• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.336-343
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• 2010

Coronary artery CT angiography has short scanning length, the exposure dose is high. Therefore, it is required to study on the organ dose when using MDCT. We compared the differences between the absorbed dose and effective dose in the major organs assessing the absorbed dose in the major organs by 16-MDCT and 64-MDCT in the subjects with coronary artery CT angiography, the same protocol by 16-MDCT and 64-MDCT. As a result, the great orders of absorbed dose when conducting coronary artery CT angiography had been shown as heart, stomach, liver, pancreas, kidney, spleen, large intestine, lung, small intestine, thyroid gland, ovary, bladder, and orbit with the absorbed dose distribution of $0.538{\pm}0.026(Mean{\pm}SD,\;p<0.05)mGy{\sim}71.316{\pm}4.316mGy$ in 16-MDCT, and heart, stomach, pancreas, spleen, liver, kidney, small intestine, large intestine, lung, thyroid gland, ovary, bladder, and orbit with the absorbed dose distribution of $0.87{\pm}0.01mGy{\sim}115.26{\pm}1.59mGy$ in 64-MDCT, demonstrating some different distributions. The exposed doses to the patient per one time scanning with coronary artery CT angiography were $71.316{\pm}4.316mGy$ in 16-MDCT as the absorbed dose based on the heart and $115.26{\pm}1.59mGy$ in 64-MDCT. The effective doses were 7.41 mSv and 12.11 mSv in 16 and 64-MDCT, respectively. Taking into account the results of brain CT with 2.8 mSv that has comparatively large scanning length and size, facial CT 0.8 mSv, chest CT 5.7 mSv, pelvic CT 7.2 mSv, and abdominal and pelvic CT 14.4 mSv, it is very high considering the scanning length of 13 cm limited to the heart for the scanning range.

• Tuberculosis and Respiratory Diseases
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• v.46 no.4
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• pp.564-573
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• 1999

Background: With variable symptoms and nonspecific radiographic appearances, pulmonary embolism (PE) is a frequent and often undiagnosed cause of mortality and morbidity. The Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study suggested that the majority of patients undergoing ventilation-perfusion (V-Q) scan would require additional studies to establish or to exclude the diagnosis of PE. Pulmonary angiography has been regarded as gold standard for diagnosis of PE. However, it is an invasive procedure that may be associated with significant notable morbidity and mortality. Thus, availability of an accurate, noninvasive screening examination is highly desirable. Method: From October 1994 to February 1997, twenty patients (male 13, female 7, range 23-91 years, median 58 years) who were suspected as pulmonary embolism on the basis of clinical evidence and underwent the spiral volumetric computed tomography (spiral CT), were studied retrospectively to evaluate the effectiveness of spiral CT as a diagnostic tool in PE. Results: PE could be excluded with spiral CT in 4 patients ; diagnoses of these patients were lung cancer, pneumonia with lung abscess, bilateral pleural effusion due to congestive heart failure, nonspecific pulmonary abnormality retrospectively. One patient who disclosed high probability in V/Q scan, could be diagnosed as pneumonia with lung abscess and underlying emphysema with spiral CT. Among 4 patients who showed intermediate and low probability in V/Q scan, 3 patients could be confirmed as PE with spiral CT. Spiral CT was helpful in 3 patients, in whom V/Q scan could not be performed due to other reasons (e.g. night time, mechanical ventilation) to confirm the diagnosis of PE. Spiral CT could demonstrate embolus above lobar artery level in 11 patients, and up to segmental artery level in 5 patients. Conclusion: This study demonstrated that spiral CT could allow accurate demonstration of thrombotic clots in centrally localized embolism. Spiral CT could be effective, specific, noninvasive and useful diagnostic screening modality for the diagnosis of pulmonary embolism.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.9-16
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• 2005

Purpose : To prospectively evaluate the use of positron emission tomography with the glucose analog fluoro-deoxyglucose (FDG-PET) to deoxyglucose (FDG-PET) to predict disease-free survival (DFS) after concurrent chemo-radiotherapy (CCRT) in patients with non-disseminated nasopharyngeal carcinoma (NPC). Materials and Methods : We studied 41 patients with non-disseminated NPC scheduled to undergo platinum-based CCRT were eligible for this study. Patients were studied by FDG-PET prior to the CCRT. FDG uptake of tumors were measured with the maximal standardized uptake value (SUV). Results : Complete response rate was $100\%$. In ten patients who presented with any component of treatment failure, the median $SUV_{max}$ was 8.55 (range: $2.49\~14.81$) in any component of failure and the median $SUV_{max}$ was 5.48 (range: $2.31\~26.07$) In the remaining patients without any such failure. Patients having tumors with high FDG uptake had a significantly lower 3-year DFS ($51\%\;{\nu}91\%$, p=0.0070) compared with patients having low uptake tumors. Conclusion : FDG uptake, as measured by the SUV, has potential value in predicting DFS in NPC treated by CCRT, High FDG uptake may be a useful parameter for Identifying patients requiring more aggressive treatment approaches.

