• Korean Journal of Radiology
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• v.20 no.1
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• pp.50-57
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• 2019

In pediatric thoracic CT, respiratory motion is generally treated as a motion artifact degrading the image quality. Conversely, respiratory motion in the thorax can be used to answer important clinical questions, that cannot be assessed adequately via conventional static thoracic CT, by utilizing four-dimensional (4D) CT. However, clinical experiences of 4D thoracic CT are quite limited. In order to use 4D thoracic CT properly, imagers should understand imaging techniques, radiation dose optimization methods, and normal as well as typical abnormal imaging appearances. In this article, the imaging techniques of pediatric thoracic 4D CT are reviewed with an emphasis on radiation dose. In addition, several clinical applications of pediatric 4D thoracic CT are addressed in various thoracic functional abnormalities, including upper airway obstruction, tracheobronchomalacia, pulmonary air trapping, abnormal diaphragmatic motion, and tumor invasion. One may further explore the clinical usefulness of 4D thoracic CT in free-breathing children, which can enrich one's clinical practice.

• Annals of Clinical Neurophysiology
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• v.22 no.2
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• pp.109-111
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• 2020

Germ-cell tumors (GCTs) are common in the central nervous system. GCTs are highly sensitive to radiotherapy and chemotherapy and can be cured without radical surgery. However, this tumor produces nonspecific imaging findings, and its rarity can make diagnosis challenging. Here we report a case in which the first diagnosis was uncertain and follow-up imaging revealed intramedullary germinoma. The patient underwent chemotherapy and radiotherapy after the diagnosis.

• Investigative Magnetic Resonance Imaging
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• v.26 no.1
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• pp.66-70
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• 2022

Paratesticular liposarcoma is a very rare tumor that is typically reported as isolated cases of or as components of larger studies of liposarcomas. Image findings are similar to those of other anatomic sites, but in less-common sites, their appearance may be less familiar, and they may be mistaken for other pathologies. In addition, atypical image findings of liposarcoma make diagnosis more difficult. Herein, we report on the case of a 45-year-old male patient who presented with a painless, palpable mass in the right scrotum. The patient was diagnosed with paratesticular liposarcoma by excisional biopsy.

• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.178-187
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• 2008

Purpose : To evaluate and compare the diagnostic accuracy of MRI and ultrasound(US) for estimation of invasion depth of gastric carcinoma by correlation with histopathologic findings in vitro and to find out the best MR pulse sequence for detection and accurate delineation of tumor. Materials and Methods : Resected specimen of total or subtotal gastrectomy from 53 patients with gastric carcinoma were done of imaging studies of MRI and US. And US was examined by using high frequency linear transducer for tumor invasion depth by a radiologist. In each case, both imaging findings of MRI and US were evaluated independently for tumor detection and invasion depth by consensus of two radiologists and were compared the diagnostic accuracy between two imaging modalities according to the histopathologic findings. MR imaging with five MR pulse sequences, spin echo T1 and in- and out-of phase gradient echo T1 weighted images, FSE and SSFSE T2 weighted images, were performed. Five MR pulse sequences were evaluated and compared on the point of detection and accurate distinction of tumor from surrounding normal tissue. Results : In EGC, diagnostic accuracy of US(77%) was superior than that of MRI(59%) but no statistically significant difference was noted between two imaging modalities(p=0.096). In AGC, both imaging modalities of MRI and US showed relatively high diagnostic accuracy as 97% and 84% respectively. Diagnostic accuracy of MRI was statistically better than that of US at the significant level(p<0.001). The best MR pulse sequence among five in each specimen was FSE T2WI(75.5%, 40/53) in both EGC and AGC. In AGC, FSE T2WI showed excellent imaging quality by showing very high ratio (93.5%, 29/31) of accurate delineation of tumor. Conclusion : MRI and US show relatively high diagnostic accuracy in the evaluation of tumor invasion depth of resected specimen in AGC. The most excellent pulse sequence of MRI for the evaluation of tumor invasion depth is FSE T2WI on the point of detection and accurate delineation of tumor in both EGC and AGC.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7193-7196
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• 2013

Ovarian cancer patients need a surveillance program for the detection of tumor progression after completion of treatment. The methods generally consist of history taking, physical examination, tumor marker monitoring and imaging. However, the details of recurrence detection with each method are not well defined. To clarify this issue, ovarian cancer patients who achieved complete or partial responses and developed tumor progression at the follow up time between January 2004 and December 2010 in University Hospital Chiang Mai, Thailand, were reviewed. Clinical data, CA 125 level and imaging results at the tumor progression time were recorded and analyzed. There were 144 ovarian cancer patients meeting the inclusion criteria with the mean age of 51 years and 62.5% of them were in an advanced stage. Complete response was achieved in 89 patients (61.8%) after primary treatment. The median progression free survival and overall survival were 15.5 months and 37.5 months, respectively. Abnormal symptoms presented in 49.3% of the studied patients and 59.7% developed physical examination abnormalities. In addition, CA 125 was elevated in 89.6% while in 74.3% of tumor progression was identified by CT-scan. Short treatment time period and a high level of CA 125 were significant independent prognostic factors in these patients. In conclusion, careful history taking, physical examination and monitoring of CA 125 levels are important methods for tumor progression detection in a surveillance program for epithelial ovarian cancer patients.

