• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.31 no.2
• /
• pp.178-182
• /
• 2005

With the development of systemic diagnostic technique in cancer, the diagnostic methods of head and neck region are developing, also. Now, it is usually used computed tomography(CT), magnetic resornance image(MRI) in head and neck cancer and positron emission tomography(PET) is being increased in diagnostic use because of tumor specificity and accuracy. However, CT and MRI show the advantage of showing precise anatomical landmarks, but the disadvantage of these methods is much affecting by anatomical variations and changes. Otherwise, PET presents the imaging of physiologic and biochemical phenomenon and the disadvantage is the difficult differentiation of normal physiologic uptake, the lack of normal anatomical landmarks. PET/CT, the combination of clinical PET and CT imaging in a single unit is introduced recently, and it helps to get more accurate diagnostic interpretation and to improve in evaluating response to therapy, in management of patients with malignant tumors. So, we report the advantages of PET/CT in the diagnosis of oral cancer with review of literatures.

• The Korean Journal of Nuclear Medicine
• /
• v.36 no.1
• /
• pp.53-63
• /
• 2002

FDG PET is a functional imaging modality whose ability to detect lesions is directly based on a change of the glycolytic metabolism of targeted tissues, may be advantageous over other techniques. Combined with excellent image qualify, high spatial resolution, and whole body imaging capability, it has become popular as a new approach in the evaluation of patients with various malignancies. Initial staging of nodal and extranodal lymphoma using FDG PET has been proven to be at least equal or superior to conventional imaging modalities. For the assessment of treatment responsiveness, FDG PET has a major impact on the management of patients in differentiating residual lymphoma from treatment related benign changes. Residual FDG uptake after the completion of chemotherapy is a good predictor of early relapse. However, it seems that the absence of FDG uptake in tumor mass may not exclude minimal residual disease causing later relapse. In the early evaluation of treatment response only after a few cycles of chemotherapy, FDG PET may have a promising role in identifying non-responders who could benefit from a different treatment strategy. At present, FDG PET appears to be the cost-effective, diagnostic modality of choice in the management of lymphoma patients. The role of FDG PET based-systems in terms of affecting long-term prognosis and survival benefit should be further elucidated in future prospective studios.

• Journal of radiological science and technology
• /
• v.42 no.2
• /
• pp.119-130
• /
• 2019

Positron emission tomography (PET) is widely used imaging modality for effective and accurate functional testing and medical diagnosis using radioactive isotopes. However, PET has difficulties in acquiring images with high image quality due to constraints such as the amount of radioactive isotopes injected into the patient, the detection time, the characteristics of the detector, and the patient's motion. In order to overcome this problem, we have succeeded to improve the image quality by using the dynamic image reconstruction method based on singular value decomposition. However, there is still some question about the characteristics of the proposed technique. In this study, the characteristics of reconstruction method based on singular value decomposition was estimated over computational simulation. As a result, we confirmed that the singular value decomposition based reconstruction technique distinguishes the images well when the signal - to - noise ratio of the input image is more than 20 decibels and the feature vector angle is more than 60 degrees. In addition, the proposed methode to estimate the characteristics of reconstruction technique can be applied to other spatio-temporal feature based dynamic image reconstruction techniques. The deduced conclusion of this study can be useful guideline to apply medical image into SVD based dynamic image reconstruction technique to improve the accuracy of medical diagnosis.