• Radiation Oncology Journal
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• v.24 no.3
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• pp.185-191
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• 2006

[ $\underline{Purpose}$ ]: Standardization quality assurance (QA) program of CyberKnife for suitable circumstances in Korea has not been established. In this research, we investigated the development of QA program for CyberKnife and evaluation of the feasibility under applications. $\underline{Materials\;and\;Methods}$: Considering the feature of constitution for systems and the therapeutic methodology of CyberKnife, the list of quality control (QC) was established and divided dependent on the each period of operations. And then all these developed QC lists were categorized into three groups such as basic QC, delivery specific QC, and patient specific QC based on the each purpose of QA. In order to verify the validity of the established QA program, this QC lists was applied to two CyberKnife centers. The acceptable tolerance was based on the undertaking inspection list from the CyberKnife manufacturer and the QC results during last three years of two CyberKnife centers in Korea. The acquired measurement results were evaluated for the analysis of the current QA status and the verification of the propriety for the developed QA program. $\underline{Results}$: The current QA status of two CyberKnife centers was evaluated from the accuracy of all measurements in relation with application of the established QA program. Each measurement result was verified having a good agreement within the acceptable tolerance limit of the developed QA program. $\underline{Conclusion}$: It is considered that the developed QA program in this research could be established the standardization of QC methods for CyberKnife and confirmed the accuracy and stability for the image-guided stereotactic radiotherapy.

• Radiation Oncology Journal
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• v.12 no.3
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• pp.393-399
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• 1994

Spinal cord compression, an oncologic emergency, is a rare complication of hematologic malignancy Our experience was obtained with a series 32 Patients following retrospective analysis for assessing the role of radiation therapy and identifying the prognostic factors affecting on treatment outcome. Diagnosis was usually made by means of radiologic study such as myelography or computerized tomography (CT) or magnetic resonance imaging (MRI) and neurologic examination. Five cases were diagnosed by subjective symptom only with high index of suspicion. In 31 cases, the treatment consisted in radiation therapy alone and the remained one patient had laminectomy before radiation therapy because of diagnostic doubts. Total treatment doses ranged from 800 cGy to 4000 cGy with median of 2000 cGy. Initially large fraction size more than 250 cGy were used in 13 patients with rapidly progressed neurologic deficit. The clinical parameters considered in evaluating the response to treatment were backache, motor-sensory performance and sphincter function. Half of all patients showed good response. Partial response and no response were noted in $37.5\%$ and $12.5\%$, respectively. Our results showed higher response rate than those of other solid tumor series. The degree of neurologic deficit at that time of diagnosis was the most important predictor of treatment outcome. The elapsed time from development of symptoms to start of treatment was significantly affected on the outcome. But histology of primary tumor total dose and use of initial large fraction size were not significantly affect on the outcome. These results confirmed the value of early diagnosis and treatment especially in radiosensitive hematologic malignancy.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.186-189
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• 2005

For the assessment of the clinical application of histogram on internal parenchymal organs, ultrasonography with a multi-frequency transducer was taken. We scanned in the region of right cranial abdomen for both liver and right kidney, and left cranial abdomen for liver, spleen and left kidney in 9 normal Beagle dogs. The data from histogram examined in a region of interest centered on each picture element of B-mode images at the same depth were compared among liver, renal cortex, spleen, cortex and medulla of each kidney. The right renal cortex showed significantly lower echogenicity than parenchyma of liver by $15{\%}$. Spleen was more echogenic than the cortex of the left kidney by $23{\%}$, and liver was more echogenic than the left renal cortex by $30{\%}$. Renal cortex was more echogenic than medulla by $47{\%}$ and $65{\%}$ on the right and left side, respectively (p<0.05). The mean (${\pm}SD$) values calculated echogenicity were $46.2{\pm}12.3\;(95\%$ confidential interval (CI), 41.0 to 55.0) and $53.4{\pm}12.1\;(95\%$ CI, 47.0 to 55.1) in in the right renal cortex and liver parenchyma, $65.0{\pm}11.8\;(95\%$ CI, 57.9 to 71.0) and $51.0{\pm}16.9\;(95\%$ CI, 42.8 to 54.1) in splenic parenchyma and renal cortex. And the mean values calculated echogenicity were $65.0{\pm}10.15\;(95\%$ CI, 60.1 to 71.5) and $52.0{\pm}9.4\;(95\$ CI, 43.8 to 60.3) in liver parenchyma and the left renal cortex, $54.5{\pm}18.3\;(95\%$ CI, 40.1 to 62.8) and $35.0{\pm}16.2\;(95\%$ CI, 24.2 to 43.6) in the left renal cortex and medulla. And the mean values calculated echogenicity were $55.0{\pm}14.4\;(95\%$ CI, 47.3 to 61.7) and $40.0{\pm}13.2\;(95\%$ CI, 34.3 to 46.7) in the right renal cortex and medulla, respectively. In addition, the echogenicity ratios were $0.86{\pm}0.11$ between the right renal cortex and liver parenchyma, $1.37{\pm}0.47$ between spleenic parenchyma and the left renal cortex, $1.30{\pm}0.19$ between liver parenchyma and the left renal cortex. All the values measured showed significant different (p<0.05). Ultrasound histogram is simple, useful and feasible to evaluate the sonographic architecture of the internal organs such as liver, spleen and kidney, quantitatively.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.989-996
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• 2005

