• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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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.

• Journal of Life Science
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• v.20 no.11
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• pp.1725-1728
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• 2010

Miniature pigs are widely used in experiments related to pulmonary disease because of their similarities with humans. However, there are not enough data about normal lung function in miniature pigs. Thus, in this study, we investigated normal lung function in miniature pigs with lung ventilation/perfusion scintigraphy and evaluated the availability of this method. Three male miniature pigs weighing 30-35 kg were used. After general anesthesia, ventilation scintigraphy was performed with 100 MBq of $^{99m}Tc$-pertechnetate (${O_4}^-$), after which perfusion scintigraphy was performed with intravenous injection of $^{99m}Tc$-macro aggregated albumin (MAA). The functional contribution of the right lung was about 55%, and left lung was about 45%, similar to humans. Lung ventilation/perfusion scintigraphy was very useful in evaluating the normal lung function of miniature pigs because it was a non-invasive procedure (no tissue damage was involved), took a short time and was easy to perform. In conclusion, miniature pigs are similar to humans in functional contributions of the lung, and this method will be helpful in future pulmonary disease studies involving miniature pigs.

• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.91-101
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• 2011

Perfusion magnetic resonance imaging (pMRI) is a special technique for evaluation of blood flow. Exogenous pMRI methods which are dynamic susceptibility contrast (DSC) and dynamic contrast-enhanced (DCE) use an intravenous bolus injection of paramagnetic contrast agent. In contrast, an endogenous pMRM method which is arterial spin labeling (ASL) use diffusible blood in body. In order to scan pMRI in human, technical optimizations are very important according to disease conditions. For examples, DSC is popularly used in patients with acute stroke due to its short scan time, while DSC or DCE provides the various perfusion indices for patients with tumor. ASL is useful for children, women who are expected to be pregnant, and in patients with kidney diseases which are problematic in nephrogenic systemic fibrosis (NSF). Perfusion MRI does not require any injection of radioisotopes. We expect that demand for perfusion MRI will be higher in evaluating drug efficacy and other treatment effects.

• Journal of Chest Surgery
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• v.8 no.2
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• pp.135-142
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• 1975

Total body perfusion using Sarns Heart-Lung-Machine, five head pump motor system with Travenol disposable bubble oxygenator was attempted in the dogs by the hemodilution method with total prime of buffered Hartman`s solution under moderate hypothermia. The first of all, the functions of Sarns Heart-Lung-Machine and effects of the hemodilution perfusion by buffered Hartman`s solution was studied. At the same time the changes of pressure of artery and vein, gas contents of the blood, and influence on the blood pictures were observed before, during, and after perfusion in 1-2 days. Hemodilution rates were the ranges of 85.0ml/kg to 97.3ml/kg and perfusion flow rates were maintained with the average 80. 5ml/kg/min [the ranges of 73.3ml/kg/min to 92.8ml/kg/min]. Hypothermia was employed between $35^{\circ}C$ and $31^{\circ} of the esophageal temperature. The total body perfusion was continued for 50-60 minutes. In the total cardiopulmonary bypass, atriotomy, ventriculotomy, and atrioventriculotomy were performed respectively. Arterial pressure was ranged approximately between 50 mmHg and 140 mmHg, but generally, it was maintained over 75 mmHg. Venous pressure was measured between 3.8 cm$H_2O$ and 16.0 cm$H_2O$. Optimum oxygenation could be achieved when oxygen flow into the oxygenator was maintained approximately at 5. 5L/min. In this way, the $pO_2$, $pCO_2$, and oxygen saturation were measured before, during, and afterperfusion in 1-2 days. The $pCO_2$ ranged approximately between 26.0 mmHg and 38.5 mmHg, but generally, it was maintained in the average 30.9-32.5mmHg. The $pO_2$ was ranged between 73.0mmHg and 332.2 mmHg, but it was maintained in the average 103.0-219.0 mmHg. Oxygen saturation was measured over 95. 0% during and after extracorporeal circulation respectively. Erythrocyte count, hemoglobin, hematocrit, and leucocyte count were decreased to 49.2%, 49.0%, 49.4%, and 21. 1% of the preoperative value during extracorporeal circulation respectively and these reductions were not recovered until 1-2 days after perfusion. These. resulted from relatively high degree of hemodilution rate and operative bleeding during these experimental studies. The platelets count was also decreased about to 71% during perfusion, on the contrary, it was increased progressively after perfusion and in 1-21 days after perfusion, the value was returned to preoperative contro1 level. Three dogs were all recovered after extracorporeal circulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4068-4074
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• 2011

