• Journal of the Korean Society of Radiology
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• v.6 no.5
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• pp.383-388
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• 2012

This study attempted to make comparisons in the magnitude of the applied power depending on gender, gliding direction and gliding grade when gliding treatment grade II and III under the Kaltenborn-Evjenth Concept$^{(R)}$ are applied to the caudal, ventral and dorsal shoulder joint using the loading cell equipment. As a result of load difference depending on gender, men showed a significantly higher load than women for all of Caudal Grade II/III, Ventral Grade II/III and Dorsal Grade II/III (p<.05). As a result of comparisons for load difference depending on the treatment direction, the ventral and dorsal loads were significantly higher than the caudal load for all of Grade II and Grade III (p<.05). As a result of comparisons for load difference depending on treatment grade, the load was significantly higher in Grade III than Grade II for all of the caudal, ventral and dorsal side (p<.05). Given the aforesaid results, it could be confirmed that the magnitude of the applied force at the same grade could be different depending on the direction and gender, when gliding II/III are applied to the caudal, ventral and dorsal of glenohumeral joint.

• Journal of the Korean Society of Radiology
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• v.11 no.2
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• pp.123-130
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• 2017

Patients diagnosed with the serious disease of cancer may have anxiety and fear of closed spaces while receiving radiation therapy. This study investigated patients receiving treatment based on Linac and Tomotherapy to look into this anxiety and fear. Study method was survey. The survey was performed according to treatment duration (treatment within 5 minutes, 10 minutes, over 20 minutes, and over 30 minutes). The patients were also surveyed about any experience of changing treatment rooms or machines due to machine failure. A total of 200 survey questionnaires with full answers were researched in this study. As a result, it was found that the less the patients' experience on radiation therapy, the higher their anxiety was. The dominating reason for this result was because the patients expected possible pain during the treatment process. In terms of treatment machine, Linac showed the highest anxiety of all for the openness of its patient stand. The most stable status was found in the case of treatment between 20 minutes and 30 minutes using Tomotherapy. The reason was the coziness of Tomotherapy machine. In the case of receiving the treatment for over 30 minutes, patients felt anxious for the isolation from the outside. The study findings are expected to serve as the necessary data for quality medical service with enhanced patient satisfaction in the clinical field.

• Journal of the Korean Society of Radiology
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• v.10 no.4
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• pp.285-290
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• 2016

The purpose of our study was to retrospectively evaluate the cause of a decreased calcium score of follow-up studies on coronary artery calcium scores (CACs) computed tomography (CT). The subjects were healthy 100 people(85 males $60.6{\pm}6.9$ years, 15 females $67.2{\pm}7.3$ years). The subjects decreased CACs were divided into 4 subgroups depending on Agatston classification, minimal (1-10), mild (11-100), moderate (101-400), severe (400<). As a result of decreased CACs were scan location disagreement 51%, motion artifact 26%, equipment changes 14%, operator mistakes 5%, input miss 2%, image loss 1%, arrhythmia 1%. In the mild group, the most common decreased CACs were 49 people. In the minimal group, the most significant variation reduction has occurred to 6 people. Scan location disagreement was considered a partial volume effects due to the scan starting position. It showed less than 100 CACs a high variation (19.7%) in more than 100 CACs, a lower variation (2.2%), these could be seen that the variation range is different that can be tolerated according to the calcification score. Motion artifact factor was found in 26%, which is so closely related to the preceding tests that affect the higher heart rate like this pulmonary function test, exercise stress test.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.163-173
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• 2014

When evaluating the spatial resolution images and evaluation of low contrast resolution using CT standard phantom, and might present a automated quantitative evaluation method for minimizing errors by subjective judgment of the evaluator be, and try to evaluate the usefulness. 120kVp and 250mAs, 10mm collimation, SFOV(scan field of view) of 25cm or more than, exposure conditions DFOV(display field of view) of 25cm, and were evaluated the 24 passing images and 20 failing images taken using a standard reconstruction algorithm by using the Nuclear Associates, Inc. AAPM CT Performance Phantom(Model 76-410). Quantitative evaluation of low contrast resolution and spatial resolution was using an evaluation program that was self-developed using the company Mathwork Matlab(Ver. 7.6. (R2008a)) software. In this study, the results were evaluated using the evaluation program that was self-developed in the evaluation of images using CT standard phantom, it was possible to evaluate an objective numerical qualitative evaluation item. First, if the contrast resolution, if EI is 0.50, 0.51, 0.52, 0.53, as a result of evaluating quantitatively the results were evaluated qualitatively match. Second, if CNR is -0.0018~-0.0010, as a result of evaluating quantitatively the results were evaluated qualitatively match. Third, if the spatial resolution, as a result of using a image segmentation technique, and automatically extract the contour boundary of the hole, as a result of evaluating quantitatively the results were evaluated qualitatively match.

