• The Korean Journal of Nuclear Medicine
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• v.37 no.1
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• pp.1-12
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• 2003

Single photon emission computed tomography(SPECT) and positron emission tomography(PET) are modern imaging techniques that allow for both qualitative and quantitative assessment of hemodynamic changes in cerebrovascular diseases. SPECT has been becoming an indispensable method to investigate regional cerebral blood flow because equipment and isotope are easily available in most general hospitals. Acetazolamide stress SPECT has also been proved to be useful to evaluate the cerebrovascular reserve of occlusive cerebrovascular diseases and to select surgical candidate. PET has gained wide spread clinical use in the evaluation of the hemodynamic and metabolic consequences of extracranial or intracranial arterial obstructive disease despite its complexity and limited availability. PET has been established as an invaluable tool in the pathophysilogy investigation of acute ischemic stroke. The potentials, limitations, and clinical applications of SPECT and PET in various cerebrovascular diseases will be discussed in this article with reviews of literatures.

• Journal of Biomedical Engineering Research
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• v.18 no.2
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• pp.113-120
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• 1997

This paper presents an optimal design for the SPECT reconstruction filter, based on a physical limit of SPECT lesion detection capability. To increase the performance of the filter on lesion detectability, the filter design was focused on increasing the local SyW ratio of a threshold lesion, that was determined by minimum detectable lesion size (MDU) from SPECT lesion detectabllity contrast-detail curve. The proposed filter showed flexible window characteristics of resolution recovery and noise smoothing for MDLSs in the resolution-limited and photon-limited regions, respectively, compennting for the relative impact of the main limitation factors on threshold detectability. The simulated results showed good adaptability of the proposed filter to the changes in physical parameters of photon counts, object contrast, and detector system resolution.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.1
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• pp.18-24
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• 2004

SPECT technology is used for the reconstructed image in the field of industry noncontact measurement system. One of the distortion problems in reconstructed image quality is a collimator characterictic. The image distortion is caused by a geometrical structure of the collimator. This paper indicated a correction method to remove the image distortion by the structure of the collimator, and compared with the existing correction method. The correction. method removed the image distortion to use deconvolution of projection data with the shift-variant blurring function in the frequency domain. In this pater, I simulated with the collimator angle and distance between the detector and the center of object. and verified with expeimental data. The validity and limitation of correction method is studied for actual industrial applications.

• Korean Journal of Biological Psychiatry
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• v.9 no.2
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• pp.152-158
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• 2002

Background & Purpose:Neuropsychological disorders after traumatic brain injury(TBI) are poorly correlated with structural lesions detected by structural neuroimaging techniques such as computed tomography(CT) scan or magnetic resonance imaging(MRI). It is well known that patients with TBI have cognitive and behavioral disorders even in the absence of structural lesions of the brain. This study investigated whether there are abnormalities of regional cerebral blood flow(rCBF) in TBI patients without structural abnormality on MRI, using technetium 99m ethyl cysteinate dimer(Tc-99m-ECD) single photon emission computed tomography(SPECT) scans. Materials and Methods:Twenty-eight TBI patients without structural abnormality on MRI(mild, n=13/moderate, n=9/severe, n=6) and fifteen normal controls were scanned by SPECT. A voxel-based analysis using statistical parametric mapping(SPM) was performed to compare the patients with the normal controls. Results:rCBF was reduced in the right uncus and the right lateral orbitofrontal gyrus in the TBI patients. However, no increase of rCBF was noted in the patients in comparison to the normal controls. Conclusions:These results suggest that the TBI patients, even in the absence of structural lesion of the brain, may have dysfunction of the brain, particularly of the orbitofrontal and anterior pole of the temporal cortex. They also suggest that SPECT can be a useful method to identify brain dysfunctions in combination with structural brain imaging and neuropsychological tests.

• International Journal of Stem Cells
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• v.16 no.4
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• pp.363-375
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• 2023

Stem cells are the foundational cells for every organ and tissue in our body. Cell-based therapeutics using stem cells in regenerative medicine have received attracting attention as a possible treatment for various diseases caused by congenital defects. Stem cells such as induced pluripotent stem cells (iPSCs) as well as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), and neuroprogenitors stem cells (NSCs) have recently been studied in various ways as a cell-based therapeutic agent. When various stem cells are transplanted into a living body, they can differentiate and perform complex functions. For stem cell transplantation, it is essential to determine the suitability of the stem cell-based treatment by evaluating the origin of stem, the route of administration, in vivo bio-distribution, transplanted cell survival, function, and mobility. Currently, these various stem cells are being imaged in vivo through various molecular imaging methods. Various imaging modalities such as optical imaging, magnetic resonance imaging (MRI), ultrasound (US), positron emission tomography (PET), and single-photon emission computed tomography (SPECT) have been introduced for the application of various stem cell imaging. In this review, we discuss the principles and recent advances of in vivo molecular imaging for application of stem cell research.

