• 한국정보통신학회논문지
• /
• 제24권9호
• /
• pp.1138-1143
• /
• 2020

복부 분야 MRI 검사는 호흡에 의한 인공물로 인해 최적의 영상 구현이 어렵다. 복부 MRI 검사를 받은 총 45명 (남자:여자 = 30:15) 중 호흡이 일정하지 않아 검사가 어려운 환자를 대상으로 메트로놈을 이용한 검사 방법에 대하여 연구 하였다. 메트로놈을 사용하지 않고 검사 한 영상을 A 그룹, 메트로놈을 사용하여 검사 한 영상을 B그룹으로 나누었다. 메트로놈을 사용한 영상에서 화질 향상이 약 30% 증대 되었고, 검사시간이 약 50초 감소되었다. 복부자기공명영상(ABD MRI) 검사 시 메트로놈(Metronome)을 사용하여 검사 한 영상이 사용하지 않은 영상에 비하여 화질과 검사시간 차이가 있었다. 호흡동조가 어려운 환자의 호흡 유도 하(RTr Scan) 복부 자기 공명 영상(Abdomen MRI) 검사 시 환자의 호흡수를 조절하는 메트로놈 (Metronome) 보조기를 사용하면 더 효과적이다.

• 대한영상의학회지
• /
• 제85권2호
• /
• pp.345-362
• /
• 2024

자기공명영상(이하 MRI)은 복부 영상에서 국소 병변의 감지와 특성을 찾을 수 있는 것 때문에 중요한 역할을 한다. 그러나 MRI 검사에 상대적으로 긴 검사 시간과 호흡 유지 기법에서 움직임 관리와 같은 몇 가지 힘든 요인이 있다. 최근에는 검사 시간을 줄이면서 적절한 이미지 품질을 유지하는 기법인 평행 이미징, 압축 감지(compressed sensing) 및 최첨단 딥 러닝(deep learning) 기술이 등장하여 문제 해결 전략을 가능하게 하고 있다. 또한, 역동적 조영증강 영상에서 자유 호흡 기법은, 추가 차원(extra-dimensional)-부피 보간 호흡 유지 검사(volumetric interpolated breath-hold examination) 및 황금 각도 방사형 희소 병렬(golden-angle radial sparse parallel), 간 가속 볼륨 획득(liver acceleration volume acquisition) 스타와 같은, 심한 호흡곤란이나 마취 중인 환자에게서 복부 MRI를 시행하는 것을 돕는다. 이 임상화보에서는 시간을 줄이면서도 이미지 품질을 유지하기 위한 다양한 고급 복부 MRI 기술과 역동적 영상을 위한 자유 호흡 기술을 제시하고 또한 이를 통한 예시들을 보여주고자 한다. 이러한 첨단 기법들의 고찰은 적용된 시퀀스의 적절한 해석에 도움을 줄 것이다.

• Investigative Magnetic Resonance Imaging
• /
• 제25권4호
• /
• pp.313-322
• /
• 2021

Purpose: To find diagnostic image features, to compare diagnostic performance of multiphase CT versus gadoxetic acid disodium-enhanced MRI (GAD-MRI), and to evaluate the impact of analyzing Liver Imaging Reporting and Data System (LI-RADS) imaging features, for distinguishing combined hepatocellular-cholangiocarcinoma (CHC) from hepatocellular carcinoma (HCC). Materials and Methods: Ninety-six patients with pathologically proven CHC (n = 48) or HCC (n = 48), diagnosed June 2008 to May 2018 were retrospectively analyzed in random order by three radiologists with different experience levels. In the first analysis, the readers independently determined the probability of CHC based on their own knowledge and experiences. In the second analysis, they evaluated imaging features defined in LI-RADS 2018. Area under the curve (AUC) values for CHC diagnosis were compared between CT and MRI, and between the first and second analyses. Interobserver agreement was assessed using Cohen's weighted κ values. Results: Targetoid LR-M image features showed better specificities and positive predictive values (PPV) than the others. Among them, rim arterial phase hyperenhancement had the highest specificity and PPV. Average sensitivity, specificity, and AUC values were higher for MRI than for CT in both the first (P = 0.008, 0.005, 0.002, respectively) and second (P = 0.017, 0.026, 0.036) analyses. Interobserver agreements were higher for MRI in both analyses (κ = 0.307 for CT, κ = 0.332 for MRI in the first analysis; κ = 0.467 for CT, κ = 0.531 for MRI in the second analysis), with greater agreement in the second analysis for both CT (P = 0.001) and MRI (P < 0.001). Conclusion: Rim arterial phase hyperenhancement on GAD-MRI can be a good indicator suggesting CHC more than HCC. GAD-MRI may provide greater accuracy than CT for distinguishing CHC from HCC. Interobserver agreement can be improved for both CT and MRI by analyzing LI-RADS imaging features.

