• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제12권2호
• /
• pp.137-142
• /
• 2012

The temporal subtraction technique as one of computer aided diagnosis has been introduced in medical fields to enhance the interval changes such as formation of new lesions and changes in existing abnormalities on deference image. With the temporal subtraction technique radiologists can easily detect lung nodules on visual screening. Until now, two-dimensional temporal subtraction imaging technique has been introduced for the clinical test. We have developed new temporal subtraction method to remove the subtraction artifacts which is caused by mis-registration on temporal subtraction images of lungs on MDCT images. In this paper, we propose a new computer aided diagnosis scheme for automatic enhancing the lung nodules from the temporal subtraction of thoracic MDCT images. At first, the candidates regions included nodules are detected by the multiple threshold technique in terms of the pixel value on the temporal subtraction images. Then, a rule-base method and artificial neural networks is utilized to remove the false positives of nodule candidates which is obtained temporal subtraction images. We have applied our detection of lung nodules to 30 thoracic MDCT image sets including lung nodules. With the detection method, satisfactory experimental results are obtained. Some experimental results are shown with discussion.

• 한국의학물리학회:학술대회논문집
• /
• 한국의학물리학회 2002년도 Proceedings
• /
• pp.454-456
• /
• 2002

The evaluation of interval changes between temporally sequential chest radiographs is necessary for the detection of new abnormalities or interval changes, such as pulmonary nodules and interstitial disease. For interstitial lung disease, the interval changes are very important for diagnosis and treatment. Especially, interstitial lung disease may show rapid changes in the radiographs, show changes in the entire lung field in minute detail, or show changes in multiple parts depending on the type. It is therefore difficult to have an accurate grasp of the condition of the disease only with conventional radiographs. The temporal subtraction technique which was developed at the University of Chicago, provides a subtraction image of the current warped image and the previous image. A temporal subtraction image, shows only differences and changes between the two images, can be very useful for a diagnosis of interstitial lung disease. However, the evaluation of the temporal subtraction technique for interstitial lung disease using receiver operating characteristic(ROC) studies has not been reported yet. Therefore, we have evaluated the clinical usefulness of a temporal subtraction technique for detection of interval changes of interstitial lung disease by ROC analysis.

• 반도체디스플레이기술학회지
• /
• 제19권2호
• /
• pp.31-36
• /
• 2020

Most of the background subtraction algorithms show good performance in static scenes. In the case of dynamic scenes, they frequently cause false alarm to "temporal clutter", a repetitive motion within a certain area. In this paper, we propose a robust technique for the multiple interval pixel sampling (MIS) algorithm to handle highly dynamic scenes. An adaptive threshold scheme is used to suppress false alarms in low-confidence regions. We also utilize multiple background models in the foreground segmentation process to handle repetitive background movements. Experimental results revealed that our approach works well in handling various temporal clutters.

• 한국의학물리학회:학술대회논문집
• /
• 한국의학물리학회 2002년도 Proceedings
• /
• pp.335-337
• /
• 2002

The aim of this study was investigate the epileptogenic zone in temporal lobe epilepsy (TLE). We evaluated the subtraction image of interictal SPECT from ictal SPECT coregistered to 3-dimensional (3D) MRI, and compared with the normal healthy SPECT using a SPM99. Forty-nine patients with TLE (M:F=28:21, mean age: 33${\pm}$2.1 years) underwent a pairs of ictal and interictal SPECT. We performed subtraction interictal SPECT from ictal SPECT in TLE patients. In addition, using SPM methods and t-statistics, SPECT images of the TLE patients were compared with normal healthy SPECT on a voxel by voxel basis. The voxels with a p-value of less than 0.05, 0.005, 0.001 were considered to be significantly different. The subtraction results by ictal and interictal SPECT coincided with the significant rCBF changes when compare of the normal healthy SPECT using a SPM99. The results suggested that analysis of difference of the two methods using healthy normal SPECT with SPM99 is useful tool in evaluation of seizure focus in epilepsy.

