• 제목/요약/키워드: Magnetic Resonance Method

검색결과 878건 처리시간 0.036초

Diagnostic Accuracy of Magnetic Resonance Imaging versus Clinical Staging in Cervical Cancer

  • Shirazi, Ahmad Soltani;Razi, Taghi;Cheraghi, Fatemeh;Rahim, Fakher;Ehsani, Sara;Davoodi, Mohammad
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권14호
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    • pp.5729-5732
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    • 2014
  • Background: Cervical cancer is the third most common gynecological cancer and a widespread malignancy in women, accounting for a large proportion of the cancer burden in developing countries. We compared accuracy of MRI staging with clinical staging and also concordance between the two methods for newly diagnosed patients with cervical cancer, using clinical staging as the reference. Materials and Methods: This prospective study was conducted on 27 newly diagnosed patients with cervical cancer from Imam Khomeini hospital from June 2012 to Feb 2014. New cases of cervical cancer with positive PAP test were staged separately with a clinical exam based on the FIGO system by a gynecologist, oncologist and also with MRI by an expert radiologist. Then we compared the predicted stage for each patient with the two methods. Results: Based on clinical staging 9 patients (33%) were observed at stage 1. MRI staging was in coordination with clinical staging in eight of them and for one patient MRI accorded stage 2B (88% concordance). Conclusions: MRI is a reliable noninvasive method with high accuracy for cervical cancer staging. Also presently it is easily obtainable, so we recommend using this technique along with clinical examination for staging cervical cancer patients. We also recommend to radiologists and residents of radiology to get experience with this method of staging.

Gamma Knife Radiosurgery after Stereotactic Aspiration for Large Cystic Brain Metastases

  • Park, Won-Hyoung;Jang, In-Seok;Kim, Chang-Jin;Kwon, Do-Hoon
    • Journal of Korean Neurosurgical Society
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    • 제46권4호
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    • pp.360-364
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    • 2009
  • Objective : Several treatment options have proven effective for metastatic brain tumors, including surgery and stereotactic radiosurgery. Tumors with cystic components, however, are difficult to treat using a single method. We retrospectively assessed the outcome and efficacy of gamma knife radiosurgery (GKRS) for cystic brain metastases after stereotactic aspiration of cystic components to decrease the tumor volume. Methods : The study population consisted of 24 patients (13 males, 11 females; mean age, 58.3 years) with cystic metastatic brain tumors treated from January 2002 to August 2008. Non-small cell lung cancer was the most common primary origin. After Leksell stereotactic frame was positioned on each patient, magnetic resonance images (MRI)-guided stereotactic cyst aspiration and GKRS were performed (mean prescription dose : 20.2 Gy). After treatment, patients were evaluated by MRI every 3 or 4 months. Results : After treatment, 13 patients (54.2%) demonstrated tumor control, 5 patients (20.8%) showed local tumor progression, and 6 patients (25.0%) showed remote progression. Mean follow-up duration was 13.1 months. During this period, 10 patients (41.7%) died, but only 1 patient (4.2%) died from brain metastases. The overall median survival after these procedures was 17.8 months. Conclusion : These results support the usefulness of GKRS after stereotactic cyst aspiration in patients with large cystic brain metastases. This method is especially effective for the patients whose general condition is very poor for general anesthesia and those with metastatic brain tumors located in eloquent areas.

심전도 게이트 심근관류 Tl-201 SPECT로 측정된 좌심실 기능 및 좌심실 용적의 정확성 (Accuracy of Ventricular Volume and Ejection Fraction Measured by Gated Tl-201 Perfusion Single Photon Emission Tomography)

