• 한국임상수의학회지
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• 제27권1호
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• pp.107-112
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• 2010

A 3-years-old female Pointer was evaluated for anorexia, dyspnea and exercise intolerance for 10 days. Auscultation revealed muffling of heart sound. There were leukocytosis, anemia, hypoalbuminaemia and hyperglobulinaemia on the blood profiles. Radiography showed severe pleural effusion. Thorax ultrasonographs described traped pleural effusion, pericardial effusion and collapsed right lung lobe(s). On CT images, thoracic neoplasia and lung torsion were ruled-out. Thoracocentesis with thoracoscopy and bacterial culture revealed pyothorax and pleuritis. The diagnosis of pyothorax in dogs and cats is based on clinical signs, radiography, thoracocentesis and cytology and culture of the exudate. In this case, various diagnostic medical imaging techniques (radiography, ultrasonography, CT and thoracoscopy) were used for diagnosis of pyothorax.

• 한국CDE학회논문집
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• 제15권4호
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• pp.297-305
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• 2010

Medical image acquisition techniques such as CT and MRI have disadvantages in that the numerous time and efforts are needed. Furthermore, a great amount of radiation exposure is an inherent proberty of the CT imaging technique, a number of side-effects are expected from such method. To improve such conventional methods, a number of novel methods that can obtain 3D medical images from a few X-ray images, such as algebraic reconstruction technique (ART), have been developed. Such methods deform a generic model of the internal body part and fit them into the X-ray images to obtain the 3D model; the initial shape, therefore, affects the entire fitting process in a great deal. From this fact, we propose a novel method that can generate a 3D vertebraic generic model based on the statistical database of CT scans in this study. Moreover, we also discuss a method to generate patient-tailored generic model using the facts obtained from the statistical analysis. To do so, the mesh topologies of CT-scanned 3D vertebra models are modified to be identical to each other, and the database is constructed based on them. Furthermore, from the results of a statistical analysis on the database, the tendency of shape distribution is characterized, and the modeling parameters are extracted. By using these modeling parameters for generating the patient-tailored generic model, the computational speed and accuracy of ART can greatly be improved. Furthermore, although this study only includes an application to the C1 (Atlas) vertebra, the entire framework of our method can be applied to other body parts generally. Therefore, it is expected that the proposed method can benefit the various medical imaging applications.

• 대한영상의학회지
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• 제81권2호
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• pp.272-289
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• 2020

전산화단층촬영(이하 CT) 영상 기술의 발전으로 박동하는 심장에 대한 섬세한 영상의학적 평가가 가능해졌다. 심초음파 및 MRI에 비해 심장 CT의 강점은 대부분의 의료기관에 보급되어 있고 고품질 이미지의 빠른 생산이 가능하며 해부학적 묘사가 뛰어나다는 것이다. 좌심방과 좌심방이에서 생기는 대부분의 변이 혹은 병리적 상태들은 CT 상의 소견만으로도 추정 진단을 내릴 수 있다. 또한 CT 영상은 성공적인 카테터 기반 시술 또는 수술에 중요한 해부학적 정보들을 제공한다. 특히 좌심방과 좌심방이는 심방세동 환자들의 치료 및 관리에 중요한데, 이는 다양한 카테터 기반 시술들이 두 구조물의 기계적 혹은 전기적 차단을 목표로 하기 때문이다. 따라서 임상적으로 의미 있는 판독을 위해서는 병리적 상태의 CT 소견 기술과 함께 좌심방 및 좌심방이의 모양, 크기 및 주변 구조물과의 상대적 위치 관계 등에 대한 포괄적인 검토를 해야 한다.

