• Imaging Science in Dentistry
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• 제30권1호
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• pp.11-15
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• 2000

Purpose: The primary objective of this study was to estimate the radiation absorbed doses in certain critical organs in the head and neck region with an Orthopos plus, a Panelipse, and a Panex-E machines. The second objective was to compare the absorbed doses between 5 inch by 12 inch and 6 inch by 12 inch image field for the Orthopos plus. Materials and Methods: Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses were measured at the thyroid gland, the submandibular gland, the parotid gland, the mouth floor, the maxillary sinus, the brain, the mandibular body, the mandibular ramus, the 2nd cervical spine and the skin over TMJ area. Results: The highest absorbed dose value was recorded at the mandibular ramus for the Orthopos plus with narrow image field. Higher absorbed dose values were recorded at the parotid gland, the mouth floor, the submandibular gland, and the 2nd cervical spine. The doses in the parotid gland were 597 μGy and 529 μGy with Orthopos plus, 638 μGy with Panelipse, and 1094μGy with Panex-E. Corresponding figures for the mandibular ramus were 2363 Gy and 1220 μGy, 248 μGy, and 118 μGy. The absorbed doses to the thyroid gland, the maxillary sinus, the brain, and the skin over TMJ were very low. Conclusion: Higher exposure values were recorded for the Orthopos plus than Panelipse and Panex-E. There was no significant differences of the absorbed doses according to the image field size.

• Nuclear Medicine and Molecular Imaging
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• 제43권4호
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• pp.259-279
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• 2009

Radioiodine ablation therapy has been considered to be a standard treatment for patient with differentiated thyroid cancer after total thyroidectomy. Patients may need to be hospitalized to reduce radiation exposure of other people and relatives from radioactive patients receiving radioiodine therapy. Medical staffs, nursing staffs and technologists sometimes hesitate to contact patients in radioiodine therapy ward. The purpose of this paper is to introduce radiation dosimetry, estimate radiation dose from patients and emphasize the safety of radiation exposure from patients treated with high dose radioiodine in therapy ward. The major component of radiation dose from patient is external exposure. However external radiation dose from these patients treated with typical therapeutic dose of 4 to 8 GBq have a very low risk of cancer induction compared with other various risks occurring in daily life. The typical annual radiation dose without shielding received by patient is estimated to be 5 to 10 mSv, which is comparable with 100 to 200 times effective dose received by chest PA examination. Therefore, when we should keep in mind the general principle of radiation protection, the risks of radiation exposure from patients are low and the medical personnel are considered to be safe from radiation exposure.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.175-179
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• 2002

Follicular carcinomas are the second most common form of thyroid cancer, accounting for 10 to 20% of all thyroid cancers. Follicular carcinomas have a propensity to metastasize via the bloodstream, spreading to bone, lungs, liver, and elsewhere. We described the case of a 48-year-old woman who presented with swelling of the left preauricular area, which was a consequence of a metastatic follicular carcinoma of the masticator space. Plain films showed illdefined erosive bony changes from the left condylar head to the mandibular notch. Contrast-enhanced CT images showed a well circumscribed round mass with well enhancement within left masticator space. On MR images, the mass was heterogenously hyperintense to the muscle on T2-weighted images and isointense or hyperintense to the muscle on Tl-weighted images, and showed good enhancement on contrast-enhanced Tl-weighted images. Upon microscopic examination, the metastatic mass was found to be composed of fairly uniform cells forming small follicles containing colloid, showing capsular and vascular invasion.

• Journal of Oral Medicine and Pain
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• 제44권4호
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• pp.179-182
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• 2019

Sjögren syndrome (SS) is a chronic autoimmune disease characterized by dryness of the mouth and eyes due to lymphocytic infiltration of the exocrine glands. In American European Consensus Group (AECG) criteria, abnormal salivary gland scintigraphy (SGS) result is one of the objective signs of SS and it has been proposed as a valid and non-invasive alternative approach to functional evaluation of salivary gland, especially in the case when unstimulated whole salivary flow is more than 1.5 mL in 15 minutes or other AECG criteria is unmet. Patients with SS are more likely to have the thyroid disease (TD), but this association remains controversial. We present a case of the use of SGS for diagnosis of primary SS and TD in patients with dry mouth and burning sensation of tongue. Through this case, we suggest the usefulness of salivary scintigraphy for screening TD in addition to diagnosis of SS.