• Korean Journal of Radiology
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• v.24 no.8
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• pp.719-728
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• 2023

Radiofrequency ablation (RFA) has been widely used to manage hepatocellular carcinomas (HCCs) equal to or smaller than 3 cm. No-touch RFA has gained attention and has recently been implemented in local ablation therapy for HCCs, despite its technical complexity, as it provides improved local tumor control compared to conventional tumor-puncturing RFA. This article presents the practice guidelines for performing no-touch RFA for HCCs, which have been endorsed by the Korean Society of Image-Guided Tumor Ablation (KSITA). The guidelines are primarily designed to assist interventional oncologists and address the limitations of conventional tumor-puncturing RFA with describing the fundamental principles, various energy delivery methods, and clinical outcomes of no-touch RFA. The clinical outcomes include technical feasibility, local tumor progression rates, survival outcomes, and potential complications.

• Investigative Magnetic Resonance Imaging
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• v.21 no.1
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• pp.43-50
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• 2017

Chronic expanding organizing hematoma (CEH) occasionally mimics a soft tissue tumor on MRI, which becomes more problematic in patients with a history of surgical resection for musculoskeletal malignancy. Herein, we present a case of CEH which we were able to differentiate from recurrent tumor through MRI follow-up, including diffusion-weighted imaging (DWI) and dynamic contrast enhanced (DCE) imaging. A 66-year-old male visited our institution under suspicion of recurrent leiomyosarcoma of the thigh, 19 months after surgery and radiation therapy. Due to inconclusive results, three US-guided biopsies and 6 MRI examinations were performed over 2 years. In the end, we could diagnose a CEH using conventional and functional MRI techniques, and it was histopathologically confirmed after surgical resection. A CEH may occur remotely after an initiating event, and it may persist and expand over several years. Functional MR sequences, in addition to conventional sequences, are helpful in differentiating CEH from malignant neoplasms.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.1713-1718
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• 2012

Advanced imaging approaches (computed tomography, CT; magnetic resonance imaging, MRI; $^{18}F$-fluorodeoxyglucose positron emission tomography, FDG PET) have increased roles in cervical cancer staging and management. The recent FIGO (International Federation of Gynecology and Obstetrics) recommendations encouraged applications to assess the clinical extension of tumors rather than relying on clinical examinations and traditional non-cross sectional investigations. MRI appears to be better than CT for primary tumors and adjacent soft tissue involvement in the pelvis. FDG-PET/CT has increased in usage with a particular benefit for whole body evaluation of tumor metabolic activity. The potential benefits of advanced imaging are assisting selection of treatment based upon actual disease extent, to adequately treat a tumor with minimal normal tissue complications, and to predict the treatment outcomes. Furthermore, sophisticated external radiation treatment and brachytherapy absolutely require advanced imaging for target localization and radiation dose calculation.

• Parasites, Hosts and Diseases
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• v.60 no.6
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• pp.413-417
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• 2022

We retrospectively evaluated the clinical and imaging features of 6 patients with bone hydatid disease confirmed by surgery and pathological examination. Among the 6 patients, 2 were infected with Echinococcosis granulosus metacestode and 4 were infected with E. multilocularis metacestode. The 2 cases with cystic echinococcosis were diagnosed by computed tomographic (CT) examination, and other 4 cases were diagnosed by magnetic resonance (MR) imaging. On the initial evaluation, 1 case each was misdiagnosed as a giant cell tumor or neurogenic tumor, and 2 were misdiagnosed as tuberculosis. The imaging manifestations of bone hydatid disease are complex, but most common findings include expansive osteolytic bone destruction, which may be associated with sclerosing edges or dead bone formation, localized soft tissue masses, and vertebral lesions with wedge-shaped changes and spinal stenosis. Combining imaging findings with the patient's epidemiological history and immunological examinations is of great help in improving the diagnosis and differential diagnosis of bone hydatid disease.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2410-2412
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• 2011

Using a single step chemical synthesis, we synthesized the potential tumor imaging agent $^{99m}Tc$-diglucose-diethylenetriamine (DGTA) from diethylenetriamine and natural D-glucose. 10 min Incubation of 10 mg of precursor with 50 ${\mu}g$ of $SnCl_2{\cdot}2H_2O$ at room temperature yielded over 95% of $^{99m}Tc$ labeling. The stability for 6 hours in saline or human plasma was over 90%. In vitro tumor cell uptake assays using the SNU-C5 and 9 L cell lines showed that, in 0-400 mg/dL glucose medium, cell uptake of $^{99m}Tc$-DGTA was 1.5-8 times higher than that of [$^{18}F$]FDG. Moreover, [$^{18}F$]FDG uptake was dependent on glucose concentration in the medium, whereas cellular uptake of $^{99m}Tc$-DGTA was not dependent on glucose concentration, suggesting that the two compounds have different uptake mechanisms by tumor cells.