The purpose of this study was to examine the usefulness of MR Breast perfusion image and time-signal intensity curve in patients diagnosed with breast cancer. We selected on 20 patients who were histologically diagnosed to have invasive ductal carcinoma (IDC) from March 2009 to December 2010. First, the Breast perfusion mapping image was reconstructed after obtaining the dynamic contrast enhancement image. The reconstructed image measured the slope, maximal relative enhancement, and time to peak on the detail including the lesion region, normal region, back ground region after obtaining the time-signal intensity curve. The lesion region and normal and slope of the back ground part were measured with the quantitive analytical method about the research and the average was compared and was analyze. In the qualitative analysis, the signal strength of each pixel was analyze with the macroscopic and being high it was low, the medium (2) performed the division of (a) by the three-point standard and the average was measured. The findings from the quantitative image analysis are the following: In the lesion region, the slope and maximal relative enhancement were the highestest among and the time to peak was the highestest in the back ground region. In the qualitative analysis, the breast perfusion image showed a diagnostic efficiency.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.193-194
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• 1998

Recently, evaluation of brain transport of taurine which is possible to effect on Alzheimer's disease has investigated in rats. Also, internal carotid artery perfusion (ICAP) method is very useful for measuring of blood-brain barrier (BBB) permeability in rats. But ICAP has difficulties to evaluate of BBB permeability in mice especially. In the present study examines neuropharmaceutials permeability through the BBB in mice by common carotid artery perfusion (CCAP) method that modify ICAP method and require simple surgery. The external carotid artery (ECA) is cannulated with coagulating pterygopalatine artery (PPA) on ICAP method, while CCA is cannulated without coagulating PPA on CCAP method. The CCAP method require 4-5 fold higher infusion rate than ICAP method because an additional factor of 2 must be incorporated to adjust for fluid loss to the extracerebral circulation.

• Journal of Biomedical Engineering Research
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• v.16 no.2
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• pp.231-238
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• 1995

Tc-99m-MIBI (Sestamibi) myocardial SPECT along with TI-201 tomographic Imaging has demonstrated wide application and high image quality sufficient for the diagnosis of myocardial perfusion defect, which consequently reflects regional myocardial blood flow. The qualitative values of myocardial SPECT with Tc-99m-MIBI as well ds the quantitative cases depend in some degree on the reconstruction techniques of multiple projections. Filtered backprojection (FBP) Is the common standard method for reconstruction rather than the complicated and time-consuming arithmetic methods. In FBP it is known that the distribution of radioactivity in reconstructed transverse slices varies with the selected litter parameters such as cutoff frequencies and order (Butterworth case) The cutoff frequencies used in clinicAl practice partially remove and decrease the true radioactive distribution and alter the pixel counts, which lead to underestimation of true counts in specific myocardial regions. In this study, we have investigated the effect of cutoff frequencies of reconstruction filter on the artifactually induced perfusion defects, which are often demonstrated near inferior and/or inferoseptal cardiac walls due to the intense hepatic uptake of Tc-99m-MIBI. A computerized method for Identifying the relative degree of artifactual perfusion defect and for comparing those degrees along with the relative amount of hepatic uptake to myocardium was developed and patient images were studied to observe the quantitative degree of underestimation of myocardial perfusion, and to propose some reasonable threshold of cutoff frequency in the diagnosis of perfusion defect quantitatively. We concluded that from the quantitative viewpoint cutoff frequencies may be used as high as possible with the sacrifice of homogeneity of image quality, and those frequencies lower than the common 0.3 Wyquist frequency would reveal severe degradation of radioactive distribution near inferior and/or inferoseptal myocardium when applying Butterworth or low pass filter.

• Progress in Medical Physics
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• v.24 no.2
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• pp.108-118
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• 2013

Currently, an arterial spin labeling (ASL) magnetic resonance imaging (MRI) technique does not routinely used in clinical studies to measure perfusion in brain because optimization of imaging protocol is required to obtain optimal perfusion signals. Therefore, the objective of this study was to investigate changes of perfusion-weighed signal intensities with varying several parameters on a pulsed arterial spin labeling MRI technique obtained from a 3T MRI system. We especially evaluated alternations of ASL-MRI signal intensities on special brain areas, including in brain tissues and lobes. The signal targeting with alternating radiofrequency (STAR) pulsed ASL method was scanned on five normal subjects (mean age: 36 years, range: 29~41 years) on a 3T MRI system. Four parameters were evaluated with varying: 1) the labeling gap, 2) the labeling delay time, 3) the labeling thickness, and 4) the slice scan order. Signal intensities were obtained from the perfusion-weighted imaging on the gray and white matters and brain lobes of the frontal, parietal, temporal, and occipital areas. The results of this study were summarized: 1) Perfusion-weighted signal intensities were decreased with increasing the labeling gap in the bilateral gray matter areas and were least affected on the parietal lobe, but most affected on the occipital lobe. 2) Perfusion-weighted signal intensities were decreased with increasing the labeling delay time until 400 ms, but increased up to 1,000 ms in the bilateral gray matter areas. 3) Perfusion-weighted signal intensities were increased with increasing the labeling thickness until 120 mm in both the gray and white matter. 4) Perfusion-weighted signal intensities were higher descending scans than asending scans in both the gray and white matter. We investigated changes of perfusion-weighted signal intensities with varying several parameters in the STAR ASL method. It should require having protocol optimization processing before applying in patients. It has limitations to apply the ASL method in the white matter on a 3T MRI system.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.65-71
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• 2011