• 응용통계연구
• /
• 제16권2호
• /
• pp.305-319
• /
• 2003

본 연구에서는 바이어스 필드에 의해 왜곡된 MRI 영상에 대한 분할을 위해 확장된 EM 알고리즘을 기반으로 한 통계적 접근법을 제시한다. 영상의 명암값을 자료로 하는 분할기법들은 고주파 성분의 잡음 뿐만 아니라 영상을 불균질하게 만드는 바이어스 필드라는 저주파 성분의 왜곡에 특히 취약하다. 이 문제를 해결하기 위해 본 논문에서는 잡음을 효과적으로 제어하기 위해 마코프랜덤필드가 적용된 정규혼합모형을 고려하며, 효과적인 바이어스 필드의 보정을 위해 페널티-우도를 도입하여 추정하는 방법으로 고안되었다.

• 대한약침학회지
• /
• 제14권3호
• /
• pp.99-107
• /
• 2011

Objectives : The purpose of this study is to report the image changes of two cases of Lumbar intervertebral Disc Sequestration after oriental medical treatment. Methods : We examined 2 patients with Lumbar intervertebral Disc Sequestration who showed changes on MRI images before/after the treatment. And we assessed clinical symptoms by using numeric rating scale(NRS) and straight leg raising test(SLRT). Results & Conclusions : In this study, the first MRI examination of Lumbar intervertebral Disc Sequestration patients was performed at the first visit and re-examination of MRI was done after treatment. In each case, the size of the disc sequestration was considerably reduced in MRI image. And both patients represented effective improvment in NRS score and SLRT test angle.

• 한국멀티미디어학회논문지
• /
• 제17권5호
• /
• pp.566-572
• /
• 2014

The hippocampus has been known as one of the most important structure related to many neurological disorders, such as Alzheimer's disease. This paper presents the snake model to segment hippocampus from brain MRI. The snake model or active contour model is widely used in medical image processing fields, especially image segmentation they look onto nearby edge, localizing them accurately. We applied a snake model on brain MRI. Then we compared our results with an active shape approach. The results show that hippocampus was successfully segmented by the snake model.

• Korean Journal of Radiology
• /
• 제22권1호
• /
• pp.9-22
• /
• 2021

Diffusion-weighted (DW) magnetic resonance imaging (MRI) is a rapid, unenhanced imaging technique that measures the motion of water molecules within tissues and provides information regarding the cell density and tissue microstructure. DW MRI has demonstrated the potential to improve the specificity of breast MRI, facilitate the evaluation of tumor response to neoadjuvant chemotherapy and can be employed in unenhanced MRI screening. However, standardization of the acquisition and interpretation of DW MRI is challenging. Recently, the European Society of Breast Radiology issued a consensus statement, which described the acquisition parameters and interpretation of DW MRI. The current article describes the basic principles, standardized acquisition protocols and interpretation guidelines, and the clinical applications of DW MRI in breast imaging.

