• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.68-73
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• 2015

Purpose The purpose of this study was to evaluate image quality change by truncated region in field of view (FOV) of attenuation correction computed tomography (AC-CT) in brain PET/CT. Materials and Methods Biograph Truepoint 40 with TrueV (Siemens) was used as a scanner. $^{68}Ge$ phantom scan was performed with and without applying brain holder using brain PET/CT protocol. PET attenuation correction factor (ACF) was evaluated according to existence of pallet in FOV of AC-CT. FBP, OSEM-3D and PSF methods were applied for PET reconstruction. Parameters of iteration 4, subsets 21 and gaussian 2 mm filter were applied for iterative reconstruction methods. Window level 2900, width 6000 and level 4, 200, width 1000 were set for visual evaluation of PET AC images. Vertical profiles of 5 slices and 20 slices summation images applied gaussian 5 mm filter were produced for evaluating integral uniformity. Results Patient pallet was not covered in FOV of AC-CT when without applying brain holder because of small size of FOV. It resulted in defect of ACF sinogram by truncated region in ACF evaluation. When without applying brain holder, defect was appeared in lower part of transverse image on condition of window level 4200, width 1000 in PET AC image evaluation. With and without applying brain holder, integral uniformities of 5 slices and 20 slices summation images were 7.2%, 6.7% and 11.7%, 6.7%. Conclusion Truncated region by small FOV results in count defect in occipital lobe of brain in clinical or research studies. It is necessary to understand effect of truncated region and apply appropriate accessory for brain PET/CT.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.62-67
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• 2014

A glomerular filtration rate (GFR) study is a test that uses radioactive materials or tracers (radiopharmaceuticals) and a computer to see how well the kidneys are working. Asan Medical Center analyzed and compared data between kidney depth, acquired from kidney donors' CT image and acquired from Gates method's GFR value that are calculated by Tonnesen equation. This study was able to confirm that kidney depth measured from CT image was higher than the Gates Method's GFR value, which was calculated by Tonnessen equation; the direct relationship among pathologic results is confirmed. Particularly, kidney donor whose kidney was at the pelvic area had direct relationship with other clinical results. During the GFR test, it is necessary to confirm the location of kidney has no change with reference of CT image. If kidney depth is manually corrected using CT image when we measures GFR of deformed or horse-shoe kidney, it would be possible to acquire the compatible value which is equivalent to clinical result. There would be a possible issue of appropriateness that whether the applied GFR using CT image's kidney depth has clinical validity. In case of a pediatric patient, the GFR derived from Tonnesen was quiet underestimated while manual method and Gordon stay in normal range. Which results may be correct among them? There have been many reports about kidney depth, to be an accurate index of GFR in children. As one of the study performers, we should contemplate what the best option for pediatric patients would be.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.372-380
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• 1997

The purpose of this study was to evaluate the usefulness of whole body F-18 FDG PET scan for detecting postoperative recurrence of cancer. One hundred four cancer patients after operation were enrolled(14 brain tumor, 15 head and neck cancer, 23 gynecologic cancer, 16 gastrointestinal cancer, 16 thyroid cancer, and 20 other cancers). Besides conventional images(CI) including CT and MRI, F-18 FDG PET scan was obtained on ECAT EXACT 47 scanner(Siemens-CTI), beginning 60 minutes after injection of 370MBq(10mCi) of F-18 FDG. Regional scan was also obtained with emission image. Transmission images using Ge-68 were carried out for attenuation correction in both whole body and regional images. Findings of PET, and CI were confirmed by pathology or clinical follow up. The sensitivity and specificity of PET for detecting recurrence were 94% and 92%, respectively. Contrarily, the sensitivity and specificity of CI were 78% and 68%. CI results were negative and PET results were positive in 11 cases. The biopsy or clinical follow-up of those cases confirmed recurrence of tumor. False negative cases of CI were frequent in patients with gynecologic cancers. Also we measured the serum concentration of tumor markers in patients with gynecologic cancer(CA125), thyroid cancer(thyroglobulin), and colorectal cancer(CEA). The sensitivity and specificity of tumor markers were 71% and 84%, respectively, We conclude that F-18 FDG PET can be used valuably in detecting recurrent foci of a wide variety of malignancy compared to conventional diagnostic methods.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.77-81
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• 2009

