• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.19-29
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• 1997

Recently, [I-123]IPT SPECT has been used for early diagnosis of Parkinson's patients(PP) by imaging dopamine transporters. The dynamic time activity curves in basal ganglia(BG) and occipital cortex(OCC) without blood samples were obtained for 2 hours. These data were then used to measure dopamine transporters by operationally defined ratio methods of (BG-OCC)/OCC at 2 hrs, binding potential $R_v=k_3/k_4$ using graphic method or $R_A$= (ABBG-ABOCC)/ABOCC for 2 hrs, where ABBG represents accumulated binding activity in basal ganglia(${\int}^{120min}_0$ BG(t)dt) and ABOCC represents accumulated binding activity in occipital cortex(${\int}^{120min}_0$ OCC(t)dt). The purpose of this study was to examine the IPT pharmacokinetics and investigate the usefulness of simplified methods of (BG-OCC)/OCC, $R_A$, and $R_v$ which are often assumed that these values reflect the true values of $k_3/k_4$. The rate constants $K_1,\;k_2\;k_3$ and $k_4$ to be used for simulations were derived using [I-123]IPT SPECT and aterialized blood data with a standard three compartmental model. The sensitivities and time activity curves in BG and OCC were computed by changing $K_l$ and $k_3$(only BG) for every 5min over 2 hours. The values (BG-OCC)/OCC, $R_A$, and $R_v$ were then computed from the time activity curves and the linear regression analysis was used to measure the accuracies of these methods. The late constants $K_l,\;k_2\;k_3\;k_4$ at BG and OCC were $1.26{\pm}5.41%,\;0.044{\pm}19.58%,\;0.031{\pm}24.36%,\;0.008{\pm}22.78%$ and $1.36{\pm}4.76%,\;0.170{\pm}6.89%,\;0.007{\pm}23.89%,\;0.007{\pm}45.09%$, respectively. The Sensitivities for ((${\Delta}S/S$)/(${\Delta}k_3/k_3$)) and ((${\Delta}S/S$)/(${\Delta}K_l/K_l$)) at 30min and 120min were measured as (0.19, 0.50) and (0.61, 0,23), respectively. The correlation coefficients and slopes of ((BG-OCC)/OCC, $R_A$, and $R_v$) with $k_3/k_4$ were (0.98, 1.00, 0.99) and (1.76, 0.47, 1.25), respectively. These simulation results indicate that a late [I-123]IPT SPECT image may represent the distribution of the dopamine transporters. Good correlations were shown between (3G-OCC)/OCC, $R_A$ or $R_v$ and true $k_3/k_4$, although the slopes between them were not unity. Pharmacokinetic computer simulations may be a very useful technique in studying dopamine transporter systems.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1308-1317
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• 1997

Background : Pulmonary aspergillomas usually arise from colonization and proliferation of Aspergillus in preexisting cavitary lung disease of any cause. About 15% of patients with tuberculous pulmonary cavities were found to have aspergilloma. We analyzed the clinical features and course of 91 patients with pulmonary aspergilloma. Method : During the ten-year period from June 1986 to May 1996, 91 patients whose condition was diagnosed as pulmonary aspergilloma at 4 university hospitals in Taegu city were reviewed. All patients fulfilled one of the following criteria : 1) histologic evidence of aspergilloma within abnormal air space in tissue sections, or 2) a positive Aspergillus serum precipitin test with the radiologic finding of a fungus ball. The histological diagno-sis was established in 81 patients(89.0%) and clinical diagnosis in 10 patients(11.0%). Results : 1) The age range was 22 to 65 years, with an average of 45 years. A male and female ratio was 1.7 : 1 (57 men and 34 women). 2) Hemoptysis was far the most frequent symptom(89%), followed by cough, dyspnea, weakness, weight loss, fever, chest pain. 3) In all but 14 cases(15.4%) there had been associated conditions. Pulmonary tuberculosis was far the most frequent underlying condition found(74.7%), followed by bronchiectasis (6.6%), cavitary neoplasm(2.2%), pulmonary sequestration(1.1%). 4) The involved area was usually in the upper lobes; the right upper lobe was involved in 39(42.9%), the left upper lobe in 31(34.1%), the left lower lobe in 13(14.3%), the right lower lobe in 7(7.7%), and the right middle lobe in 1(1.1%). 5) On standard chest roent geno gram the classic "bell-like" image of a fungus ball was found in 62.6% of the subjects. On CT scan, 88.1% of the subjects in which they were done. 6) The surgical therapy was undertaken in 76 patients, and medical therapy in 15 patients, including 4 patients with intracavitary instillation of amphotericin B. 7) The surgical modality was lobectomy in 55 patients(72.4%), segmentectomy in 16 patients(21.1%), pneumonectomy in 4 patients(5.3%), wedge resection in 1 patient(1.3%). The mortality rate was 3.9% (3 patients) ; 2 patients died of sepsis and 1 died of hemoptysis. The postoperative complications were encountered in 6 patients (7.9%), including each one patient with respiratory failure, bleeding, bronchopleural fistula, empyema, and vocal cord paralysis. 8) In the follow-up cases, each 2 patients of 71 patients with surgical treatment and 10 patients with medical treatment had recurrent hemoptysis. Conclusion : During follow-up of the chronic pulmonary disease with abnormal air space, if the standard chest roentgenograms are insufficient to detect a fungus ball, computed tomographic scan and serum precipitin test are likely to aid the diagnosis of patients with suspected pulmonary aspergilloma. A reasonable recommendation for management of a patient with aspergilloma would be to reserve surgical resection for those patients who have had severe, recurrent hemoptysis. And a well controlled cooperative study to the medical treatment such as intracavitary antifungal therapy is further needed.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.109-120
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• 2010

