• Journal of Chest Surgery
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• v.34 no.7
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• pp.534-538
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• 2001

Background: Knowledge of size and morphology of the normal trachea is important for airway management and tracheal reconstruction. Conventional radiography is a simple method used to measure the tracheal diameter, but it is not accurate because of the artifacts related to image magnification and overlapping by the shoulder. The purpose of this study was to provide the normal values of the tracheal size and anatomy in Korean adults using Computerized Topography. Material and Method: There were 43 men and 34 women included in this study. They were divided into three age groups(group 1, 20-39 years ; group 2, 40-59 yeas , groups 3, $\geq$60 years). The anteroposterior and transverse diameters and cross - sectional areas of the trachea were measured at the level of the thoracic inlet(Level 1) and the aortic arch(Level 2). These values obtained at each level were compared between age groups and sexes. Result: In 43 men, the anteroposterior / transverse diameters(mean SD in millimeters) of the trachea at levels 1 and 2 were 19.95$\pm$2.99 / 17.72$\pm$2.13 and 19.77$\pm$2.57 / 18.02$\pm$2.19, respectively. In 34 women, those values at levels 1 and 2 were 15.56$\pm$2.12 / 14.18$\pm$2.07 and 15.35$\pm$1.82 / 15.00$\pm$1.60, respectively. At both levels, the anteroposterior and transverse diameters were significantly greater in men than in women (p<0.05). The cross-sectional area of the trachea at levels 1 and 2 were 279.14$\pm$61.37 / 281.93$\pm$63.97 $\textrm{mm}^2$ in men and 173.29$\pm$35.81 / 181.88$\pm$34.74 in women, respectively. They also showed significantly greater values in men than in women(P<0.05). There was no significant difference in diameters and cross-sectional areas of the trachea between age groups. Conclusion: There are significant differences in the internal diameter and cross- sectional area of the trachea between men and women in normal Korean adults, while the age difference was insignificant. We believed CT is a relatively accurate and safe way to measure the internal diameter and cross-sectional areas of the trachea.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.65-75
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• 1999

Purpose: The aim of this study is to demonstrate the feasibility of 2-[fluorine-18] fluoro-2-deoxy-D-glucose (F-18-FDG) whole body scan (FDG W/B Scan) using dual-head gamma camera equipped with ultra high energy collimator in patients with various cancers, and compare the results with those of coincidence imaging. Materials and Methods: Phantom studies of planar imaging with ultra high energy and coincidence tomography (FDG CoDe PET) were performed. Fourteen patients with known or suspected malignancy were examined. F-18-FDG whole body scan was performed using dual-head gamma camera with high energy (511 keV) collimators and regional FDG CoDe PET immediately followed it Radiological, clinical follow up and histologic results were correlated with F-18-FDG findings. Results: Planar phantom study showed 13.1 mm spatial resolution at 10 cm with a sensitivity of 2638 cpm/MBq/ml. In coincidence PET, spatial resolution was 7.49 mm and sensitivity was 5351 cpm/MBq/ml. Eight out of 14 patients showed hypermetabolic sites in primary or metastatic tumors in FDG CoDe PET. The lesions showing no hypermetabolic uptake of FDG in both methods were all less than 1 cm except one lesion of 2 cm sized metastatic lymph node. The metastatic lymph nodes of positive FDG uptake were more than 1.5 cm in size or conglomerated lesions of lymph nodes less than 1cm in size. FDG W/B scan showed similar results but had additional false positive and false negative cases. FDG W/B scan could not visualize liver metastasis in one case that showed multiple metastatic sites in FDG CoDe PET. Conclusion: FDG W/B scan with specially designed collimators depicted some cancers and their metastatic sites, although it had a limitation in image quality compared to that of FDG CoDe PET. This study suggests that F-18-FDG positron imaging using dual-head gamma camera is feasible in oncology and helpful if it should be more available by regional distribution of FDG.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.238-248
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• 2010