Purpose: The PET of the PET/CT (Positron Emission Tomography/Computed Tomography) quantitatively shows the biological and chemical information of the body, but has limitation of presenting the clear anatomic structure. Thus combining the PET with CT, it is not only possible to offer the higher resolution but also effectively shorten the scanning time and reduce the noises by using CT data in attenuation correction. And because, at the CT scanning, the contrast media makes it easy to determine a exact range of the lesion and distinguish the normal organs, there is a certain increase in the use of it. However, in the case of using the contrast media, it affects semi-quantitative measures of the PET/CT images. In this study, therefore, we will be to establish the reliability of the SUV (Standardized Uptake Value) with CT data correction so that it can help more accurate diagnosis. Materials and Methods: In this experiment, a total of 30 people are targeted - age range: from 27 to 72, average age : 49.6 - and DSTe (General Electric Healthcare, Milwaukee, MI, USA) is used for equipment. $^{18}F$- FDG 370~555 MBq is injected into the subjects depending on their weight and, after about 60 minutes of their stable position, a whole-body scan is taken. The CT scan is set to 140 kV and 210 mA, and the injected amount of the contrast media is 2 cc per 1 kg of the patients' weight. With the raw data from the scan, we obtain a image showing the effect of the contrast media through the attenuation correction by both of the corrected and uncorrected CT data. Then we mark out ROI (Region of Interest) in each area to measure SUV and analyze the difference. Results: According to the analysis, the SUV is decreased in the liver and heart which have more bloodstream than the others, because of the contrast media correction. On the other hand, there is no difference in the lungs. Conclusions: Whereas the CT scan images with the contrast media from the PET/CT increase the contrast of the targeted region for the test so that it can improve efficiency of diagnosis, there occurred an increase of SUV, a semi-quantitative analytical method. In this research, we measure the variation of SUV through the correction of the influence of contrast media and compare the differences. As we revise the SUV which is increasing in the image with attenuation correction by using contrast media, we can expect anatomical images of high-resolution. Furthermore, it is considered that through this trusted semi-quantitative method, it will definitely enhance the diagnostic value.

• 대한핵의학회:학술대회논문집
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• 2004.11a
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• pp.400.1-400.1
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• 2004

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.1
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• pp.65-69
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• 2017

Purpose KSNMT(Korea Society of Nuclear Medicine Technology) stepping first step in 1997, has published first journal related with nuclear medicine technology in 1985. With classifying In Vivo Session Dissertation reported in the entire journal, trend of the Dissertation will be studied. Materials and Methods Dissertations which published from 1985 to first half of 2016 in the journal are classified with presentation form and with scanner, And all the data is organized with Excel program. Through the data, the number of dissertations published in each year, the number of dissertation published in details, and keyword distributions in each period are analyzed. Results The number of In-vivo section dissertations was 1151 and the number of In-vivo section dissertations that have common subject with In-vitro section was 28. The number of In-vivo section dissertation in 1980s was 46, in 1990s was 149, in 2000 was 467 and from 2010 to the first half of 2016 was 517. The number of dissertation with original articles was 571, with abstract was 529, with symposium was 31, with special lecture was 25, with review was 11, with interesting image was 7, with poster was 3 and with case report was 2. With symposium and special lecture excluded, which count 56, the number of dissertation with PET was 319, with Planar was 302, with SPECT was 172, with radiopharmaceutical was 113, with guard and safety management 103, with BMD was 28, etc. was 86. The number of dissertation about oncology was 201, about scanner was 179, about cardiovascular and circulatory system was 102, about safe environment was 82, about musculoskeletal system was 76, about nervous nuclear medicine was 66, about quality assurance was 61, about genitourinary system was 56, about endocrine system was 49, about digestive system was 44, about Therapy, about industrial safety was 24, about molecular imaging was 15, infection and inflammation was 9, about respiratory system was 8 and etc. was 108. The mostly used keyword through 1999 to 2005 was PET and through 2006 to 2016 was PET/CT. Conclusion To encourage various dissertations to be submitted, Korea Society of Nuclear Medicine should analyze date about not only about dissertations that are already published, but also about various research materials. Moreover, Korea Society of Nuclear Medicine also have to provide technical support such as sharing big data from homepage and systematical support to its member to publish dissertation that has high impact factor. It is important each individual researcher to have continuing effort as well as each organization cooperation.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.153-163
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• 2008

