• Tuberculosis and Respiratory Diseases
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• v.66 no.1
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• pp.20-26
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• 2009

Background: $^{18}F$-Fluorodeoxyglucose positron emission tomography (FDG-PET) is widely used for the diagnosis and staging of non-small cell lung cancer (NSCLC). The aim of this study is to determine whether the bone marrow hypermetabolism seen on FDG-PET predicts a response to chemotherapy in patients with NSCLC. Methods: We evaluated the patients with advanced NSCLC and who were treated with combination chemotherapy. For determination of the standardized uptake value (SUV) of the bone marrow (BM SUV) on FDG-PET, regions of interest (ROIs) were manually drawn over the lumbar vertebrae (L1, 2, 3). ROIs were also drawn on a homogenous transaxial slice of the liver to obtain the bone marrow/ liver SUV ratio (BM/L SUV ratio). The response to chemotherapy was evaluated according to the Response Evaluation Criteria in Solid Tumor (RECIST) criteria after three cycles of chemotherapy. Results: Fifty-nine NSCLC patients were included in the study. Multivariate analysis was performed using a logistic regression model. The BM SUV and the BM/L SUV ratio on FDG-PET were not associated with a response to chemotherapy in NSCLC patients (p=0.142 and 0.978, respectively). Conclusion: The bone marrow hypermetabolism seen on FDG-PET can not predict a response to chemotherapy in NSCLC patients.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.45-50
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• 2011

Purpose: It appears the different value when the injection dose is calculating for patients on each PET/CT systems. It directly affects the technologists' radiation exposed dose. We studied the effect of the variable injection doses from several PET/CT systems to exposure dose for technologists. Materials and Methods: Six technologists have worked for 5 months through unit rotations with 3 PET/CT systems {Scanner 1 (S1): 0.15 mCi/kg, Scanner 2 (S2): 0.17 mCi/kg, Scanner 3 (S3): 0.12 mCi/kg}. Eighteen to 19 patients have had examinations per a day on each PET/CT systems. Examination parameters were adjusted to the same. TLDs were used for checking the exposure dose of technologists. Results: Each technologists' the monthly average exposure dose was as follows; S1: 0.76 mSv, S2: 0.93 mSv, S3: 0.47 mSv. The maximum exposure dose was 1.12 mSv, and minimum was 0.42 mSv. The results showed significance in the correlation between the PET/CT system and the exposure dose (p<0.005). Conclusion: When the amount of injection dose was small, the exposure dose was decreased not only the patients but also the technologists. The exposure dose was decreased by the individual proficiency of technologists. However, the low injection dose can highly reduce the exposure dose for technologist so that there will be needed to following studies.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.369-376
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• 2016

Positron Emission Tomography(PET) is nuclear medical tests which is a combination of several compounds with a radioactive isotope that can be injected into body to quantitatively measure the metabolic rate (in the body). Especially, Phenomena that increase (sing) glucose metabolism in cancer tissue using the $^{18}F$-FDG (Fluorodeoxyglucose) is utilized widely in cancer diagnosis. And then, Numerous studies have been reported that incidence seems high availability even in the modern diagnosis of dementia and Parkinson's (disease) in brain disease. When using a dynamic PET iamge including the time information in the static information that is provided for the diagnosis many can increase the accuracy of diagnosis. For this reason, clinical researchers getting great attention but, it is the lack of tools to conduct research. And, it interfered complex mathematical algorithm and programming skills for activation of research. In this study, in order to easy to use and enable research dPET, we developed the software based graphic user interface(GUI). In the future, by many clinical researcher using DIA-Tool is expected to be of great help to dPET research.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2009.04a
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• pp.298-298
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• 2009

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.218-224
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• 2004

