• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.11-27
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• 1999

Peptide imaging is a new diagnostic modality in nuclear medicine. $^{111}In$-pentetreotide ($Octreoscan^R$) is the first commercially available peptide radiopharmaceutical. This review article presents the results of previous studies using $^{111}In$-pentetreotide for several disease states, including neuroendocrine tumors, breast cancer and malignant lymphoma. The use of hand-held probe during surgery and the preliminary results of radiotherapy using radiolabeled somatostatin analogues are also reviewed. It can be concluded that somatostatin receptor scintigraphy is a promising diagnostic tool for localizing primary tumors that express receptors for somatostatin, staging secondary spread of tumor tissue, following up after therapy and identifying patients who may benefit from therapy with unlabelled or radiolabeled octreotide. The somatostatin receptor imaging will stimulate the development of new radiopharmaceuticals for other receptors and enhance the therapeutic use of radiolabeled peptides.

• Korean Journal of Digital Imaging in Medicine
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• v.16 no.2
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• pp.25-29
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• 2014

The full-field digital mammography (FFDM), which has been known as a digital breast imaging system, carries out more outstanding performance than the screen-film mammography in overall image quality, skin & nipple, description of pectoral muscle and expression of micro-calcification. Thus, in this thesis, I perform experiments for both the enhancement of image quality and accurate estimation of the result in question, when detecting the very tiny-sized lesions in mammography. The image of digital breast X-rays is the important diagnostic tool for detecting early breast cancer and micro calcification lesion. The experiment of how much compression rate has an effect on the result of diagnosis in the case of microcalcification lesion, with JPEG2000 40:1 compression and over 50% enlargement led to obscure or definitely unacceptable diagnostic results is performed. And in another study of assessment of PSNR degree. I recognized the importance of standardized management system in mammography, where not to mention the accurate reading of the image has the most crucial role in diagnosis

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.909-910
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• 2007

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.1 no.2
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• pp.95-97
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• 2015

The translocator protein (TSPO) is one of the important targets for Positron Emission Tomography (PET) imaging because it is associated with brain cancer, stroke, and neurodegeneration. Recently, a novel quinoline compound with high affinity agent for the translocator protein has been developed. In this highlight review, major studies for the quinoline compound are described.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.8 no.1
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• pp.25-32
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• 2022

Malignant melanoma has an aggressive nature and high metastatic potential that result in one of the highest cancer mortality rates. Over the past three decades, primary and metastatic melanoma incidence has rapidly increased. The recent advances in diagnostic technology have shown promise, but there is still an enormous need for specific detection methods to diagnose malignant melanoma. Positron emission tomography can visualize a particular biomarker of malignant melanoma and promise a noninvasive image of micrometastases. However, the development of PET radiopharmaceuticals remains necessary for diagnosing malignant melanoma by using positron emission tomography. In this review, the history and a general overview of PET radionuclide labeled benzamide derivatives, including their radiosynthesis, in vivo characterization, and evaluation, are provided as imaging agents for malignant melanoma.

• Korean Journal of Radiology
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• v.22 no.9
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• pp.1569-1578
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• 2021

The Korean Thyroid Imaging Reporting and Data System (K-TIRADS) is an ultrasound-based risk stratification system for thyroid nodules that has been widely applied for the diagnosis and management of thyroid nodules since 2016. This review article provides an overview of the use of the K-TIRADS compared with other risk stratification systems. Moreover, this review describes the challenges in the clinical application of the K-TIRADS, as well as future development directions toward the personalized management of patients with thyroid nodules.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2287-2290
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• 2014

Background: In the past few years, a considerable number of preclinical studies have been proposed metformin as a potential anticancer agent, but some of these studies suffer from a number of methodological limitations such as assessment of cytotoxicity in the presence of supraphysiological glucose concentrations or applying suprapharmacological levels of the drug. These objections have limited the translation of published preclinical data to the clinical setting. The present study aimed to investigate direct anticancer effects of metformin on different molecular subtypes of breast cancer with pharmacological concentrations and under normoglycemic conditions in vitro. Materials and Methods: Breast cancer cell lines from luminal A, luminal B, ErbB2 and triple-negative molecular subtypes were treated with a pharmacological concentration of metformin (2mM) at a glucose concentration of 5.5mM. Time-dependant cell viability was assessed by dye exclusion assay. MTTbased cytotoxicity assays were also performed with metformin alone or in combination with paclitaxel. Results: Metformin did not show any growth inhibitory effects or time-dependant cytotoxicity on breast cancer cell lines in the presence of normal glucose concentrations at the therapeutic plasma level. No augmentation of the antineoplastic properties of paclitaxel was apparent under the tested conditions. Conclusions: Metformin is probably unable to exert cytotoxic or cytostatic effects on breast cancer subtypes at pharmacological concentrations and normal plasma glucose levels. These results highlight the importance of establishing a higher steady-state plasma concentration of metformin in the clinical setting for assessment of anticancer effects in normoglycemic patients.