Medical imaging modalities to image either anatomical structure or functional processes have developed along somewhat independent paths. Functional images with single photon emission computed tomography (SPECT) and positron emission tomography (PET) are playing an increasingly important role in the diagnosis and staging of malignant disease, image-guided therapy planning, and treatment monitoring. SPECT and PET complement the more conventional anatomic imaging modalities of computed tomography (CT) and magnetic resonance (MR) imaging. When the functional imaging modality was combined with the anatomic imaging modality, the multimodality can help both identify and localize functional abnormalities. Combining PET with a high-resolution anatomical imaging modality such as CT can resolve the localization issue as long as the images from the two modalities are accurately coregistered. Software-based registration techniques have difficulty accounting for differences in patient positioning and involuntary movement of internal organs, often necessitating labor-intensive nonlinear mapping that may not converge to a satisfactory result. These challenges have recently been addressed by the introduction of the combined PET/CT scanner and SPECT/CT scanner, a hardware-oriented approach to image fusion. Combined PET/CT and SPECT/CT devices are playing an increasingly important role in the diagnosis and staging of human disease. The paper will review the development of multi modality instrumentations for clinical use from conception to present-day technology and the application software.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.305-308
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• 1993

Metastatic thyroid carcinoma in bone shows characteristic expansile, trabeculated lysis on radio-gram. The ordinary scintigraphy manifests with a simple photopenic defect. We were able to portray trabeculation within photopenic defects. We present papillary thyroid carcinoma and follicular thyroid carcinoma, one each, pinhole bone scintigraphic findings of which are cold area with septated increased uptake at the iliae bone. These findings correspond very well with their X-ray pictures.

• The Korean Journal of Nuclear Medicine
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• v.34 no.3
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• pp.159-168
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• 2000

In the 1980s, techniques to image the human subjects in a three-dimensional direction were developed. Two major techniques are SPECT (Single Photon Emission Computed Tomography) and PET (Positron Emission Tomography) which allow the detector to detect a single photon or annihilation photons emitted from the subjects injected with radiopharmaceuticals. Since the latter two techniques can measure the density of receptors, enzymes and transporters in living human, it may be very important project to develop selective methods of labeling with radionuclides and to develop new radiopharmaceuticals. There has been a considerable interest in developing new compounds which specifically bind to dopamine and serotonin receptor and transporters, and it will be thus very useful to label those compounds with radionuclides in order to gain a better understanding in biochemical and pharmacological interactions in living human. This review mentions the characteristics of radioligands for the imaging of dopamine and serotonin receptors and transporters. Although significant progress has been achieved in the development of new PET and SPECT ligands for in vivo imaging of those receptors and transporters, there are continuous needs of new diagnostic radioligands.

• The Korean Journal of Nuclear Medicine
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• v.37 no.1
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• pp.53-62
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• 2003

After the development of two major techniques - SPECT (Single Photon Emission Computed Tomography) and PET (Positron Emission Tomography) to image the human subjects in a three-dimensional direction in the 1980s, many radiotracers have been used for functional neuroimaging. Still it would be very important study to develop selective radiotracers for functional neuroimaging. New radiotracers will help to expand the knowledge of neurotransmitter systems and of the genetic contribution to receptor or transporter availability. Neurotransmitter depletion-restoration studies, the distribution of brain functions and their modulation by neurotransmitter system aid in better understanding and limiting the side effects of drugs used as well as newly developed. In audition, these radiotracers will be thus very useful to gain a better understanding in biochemical and pharmacological interactions in living human. This review mentions the introduction of radioligands for the functional neuroimaging. Although significant progress has been achieved in the development of new PET and SPECT ligands for in vivo imaging of those receptors and transporters, there are continuous needs of new diagnostic radioligands.