training program for the transverse abdominis and the multifidus muscle is necessary according to specific purposes among adults with spinal malalignment.

딥러닝 기반 균열 추출 기법을 통한 수압 파쇄 균열 형상 분석 (Morphological Analysis of Hydraulically Stimulated Fractures by Deep-Learning Segmentation Method)

  • 박지민;김광염;윤태섭
    • 한국지반공학회논문집
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    • 제39권8호
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    • pp.17-28
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    • 2023
  • 본 연구에서는 화강암 시편을 대상으로 파쇄 유체의 점성과 주입 속도를 변화시키며 실내 수압 파쇄 실험을 수행하였고, 3D X-ray CT 촬영을 통해 파쇄 후 시편 내부를 관찰하였다. 이미지 처리에 탁월한 성능을 보이는 합성곱 신경망(Convolutional Neural Network, CNN) 기반 Nested U-Net 모델 구조를 활용하여 CT 이미지 내 수압 파쇄 균열 추출을 수행하였고, 복잡한 형상의 미세균열을 정교하게 추출할 수 있었다. CNN 기반 모델로 추출된 균열을 3차원으로 재구성하여 균열의 부피, 두께, 굴곡도, 균열면 거칠기를 분석하였다. 그 결과 파쇄 유체의 점성이 클수록 균열 부피와 두께가 증가하였고, 굴곡도와 균열면의 거칠기가 감소하는 경향을 보였다. 또한 균열면의 굴곡도와 거칠기 이방성이 존재함을 확인할 수 있었다. 본 연구는, CNN 기반의 균열 추출 모델을 활용해 전통적인 이미지 처리 방법보다 정교한 균열 추출을 수행하고, 이를 기반으로 수압 파쇄 균열의 정량 분석을 성공적으로 수행하였다.

Colloidal Optics and Photonics: Photonic Crystals, Plasmonics, and Metamaterials

  • Jaewon Lee;Seungwoo Lee
    • Current Optics and Photonics
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    • 제7권6호
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    • pp.608-637
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    • 2023
  • The initial motivation in colloid science and engineering was driven by the fact that colloids can serve as excellent models to study atomic and molecular behavior at the mesoscale or microscale. The thermal behaviors of actual atoms and molecules are similar to those of colloids at the mesoscale or microscale, with the primary distinction being the slower dynamics of the latter. While atoms and molecules are challenging to observe directly in situ, colloidal motions can be easily monitored in situ using simple and versatile optical microscopic imaging. This foundational approach in colloid research persisted until the 1980s, and began to be extensively implemented in optics and photonics research in the 1990s. This shift in research direction was brought by an interplay of several factors. In 1987, Yablonovitch and John modernized the concept of photonic crystals (initially conceptualized by Lord Rayleigh in 1887). Around this time, mesoscale dielectric colloids, which were predominantly in a suspended state, began to be self-assembled into three-dimensional (3D) crystals. For photonic crystals operating at optical frequencies (visible to near-infrared), mesoscale crystal units are needed. At that time, no manufacturing process could achieve this, except through colloidal self-assembly. This convergence of the thirst for advances in optics and photonics and the interest in the expanding field of colloids led to a significant shift in the research paradigm of colloids. Initially limited to polymers and ceramics, colloidal elements subsequently expanded to include semiconductors, metals, and DNA after the year 2000. As a result, the application of colloids extended beyond dielectric-based photonic crystals to encompass plasmonics, metamaterials, and metasurfaces, shaping the present field of colloidal optics and photonics. In this review we aim to introduce the research trajectory of colloidal optics and photonics over the past three decades; To elucidate the utility of colloids in photonic crystals, plasmonics, and metamaterials; And to present the challenges that must be overcome and potential research prospects for the future.