• Investigative Magnetic Resonance Imaging
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• v.18 no.2
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• pp.120-132
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• 2014

Purpose : To compare dynamic susceptibility contrast imaging, diffusion-weighted imaging, and susceptibility-weighted imaging (SWI) for the differentiation of tumor recurrence and delayed radiation therapy (RT)-related changes in patients treated with RT for primary brain tumors. Materials and Methods: We enrolled 24 patients treated with RT for various primary brain tumors, who showed newly appearing enhancing lesions more than one year after completion of RT on follow-up MRI. The enhancing-lesions were confirmed as recurrences (n=14) or RT-changes (n=10). We calculated the mean values of normalized cerebral blood volume (nCBV), apparent diffusion coefficient (ADC), and proportion of dark signal intensity on SWI (proSWI) for the enhancing-lesions. All the values between the two groups were compared using t-test. A multivariable logistic regression model was used to determine the best predictor of differential diagnosis. The cutoff value of the best predictor obtained from receiver-operating characteristic curve analysis was applied to calculate the sensitivity, specificity, and accuracy for the diagnosis. Results: The mean nCBV value was significantly higher in the recurrence group than in the RT-change group (P=.004), and the mean proSWI was significantly lower in the recurrence group (P<.001). However, no significant difference was observed in the mean ADC values between the two groups. A multivariable logistic regression analysis showed that proSWI was the only independent variable for the differentiation; the sensitivity, specificity, and accuracy were 78.6% (11 of 14), 100% (10 of 10), and 87.5% (21 of 24), respectively. Conclusion: The proSWI was the most promising parameter for the differentiation of newly developed enhancing-lesions more than one year after RT completion in brain tumor patients.

• Progress in Medical Physics
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• v.24 no.1
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• pp.76-83
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• 2013

Previous studies about effect of respiratory motion on diagnostic imaging and radiation therapy have been performed by monitoring external motions but these can not reflect internal organ motion well. The aim of this study was to develope the artificial pulmonary nodule able to perform non-invasive implantation to dogs in the thorax and to evaluate applicability of the model to respiratory motion studies on PET image acquisition and radiation delivery by phantom studies. Artificial pulmonary nodule was developed on the basis of 8 Fr disposable gastric feeding tube. Four anesthetized dogs underwent implantation of the models via trachea and implanted locations of the models were confirmed by fluoroscopic images. Artificial pulmonary nodule models for PET injected $^{18}F$-FDG and mounted on the respiratory motion phantom. PET images of those acquired under static, 10-rpm- and 15-rpm-longitudinal round motion status. Artificial pulmonary nodule models for radiation delivery inserted glass dosemeter and mounted on the respiratory motion phantom. Radiation delivery was performed at 1 Gy under static, 10-rpm- and 15-rpm-longitudinal round motion status. Fluoroscpic images showed that all models implanted in the proximal caudal bronchiole and location of models changed as respiratory cycle. Artificial pulmonary nodule model showed motion artifact as respiratory motion on PET images. SNR of respiratory gated images was 7.21. which was decreased when compared with that of reference images 10.15. However, counts of respiratory images on profiles showed similar pattern with those of reference images when compared with those of static images, and it is assured that reconstruction of images using by respiratory gating improved image quality. Delivery dose to glass dosemeter inserted in the models were same under static and 10-rpm-longitudinal motion status with 0.91 Gy, but dose delivered under 15-rpm-longitudinal motion status was decreased with 0.90 Gy. Mild decrease of delivered radiation dose confirmed by electrometer. The model implanted in the proximal caudal bronchiole with high feasibility and reflected pulmonary internal motion on fluoroscopic images. Motion artifact could show on PET images and respiratory motion resulted in mild blurring during radiation delivery. So, the artificial pulmonary nodule model will be useful tools for study about evaluation of motion on diagnostic imaging and radiation therapy using laboratory animals.

• Journal of Biomedical Engineering Research
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• v.42 no.5
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• pp.241-249
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• 2021

Recently, artificial intelligence for diagnosis system of obstetric diseases have been actively studied. Artificial intelligence diagnostic assist systems, which support medical diagnosis benefits of efficiency and accuracy, may experience problems of poor learning accuracy and reliability when inappropriate images are the model's input data. For this reason, before learning, We proposed an algorithm to exclude unread cervical imaging. 2,000 images of read cervical imaging and 257 images of unread cervical imaging were used for this study. Experiments were conducted based on the statistical method Radiomics to extract feature values of the entire images for classification of unread images from the entire images and to obtain a range of read threshold values. The degree to which brightness, blur, and cervical regions were photographed adequately in the image was determined as classification indicators. We compared the classification performance by learning read cervical imaging classified by the algorithm proposed in this paper and unread cervical imaging for deep learning classification model. We evaluate the classification accuracy for unread Cervical imaging of the algorithm by comparing the performance. Images for the algorithm showed higher accuracy of 91.6% on average. It is expected that the algorithm proposed in this paper will improve reliability by effectively excluding unread cervical imaging and ultimately reducing errors in artificial intelligence diagnosis.