• 한방재활의학과학회지
• /
• 제27권3호
• /
• pp.107-115
• /
• 2017

Objectives This study is planned to classify correlation between HIVD of L-spine MRI and Digital Infrared Thermal Image (DITI). Methods We measured the temperature of both leg whose 120 men and 116 women patients with lumbar pain in Bucheon Jaseng Korean Medicine Hospital. And We use Magnetic Resonance Imaging (MRI) for classifying the patients who has lumbar intervertebral disc or not. Results 1) There was no statistical relation between difference of both leg's temperature and gender (p>0.05). 2) There was meaningful statistical relation between difference of both leg's temperature and age (p<0.05). 3) There was meaningful statistical relation between direction of HIVD of L-spine and direction of temperature reduction. 4) There was meaningful statistical relation between the severity of HIVD of L5/S1 and degree of temperature reduction. But there was no statistical relation between the severity of HIVD of L3/4, L4/5 and degree of temperature reduction. Conclusions We can use Digital Infrared thermal image (DITI) on low back pain patients for diagnosis. But we should not use DITI alone. DITI has limit in diagnosis.

• Journal of Korean Neurosurgical Society
• /
• 제46권4호
• /
• pp.365-369
• /
• 2009

Objective : Susceptibility-weighted image (SWI) is a sensitive magnetic resonance image (MRI) technique to detect cerebral microbleeds (MBLs). which would not be detected by conventional MRI. We performed SWI to detect MBLs and investigated its usefulness in the evaluation of mild traumatic brain injury (MTBI) patients. Methods : From December 2006 to June 2007, twenty-one MTBI patients without any parenchymal hemorrhage on conventional MRI were selected. Forty-two patients without trauma were selected for control group. According to the presence of MBLs, we divided the MTBI group into MBLs positive [SWI (+)] and negative [SWI (-)] group. Regional distribution of MBLs and clinical factors were compared between groups. Results : Fifty-one MBLs appeared in 16 patients of SWI (+) group and 16 MBLs in 10 patients of control group [control (+)], respectively. In SWI (+) group, MBLs were located more frequently in white matters than in deep nucleus different from the control (+) group (p<0.05). Nine patients (56.3%) of SW (+) group had various neurological deficits (disorientation in 4, visual field defect in 2, hearing difficulty in 2 and Parkinson syndrome in 1). Initial Glasgow Coma Scale (GCS)/mean Glasgow Outcome Scale (GOS) were $13.9{\pm}1.5/4.7{\pm}0.8$ and $15.0{\pm}0.0/5.0{\pm}0.0$ in SWI (+) and SWI (-) groups, respectively (p<0.05). Conclusion : Traumatic cerebral MBLs showed characteristic regional distribution, and seemed to have an importance on the initial neurological status and the prognosis. SWI is useful for detection of traumatic cerebral MBLs, and can provide etiologic evidences for some post-traumatic neurologic deficits which were unexplainable with conventional MRI.

• International Journal of Computer Science & Network Security
• /
• 제24권2호
• /
• pp.43-52
• /
• 2024

Medical imaginings assume a important part in the analysis of tumors and cerebrospinal fluid (CSF) leak. Magnetic resonance imaging (MRI) is an image segmentation technology, which shows an angular sectional perspective of the body which provides convenience to medical specialists to examine the patients. The images generated by MRI are detailed, which enable medical specialists to identify affected areas to help them diagnose disease. MRI imaging is usually a basic part of diagnostic and treatment. In this research, we propose new techniques using the 4D-MRI image segmentation process to detect the brain tumor in the skull. We identify the issues related to the quality of cerebrum disease images or CSF leakage (discover fluid inside the brain). The aim of this research is to construct a framework that can identify cancer-damaged areas to be isolated from non-tumor. We use 4D image light field segmentation, which is followed by MATLAB modeling techniques, and measure the size of brain-damaged cells deep inside CSF. Data is usually collected from the support vector machine (SVM) tool using MATLAB's included K-Nearest Neighbor (KNN) algorithm. We propose a 4D light field tool (LFT) modulation method that can be used for the light editing field application. Depending on the input of the user, an objective evaluation of each ray is evaluated using the KNN to maintain the 4D frequency (redundancy). These light fields' approaches can help increase the efficiency of device segmentation and light field composite pipeline editing, as they minimize boundary artefacts.