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.297-303
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• 2019

The nuclear medicine department of a domestic medical institution uses $^{99m}TcI$, a radionuclide, from $^{99}Mo/^{99m}TcI$ Generator, to inject radioactive drugs into patients. Among the expired generators, imported from foreign countries, the medical institution implements its own disposal. Each medical institution shall satisfy the permitted in-house disposal concentration of radioactive wastes. The guidelines for self-disposal presented in Korea suggested that self-disposal can be performed 80 days after the generator is used. The purpose of these guidelines is to analyze them by comparing them with the data measured directly with the generator and to study if they are feasible. As a result, the generator with a capacity of 1,000 mCi has the longest half-life, and when tested with a high-radiation Mo(molybdenum) column, the number of days that are below the permitted concentration of body disposal with radioactive waste was 72 days and 71 days that were derived from direct column measurement. The results of the direct study confirmed that the guidelines for in-house disposal in Korea were reasonable, as there were 8 to 9 days of storage compared to the number of in-house disposal days provided in the guidelines.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.603-609
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• 2022

The dose distribution in the human body was evaluated and analyzed through dosimetry data using water phantom, ionization chamber and simulated by Monte Carlo simulation for ^99mTc and ¹⁸F sources, which are frequently used in the nuclear medicine in this study. As a result of this study, it was found that the dose decreased exponentially as the distance from the radioisotope increased, and it particularly showed a tendency to decrease sharply when the radioisotope was separated by 5 cm. It means that a large amount of dose is delivered to an organ located within 4 cm of source's movement path when a source uptake in the human body. Numerically, it was formed in the rage of 0.16 to 2.16 pC/min for ^99mTc and 0.49 to 9.29 pC/min for ¹⁸F. In addition, the energy transfer coefficient calculated using the result was found to be similar to the measured value and the simulation value in the range of 0.240 to 0.260. Especially, when the measured data and the simulation value were compared, there was a difference is within 2%, so the reliability of the data was secured. In this study, the distribution of radiation generated from a source was calculated to quantitatively evaluate the internal dose by radioisotopes. It presented reliable results through comparative analysis of the measurement value and simulation value. Above all, it has a great significance to the point that it was presented by directly measuring the distribution of radiation in the human body.

• Journal of the Korean Society of Radiology
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• v.18 no.1
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• pp.27-36
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• 2024

In this study, When acquisition thyroid scintigraphy images, a parallel hole collimator was applied, and the difference from the pinhole collimator was quantitatively analyzed under each image acquisition condition. Visual size, resolution, sensitivity, signal to noise ratio (SNR), and contrast to noise ratio (CNR) were evaluated using thyroid phantom and point source. When comparing visual size, it was confirmed that an image similar to the size of the pinhole collimator could be obtained only when a magnification ratio of about 2.00 to 2.09 times when applying a parallel hole collimator. There was no tendency in FWHM(mm) measurement using a point source, and sensitivity was high in the parallel hole collimator. SNR and CNR were high when using a low magnification ratio, matrix size of 128×128, and a parallel hole collimator. In images of similar size to the naked eye, when the matrix size was the same, both SNR and CNR were high in the pinhole collimator. Therefore, when performing a thyroid scintigraphy test, if appropriate conditions are set according to the situation of each hospital and a parallel hole collimator is applied, it can be a good option in terms of equipment utilization and work efficiency.

• Korean Journal of Radiology
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• v.24 no.9
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• pp.827-837
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• 2023