Purpose: To compare the dose distributions between three-dimensional (3D) and four-dimensional (4D) radiation treatment plans calculated by Ray-tracing or the Monte Carlo algorithm, and to highlight the difference of dose calculation between two algorithms for lung heterogeneity correction in lung cancers. Materials and Methods: Prospectively gated 4D CTs in seven patients were obtained with a Brilliance CT64-Channel scanner along with a respiratory bellows gating device. After 4D treatment planning with the Ray Tracing algorithm in Multiplan 3.5.1, a CyberKnife stereotactic radiotherapy planning system, 3D Ray Tracing, 3D and 4D Monte Carlo dose calculations were performed under the same beam conditions (same number, directions, monitor units of beams). The 3D plan was performed in a primary CT image setting corresponding to middle phase expiration (50%). Relative dose coverage, D95 of gross tumor volume and planning target volume, maximum doses of tumor, and the spinal cord were compared for each plan, taking into consideration the tumor location. Results: According to the Monte Carlo calculations, mean tumor volume coverage of the 4D plans was 4.4% higher than the 3D plans when tumors were located in the lower lobes of the lung, but were 4.6% lower when tumors were located in the upper lobes of the lung. Similarly, the D95 of 4D plans was 4.8% higher than 3D plans when tumors were located in the lower lobes of lung, but was 1.7% lower when tumors were located in the upper lobes of lung. This tendency was also observed at the maximum dose of the spinal cord. Lastly, a 30% reduction in the PTV volume coverage was observed for the Monte Carlo calculation compared with the Ray-tracing calculation. Conclusion: 3D and 4D robotic radiotherapy treatment plans for lung cancers were compared according to a dosimetric viewpoint for a tumor and the spinal cord. The difference of tumor dose distributions between 3D and 4D treatment plans was only significant when large tumor movement and deformation was suspected. Therefore, 4D treatment planning is only necessary for large tumor motion and deformation. However, a Monte Carlo calculation is always necessary, independent of tumor motion in the lung.

• Radiation Oncology Journal
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• v.25 no.3
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• pp.170-176
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• 2007

Purpose: To determine the role of radiotherapy for the treatment of portal vein thrombosis (PVT) from hepatocellular carcinoma (HCC). Material and Methods: A retrospective analysis was performed on 70 patients that had been diagnosed with HCC and were treated with three-dimensional conformal radiotherapy (3D-CRT) for the PVT. The radiation dose ranged from 40 Gy to 60 Gy (median dose: 48 Gy) and the biological effective dose (BED) ranged from 31.3 Gy to 78.0 $Gy_{10}$ (median dose: 61.6 $Gy_{10}$). Response was determined by measuring the extent of the PVT on a CT image at 0, 1 and 3 months after completion of the radiotherapy. The median follow-up period was 9 months. Results: The response rate was 47.1% (33 patients), with two patients (2.9%) showing a complete response, 31 patients (44.3%) showing a partial response, and 35 patients (50%) showing stable disease or no response. The 1-year progression-free survival rate was 60%, and the median progression-free survival time was 17 months. The median overall survival time was 11 months, the median survival time in the responders was 15 months and in the nonresponders was 8 months (p=0.032). Four patients (5.7%) had transient liver function impairment during treatment. Radiation induced liver disease (RILD) was observed in only one patient (1.4%). Conclusion: Three-dimensional conformal radiotherapy for the treatment of PVT from advanced HCC was a relatively effective and safe method.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.136-142
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• 2009

Bone density in the recipient implant site seems to be an important factor for long term success of endosseous implants. Preoperative evaluation of bone density is very helpful to assist the clinician with the treatment planning of implant therapy. Accurate information on bone density will help the surgeon identify suitable implant sites, thereby improving the success rate of the procedure. Purpose; The aim of this study was to evaluate a correlation between bone density measured preoperatively with computerized tomography and histologically measured bone density by bone biopsy. Patients and methods; Twenty seven patients were selected. All the patients were in good health, with no systemic disorder and additional bone graft. Preoperatively the patients underwent CT scanning to evaluate Houmsfield Unit(HU). Each patients wore a surgical template for implant placement. During surgery 2mm in diameter and 6mm in length specimens were taken. Histomorphometric analysis was performed using digitalized image analysis software Axiovision 4.3. Also, the Resonance frequency analysis(RFA) and insertion torque values were recorded. Results; The highest histomorphometric values was found in the posterior mandible $32.3{\pm}3.8$, followed by $29.9{\pm}2.6$ for the posterior maxilla, $29.4{\pm}2.6$ for the anterior maxilla, $28.6{\pm}2.3$ for the anterior mandible(p=0.214). The hounsfield unit was $989.2{\pm}258.1$ in the posterior mandible, $845.0{\pm}241.5$ in the anterior maxilla, $744.5{\pm}92.6$ in the anterior mandible, $697.3{\pm}136.9$ in the posterior maxilla(p=0.045). This results may suggest that there are strong correlation between the histomorphometric values and hounsfield unit(r=0.760, p<0.05). The RF measurements were $81.9{\pm}2.4$ ISQ in the posterior mandible, $79.0{\pm}1.4$ ISQ in the anterior mandible, $78.3{\pm}4.6$ ISQ in the posterior maxilla, $76.5{\pm}5.0$ ISQ in the anterior maxilla(p=0.048). The insertion torque values was $43.2{\pm}4.2\;Ncm$ in the posterior mandible, $42.0{\pm}0.0\;Ncm$ in the anterior mandible, $41.3{\pm}4.1\;Ncm$ in the posterior maxilla, $40.8{\pm}3.8\;Ncm$ in the anterior maxilla(p=0.612). This results may suggest that there are statistical significance between the hounsfield unit and the insertion torque values(r=0.494, p<0.05), the histomorphometric values and the insertion torque values(r=0.689, p<0.05). But there was no correlation between histomorphometric values and ISQ. There was no statistical significance in age and gender effect on parameters. Conclusions; There was significant correlations between bone density and implant stability parameters. The bone density measurements using preoperative CT may help clinicians to predict primary stability before implant insertion, which is associated with implant survival rates.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.1
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• pp.65-69
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• 2017