  • 배문선;문대혁
    • 대한핵의학회지
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    • 제39권2호
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    • pp.94-99
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    • 2005
  • Electrocardiogram-gated single photon omission computed tomography (SPECT) provides valuable information in the assessment of both myocardial perfusion and ventricular function. Tl-201 is a suboptimal isotope for gating. Tl-201 images are more blurred compared with Tc-99m tracers due to the increased amount of scattered photons and use of a smooth filter. The average myocardial count densities are approximately one-half those of conventional technetium tracers. However, Tl-201 is still widely used because of its well-established utility for assessing myocardial perfusion, viability and risk stratification. Gated SPECT with Tl-201 enables us to assess both post-stress and rest left ventricular volume and function. Previous studies with gated Tl-201 SPECT measurements of ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV) have shown high correlation with first-pass radionuclide angiography, gated blood pool scan, Tc-99m-MIBI gated SPECT, contrast ventriculography, echocardiography, and 3-dimensional magnetic resonance imaging. However, problems related to these studies include few agreement data of EDV and ESV, use of a reference method that is likely to have the same systemic errors (gated Tc-99m-MIBI SPECT), and other technical factors related to the count density of gated SPECT. With optimization of gated imaging protocols and more validation studies, gated Tl-201 SPECT would be an accurate method to provide perfusion and function information in patients with coronary artery disease.

동적 초음파를 이용하여 진단한 주관절 척골 신경 아탈구 (Ulnar Nerve Subluxation Diagnosed by Dynamic Ultrasonography)

  • 지종훈;정재중;김영율;강현택;박상은;김동진
    • 대한정형외과 초음파학회지
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    • 제3권2호
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    • pp.79-83
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    • 2010
  • 근골격계 초음파는 오랜 기간 동안 다양한 정형외과적 질환의 진단을 위해 유용하고 간단한 방법으로 사용되어 왔다. 일반적으로 MRI가 해부학적 구조나 변이를 발견하기 위한 가장 좋은 방법으로 알려져 있으나 건이나 신경의 탈구 또는 아탈구 등과 같은 동적인 조건의 경우에는 초음파, 특히 동적 초음파의 유용성에는 미치지 못하는 것으로 알려져 있다. 본원에서는 주관 증후군 유사 증상을 보인 환자에서 동적 초음파 검사를 이용하여 척골 신경 아탈구를 확인한 후, 척골 신경 이전술을 시행하여 만족스러운 결과를 보여, 주관 증후군과 유사한 증상을 유발하는 척골 신경 아탈구 환자에게 동적 초음파의 이용은 매우 유용한 방법으로 생각하여 그 증례를 보고하고자 한다.

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초음파 전립선 영상에서 전립선 경계 분할을 위한 평균 형상 모델 (An Average Shape Model for Segmenting Prostate Boundary of TRUS Prostate Image)

  • 김상복;정주영;서영건
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제3권5호
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    • pp.187-194
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    • 2014
  • 전립선암은 전립선에 나타나는 악성 종양이다. 현재 그 발병률이 높아지고 있다. 전립선암의 구조를 가장 정확하게 확인할 수 있는 검사 방법은 MRI를 이용하는 것이나, 그 비용 때문에 모든 환자에게 적용하기는 어려운 실정이다. 그래서 많은 환자들은 가격이 저렴한 초음파검사를 이용하여 전립선암을 진단하고 있다. 전통적으로 의사들은 영상을 눈으로 확인하여 전립선의 경계를 수동으로 분할하였다. 그러나 수동으로 분할하는 과정은 시간이 많이 소요되며, 의사에 따라서 그 경계가 일정하지 않게 얻어진다. 이 문제를 해결하기 위하여 전립선의 자동 분할에 관한 연구가 되었고, 환자들에게 신뢰를 줄 수 있었다. 본 연구는 초음파 전립선 영상에서 전립선의 경계를 분할하는데 평균 형상 모델을 적용하는 것이다. 먼저, 에지 분포를 이용하여 프로브를 찾고, 프로브와 연결된 두 직선을 찾는다. 이 후에 이 정보를 이용하여 전립선 영상 위에 평균 형상을 위치시킨다.