Objective: To investigate the predictive value of radiomics features based on cardiac magnetic resonance (CMR) cine images for left ventricular adverse remodeling (LVAR) after acute ST-segment elevation myocardial infarction (STEMI). Materials and Methods: We conducted a retrospective, single-center, cohort study involving 244 patients (random-split into 170 and 74 for training and testing, respectively) having an acute STEMI (88.5% males, 57.0 ± 10.3 years of age) who underwent CMR examination at one week and six months after percutaneous coronary intervention. LVAR was defined as a 20% increase in left ventricular end-diastolic volume 6 months after acute STEMI. Radiomics features were extracted from the oneweek CMR cine images using the least absolute shrinkage and selection operator regression (LASSO) analysis. The predictive performance of the selected features was evaluated using receiver operating characteristic curve analysis and the area under the curve (AUC). Results: Nine radiomics features with non-zero coefficients were included in the LASSO regression of the radiomics score (RAD score). Infarct size (odds ratio [OR]: 1.04 (1.00-1.07); P = 0.031) and RAD score (OR: 3.43 (2.34-5.28); P < 0.001) were independent predictors of LVAR. The RAD score predicted LVAR, with an AUC (95% confidence interval [CI]) of 0.82 (0.75-0.89) in the training set and 0.75 (0.62-0.89) in the testing set. Combining the RAD score with infarct size yielded favorable performance in predicting LVAR, with an AUC of 0.84 (0.72-0.95). Moreover, the addition of the RAD score to the left ventricular ejection fraction (LVEF) significantly increased the AUC from 0.68 (0.52-0.84) to 0.82 (0.70-0.93) (P = 0.018), which was also comparable to the prediction provided by the combined microvascular obstruction, infarct size, and LVEF with an AUC of 0.79 (0.65-0.94) (P = 0.727). Conclusion: Radiomics analysis using non-contrast cine CMR can predict LVAR after STEMI independently and incrementally to LVEF and may provide an alternative to traditional CMR parameters.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.2
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• pp.71-77
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• 2010

Introduction: The purpose of this study is to evaluate the effect of platelet rich plasma in bone formation and osseointegration of implant installed in the bone marrow space. Materials and Methods: Five beagle dogs were used as experimental animals. Two implants were installed on each tibia in the dogs. Implants of the control group were installed with no additional graft. Those of the experimental group 1 were installed with autogenous bone graft from the ilium autogenous bone. Platelet rich plasma (PRP) alone was used in experimental group 2 and the mixture of PRP and autogenous bone was used in experimental group 3. The animals were sacrificed at 8 weeks after implantation. The parts of tibia containing implant were harvested and radiographs were taken for radiographic examination. The specimens were prepared for histological examination and histomorphometric analysis of implant-bone contact ratios. Results: 1. All implants showed sufficient osseointegration in the cortical bone radiographically and histologically, but osseointergration in the marrow space was not satisfactory. 2. Histomorphometrically, the implant-bone contact ratios in the bone marrow was sequentially high in the experimental group 3 (autogenous bone + PRP group), group 1 (autogenous bone group), group 2 (PRP group), and control group (non-additive). 3. It was verified that there was statistical significance between two experimental groups (group 1 and 3) and the other groups (group 2 and control group). (P<0.005) 4. However, there was no statistical significance between group 3 and group 1, also group 2 and control group respectively. Conclusion: These results suggest that platelet rich plasma is effective to osseointegration in the implant installation but there is no statistical significance.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.43.1-43.5
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• 2019

Background: Reconstructive surgery is often required for tumors of the oral and maxillofacial region, irrespective of whether they are benign or malignant, the area involved, and the tumor size. Recently, three-dimensional (3D) models are increasingly used in reconstructive surgery. However, these models have rarely been adapted for the fabrication of custom-made reconstruction materials. In this report, we present a case of maxillary reconstruction using a laboratory-engineered, custom-made mesh plate from a 3D model. Case presentation: The patient was a 56-year-old female, who had undergone maxillary resection in 2011 for intraoral squamous cell carcinoma that presented as a swelling of the anterior maxillary gingiva. Five years later, there was no recurrence of the malignant tumor and a maxillary reconstruction was planned. Computed tomography (CT) revealed a large bony defect in the dental-alveolar area of the anterior maxilla. Using the CT data, a 3D model of the maxilla was prepared, and the site of reconstruction determined. A custom-made mesh plate was fabricated using the 3D model (Okada Medical Supply, Tokyo, Japan). We performed the reconstruction using the custom-made titanium mesh plate and the particulate cancellous bone and marrow graft from her iliac bone. We employed the tunneling flap technique without alveolar crest incision, to prevent surgical wound dehiscence, mesh exposure, and alveolar bone loss. Ten months later, three dental implants were inserted in the graft. Before the final crown setting, we performed a gingivoplasty with palate mucosal graft. The patient has expressed total satisfaction with both the functional and esthetic outcomes of the procedure. Conclusion: We have successfully performed a maxillary and dental reconstruction using a custom-made, pre-bent titanium mesh plate.