Purpose KSNMT(Korea Society of Nuclear Medicine Technology) stepping first step in 1997, has published first journal related with nuclear medicine technology in 1985. With classifying In Vivo Session Dissertation reported in the entire journal, trend of the Dissertation will be studied. Materials and Methods Dissertations which published from 1985 to first half of 2016 in the journal are classified with presentation form and with scanner, And all the data is organized with Excel program. Through the data, the number of dissertations published in each year, the number of dissertation published in details, and keyword distributions in each period are analyzed. Results The number of In-vivo section dissertations was 1151 and the number of In-vivo section dissertations that have common subject with In-vitro section was 28. The number of In-vivo section dissertation in 1980s was 46, in 1990s was 149, in 2000 was 467 and from 2010 to the first half of 2016 was 517. The number of dissertation with original articles was 571, with abstract was 529, with symposium was 31, with special lecture was 25, with review was 11, with interesting image was 7, with poster was 3 and with case report was 2. With symposium and special lecture excluded, which count 56, the number of dissertation with PET was 319, with Planar was 302, with SPECT was 172, with radiopharmaceutical was 113, with guard and safety management 103, with BMD was 28, etc. was 86. The number of dissertation about oncology was 201, about scanner was 179, about cardiovascular and circulatory system was 102, about safe environment was 82, about musculoskeletal system was 76, about nervous nuclear medicine was 66, about quality assurance was 61, about genitourinary system was 56, about endocrine system was 49, about digestive system was 44, about Therapy, about industrial safety was 24, about molecular imaging was 15, infection and inflammation was 9, about respiratory system was 8 and etc. was 108. The mostly used keyword through 1999 to 2005 was PET and through 2006 to 2016 was PET/CT. Conclusion To encourage various dissertations to be submitted, Korea Society of Nuclear Medicine should analyze date about not only about dissertations that are already published, but also about various research materials. Moreover, Korea Society of Nuclear Medicine also have to provide technical support such as sharing big data from homepage and systematical support to its member to publish dissertation that has high impact factor. It is important each individual researcher to have continuing effort as well as each organization cooperation.

• Conservation Science in Museum
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• v.26
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• pp.161-182
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• 2021

A jungwangu, a type of medium-sized mortar, is a firearm with a barrel and a bowl-shaped projectileloading component. A bigyeokjincheonroe (bombshell) or a danseok (stone ball) could be used as a projectile. According to the Hwaposik eonhae (Korean Translation of the Method of Production and Use of Artillery, 1635) by Yi Seo, mortars were classified into four types according to its size: large, medium, small, or extra-small. A total of three mortars from the Joseon period have survived, including one large mortar (Treasure No. 857) and two medium versions (Treasure Nos. 858 and 859). In this study, the production method for medium mortars was investigated based on scientific analysis of the two extant medium mortars, respectively housed in the Jinju National Museum (Treasure No. 858) and the Korea Naval Academy Museum (Treasure No. 859). Since only two medium mortars remain in Korea, detailed specifications were compared between them based on precise 3D scanning information of the items, and the measurements were compared with the figures in relevant records from the period. According to the investigation, the two mortars showed only a minute difference in overall size but their weight differed by 5,507 grams. In particular, the location of the wick hole and the length of the handle were distinct. The extant medium mortars are highly similar to the specifications listed in the Hwaposik eonhae. The composition of the medium mortars was analyzed and compared with other bronze gunpowder weapons. The surface composition analysis showed that the medium mortars were made of a ternary alloy of Cu-Sn-Pb with average respective proportions of (wt%) 85.24, 10.16, and 2.98. The material composition of the medium mortars was very similar to the average composition of the small gun from the Joseon period analyzed in previous research. It also showed a similarity with that of bronze gun-metal from medieval Europe. The casting technique was investigated based on a casting defect on the surface and the CT image. Judging by the mold line on the side, it appears that they were made in a piece-mold wherein the mold was halved and using a vertical design with molten metal poured through the end of the chamber and the muzzle was at the bottom. Chaplets, an auxiliary device that fixed the mold and the core to the barrel wall, were identified, which may have been applied to maintain the uniformity of the barrel wall. While the two medium mortars (Treasure Nos. 858 and 859) are highly similar to each other in appearance, considering the difference in the arrangement of the chaplets between the two items it is likely that a different mold design was used for each item.