Polystyrene-b-poly(oligo(ethylene oxide) Monomethyl Ether Methacrylate)-b-polystyrene Triblock Copolymers as Potential Carriers for Hydrophobic Drugs

  • You, Qianqian;Chang, Haibo;Guo, Qipeng;Zhang, Yudong;Zhang, Puyu
    • Bulletin of the Korean Chemical Society
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    • 제34권2호
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    • pp.558-564
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    • 2013
  • A simple and effective method is introduced to synthesize a series of polystyrene-b-poly(oligo(ethylene oxide) monomethyl ether methacrylate)-b-polystyrene (PSt-b-POEOMA-b-PSt) triblock copolymers. The structures of PSt-b-POEOMA-b-PSt copolymers were characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance ($^1H$ NMR) spectroscopy. The molecular weight and molecular weight distribution of the copolymer were measured by gel permeation chromatography (GPC). Furthermore, the self-assembling and drug-loaded behaviours of three different ratios of PSt-b-POEOMA-b-PSt were studied. These copolymers could readily self-assemble into micelles in aqueous solution. The vitamin E-loaded copolymer micelles were produced by the dialysis method. The micelle size and core-shell structure of the block copolymer micelles and the drug-loaded micelles were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The thermal properties of the copolymer micelles before and after drug-loaded were investigated by different scanning calorimetry (DSC). The results show that the micelle size is slightly increased with increasing the content of hydrophobic segments and the micelles are still core-shell spherical structures after drug-loaded. Moreover, the glass transition temperature (Tg) of polystyrene is reduced after the drug loaded. The drug loading content (DLC) of the copolymer micelles is 70%-80% by ultraviolet (UV) photolithography analysis. These properties indicate the micelles self-assembled from PSt-b-POEOMA-b-PSt copolymers would have potential as carriers for the encapsulation of hydrophobic drugs.

Spin Wave Interference in Magnetic Nanostructures

  • Yang, Hyun-Soo;Kwon, Jae-Hyun;Mukherjee, Sankha Subhra;Jamali, Mahdi;Hayashi, Masamitsu
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2011년도 자성 및 자성재료 국제학술대회
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    • pp.7-8
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    • 2011
  • Although yttrium iron garnet (YIG) has provided a great vehicle for the study of spin waves in the past, associated difficulties in film deposition and device fabrication using YIG had limited the applicability of spin waves to practical devices. However, microfabrication techniques have made it possible to characterize both the resonant as well as the travelling characteristics of spin waves in permalloy (Py). A variety of methods have been used for measuring spin waves, including Brillouin light scattering (BLS), magneto-optic Kerr effect (MOKE), vector network analyzer ferromagnetic resonance (VNA-FMR), and pulse inductive microwave magnetometry (PIMM). PIMM is one of the most preferred methodologies of measuring travelling spin waves. In this method, an electrical impulse is applied at one of two coplanar waveguides patterned on top of oxide-insulated Py, producing a local disturbance in the magnetization of the Py. The resulting disturbance travels down the Py in the form of waves, and is inductively picked up by the other coplanar waveguide. We investigate the effect of the pulse width of excitation pulses on the generated spin wave packets using both experimental results and micromagnetic simulations. We show that spin wave packets generated from electrical pulses are a superposition of two separate spin wave packets, one generated from the rising edge and the other from the falling edge, which interfere either constructively or destructively with one another, depending upon the magnitude and direction of the field bias conditions. A method of spin wave amplitude modulation is also presented by the linear superposition of spin waves. We use interfering spin waves resulting from two closely spaced voltage impulses for the modulation of the magnitude of the resultant spin wave packets.

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영역 성장 분할 기법을 이용한 무손실 영상 압축 (Region-Growing Segmentation Algorithm for Rossless Image Compression to High-Resolution Medical Image)

  • 박정선;김길중;전계록
    • 융합신호처리학회논문지
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    • 제3권1호
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    • pp.33-40
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    • 2002
  • 본 연구에서는 의료영상 저장 및 전송 시스템에 필수적인 무손실 의료영상 압축 기법을 제안하였다. 의료영상은 방사선 영상 중에서 유방영상(mammography)과 자기공명영상을 사용하였으며, 이들 영상을 무손실로 압축하기 위하여 영역성장에 의한 영상분할 알고리듬을 제안하였다. 제안된 알고리듬은 원 영상이 에러 영상과 불연속 계수 영상, 그리고 상위 비트 데이터 등 세 가지의 부 영역으로 분할되도록 하였다. 그리고 영역성장 과정 후 생성된 불연속 계수 영상 데이터와 에러 영상을 국제 이진영상압축 표준이며 그레이코드(graycode)화된 영상의 압축에 적합한 JBIG(Joint Bi-level Image expert Group) 알고리듬을 이용하여 압축시켰다. 제안한 알고리듬과 타 연구에서 사용된 기법들을 비교 검토 한 결과 제안한 무손실 압축 기법을 적용하여 얻어지는 압축율은 JBIG, JPEG, LZ 기법에 비해 평균적으로 각각 3.7%, 7.9%, 23.6% 정도 개선됨을 알 수 있었다.