The purpose of this study was first to analyze the utilization of dental examination through questionnaire to develop a diagnostic reference level of patient doses for dental radiography in korea. 77 dental institutions were classified into three groups: A group for the dental hospitals of the college of dentistry (11 institutions), B group for dental hospitals (30 institutions) and C group for dental clinics (36 institutions). The results were as follows : The mean numbers of unit chairs and medical staffs were 140.2, 15.3 and 5.8 sets, 112.6, 7.3 and 1.7 dentists, 3.1, 0.5 and no one radiologic technologists, and 19.7, 12.5 and 3.3 dental hygienists in A, B and C groups, respectively. The mean numbers of dental X-ray equipments were 14.64, 3.21 and 2.19 in A, B and C groups, respectively. Intraoral dental X-ray unit was used the most, the following equipments were panoramic, cephalometric, and cone-beam CT units. The most used X-ray imaging system was also digital system (above 50%) in all three groups. Insight dental film (Kodak, USA) having high sensitivity was routinely used for periapical radiography. The automatic processor was not used in many dental institutions, but the film-holding device was used in many dental institutions. The utilization rates of PACS in A, B and C groups were 90.9%, 83.3% and 16.7% respectively, and the PACS software program was used the most PiView STAR (Infinitt, Korea). The annual mean number of radiographic cases in one dental institution in 2008 for A group was 6.8 times and 21.2 times more than those for B and C groups, and periapical and panoramic radiographs were taken mostly. Tube voltage (kVp) and tube current (mA) for periapical radiography were similar in all three groups, but exposure time in C group was 12.0 times and 3.5 times longer than those in B and C groups. The amount of radiation exposure in C group, in which dental hygienists take dental radiographs, was more than those in other groups. The exposure parameters for panoramic radiography were similar in all three groups. In conclusion, the exposure parameters in dental radiography should be determined with reference level, not past experiences. Use of automatic processor and film-holding devices reduces the radiation exposure in film system. The quality assurance of dental equipments are necessary for the reduction of the patient dose and the improvement of X-ray image quality.

• Clinical and Experimental Pediatrics
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• v.51 no.2
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• pp.134-144
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• 2008

Purpose : This study aimed to investigate body shape perception, weight control behaviors and eating habits of adolescent girls in urban, suburban and rural areas of Korea to obtain basis for establishing adequate weight control program for adolescent. Methods : From May 2002 to November 2002, a cross-sectional questionnaire survey and physical examination were conducted to examine body shape perception, weight control behaviors, eating habits and health status of 2,891 adolescent girls and 891 boys in Seoul, Ansan and Paju. Results : The proportion of underweight adolescent girl was decreased in rural area than in urban area. 46.3% of girls considered themselves to be somehow or very obese. Notably 3.2% of underweight girls considered themselves obese. 57.9% were unsatisfied with their own body shape. The proportion of dissatisfaction increased with age and body mass index (BMI), but there were no differences among area. The experiences of weight control increased by age, BMI and dissatisfaction of own body shape. The eating attitudes test-26 (EAT-26) score of girls was significantly higher than that of boys. The girls with high risk of eating disorder were 10.9%. And risk factors of eating disorder were living in urban area, severe stress for weight control excessive expenditure for appearance and think themselves unhealthy. Conclusion : The findings of this study demonstrate that there were serious impairment of body shape perception of adolescent girls and unhealthy, inadequate weight control behaviors were widely done. Therefore adequate weight control program for adolescent girl should be established promptly.