• Imaging Science in Dentistry
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• v.36 no.1
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• pp.49-54
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• 2006

Purpose : To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. Materials and Methods : One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant differences between the direct measurements and those using the 3D images (p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. Conclusion : The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissues thickness more easily in forensic science and anthropology.

• Progress in Medical Physics
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• v.22 no.4
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• pp.184-189
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• 2011

The purpose of this study was to compare the image between DSA and MDCT Angiography and to examine whether MDCT Angiography could be useful as a screening test for the diagnosis of cerebral aneurysm in patients who were diagnosed with cerebral aneurysm on DSA. Of patients who were diagnosed with cerebral aneurysm DSA at University Hospital, 194 patients who concomitantly underwent MDCT Angiography were enrolled in the current retrospective study. The methods for analyzing cerebral aneurysm were to analyze the presence of cerebral aneurysm on DSA and MDCT Angiography. In cases in which it exceeded 1, the corresponding cases were classified as narrow-neck aneurysms. In otherwise cases, they were classified as wide-neck aneurysms. Thus, a comparative analysis could be performed to ascertain if cases were narrow-neck or wide-neck aneurysms. As compared with DSA, the sensitivity of MDCT Angiography for cerebral aneurysm was measured to be 97.4%. The degree of consistency between narrow-neck and wide-neck aneurysms was 90.2% and the proportion of undetectable an at MDCT Angiography was 2.54%. mean size was 2.4 mm. It is expected that a non-invasive diagnostic modality for a screening test for cerebral aneurysm, MDCT Angiography might be a very useful regimen as compared with an invasive one, DSA.

• Investigative Magnetic Resonance Imaging
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• v.24 no.1
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• pp.38-45
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• 2020

Background: Differentiation of cerebellopontine angle (CPA) schwannoma from meningioma is often a difficult process to identify. Purpose: To identify imaging features for distinguishing CPA schwannoma from meningioma and to investigate the usefulness of susceptibility-weighted imaging (SWI) in differentiating them. Materials and Methods: Between March 2010 and January 2015, this study pathologically confirmed 11 meningiomas and 20 schwannomas involving CPA with preoperative SWI were retrospectively reviewed. Generally, the following MRI features were evaluated: 1) maximal diameter on axial image, 2) angle between tumor border and adjacent petrous bone, 3) presence of intratumoral dark signal intensity on SWI, 4) tumor consistency, 5) blood-fluid level, 6) involvement of internal auditory canal (IAC), 7) dural tail, and 8) involvement of adjacent intracranial space. On CT, 1) presence of dilatation of IAC, 2) intratumoral calcification, and 3) adjacent hyperostosis were evaluated. All features were compared using Chi-squared tests and Fisher's exact tests. The univariate and multivariate logistic regression analysis were performed to identify imaging features that differentiate both tumors. Results: The results noted that schwannomas more frequently demonstrated dark spots on SWI (P = 0.025), cystic consistency (P = 0.034), and globular angle (P = 0.008); schwannomas showed more dilatation of internal auditory meatus and lack of calcification (P = 0.008 and P = 0.02, respectively). However, it was shown that dural tail was more common in meningiomas (P < 0.007). In general, dark spots on SWI and dural tail remained significant in multivariate analysis (P = 0.037 and P = 0.012, respectively). In this case, the combination of two features showed a sensitivity and specificity of 80% and 100% respectively, with an area under the receiver operating characteristic curve of 0.9. Conclusion: In conclusion, dark spots on SWI were found to be helpful in differentiating CPA schwannoma from meningioma. It is noted that combining dural tail with dark spots on SWI yielded strong diagnostic value in differentiating both tumors.