• Progress in Medical Physics
• /
• v.17 no.3
• /
• pp.173-178
• /
• 2006

The purpose of this study was to evaluate the radiation dose for clinical PET/CT protocols in clinical environments using Alderson phantom and TLDs. Radiation doses were evaluated for both Philips GEMINI 16 slice PET/CT system and GE DSTe 16 slice PET/CT system. Specific organ doses with $^{137}Cs$ transmission scan, high quality CT scan and topogram in philips GEMINI PET/CT system were measured. Specific organ doses with CT scan for attenuation map, CT scan for diagnosis and topogram in GE DSTe PET/CT system were also measured. The organs were selected based on ICRP60 recommendation. The TLDs used for measurements were selected for within an accuracy of ${\pm}5%$ and calibrated in 10 MV X-ray radiation field. The effective doses for $^{137}Cs$ transmission scan, high qualify scan, and topogram in Philips GEMINI PET/CT system were $0.14{\pm}0.950,\;29.49{\pm}1.508\;and\;0.72{\pm}0.032mSv$ respectively. The effective doses for CT scan to make attenuation map, CT scan to diagnose and topogram in GE DSTe PET/CT system were $20.06{\pm}1.003,\;24.83{\pm}0.805\;and\;0.27{\pm}0.008mSv$ respectively. We evaluated the total effective dose by adding effective dose for PET Image. The total PET/CT doses for Philips GEMINI PET/CT (Topogram+$^{137}Cs$ transmission scan+PET, Topogram+high qualify CT+PET) and GE DSTe PET/CT (Topogram +CT for attenuation map+ PET, Topogram+diagnostic CT+ PET) are $7.65{\pm}0.951,\;37.00{\pm}1.508,\;27.12{\pm}1.003\;and\;31.89{\pm}0.805mSv$ respectively. Further study may be needed to be peformed to find optimal PET/CT acquisition protocols for reducing the patient exposure with good image qualify.

• Journal of the Korean Society of Radiology
• /
• v.9 no.4
• /
• pp.249-255
• /
• 2015

In this study, through the additional information of the PET / CT images by utilizing the basic data of TPS clinical application on the basis of the image re-forming synthetic function, the True-D technology and MIM software for continued research and development in combination, based on the combination-work between the respective images, reducing the time and cost of useful reading in clinical wide use of image width, efficient, effective tool for tumor targeting at diagnosis and radiation therapy by use as, by using the precise therapeutic effect determination, the time taken to read in the clinical, unnecessary and expect to a can reduce the additional examination by the creation of tumor patients read reports and PACS such asWe expect to be utilized for compatibility development with other software to evaluate the performance of PET / CT equipment.

• Journal of Korea Society of Industrial Information Systems
• /
• v.13 no.4
• /
• pp.145-154
• /
• 2008

In this paper, we propose the pet robot control system using hand gesture recognition in image sequences acquired from a camera affixed to the pet robot. The proposed system consists of 4 steps; hand detection, feature extraction, gesture recognition and robot control. The hand region is first detected from the input images using the skin color model in HSI color space and connected component analysis. Next, the hand shape and motion features from the image sequences are extracted. Then we consider the hand shape for classification of meaning gestures. Thereafter the hand gesture is recognized by using HMMs (hidden markov models) which have the input as the quantized symbol sequence by the hand motion. Finally the pet robot is controlled by a order corresponding to the recognized hand gesture. We defined four commands of sit down, stand up, lie flat and shake hands for control of pet robot. And we show that user is able to control of pet robot through proposed system in the experiment.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.21 no.1
• /
• pp.29-33
• /
• 2017

Purpose In this study, we evaluated image by applying normalization factor during 30 days to the PET images. Materials and Methods Normalization factor was acquired during 30 days. We compared with 30 normalization factors. We selected 3 clinical case (PNS study). We applied for normalization factor to PET raw data and evaluated SUV and count (kBq/ml) by drawing ROI to liver and lesion. Results There is no significant difference normalization factor. SUV and count are not different for PET image according to normalization factor. Conclusion We can get a lot of information doing the quality assurance such as performance of sinogram and detector. That's why we need to do quality assurance daily.

• Journal of radiological science and technology
• /
• v.37 no.1
• /
• pp.49-56
• /
• 2014