• Journal of Electrical Engineering and Technology
• /
• 제10권1호
• /
• pp.372-378
• /
• 2015

Background subtraction is the first processing stage in video surveillance. It is a general term for a process which aims to separate foreground objects from a background. The goal is to construct and maintain a statistical representation of the scene that the camera sees. The output of background subtraction will be an input to a higher-level process. Background subtraction under dynamic environment in the video sequences is one such complex task. It is an important research topic in image analysis and computer vision domains. This work deals background modeling based on modified adaptive Gaussian mixture model (GMM) with three temporal differencing (TTD) method in dynamic environment. The results of background subtraction on several sequences in various testing environments show that the proposed method is efficient and robust for the dynamic environment and achieves good accuracy.

• 대한두개안면성형외과학회지
• /
• 제11권1호
• /
• pp.49-52
• /
• 2010

Posttraumatic pseudoaneurysm of the superficial temporal artery is very rare and occurs secondary to trauma. Clinical diagnosis is based on past history of trauma and physical examination and can be confirmed by duplex ultrasonogram, digital subtraction angiography, CT and MRI. Ligation of proximal and distal ends of the superficial temporal artery and excision of the pseudoaneurysm has been the standard treatment. Compressive therapy, endovascular coil embolization, percutaneous thrombin injection under ultrasound guidance have been reported as alternative treatment methods. When surgical excision of the superficial temporal artery pseudoaneurysm is performed, surgeon must be concerned about the anatomical relation between superficial temporal artery and temporal branches of the facial nerve. In this article, we report a rare case of superficial temporal artery pseudoaneurysm with some review of the literatures about anatomical relation between superficial temporal artery and temporal branches of facial nerve.

• 제어로봇시스템학회논문지
• /
• 제15권9호
• /
• pp.939-945
• /
• 2009

In this paper, we proposed a method which corresponds people under the structured spaces with multiple cameras. The correspondence takes an important role for using multiple camera system. For solving this correspondence, the proposed method consists of three main steps. Firstly, moving objects are detected by background subtraction using a multiple background model. The temporal difference is simultaneously used to reduce a noise in the temporal change. When more than two people are detected, those detected regions are divided into each label to represent an individual person. Secondly, the detected region is segmented as features for correspondence by a criterion with the color distribution and context information of human body. The segmented region is represented as a set of blobs. Each blob is described as Gaussian probability distribution, i.e., a person model is generated from the blobs as a Gaussian Mixture Model (GMM). Finally, a GMM of each person from a camera is matched with the model of other people from different cameras by maximum likelihood. From those results, we identify a same person in different view. The experiment was performed according to three scenarios and verified the performance in qualitative and quantitative results.

• 대한핵의학회지
• /
• 제32권1호
• /
• pp.20-31
• /
• 1998

수술로서 간질 병소가 확인된 환자들을 대상으로 한 이 연구에서 발작기-발작간기 SPECT를 비교 판독하여 간질병소를 국소화한 것과 영상을 위치 이동하여 좌표를 일치시키고 정규화 하여 감산하여 얻은 감산 SPECT로 국소화한 것이 대등한 진단성능을 지니고 있으며 감산 SPECT로부터 MR이나 PET과 같은 수준의 정보를 얻을 수 있음을 확인하였다. 감산 SPECT에서 발작기 혈류 증가를 범위와 강도를 고려한 적절한 역치를 설정하여 발작기-발작간기 SPECT에 더하여 감산 SPECT가 얼마나 부가적 진단가치를 가지는지 확립하여야 한다고 생각하였다.