We compared rest perfusion PET with redistribution perfusion SPECT to investigate the concordant rate between PET and SPECT images and analyze the discordant pattern. Materials and Methods: Rest N-13 ammonia and F-18 FDG PET were performed on 18 patients with old myocardial infarction and left ventricular dysfunction whose dipyridamole - 4hr redistribution TI-201 SPECT showed one or more severe fixed defects. Regional perfusion and metabolism were evaluated visually and quantitatively with 5-segment myocardial model. Results: There were high concordant rate in uptake pattern (80/90 segments, 88.9%) and high correlation coefficient on quantitative analysis (R=0.81, p<0.001) between redistribution TI-201 SPECT and N-13 ammonia PET images. Nine of 18 patients had SPECT-PET concordant pattern (Group I). Ten segments (9 in inferior wall, 1 in apex) from the remaining 9 patients showed SPECT-PET discordant pattern with abnormal TI-201 defect and near normal N-13 ammonia uptake (Group II). The diastolic and systolic left ventricular dimensions were significantly increased in Group II compared to those of Group I. When attenuation uncorrected N-13 ammonia PET images were reconstructed in Group II, it resulted in PET images with severe inferior wall defects nearly identical to those seen in redistribution TI-201 SPECT images. Conclusion: Redistribution TI-201 SPECT images showed high concordant rate and correlation with rest N-13 ammonia PET images. Most of discordant segments had fixed thallium defects in inferior wall with nearly normal N-13 ammonia uptake, which may result from severe left ventricular dilatation and attenuation by the left hemidiaphragm and cardiac blood pool.

• Clinical and Experimental Pediatrics
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• v.51 no.3
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• pp.286-292
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• 2008

Purpose : We performed EEG and PET on children with epilepsy concomitantly in order to evaluate the effects of epileptiform and non-epileptiform discharge of EEG on glucose metabolism. Methods : Seventy three children with epilepsy who had PET and EEG simultaneously were included in our study. The subjects were classified in two ways: (1) based on the frequency of epileptiform discharge and (2) the severity of non-epileptiform discharge. We evaluated the clinical aspects of their seizures, the severity of focal slow waves during the interictal period with the frequency of spikes or sharp waves in order to compare with the PET results. Results : The subjects were divided by the frequency of epileptiform discharge, with 13 in the no/rare group, 7 in the occasional group, and 53 children in the frequent group. The concordant rates with PET in each group were 0%, 42.9%, and 67.9%, respectively, showing high correlations with the frequency of epileptiform discharge (P<0.05, r=0.491). The subjects as divided by the severity of non-epileptiform discharge were 15 in the no group, 25 in the infrequent group, 17 in the intermediate group, and 16 in the continuous group. The concurrence rates with PET for each group were 13.3%, 52.0%, 64.7%, and 68.8%, respectively, also showing a high correlation with the severity of non-epileptiform discharge (P<0.05, r= 0.365). Conclusion : Epileptiform discharge and non-epileptiform discharge in EEG showed a certain association with hypometabolism in PET. We recommend EEG to reduce false lateralization and to localize lesions in cases of high frequency and severity.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.553-560
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• 2018

PET-CT and PET-MRI which integrates CT using ionized radiation and MRI using phenomena of magnetic resonance are determined to have the limitation to apply the semi-quantitative index, standardized uptake value (SUV), with the same level due to the fundamental differences of image capturing principle and reorganization, hence, their correlations were analyzed to provide their clinical information. To 30 study subjects maintaining pre-treatment, $^{18}F-FDG$ (5.18 MBq/㎏) was injected and they were scanned continuously without delaying time using $Biograph^{TM}$ mMR 3T (Siemens, Munich) and Biograph mCT 64 (Siemens, Germany), which is an integral type, under the optimized condition except the structural differences of both scanners. Upon the measurement results of $SUV_{max}$ setting volume region of interest with evenly distributed radioactive pharmaceuticals by captured images, $SUV_{max}$ mean values of PET-CT and PET-MRI were $2.94{\pm}0.55$ and $2.45{\pm}0.52$, respectively, and the value of PET-MRI was measured lower by $-20.85{\pm}7.26%$ than that of PET-CT. Also, there was a statistically significant difference in SUVs between two scanners (P<0.001), hence, SUV of PET-CT and PET-MRI cannot express the clinical meanings in the same level. Therefore, in case of the patients who undergo cross follow-up tests with PET-CT and PET-MRI, diagnostic information should be analyzed considering the conditions of SUV differences in both scanners.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.12-16
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• 2012