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소리쟁이 뿌리로부터 세포독성물질 분리 및 정제 (Purification and Identification of Cytotoxic Compounds from the Root of Rumex crispus L.)

  • 조용범;김재연;권남우;황방연;김준구;우선희;이문순
    • 한국약용작물학회지
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    • 제27권3호
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    • pp.208-217
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    • 2019
  • Background: In the present study, we identified two cytotoxic compounds from the root of Rumex crispus L. using a bioassay-based method. Methods and Results: Compared with the other fractions, the diethyl ether ($Et_2O$) fraction of R. crispus root extract exhibited the strongest of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging effect [scavenging concentration 50% $(SC_{50})=63.8{\pm}1.47{\mu}g/m{\ell}$], nitric oxide (NO) production inhibitory effect on the mouse macrophage cell line RAW264.7 [inhibitory concentration 50% $(IC_{50})=60.9{\pm}7.52{\mu}g/m{\ell}$] and cytotoxicity effect on the human hepatoma cell line, HepG2 [lethal concentration 50% $(LC_{50})=115.4{\pm}1.86{\mu}g/m{\ell}$]. According to the bioassay-based method, two cytotoxic compounds were purified from the $Et_2O$ fraction by using column chromatography and preparative high performance liquid chromatography (prep-HPLC). These two compounds were identified as parietin and chrysophanol by using nuclear magnetic resonance (NMR) and liquid chromatography quadruple time of flight mass spectrometry (LC-QTOF-MS). In addition, both parietin and chrysophanol exhibited a cytotoxicity effect on HepG2 cells, their $LC_{50}$ values were $169.1{\pm}17.67{\mu}M$ and $111.5{\pm}6.62{\mu}M$, respectively. Conclusions: Parietin and chrysophanol isolated from the $Et_2O$ fraction of the R. crispus root extract showed cytotoxicity in HepG2 cell.

Reliability of Quantifying Maximal Mouth Opening and Lateral Mandibular Shift in Individuals With and Without Temporomandibular Disorder Using Three-dimensional Ultrasound-based Motion Analysis

  • Oh, Jae-seop;Kim, Si-hyun;Kyung, Moon-su;Park, Kyue-nam
    • 한국전문물리치료학회지
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    • 제26권3호
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    • pp.99-105
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    • 2019
  • Background: Although magnetic resonance imaging is accurate, it is expensive to measure the movement of temporomandibular joint. The three-dimensional (3D) motion analysis system is an inexpensive measurement tool. Objects: This study examined the reliability of quantifying the mouth opening and lateral mandibular shift and differences between individuals with and without temporomandibular disorder (TMD) using the hygienic method of surface markers on the skin with 3D ultrasound-based motion analysis. Methods: This study included 24 subjects (12 with and 12 without TMD). Temporomandibular joint motion during mouth opening was recorded using two surface markers with 3D ultrasound-based motion analysis. An intraclass correlation coefficient [ICC (3,k)] was used to confirm the intrarater reliability of quantifying kinematic temporomandibular joint motion, and an independent t-test was used to evaluate differences in maximal mouth opening and lateral mandibular shift between the two groups. Results: Assessment of mouth opening and lateral mandibular shift showed excellent test-retest reliability with low standard error of measurement. The lateral mandibular shift and opening-lateral mandibular shift ratio were significantly increased in the TMD group during maximum mouth opening (p<.05). However, no significant difference in maximal mouth opening was observed between the groups with and without TMD (p>.05). Conclusion: This hygienic and simple surface marker method can be used to quantify the mouth opening and lateral mandibular shift at the end-range of mouth opening. The TMD group showed an increased lateral mandibular shift movement at the end-range of mouth opening. The lateral mandibular shift movement can be regarded as a symptom in the diagnosis and treatment of TMD.