Recently with CT developed, various studies for reduction of exposure dose is underway. Study of bismuth shields in these studies is actively underway, and has already been applied in the clinical. However, the application of the PET/CT examination was not activated. Therefore, through this study, depending on the application of bismuth shields in the PET/CT examination, we identify the quality of the image and the impact on the Standard Uptake Value (SUV). In this study, to apply to the shielding of the breast, by using the bismuth shields that contains 0.06 mm Pb ingredients, was applied to the PET/CT GEMINI TF 64 (Philips Healthcare, Cleveland, USA). Phantom experiments using the NEMA IEC Body Phantom, images were acquired according to the presence or absence of bismuth shields apply. Also, When applying, images were obtained by varying the spacing 0, 1, 2 cm each image set to the interest range in the depth of the phantom by using EBW-NM ver.1.0. When image of the PET Emission acquires, the SUV was in increased depending on the use of bismuth shields, difference in the depth to the surface from deep in the phantom increasingly SUV increased (P<0.005). Also, when using shields, as the more gab decreased, SUV is more increased (P<0.005). Through this study, PET/CT examination by using of bismuth shields which is used as purpose of reduction dose. When using shields, the difference of SUV resulting from the application of bismuth shields exist and that difference when gab is decrease and surface is wider. Therefore, setting spacing of shield should be considered, if considering the reduction of the variation of SUV and image quality, disease of deep organs should be a priority rather than superficial organ disease. Use of bismuth shielding factor considering the standard clinical examination, decrease unnecessary exposure can be expected to be considered.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.17 no.1
• /
• pp.36-42
• /
• 2013

Purpose: Recently with CT developed, various studies for reduction of exposure dose is underway. Study of bismuth shields in these studies is actively underway, and has already been applied in the clinical. However, the application of the PET/CT examination was not activated. Therefore, through this study, depending on the application of bismuth shields in the PET/CT examination, we want to identify the quality of the image and the impact on the SUV. Materials and Methods: In this study, to apply to the shielding of the breast, by using the bismuth shields that contains 0.06 mmPb ingredients, was applied to the PET/CT GEMINI TF 64 (Philips Healthcare, Cleveland, USA). Phantom experiments using the NEMA IEC Body Phantom, images were acquired according to the presence or absence of bismuth shields apply. Also, When applying, images were obtained by varying the spacing 0, 1, 2 cm each image set to the interest range in the depth of the phantom by using EBW-NM ver.1.0. Results: When image of the PET Emission acquires, the SUV was in increased depending on the use of bismuth shields, difference in the depth to the surface from deep in the phantom increasingly SUV increased (P<0.005). Also, when using shields, as the more gab decreased, SUV is more increased (P<0.005). Conclusion: Through this study, PET/CT examination by using of bismuth shields which is used as purpose of reduction dose be considered. When using shields, the difference of SUV resulting from the application of bismuth shields exist and that difference is more decreased as gab of shields and surface is wider. Therefore, setting spacing of shield should be considered, if considering the reduction of the variation of SUV and image quality, disease of deep or other organs should be a priority rather than superficial disease. Through this study, when applying identified to clinical examination, the reduction of unnecessary exposure is considered.

• Nuclear Medicine and Molecular Imaging
• /
• v.43 no.6
• /
• pp.565-571
• /
• 2009

Purpose: The aim of this study was to evaluate the clinical value of rectal gas distension F-18 FDG PET/CT imaging for the differentiation of the rectal focal uptake lesions. Materials and Methods: Twenty four patients (M:F=11:13, Age $62.8{\pm}12.4$ years) underwent rectal gas distension F-18 FDG PET/CT, prospectively: initial image at 50-60 min after the intravenous injection of F-18 FDG and rectal distension image after the infusion of air through the anus. Focally increased uptake lesions on initial images but disappeared on rectal distension images defined a physiological uptake. For the differential evaluation of persistent focal uptake lesions on rectal distension images, colonoscopy and histopathologic examination were performed. Results: Among the 24 patients, 27 lesions of focal rectal uptake were detected on initial images of F-18 FDG PET/CT. Of these, 7 lesions were able to judge with physiological uptake because the focal increased uptake disappeared from rectal distension image. Remaining 3 lesions were non-rectal lesions (2 lesions: rectovesical space, 1 lesion: uterine myoma). Among 17 lesions which was showed persistent increased uptake in rectal distension image, 15 lesions were confirmed as the malignant tumor (SUVmax=$15.9{\pm}6.8$) and 2 lesions were confirmed as the benign lesions including adenoma and inflammatory disease. Conclusion: The rectal distension F-18 FDG PET/CT imaging could be an important noninvasive method for the differentiation of malignant and benign focal rectal uptake lesions including physiologic uptake.