• Imaging Science in Dentistry
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• 제37권2호
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• pp.87-92
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• 2007

Purpose: To measure the absorbed doses of cone beam computed tomography (CBCT), which is recently being more frequently used, and to compare them with those of panoramic radiography. Materials and Methods: To measure the absorbed doses of CBCT ($PSR-9000N^{TM}$, Asahi Roentgen Ind. Co., Japan), we placed TLD chips on the skin regions above the parotid and thyroid glands, and on the dorsum of tongue in a dental head phantom. We used two image acquisition modes of the Dental and Panoramic modes of CBCT, which differed in the field of view. Also, panoramic radiographs (Auto IIIN, Asahi Roentgen Ind. Co., Japan) were taken to compare with the absorbed doses of CBCT. Result: In the Dental mode of CBCT, the absorbed doses of the parotid gland, dorsum of tongue, and thyroid gland were 3.53, 3.13, and 0.36 mGy, respectively. In the Panoramic mode of CBCT, they were 9.57, 9.15, and 0.85 mGy, respectively. The panoramic mode showed higher absorbed doses than those of the Dental mode. In the panoramic radiography, the absorbed doses of the parotid gland, dorsum of tongue, and thyroid gland were 1.21, 1.19, and 0.16 mGy, respectively. And they were about 1/3 of the Dental mode and 1/9 of the Panoramic mode of CBCT. Conclusion: Absorbed doses of CBCT are higher than those of panoramic radiography, and dependent upon the field of view.

• Healthcare Informatics Research
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• 제24권4호
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• pp.394-401
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• 2018

Objectives: Augmented reality (AR) technology has become rapidly available and is suitable for various medical applications since it can provide effective visualization of intricate anatomical structures inside the human body. This paper describes the procedure to develop an AR app with Unity3D and Vuforia software development kit and publish it to a smartphone for the localization of critical tissues or organs that cannot be seen easily by the naked eye during surgery. Methods: In this study, Vuforia version 6.5 integrated with the Unity Editor was installed on a desktop computer and configured to develop the Android AR app for the visualization of internal organs. Three-dimensional segmented human organs were extracted from a computerized tomography file using Seg3D software, and overlaid on a target body surface through the developed app with an artificial marker. Results: To aid beginners in using the AR technology for medical applications, a 3D model of the thyroid and surrounding structures was created from a thyroid cancer patient's DICOM file, and was visualized on the neck of a medical training mannequin through the developed AR app. The individual organs, including the thyroid, trachea, carotid artery, jugular vein, and esophagus were localized by the surgeon's Android smartphone. Conclusions: Vuforia software can help even researchers, students, or surgeons who do not possess computer vision expertise to easily develop an AR app in a user-friendly manner and use it to visualize and localize critical internal organs without incision. It could allow AR technology to be extensively utilized for various medical applications.

• 대한방사선기술학회지:방사선기술과학
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• 제47권1호
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• pp.29-37
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• 2024

This study aims to evaluate the performance of the U-Net based learning model that may vary depending on the histogram equalization algorithm. The subject of the experiment were 17 radiology students of this college, and 1,727 data sets in which the region of interest was set in the thyroid after acquiring ultrasound image data were used. The training set consisted of 1,383 images, the validation set consisted of 172 and the test data set consisted of 172. The equalization algorithm was divided into Histogram Equalization(HE) and Contrast Limited Adaptive Histogram Equalization(CLAHE), and according to the clip limit, it was divided into CLAHE8-1, CLAHE8-2. CLAHE8-3. Deep Learning was learned through size control, histogram equalization, Z-score normalization, and data augmentation. As a result of the experiment, the Attention U-Net showed the highest performance from CLAHE8-2 to 0.8355, and the U-Net and BSU-Net showed the highest performance from CLAHE8-3 to 0.8303 and 0.8277. In the case of mIoU, the Attention U-Net was 0.7175 in CLAHE8-2, the U-Net was 0.7098 and the BSU-Net was 0.7060 in CLAHE8-3. This study attempted to confirm the effects of U-Net, Attention U-Net, and BSU-Net models when histogram equalization is performed on ultrasound images. The increase in Clip Limit can be expected to increase the ROI match with the prediction mask by clarifying the boundaries, which affects the improvement of the contrast of the thyroid area in deep learning model learning, and consequently affects the performance improvement.