Ultraviolet (UV) induces photo aging, erythema, sunburn, photo-toxicity, photo-allergy, and skin tumor, To investigate photo-protective effects of AmorePacific Beauty-03 (APB-03; mixture of red ginseng extract powder and soybean extract powder) on UV-induced damaged skins, 40 SKH hairless female mice were orally administered APB-03 or saline five times a week and irradiated with UV three times per week far up to 12 weeks. Visible skin changes and skin damage in dermis and epidermis by replica image analysis and histological analysis. In APB-03-treated group, better skin, negative replica appearance and less wrinkle formation were observed compared to the UV control group. These results demonstrate oral administration of APB-03 have photo-protective effects on UV-damaged hairless mouse skin.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.148-155
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• 2002

Multithreaded models improve the efficiency of parallel systems by combining inner parallelism, asynchronous data availability and the locality of von Neumann model. This model executes thread code which is generated by compiler and of which quality is given by the method of generation. But multithreaded models have the demerit that execution model is restricted to a specific platform. On the contrary, Java has the platform independency, so if we can translate from threads code to Java bytecode, we can use the advantages of multithreaded models in many platforms. Java executes Java bytecode which is intermediate language format for Java virtual machine. Java bytecode plays a role of an intermediate language in translator and Java virtual machine work as back-end in translator. But, Java bytecode which is translated from multithreaded models have the demerit that it is not secure. This paper, multhithread code whose feature of platform independent can execute in java virtual machine. We design and implement translator which translate from thread code of multithreaded code to Java bytecode and which check secure problems from Java bytecode.

• Progress in Medical Physics
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• v.23 no.4
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• pp.279-284
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• 2012

The X ray has been widely used in both diagnosis and treatment. Recently, a miniature X ray tube has been developed for radiotherapy. The miniature X ray tube is directly inserted into the body irradiated, so that X rays can be guided to a target at various incident angles according to collimator geometry and, thus, minimize patient dose. If such features of the miniature X ray tube can be applied to development of X ray imaging as well as radiation treatment, it is expected to open a new chapter in the field of diagnostic X ray. However, the miniature X ray tube requires an added filter and a collimator for diagnostic purpose because it was designed for radiotherapy. Therefore, a collimator and an added filter were manufactured for the miniature X ray tube, and mounted on. In this study, we evaluated beam characteristics of the miniature X ray tube for diagnostic X ray system and accuracy of measuring the HVL. We used the Si PIN Photodiode type Piranha detector (Piranha, RTI, Sweden) and estimated the HVL of the miniature X ray tube with added filter and without added filter. Through an another measurement using Al filter, we evaluated the accuracy of the HVL obtained from a direct measurement using the automatic HVL calculation function provided by the Piranha detector. As a result, the HVL of the miniature X ray tube was increased around 1.9 times with the added filter mounted on. So we demonstrated that the HVL was suitable for diagnostic X ray system. In the case that the added filter was not mounted on, the HVL obtained from use of the automatic HVL calculation function provided by Piranha detector was 50% higher than the HVL estimated using Al filter. Therefore, the HVL automatic measurement from the Piranha detector cannot be used for the HVL calculation. However, when the added filter was mounted on, the HVL automatic measurement value using the Piranha detector was approximately 15% lower than the estimated value using Al filter. It implies that the HVL automatic measurement can be used to estimate the HVL of the miniature X ray tube with the added filter mounted on without a more complicated measurement method using Al filter. It is expected that the automatic HVL measurement provided by the Piranha detector enables to make kV-X ray characterization easier.

• Investigative Magnetic Resonance Imaging
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• v.17 no.3
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• pp.207-214
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• 2013

Purpose : To evaluate the MRI findings of breast cancer with BRCA mutation. Materials and Methods: We collected information of the breast cancer patients who underwent the test for BRCA gene mutation as well as preoperative breast MRI from January 2007 to December 2010. A total of 185 patients were enrolled; 33 of these patients had BRCA mutations and 152 patients did not. Among them, a total of 231 breast cancers were detected. Images of the 47 breast cancers with BRCA mutation and of the 184 breast cancers without mutations were evaluated to compare the morphologic and enhancement features on MRI. Results: With MR imaging, there were no significant difference in morphologic characteristic between two groups. However, enhancement pattern in the group with BRCA mutation were more likely to have persistent enhancement (p < 0.233), and LN metastasis was more common in breast cancers without BRCA mutation. Breast cancers with BRCA 2 mutation tend to show more persistent enhancement pattern than BRCA 1 mutation. Conclusion: In breast cancer patients with BRCA mutation, MRI didn't show significant difference in morphologic characteristics, however breast cancers with BRCA gene mutation carriers tend to have benign morphologic features on MRI, such as Type 1 kinetic curve enhancement.