Purpose: The recently adopted multiple confocal SPECT SYSTEM (hereinafter called IQ SPECT$^{TM}$) has a high difference from the conventional myocardial perfusion SPECT in the collimator form, image capture method, and image reconstruction method. This study was conducted to compare this novice equipment with the conventional one to design a protocol meeting the IQ SPECT, and also determine the characteristics and usefulness of IQ SPECT. Materials and Methods: 1. For the objects of LEHR (Low energy high resolution) collimator and Multiple confocal collimator, $^{99m}Tc$ 37MBq was put in the acrylic dish then each sensitivity ($cpm/{\mu}Ci$) was measured at the distance of 5 cm, 10 cm, 20 cm, 30 cm, and 40 cm respectively. 2. Based on the sensitivity measure results, IQ SPECT Protocol was designed according to the conventional general myocardial SPECT, then respectively 278 kBq/mL, 7.4 kBq/mL, and 48 kBq/mL of $^{99m}Tc$ were injected into the myocardial and soft tissues and liver site by using the anthropomorphic torso phantom then the myocardial perfusion SPECT was run. 3. For the comparison of FWHMs (Full Width at Half Maximum) resulted from the image reconstruction of LEHR collimator, the FWHMs (mm) were measured with only algorithms changed, in the case of the FBP (Filtered Back projection) method- a reconstruction method of conventional myocardial perfusion SPECT, and the 3D OSEM (Ordered subsets expectation maximization) method of IQ SPECT, by using $^{99m}Tc$ Line source. Results: 1. The values of IQ SPECT collimator sensitivity ($cpm/{\mu}Ci$) were 302, 382, 655, 816, 1178, and those of LEHR collimator were measured as 204, 204, 202, 201, 198, both at the distance of 5 cm, 10 cm, 20 cm, 30 cm, and 40 cm respectively. It was found the difference of sensitivity increases up to 4 times at the distance of 30 cm in the cases of IQ SPECT and LEHR. 2. The myocardial perfusion SPECT Protocol was designed according to the geometric characteristics of IQ SPECT based on the sensitivity results, then the phantom test for the aforesaid protocol was conducted. As a result, it was found the examination time can be reduced 1/4 compared to the past. 3. In the comparison of FWHMs according to the reconstructed algorithm in the FBP method and 3D OSEM method followed after the SEPCT test using a LEHR collimator, the result was obtained that FWHM rose around twice in the 3D OSEM method. Conclusion : The IQ SPECT uses the Multiple confocal collimator for the myocardial perfusion SPECT to enhance the sensitivity and also reduces examination time and contributes to improvement of visual screen quality through the myocardial-specific geometric image capture method and image reconstruction method. Due to such benefits, it is expected patients will receive more comfortable and more accurate examinations and it is considered a further study is required using additional clinical materials.

• Investigative Magnetic Resonance Imaging
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• v.21 no.1
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• pp.9-19
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• 2017

Background: Normalized cerebral blood volume (nCBV) can be measured using manual or semiautomatic segmentation method. However, the difference in diagnostic performance on brain tumor differentiation between differently measured nCBV has not been evaluated. Purpose: To compare the diagnostic performance of manually obtained nCBV to that of semiautomatically obtained nCBV on glioblastoma (GBM) and primary central nervous system lymphoma (PCNSL) differentiation. Materials and Methods: Histopathologically confirmed forty GBM and eleven PCNSL patients underwent 3T MR imaging with dynamic susceptibility contrast-enhanced perfusion MR imaging before any treatment or biopsy. Based on the contrast-enhanced T1-weighted imaging, the mean nCBV (mCBV) was measured using the manual method (manual mCBV), random regions of interest (ROIs) placement by the observer, or the semiautomatic segmentation method (semiautomatic mCBV). The volume of enhancing portion of the tumor was also measured during semiautomatic segmentation process. T-test, ROC curve analysis, Fisher's exact test and multivariate regression analysis were performed to compare the value and evaluate the diagnostic performance of each parameter. Results: GBM showed a higher enhancing volume (P = 0.0307), a higher manual mCBV (P = 0.018) and a higher semiautomatic mCBV (P = 0.0111) than that of the PCNSL. Semiautomatic mCBV had the highest value (0.815) for the area under the curve (AUC), however, the AUCs of the three parameters were not significantly different from each other. The semiautomatic mCBV was the best independent predictor for the GBM and PCNSL differential diagnosis according to the stepwise multiple regression analysis. Conclusion: We found that the semiautomatic mCBV could be a better predictor than the manual mCBV for the GBM and PCNSL differentiation. We believe that the semiautomatic segmentation method can contribute to the advancement of perfusion based brain tumor evaluation.