• Journal of the Korean Society of Radiology
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• v.3 no.2
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• pp.5-10
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• 2009

Myocardial imaging in SPECT (Single Photon Emission Computed tomography) scan of the gamma-ray emitting radiopharmaceuticals to patients after intravenous radiopharmaceuticals evenly spread in the heart region of interest by recording changes in the disease caused by a computer using the PSA test is to diagnose. Containing information on the functional myocardial perfusion imaging is a useful way to examine non-invasive heart disease, but the argument by noise and low resolution of the physical landscape that is difficult to give. For this paper, the level of myocardial imaging by using the three algorithms to split the video into 3-D implementation of the partitioned area to help you read the proposed plan. To solve the difficulty of reading level, interest in using the sheet set, partitioned area of the left ventricle was ranked the partitioned area was modeled as a 3-D images.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3403-3414
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• 2022

The purpose of this study is to model and optimize the block-matching and 3D filtering (BM3D) algorithm and to evaluate its applicability in brain single-photon emission computed tomography (SPECT) images using a fan beam collimator. For quantitative evaluation of the noise level, the coefficient of variation (COV) and contrast-to-noise ratio (CNR) were used, and finally, a no-reference-based evaluation parameter was used for optimization of the BM3D algorithm in the brain SPECT images. As a result, optimized results were derived when the sigma values of the BM3D algorithm were 0.15, 0.2, and 0.25 in brain SPECT images acquired for 5, 10, and 15 s, respectively. In addition, when the sigma value of the optimized BM3D algorithm was applied, superior results were obtained compared with conventional filtering methods. In particular, we confirmed that the COV and CNR of the images obtained using the BM3D algorithm were improved by 2.40 and 2.33 times, respectively, compared with the original image. In conclusion, the usefulness of the optimized BM3D algorithm in brain SPECT images using a fan beam collimator has been proven, and based on the results, it is expected that its application in various nuclear medicine examinations will be possible.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.97-101
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• 2007

Correct localization of epileptogenic zone is important for the successful epilepsy surgery. Both ictal perfusion single photon emission computed tomography (SPECT) and interictal F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) can provide useful information in the presurgical localization of intractable partial epilepsy. These imaging modalities have excellent diagnostic sensitivity in medial temporal lobe epilepsy and provide good presurgical information in neocortical epilepsy. Also provide functional information about cellular functions to better understand the neurobiology of epilepsy and to better define the ictal onset zone, symptomatogenic zone, propagation pathways, functional deficit zone and surround inhibition zones. Multimodality imaging and developments in analysis methods of ictal perfusion SPECT and new PET ligand other than FDG help to better define the localization.

• The Korean Journal of Nuclear Medicine
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• v.37 no.1
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• pp.24-33
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• 2003

Finding epileptogenic zone is the most important step for the successful epilepsy surgery. F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and single photon emission computed tomography (SPECT) can be used in the localization of epileptogenic foci. In medial temporal lobe epilepsy, the diagnostic sensitivity of FDG-PET and ictal SPECT is excellent. However, detection of hippocampal sclerosis by MRI is so certain that use of FDG-PET and ictal SPECT in medial temporal lobe epilepsy is limited for some occasions. In neocortical epilepsy, the sensitivities of FDG-PET or ictal SPECT are fair. However, FDG-PET and ictal SPECT can have a crucial role in the localization of epileptogenic foci for non-lesional neocortical epilepsy. Interpretation of FDG-PET has been recently advanced by voxel-based analysis and automatic volume of interest analysis based on a population template. Both analytical methods can aid the objective diagnosis of epileptogenic foci. Ictal SPECT was analyzed using subtraction methods and voxel-based analysis. Rapidity of injection of tracers, ictal EEG findings during injection of tracer, and repeated ictal SPECT were important technical issues of ictal SPECT. SPECT can also be used in the evaluation of validity of Wada test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2240-2245
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• 2010

Myocardial imaging in SPECT (Single Photon Emission Computed tomography) scan of the gamma-ray emitting radiopharmaceuticals to patients after intravenous radiopharmaceuticals evenly spread in the heart region of interest by recording changes in the disease caused by a computer using the PSA test is to diagnose. Containing information on the functional myocardial perfusion imaging is a useful way to examine non-invasive heart disease, but the argument by noise and low resolution of the physical landscape that is difficult to give. For this paper, the level of myocardial imaging by using the three algorithms to split the video into 3-D implementation of the partitioned area to help you read the proposed plan. To solve the difficulty of reading level, interest in using the sheet set, partitioned area of the left ventricle was ranked the partitioned area was modeled as a 3-D images.