• 대한핵의학회지
• /
• 제35권1호
• /
• pp.12-22
• /
• 2001

목적: 측두엽 간질환자에서 소뇌와 기저핵의 발작기 뇌혈류 변화에 대한 구체적인 연구는 아직 까지 없었다. 저자들은 SPECT 감영영상을 이용하여 측두엽 간질 발작동안 측두엽과 전두엽의 혈류증가와 관련된 소뇌와 기저핵의 혈류변화에 대하여 연구하였다. 대상 및 방법: 발작간기와 발작기 뇌 SPECT, 비디오-뇌파 감시검사, SPGR MRI, SPECT subtraction with MRI co-registration을 측두엽 간질환자 33명에서 시행하였다. 결과. 29명(87.8%)에서 소뇌의 혈류증가가 관찰되었으며 이중 소뇌 충부의 혈류증가는 26명(78.8%),소뇌 반구의 혈류증가는 25명(75.8%)에서 보였다. 간질병소인 측두엽의 동측 소뇌반구의 혈류 증가가 관찰된 경우는 7명(28.0%), 반대편 소뇌 반구에 혈류증가가 관찰된 경우는 15명(60%), 그리고 양측 소뇌반구에 혈류증가가 관찰된 경우는 3명(12.0%)이었다. 소뇌의 혈류증가는 오직 측두엽에서만 혈류증가가 있었던 측두엽 간질환자(11/18, 61.1%)에서 보다 측두엽 외에 전두엽까지 혈류증가가 동반된 환자(14/15, 93.3%)에서 더 흔하게 관찰되었다. 기저핵의 혈류증가는 측두엽에서만 혈류가 증가한 환자군에서는 18명중 11명(61.1%), 그리고 측두엽과 전두엽 모두 혈류가 증가한 환자군에서는 15명중 11명(73.3%)에서 관찰되었다. 편측의 기저핵 혈류증가를 보이는 17명중에서 기저핵 혈류증가의 반대편 소뇌에 혈류증가가 관찰된 경우는 14명(82.5%)이었고 동측의 소뇌 혈류증가가 관찰된 경우는 2명(11.8%), 그리고 양측 소뇌의 혈류증가가 관찰된 경우가 1명(5.9%) 있었다. 결론: 측두엽 간질 발작 중에 소뇌와 기저핵의 혈류증가는 발작병소의 동측, 반대측, 그리고 양측 모두에서 관찰될 수 있다. 측두엽의 혈류증가와 함께 전두엽과 기저핵의 혈류증가가 동반되면 반대편 소뇌에 더 자주 발생하였으나, 발작 중 일측 측두엽의 뇌혈류증가는 반대측 또는 동측 소뇌의 혈류증가를 동반하는 것으로 밝혀졌다. 그러나 측두엽에서 만의 혈류증가는 그 동측 또는 반대측 소뇌 모두에서 혈류증가가 관찰될 수 있다.

• 대한원격탐사학회지
• /
• 제31권4호
• /
• pp.321-330
• /
• 2015

Atmospheric correction is an essential part in time-series analysis on biophysical parameters of surface features. In this study, we tried to examine possible problems in atmospheric correction of multitemporal High Spatial Resolution (HSR) images obtained from two different sensor systems. Three KOMPSAT-2 and two IKONOS-2 multispectral images were used. Three atmospheric correction methods were applied to derive surface reflectance: (1) Radiative Transfer (RT) - based absolute atmospheric correction method, (2) the Dark Object Subtraction (DOS) method, and (3) the Cosine Of the Uun zeniTh angle (COST) method. Atmospheric correction results were evaluated by comparing spectral reflectance values extracted from invariant targets and vegetation cover types. In overall, multi-temporal reflectance from five images obtained from January to December did not show consistent pattern in invariant targets and did not follow a typical profile of vegetation growth in forests and rice field. The multi-temporal reflectance values were different by sensor type and atmospheric correction methods. The inconsistent atmospheric correction results from these multi-temporal HSR images may be explained by several factors including unstable radiometric calibration coefficients for each sensor and wide range of sun and sensor geometry with the off-nadir viewing HSR images.