• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.291-298
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• 1997

• Journal of Korean Neurosurgical Society
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• v.60 no.1
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• pp.98-101
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• 2017

We report a case of primary intracranial malignant melanoma (PIMM) with extracranial metastases. The patient was an 82-year-old woman diagnosed with PIMM under the left cerebellar tentorium. We performed a tumor resection followed by gamma knife surgery. An magnetic resonance imaging at 11 months after surgery showed a local intracranial recurrence. At 12 months, vertebral metastasis was suspected, and 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) showed multiple extracranial metastases. She died at 13 months after surgery. Although extracranial metastases of PIMM are extremely rare, we should carefully follow up extracranial metastases together with intracranial ones, especially by FDG-PET/CT, even at an early asymptomatic stage.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.3
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• pp.207-214
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• 2009

Positron emission tomogrpahy (PET) represents the most advanced scintigraphic imaging technology. With the increase in availability of PET, the clinical use of PET has grown in medical fields. This can be employed for cardiovascular research as well as for clinical applications in patients with various cardiovascular disease. PET allows non-invasive functional assessment of myocardial perfusion, substrate metabolism and cardiac innervation and receptors as well as gene expression in vivo. PET is regarded as the gold standard for the detection of myocardial viability, and it is the only method available for the quantitative assessment of myocardial blood flow. This review focuses on the clinical applications of myocardial perfusion PET in coronary artery disease.

• The Korean Journal of Nuclear Medicine
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• v.32 no.6
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• pp.534-541
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• 1998

We describe a 27-year-old man who developed gait disturbance and dysarthria 2 years after the onset of cardinal symptoms of Behcet's disease. Positron emission tomography with $^{18}F$-fluorodeoxyglucose revealed severe hypometabolisrn in the cerebellum, in accordance with cerebellar symptoms and signs of the patient. However, single-photon emission tomography with $^{99m}Tc$-HMPAO and $^{99m}Tc$-ECD did not disclose significant perfusion abnormalities in the brain. Routine brain magnetic resonance imaging did not show signal abnormalities. The findings of imaging studies compared with neurological manifestations of the patient are discussed.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.63-71
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• 2008

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.363-365
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• 2009

Kikuchi's disease is a self-limiting benign disease characterized by cervical lymphadenopathy, but it can be mistaken for malignant disease, and when involved lymph nodes are unusually located, diagnosis can be more difficult. The authors report the case of a 19-year-old man with Kikuchi's disease, who had isolated intra-abdominal lymphadenopathy and increased 18-fluoro-deoxyglucose (FDG) uptake in positron emission tomography-computed tomography (PET-CT). Although its incidence is extremely rare, intra-abdominal Kikuchi's disease with increased FDG uptake in PET-CT image should be considered in the differential diagnosis when constitutional symptoms mimic those of malignant lymphoma.

• The Korean Journal of Nuclear Medicine
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• v.36 no.1
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• pp.74-79
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• 2002

In addition to the well-established use of positron emission tomography (PET) in clinical oncology, novel roles for PET are rapidly emerging in the field of gene therapy. Methods for controlled gene delivery to living bodies, made available through advances in molecular biology, are currently being employed in animals for research purposes and in humans to treat diseases such as cancer. Although gene therapy is still in its early developmental stage, it is perceived that many serious illnesses could be treated successfully by the use of therapeutic gene delivery. A major challenge for the widespread use of human gene therapy is to achieve a controlled and effective delivery of foreign genes to target cells and subsequently, adequate levels of expression. As such, the availability of noninvasive imaging methods to accurately assess the location, duration, and level of transgene expression is critical for optimizing gene therapy strategies. Current endeavors to achieve this goal include methods that utilize magnetic resonance imaging, optical imaging, and nuclear imaging techniques. As for PET, reporter systems that utilize genes encoding enzymes that accumulate positron labeled substrates and those transcribing surface receptors that bind specific positron labeled ligands have been successfully developed. More recent advances in this area include improved reporter gene constructs and radiotracers, introduction of potential strategies to monitor endogenous gene expression, and human pilot studies evaluating the distribution and safety of reporter PET tracers. The remarkably rapid progress occurring in gene imaging technology indicates its importance and wide range of application. As such, gene imaging is likely to become a major and exciting new area for future application of PET technology.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.5
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• pp.305-310
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• 2015

We propose a new concept for a depth of interaction (DOI) positron emission tomography (PET) detector based on dual-ended-scintillator (DES) readout for small animal imaging. The detector consists of lutetium yttrium orthosilicate (LYSO) arrays coupled with orthogonal wavelength-shifting (WLS) fibre placed on the top and bottom of the arrays. On every other line, crystals that are 2 mm shorter are arranged to create grooves. WLS fibre is inserted into these grooves. This paper describes the design and performance evaluation of this PET detector using Monte Carlo simulations. To investigate sensitivity by crystal size, five types of PET detectors were simulated. Because the proposed detector is composed of crystals with three different lengths, degradation in sensitivity across the field of view was also explored by simulation. In addition, the effect of DOI resolution on image quality was demonstrated. The simulation results proved that the devised PET detector with excellent DOI resolution is helpful for reducing the channels of sensors/electronics and minimizing gamma ray attenuation and scattering while maintaining good detector performance.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.222-228
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• 2023

This study aimed to analyze the applicability of the improved median filter in positron emission tomography (PET)/magnetic resonance (MR) fusion images based on parallel imaging using generalized autocalibrating partially parallel acquisition (GRAPPA). In this study, a PET/MR fusion imaging system based on a 3.0T magnetic field and ¹⁸F radioisotope were used. An improved median filter that can set a mask of the median value more efficiently than before was modeled and applied to the acquired image. As quantitative evaluation parameters of the noise level, the contrast to noise ratio (CNR) and coefficient of variation (COV) were calculated. Additionally, no-reference-based evaluation parameters were used to analyze the overall image quality. We confirmed that the CNR and COV values of the PET/MR fusion images to which the improved median filter was applied improved by approximately 3.32 and 2.19 times on average, respectively, compared to the noisy image. In addition, the no-reference-based evaluation results showed a similar trend for the noise-level results. In conclusion, we demonstrated that it can be supplemented by using an improved median filter, which suggests the problem of image quality degradation of PET/MR fusion images that shortens scan time using GRAPPA.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.2
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• pp.129-132
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• 2023

Purpose: Positron emisson tomography (PET) is a crucial medical imaging scanner for the detection of cancer lesions. In order to maintain the improved image quality, it is crucial to apply detectors of superior performance. Therefore, the purpose of this study was to compare PET image quality using Monte Carlo simulation based on the detector materials of BGO, LSO, and LuAP. Materials and Methods: The Geant4 Application for Tomographic Emission (GATE) was used to design the PET detector. Scintillations with BGO, LSO and LuAP were modelled, with a size of 3.95 × 5.3 mm2 (width × height) and 25.0 mm (thickness). The PET detector consisted of 34 blocks per ring and a total of 4 rings. A line source of 1 MBq was modelled and acquired with a radius of 1 mm and length of 20 mm for 20 seconds. The acquired image was reconstructed maximum likelihood expectation maximization with 2 iteration and 10 subsets. The count comparison was carried out. Results and Discussion: The highest true, random, and scatter counts were obtained from the BGO scintillation detector compared to LSO and LuAP. Conclusion: The BGO scintillation detector material indicated excellent performance in terms of detection of gamma rays from emitted PET phantom.