• 한국의학물리학회지:의학물리
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• 제24권4호
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• pp.205-212
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• 2013

Cone Beam CT (CBCT)와 On Board Imaging (OBI)를 비롯하여 최근에 개발되고 있는 방사선 치료용 영상 장치(Image Guided Radiation Therapy, IGRT)의 사용으로 방사선 치료가 더욱 정확해지고 있다. 점차 사용 범위가 넓어지면서 표준치료법으로 자리잡았고 앞으로 사용하는 기관과 빈도가 더 늘어날 것으로 전망한다. IGRT는 그러나 안전하고 용도에 맞게 사용할 때만 효능을 볼 수 있다. 이를 위해 IGRT를 임상에 적용하기 전에 장치의 특성을 이해하고 병원의 임상 요구에 적합한 지침서를 미리 만들 필요가 있다. QA 프로그램과 환자가 받을 추가 선량에 대한 고려도 미리 준비해둘 필요가 있다.

• Tuberculosis and Respiratory Diseases
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• 제56권6호
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• pp.571-584
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• 2004

Magnetic Resonance Imaging (MRI) is one of the most advanced imaging techniques in clinical and research medicine. However, clinical application of MRI to the lung or thorax has been limited due to various drawbacks. Low signal intensity of the lung and cardiac and respiratory movements are the most serious problems with MRI in thorax. Nevertheless, MRI is superior to CT in some selected patients with thoracic diseases. The role of clinical MRI in thoracic disease has been widened with improvement of MR equipments and development of new pulse sequences. Otherwise, functional assessment of lung by MRI has been studied for the last decade. These include perfusion MRI with or without contrast enhancement and ventilation MRI with oxygen-enhancement or hyperpolarized noble gas, $^3He$ and $^{129}Xe$.

• 한국의학물리학회지:의학물리
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• 제23권4호
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• pp.292-302
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• 2012

최근 방사선치료 분야에 있어서 환자 선량이 중요한 쟁점이 되고 있다. 선량 감소를 위해 선진 기술을 이용한 방사선치료 시 사용하는 진단영상 장비에 대한 평가가 이루어져야 한다. 특히 CT는 방사선치료 분야에서 널리 사용되는 영상 장비이며, 본 연구에서는 CT의 선량과 영상에 대한 평가를 실시하였다. 선량과 영상을 동시에 비교할 수 있도록 동일한 조건 하에서 평가를 실시하였다. 또한 몬테카를로 시뮬레이션 툴인 MCNPX를 이용한 선량과 영상 평가가 가능하다는 것을 확인하였다. 저 선량 CT 영상의 질을 향상시키기 위하여 MLEM기법을 이용한 반복적 영상재구성 기법을 구축하였다. 본 연구의 평가 방법을 통해 방사선 치료 분야에서의 환자 선량을 줄이는 것뿐만 아니라 산업 연구 분야에서의 영상장비들의 총체적인 평가가 가능할 것이다.

• Korean Journal of Radiology
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• 제23권5호
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• pp.529-538
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• 2022

Objective: Since its introduction in 2011, the CT/MRI diagnostic Liver Imaging Reporting and Data System (LI-RADS) has been updated in 2014, 2017, and 2018. We evaluated the impact of CT/MRI diagnostic LI-RADS on liver MRI research methodology for the diagnosis of hepatocellular carcinoma (HCC). Materials and Methods: The MEDLINE, EMBASE, and Cochrane databases were searched for original articles reporting the diagnostic performance of liver MRI for HCC between 2011 and 2019. The MRI techniques, image analysis methods, and diagnostic criteria for HCC used in each study were investigated. The studies were classified into three groups according to the year of publication (2011-2013, 2014-2016, and 2017-2019). We compared the percentage of studies adopting MRI techniques recommended by LI-RADS, image analysis methods in accordance with the lexicon defined in LI-RADS, and diagnostic criteria endorsed by LI-RADS. We compared the pooled sensitivity and specificity between studies that used the LI-RADS and those that did not. Results: This systematic review included 179 studies. The percentages of studies using imaging techniques recommended by LI-RADS were 77.8% for 2011-2013, 85.7% for 2014-2016, and 84.2% for 2017-2019, with no significant difference (p = 0.951). After the introduction of LI-RADS, the percentages of studies following the LI-RADS lexicon were 0.0%, 18.4%, and 56.6% in the respective periods (p < 0.001), while the percentages of studies using the LI-RADS diagnostic imaging criteria were 0.0%, 22.9%, and 60.7%, respectively (p < 0.001). Studies that did not use the LI-RADS and those that used the LIRADS version 2018 showed no significant difference in sensitivity and specificity (86.3% vs. 77.7%, p = 0.102 and 91.4% vs. 89.9%, p = 0.770, respectively), with some difference in heterogeneity (I² = 94.3% vs. 86.7% in sensitivity and I² = 86.6% vs. 53.2% in specificity). Conclusion: LI-RADS imparted significant changes in the image analysis methods and diagnostic criteria used in liver MRI research for the diagnosis of HCC.

• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.2197-2204
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• 2015

In recent years, medical image diagnosis has growing significant momentous in the medicinal field. Brain and lung image of patient are distorted with salt and pepper noise is caused by moving the head and chest during scanning process of patients. Reconstruction of these images is a most significant field of diagnostic evaluation and is produced clearly through techniques such as linear or non-linear filtering. However, restored images are produced with smaller amount of noise reduction in the presence of huge magnitude of salt and pepper noises. To eliminate the high density of salt and pepper noises from the reproduction of images, a new efficient fuzzy based median filtering algorithm with a moderate elapsed time is proposed in this paper. Reproduction image results show enhanced performance for the proposed algorithm over other available noise reduction filtering techniques in terms of peak signal -to -noise ratio (PSNR), mean square error (MSE), root mean square error (RMSE), mean absolute error (MAE), image enhancement factor (IMF) and structural similarity (SSIM) value when tested on different medical images like magnetic resonance imaging (MRI) and computer tomography (CT) scan brain image and CT scan lung image. The introduced algorithm is switching filter that recognize the noise pixels and then corrects them by using median filter with fuzzy two-sided π- membership function for extracting the local information.

• Nuclear Medicine and Molecular Imaging
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• 제43권3호
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• pp.222-228
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• 2009

Risk stratification and assessment of prognosis in patients with known or suspected CAD is of crucial important for the practice of contemporary medicine. Noninvasive testing such as myocardial perfusion scintigraphy, coronary artery calcium scoring or CT coronary angiography is increasingly being used to determine the need for aggressive medical therapy and to select patients for catheterization. The integrated anatomic and functional information may provide more additional information for the cardiologist or other clinician by the improved risk stratification and diagnostic accuracy of integrated techniques. The development of SPECT/CT or PET/CT hybrid systems is therefore of important value for the nuclear cardiology.

• 대한방사선기술학회지:방사선기술과학
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• 제30권3호
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• pp.281-287
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• 2007

전산화단층촬영에서 조영제를 자동주입기로 주입하는 과정에서 발생하는 혈관외유출은 조직의 괴사 및 손상의 원인이 되고 있다. 대량의 혈관외유출은 구획증후군으로 발전하여 근막절개술을 시행하는 경우가 발생한다. 혈관외유출이 발생한 환자를 대상으로 혈관외유출 범위 및 부위 정도를 평가하기 위해 CT 검사에서 경정맥에 조영제을 주입하는 과정에서 혈관외유출이 발생한 환자를 대상으로 하였다. 조영제에 의한 혈관외유출 범위 및 손상을 확인하기 조영제 주입부위의 목 및 가슴의 부위를 MDCT를 이용하여 스캔하였다. 경정맥 주사부위의 혈관외유출부위를 MPR, MIP와 볼륨 렌더링의 3차원영상을 3D 프로그램을 이용하여 묘출하였다. 3차원 재구성 영상은 높은 해상력과 정확도를 제공하여 혈관외유출 범위 및 부위를 확인 하여, 환자의 예방의 필요성 및 사후 조치 및 적절한 치료와 수술 계획에 유용하게 이용될 것으로 기대된다.