• Investigative Magnetic Resonance Imaging
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• v.16 no.1
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• pp.25-30
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• 2012

Purpose : To compare the enhancement pattern of normal facial nerves on 3D-FLAIR and 3D-T1-FFE-F) sequences at 3.0 T MR units. Materials and Methods: We assessed 20 consecutive subjects without a history of facial nerve abnormalities who underwent temporal bone MRI with contrast enhancement between January 2008 and March 2009. Two neuroradiologists independently reviewed pre-/post-enhanced 3D-T1-FFE-FS and 3D-FLAIR images respectively with 2-week interval to assess the enhancement of normal facial nerves divided into five anatomical segments. The degree of enhancement in each segment was graded as none, mild or strong, and the results of 3D-FLAIR and 3D-T1-FFE-FS image sets were compared. Results: On 3D-FLAIR images, one of the two reviewers observed mild enhancement of the genu segment in two (10%) subjects. On 3D-T1-FFE-FS images, at least one segment of the facial nerve was enhanced in 13 (65%) subjects. At least one reviewer found that 17 of the 100 segments showed enhancement on 3D-T1-FFE-FS images, with the mastoid segment being the most commonly enhanced. Interobserver agreement on 3D-T1-FFE-FS images was good for enhancement of the normal facial nerve (${\kappa}$= 0.589). Conclusion: In contrast to 3D-T1-FFE-FS, normal facial nerve segments rarely showed enhancement on 3D-FLAIR images.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.363-368
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• 2014

Purpose : The aim of this study was to appraise properties for radiation therapy techniques and effectiveness of time and economy to a patient in the case of applying flattening filter-free (3F) and flattening filter (2F) beam to the radiation therapy. Materials and Methods : Alderson rando phantom was scanned for computed tomography image. Treatment plans for intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) and stereotactic body radiation therapy (SBRT) with 3F and 2F beam were designed for prostate cancer. To evaluate the differences between the 3F and 2F beam, total monitor units (MUs), beam on time (BOT) and gantry rotation time (GRT) were used and measured with $TrueBeam^{TM}$ STx and Surveillance And Measurement (SAM) 940 detector was used for photoneutron emitted by using 3F and 2F. To assess temporal and economical aspect for a patient, total treatment periods and medical fees were estimated. Results : In using 3F beam, total MUs in IMRT plan increased the highest up to 34.0% and in the test of BOT, GRT and photoneutron, the values in SBRT plan decreased the lowest 39.8, 38.6 and 48.1%, respectively. In the temporal and economical aspect, there were no differences between 3F and 2F beam in all of plans and the results showed that 10 days and 169,560 won was lowest in SBRT plan. Conclusion : According as the results, total MUs increased by using 3F beam than 2F beam but BOT, GRT and photoneutron decreased. From above the results, using 3F beam can decrease intra-fraction setup error and risk of radiation-induced secondary malignancy. But, using 3F beam did not make the benefits of temporal and economical aspect for a patient with the radiation therapy.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.742-749
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• 2009

The use of cone-beam computed tomography(CBCT) has been proposed for guiding the delivery of radiation therapy. A kilovoltage imaging system capable of radiography, fluoroscopy, and cone-beam computed tomography(CT) has been integrated with a medical linear accelerator. A standard clinical linear accelerator, operating in arc therapy mode, and an amorphous-silicon (a-Si) with an on-board electronic portal imager can be used to treat palliative patient and verify the patient's position prior to treatment. On-board CBCT images are used to generate patient geometric models to assist patient setup. The image data can also, potentially, be used for dose reconstruction in combination with the fluence maps from treatment plan. In this study, the accuracy of Hounsfield Units of CBCT images as well as the accuracy of dose calculations based on CBCT images of a phantom and compared the results with those of using CT simulator images. Phantom and patient studies were carried out to evaluate the achievable accuracy in using CBCT and CT stimulator for dose calculation. Relative electron density as a function of HU was obtained for both planning CT stimulator and CBCT using a Catphan-600 (The Phantom Laboratory, USA) calibration phantom. A clinical treatment planning system was employed for CT stimulator and CBCT based dose calculations and subsequent comparisons. The dosimetric consequence as the result of HU variation in CBCT was evaluated by comparing MU/cCy. The differences were about 2.7% (3-4MU/100cGy) in phantom and 2.5% (1-3MU/100cGy) in patients. The difference in HU values in Catphan was small. However, the magnitude of scatter and artifacts in CBCT images are affected by limitation of detector's FOV and patient's involuntary motions. CBCT images included scatters and artifacts due to In addition to guide the patient setup process, CBCT data acquired prior to the treatment be used to recalculate or verify the treatment plan based on the patient anatomy of the treatment area. And the CBCT has potential to become a very useful tool for on-line ART.)