Purpose : In conventional PET image reconstruction, iterative reconstruction methods such as OSEM (Ordered Subsets Expectation Maximization) have now generally replaced traditional analytic methods such as filtered back-projection. This includes improvements in components of the system model geometry, fully 3D scatter and low noise randoms estimates. SharpIR algorithm is to improve PET image contrast to noise by incorporating information about the PET detector response into the 3D iterative reconstruction algorithm. The aim of this study is evaluation of SharpIR reconstruction method in PET/CT. Materials and Methods: For the measurement of detector response for the spatial resolution, a capillary tube was filled with FDG and scanned at varying distances from the iso-center (5, 10, 15, 20 cm). To measure image quality for contrast recovery, the NEMA IEC body phantom (Data Spectrum Corporation, Hillsborough, NC) with diameters of 1, 13, 17 and 22 for simulating hot and 28 and 37 mm for simulating cold lesions. A solution of 5.4 kBq/mL of $^{18}F$-FDG in water was used as a radioactive background obtaining a lesion of background ratio of 4.0. Images were reconstructed with VUE point HD and VUE point HD using SharpIR reconstruction algorithm. For the clinical evaluation, a whole body FDG scan acquired and to demonstrate contrast recovery, ROIs were drawn on a metabolic hot spot and also on a uniform region of the liver. Images were reconstructed with function of varying iteration number (1~10). Results: The result of increases axial distance from iso-center, full width at half maximum (FWHM) is also increasing in VUE point HD reconstruction image. Even showed an increasing distances constant FWHM. VUE point HD with SharpIR than VUE point HD showed improves contrast recovery in phantom and clinical study. Conclusion: By incorporating more information about the detector system response, the SharpIR algorithm improves the accuracy of underlying model used in VUE point HD. SharpIR algorithm improve spatial resolution for a line source in air, and improves contrast recovery at equivalent noise levels in phantoms and clinical studies. Therefore, SharpIR algorithm can be applied as through a longitudinal study will be useful in clinical.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.21-25
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• 2010

Purpose: For better PET imaging with accuracy the transmission scanning is inevitably required for attenuation correction. The attenuation is affected by condition of acquisition and patient position, consequently quantitative accuracy may be decreased in emission scan imaging. In this paper, the present study aims at providing the measurement for attenuation varying with the positions of the patient's arm in whole body PET/CT, further performing the comparative analysis over its SUV changes. Materials and Methods: NEMA 1994 PET phantom was filled with $^{18}F$-FDG and the concentration ratio of insert cylinder and background water fit to 4:1. Phantom images were acquired through emission scanning for 4min after conducting transmission scanning by using CT. In an attempt to acquire image at the state that the arm of the patient was positioned at the lower of ahead, image was acquired in away that two pieces of Teflon inserts were used additionally by fixing phantoms at both sides of phantom. The acquired imaged at a were reconstructed by applying the iterative reconstruction method (iteration: 2, subset: 28) as well as attenuation correction using the CT, and then VOI was drawn on each image plane so as to measure CT number and SUV and comparatively analyze axial uniformity (A.U=Standard deviation/Average SUV) of PET images. Results: It was found from the above phantom test that, when comparing two cases of whether Teflon insert was fixed or removed, the CT number of cylinder increased from -5.76 HU to 0 HU, while SUV decreased from 24.64 to 24.29 and A.U from 0.064 to 0.052. And the CT number of background water was identified to increase from -6.14 HU to -0.43 HU, whereas SUV decreased from 6.3 to 5.6 and A.U also decreased from 0.12 to 0.10. In addition, as for the patient image, CT number was verified to increase from 53.09 HU to 58.31 HU and SUV decreased from 24.96 to 21.81 when the patient's arm was positioned over the head rather than when it was lowered. Conclusion: When arms up protocol was applied, the SUV of phantom and patient image was decreased by 1.4% and 9.2% respectively. With the present study it was concluded that in case of PET/CT scanning against the whole body of a patient the position of patient's arm was not so much significant. Especially, the scanning under the condition that the arm is raised over to the head gives rise to more probability that the patient is likely to move due to long scanning time that causes the increase of uptake of $^{18}F$-FDG of brown fat at the shoulder part together with increased pain imposing to the shoulder and discomfort to a patient. As regarding consideration all of such factors, it could be rationally drawn that PET/CT scanning could be made with the arm of the subject lowered.

• BMB Reports
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• v.42 no.6
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• pp.350-355
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• 2009

Although previous studies on hexokinase (HK) II indicate both the N- and C-terminal halves are catalytically active, we show in this study the N-terminal half is significantly more catalytic than the C-terminal half in addition to having a significantly higher $K_m$ for ATP and Glu. Furthermore, truncated forms of intact HK II lacking its first N-terminal 18 amino acids ($\Delta$18) and a truncated N-terminal half lacking its first 18 amino acids ($\Delta$18N) have higher catalytic activity than other mutants tested. Similar results were obtained by PET-scan analysis using $^{18}F-FDG$. Our results collectively suggest that each domain of HK II possesses enzyme activity, unlike HK I, with the N-terminal half showing higher enzyme activity than the C-terminal half.