• Korean Journal of Radiology
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• 제23권2호
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• pp.280-288
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• 2022

Objective: To compare core needle biopsy (CNB) and repeat fine-needle aspiration (rFNA) to reduce the rate of diagnostic surgery and prevent unnecessary surgery in nodules initially diagnosed as atypia/follicular lesions of undetermined significance (AUS/FLUS). Materials and Methods: This study included 231 consecutive patients (150 female and 81 male; mean age ± standard deviation, 51.9 ± 11.7 years) with 235 thyroid nodules (≥ 1 cm) initially diagnosed as AUS/FLUS, who later underwent both rFNA and CNB. The nodules that required diagnostic surgery after the biopsy were defined using three different scenarios according to the rFNA and CNB results: criterion 1, surgery for low-risk indeterminate (categories I and III); criterion 2, surgery for high-risk indeterminate (categories IV and V); and criterion 3, surgery for all indeterminate nodules (categories I, III, IV, and V). We compared the expected rates of diagnostic surgery between CNB and rFNA in all 235 nodules using the three surgical criteria. In addition, the expected rates of unnecessary surgery (i.e., surgery for benign pathology) were compared in a subgroup of 182 nodules with available final diagnoses. Results: CNB showed significantly lower rates of nondiagnostic, AUS/FLUS, and suspicious for malignancy diagnoses (p ≤ 0.016) and higher rates of follicular neoplasm or suspicious for a follicular neoplasm (p < 0.001) and malignant diagnoses (p = 0.031). CNB showed a significantly lower expected rate of diagnostic surgery than rFNA for criterion 1 (29.8% vs. 48.1%, p < 0.001) and criterion 3 (46.4% vs. 55.3%, p = 0.029), and a significantly higher rate for criterion 2 (16.6% vs. 7.2%, p = 0.001). CNB showed a significantly lower expected rate of unnecessary surgery than rFNA for criterion 1 (18.7% vs. 29.7%, p = 0.024). Conclusion: CNB was superior to rFNA in reducing the rates of potential diagnostic surgery and unnecessary surgery for nodules initially diagnosed as AUS/FLUS in a scenario where nodules with low-risk indeterminate results (categories I and III) would undergo surgery.

• Nuclear Medicine and Molecular Imaging
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• 제41권3호
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• pp.218-225
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• 2007

목적: 이 연구에서는 갑상선 암 수술 후 방사선요오드-131 치료를 받은 환자가 방사선 안전 퇴원 기준에 따라 즉시 퇴원 했을 때 환자의 가족이 받는 방사선량을 측정하여 정부의 허용범위와 비교하고자 하였다. 대상 및 방법: 의사가 설명한 방사선 안전지침을 이해하고 그대로 준수하기로 동의한 11명의 외래 환자에게 3.70 - 5.55 GBq의 NaI-131을 투여하고 가족과 환자가 생활하는 방 주변의 방사선량을 측정하였다. 결과: 환자의 가족이 받은 최대 방사선량은 정부의 허용범위 보다 훨씬 적은(5% 이내) 것으로 나타났다. 결론: 본 연구자들은 외래환자 I-131 치료가 안전하다는 것을 확인하였다. 따라서 외래환자 I-131 치료를 통해 격리 시설부족으로 인한 치료지연을 줄일 수 있고, 앞으로 갑상선 암환자 치료 관리에 도움을 줄 수 있을 것으로 확신한다. 또한 환자와 정부의 의료비용 절감 효과도 기대된다.

• 대한두경부종양학회지
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• 제39권2호
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• pp.13-17
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• 2023

아직까지 원발성 갑상선 림프종은 대규모 전향적 임상 연구가 부족하여 각 증례에서의 적절한 치료 계획에 대해 의논의 여지가 많고, 관련 임상과들의 다학제적 접근이 요구된다. 비교적 저등급 림프종으로 분류되는 MALT 림프종 역시 조직학적 형질전환을 포함한 다양한 임상 경과를 보이고, 부분적인 생검만으로는 림프종의 정확한 진단에 어려움이 있는 만큼, 환자의 증상과 상황에 맞는 최선의 의사 결정이 요구된다. 아울러 갑상선의 기관 특성을 고려한 림프종의 각 아형별 표준 치료의 정립이 지속적으로 논의되어야 할 것으로 사료된다.