• The Journal of the Korean bone and joint tumor society
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• v.14 no.2
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• pp.163-171
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• 2008

Purpose: We analyze the characteristics of soft tissue sarcomas presented with hematoma, which were misdiagnosed as simple hematoma initially and the proper management were delayed. Materials and Methods: The 7 patients with histologically proven soft tissue sarcoma with hematoma presented since February 1997 were evaluated retrospectively. Neither patient had a medical history of bleeding tendency nor anticoagulant therapy. Two of them had minor traumas. There were 2 men and 5 women. Average follow up period was 58 months. MRI findings, provided treatments and oncologic outcome were reviewed with the reference of related articles. Results: Retrospective review of initial MR images revealed deep seated intramuscular masses with focal solid enhanced nodules at the peripheral margin. The diagnoses were delayed at least 1 month in 3 of them which included 2 cases of simple hematoma evacuation without biopsy initially. After histologic diagnosis of soft tissue sarcoma, wide resections were performed in 4 cases. one patient underwent above knee amputation and the remained 2 patients were managed with wide resection followed by amputation due to local recurrence. At last follow up there were CDF and NED in 2 cases, respectively and AWD in 3 cases. Conclusion: To avoid the delay of diagnosis and treatment of soft tissue sarcomas presented with hematoma, high degree of clinical suspicion, careful analysis of MR images and early biopsy were important.

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.289-297
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• 1999

Purpose: Misonidazole is a radiosensitizer that binds in hypoxic cells. The purpose of this study was to find out the feasibility of I-131-Iodomisonidazole (IMISO) for imaging of tumor hypoxia. Materials and Methods: Tosyl precursor was dissolved in acetonitrile and I-131-NaI was added to synthesize IMISO. Balb/c mice inoculated with CT-26 adenocarcinoma were injected with IMISO. Mice were sacrificed at 1, 2, 4, 24 hr and % of injected dose per gram of tissue (%ID/g) was determined. For scintigraphy and MRI, mouse bearing CT-26 adenocarcinoma was administered with IMISO and imaging was performed 4 hr after. Then, mouse body was fixed and microtomized slice was placed on radiographic film for autoradiography Results: %ID/g of tumor was 1.64 (1h), 0.98 (2h), 0.85 (4h) and 0.20 (24h), respectively. At 24h, %ID/g of tumor was higher than that of all other tissues except thyroid. Tumor to muscle ratio increased with time and tumor to blood ratio also increased with time and reached 1.53 at 24 hr. On autoradiogram, tumor was well visualized as an increased activity in central hypoxic area of the tumor which corresponds to the area of high signal intensity on T2-weighted MR image. On scintigraphy, tumor uptake was visualized. Conclusion: This results suggest that IMISO may have a potential for tumor hypoxia imaging in mouse model. However, further study is needed to improve it's localization in tumor tissue and to achieve acceptable images of tumor hypoxia.

• Childhood Kidney Diseases
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• v.13 no.2
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• pp.215-221
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• 2009

Purpose : Thymus is a lymphoproliferative organ that changes size in various physiological states in addition to some pathological conditions. Thymus is susceptible to involution, and shows a dramatic response to severe stress. Thymic measurements may be helpful in various diseases. UTI (urinary tract infection) is most common bacterial infection in infants and VUR (vesicoureteral reflux) is a common abnormality associated with UTI. In our study, the size of thymus was compared on the premise that a greater stress is exerted on the body when UTI is accompanied by VUR, than when occurs on its own. Methods : Thymic size was measured on standard chest anteroposterior radiographs and expressed as the ratio between the transverse diameter of the cardiothymic image at the level of the carina and that of the thorax (CT/T). The medical records of 99 febrile urinary tract infection infants without other genitourinary anomalies except VUR were reviewed retrospectively. Results : Among 99 patients with febrile UTIs, 25 were febrile UTI without VUR and 74 with VUR. For the UTI with VUR group, there was a significant decrease in the thymic size compared to the those without VUR group ($0.382{\pm}0.048$ vs $0.439{\pm}0.079$, P<0.05). However, there were no differences in the duration of fever and WBC, CRP between the UTI with VUR and UTI without VUR. In addition, there were no differences in the cardiothymic/thoracic ratios between renal defects and renal scars in febrile UTI patients. Conclusion : The results of this study show that the shirinkage of thymus was more frequently found in the UTI patients with VUR. Therefore, awareness of the risks associated with thymic size is important for the appropriate work up and management of UTI patients.