• Title/Summary/Keyword: Radiology science department

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Lens Dose Reduction Methods and Image Quality in Orbital Computed Tomography Scan (안와 전산화단층촬영검사 시 수정체 선량감소 방법과 영상 평가)

  • Moon, Se-Young;Hong, Sang-Woo;Seo, Ji-Sook;Kim, Yeong-Beom;Kwak, Wan-Sin;Lee, Seong-Yeong;Kim, Jung-Soo
    • Journal of radiological science and technology
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    • v.43 no.5
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    • pp.343-351
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    • 2020
  • This study analyzed dose reduction and quality of images through dose reduction tools and shielding board to protect sensitive eye lens in radiation during orbit CT examinations for clinical data use. During CT scans of the phantom, surface dose (CT scanner dosimetry phantom, ion chamber-3 times) and quality of image (radiosurgery head phantom, visual assessment-2 times, HU standard deviation) were evaluated using X-care which is dose reduction tools and bismuth shielding board. The results of experiments of eight conditions showed a relatively reduced dose in all other conditions compared to when no conditions were set. In particular, the area corresponding to the ophthalmic part reduced the surface dose by up to 45.7 %. The visual evaluation of images by specialists and the quality evaluation of images analyzed by HU standard deviation were clinically closest to the use of X-care and shielding board (1 cm in height). Therefore, it is believed that the use of shielding board in a suitable location with dose reduction tools while investigating the optimal radiation dose will reduce the exposure dose of sensitive lens at radiation while maintaining the quality of the images with high diagnostic value.

A Study on the Composition of Plan of the Diagnostic Radiology Department in General Hospital (종합병원(綜合病院) 방사선진단부(放射線診斷部)의 평면구성(平面構成)에 관한 연구(硏究))

  • Yu, Young-Min
    • Journal of radiological science and technology
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    • v.9 no.1
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    • pp.93-123
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    • 1986
  • The aim of this study is to propose the desirable plan of the diagnostic radiology department in general hospital. The main contents and results of this study are as follows. 1. By investigating and analyzing the activities and circulation of the patients and staffs in diagnostic radiology department, the activity model of the department was extracted. 2. The types of operating system of the department were extracted and activity model by the operating systems were made. 3. The types of the plan of the department were classified into three types, such as confusing-corridor type, separated-corridor type and contract type. 4. After dividing them into eight types in detail, the merits and demerits of each type were analyzed. 5. Among those types contact types were evaluated best in comparison with the other types in terms of efficiency of staff's work, access of patients to staffs and reduction of staffs movement.

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Radiographic features of desmoplastic ameloblastoma: Report of 3 cases (결합조직형성 법랑모세포종의 방사선학적 소견 : 증례보고 3례)

  • Choi Da-Hye;Huh Kyung-Hoe;Moon Je-Woon;Yi Won-Jin;Heo Min-Suk;Lee Sam-Sun;Choi Soon-Chul;Park Kwan-Soo
    • Imaging Science in Dentistry
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    • v.36 no.1
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    • pp.63-68
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    • 2006
  • Desmoplastic ameloblastoma is a rare histologic variant of ameloblastoma. It shows important differences in anatomic distribution, histologic appearance, and radiographic findings compared with the general type of ameloblastoma. It is histologically characterized by an abundance of densely collagenous stroma and radiographically a mixed radiolucent-radiopaque lesion. We present three cases of desmoplastic ameloblastoma. All the patients complained on buccal swelling with or without pain and the sites of occurrence were the anterior and the premolar region. Plain radiographs showed mixed radiopaque-radiolucent lesion with ill-defined or diffuse sclerotic margin and no external root resorption. Additionally, CT scans revealetl buccal expansion and relatively well-defined margin of the lesions. The clinical and radiographic features of the presented cases were compared with those of the desmoplastic ameloblastoma in the previous literatures.

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Positioning errors and quality assessment in panoramic radiography

  • Dhillon, Manu;Raju, Srinivasa M.;Verma, Sankalp;Tomar, Divya;Mohan, Raviprakash S.;Lakhanpal, Manisha;Krishnamoorthy, Bhuvana
    • Imaging Science in Dentistry
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    • v.42 no.4
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    • pp.207-212
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    • 2012
  • Purpose: This study was performed to determine the relative frequency of positioning errors, to identify those errors directly responsible for diagnostically inadequate images, and to assess the quality of panoramic radiographs in a sample of records collected from a dental college. Materials and Methods: This study consisted of 1,782 panoramic radiographs obtained from the Department of Oral and Maxillofacial Radiology. The positioning errors of the radiographs were assessed and categorized into nine groups: the chin tipped high, chin tipped low, a slumped position, the patient positioned forward, the patient positioned backward, failure to position the tongue against the palate, patient movement during exposure, the head tilted, and the head turned to one side. The quality of the radiographs was further judged as being 'excellent', 'diagnostically acceptable', or 'unacceptable'. Results: Out of 1,782 radiographs, 196 (11%) were error free and 1,586 (89%) were present with positioning errors. The most common error observed was the failure to position the tongue against the palate (55.7%) and the least commonly experienced error was patient movement during exposure (1.6%). Only 11% of the radiographs were excellent, 64.1% were diagnostically acceptable, and 24.9% were unacceptable. Conclusion: The positioning errors found on panoramic radiographs were relatively common in our study. The quality of panoramic radiographs could be improved by careful attention to patient positioning.

Pre- and Post-Treatment Imaging of Primary Central Nervous System Tumors in the Molecular and Genetic Era

  • Sung Soo Ahn;Soonmee Cha
    • Korean Journal of Radiology
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    • v.22 no.11
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    • pp.1858-1874
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    • 2021
  • Recent advances in the molecular and genetic characterization of central nervous system (CNS) tumors have ushered in a new era of tumor classification, diagnosis, and prognostic assessment. In this emerging and rapidly evolving molecular genetic era, imaging plays a critical role in the preoperative diagnosis and surgical planning, molecular marker prediction, targeted treatment planning, and post-therapy assessment of CNS tumors. This review provides an overview of the current imaging methods relevant to the molecular genetic classification of CNS tumors. Specifically, we focused on 1) the correlates between imaging features and specific molecular genetic markers and 2) the post-therapy imaging used for therapeutic assessment.

Introduction of a New Staging System of Breast Cancer for Radiologists: An Emphasis on the Prognostic Stage

  • Jieun Koh;Min Jung Kim
    • Korean Journal of Radiology
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    • v.20 no.1
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    • pp.69-82
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    • 2019
  • In 2017, the American Joint Committee on Cancer announced the 8th edition of its cancer staging system. For breast cancer, the most significant change in the staging system is the incorporation of biomarkers into the anatomic staging to create prognostic stages. Different prognostic stages are assigned to tumors with the same anatomic stages according to the tumor grade, hormone receptor (estrogen receptor; progesterone receptor) status, and HER2 status. A Clinical Prognostic Stage is assigned to all patients regardless of the type of therapy used; in contrast, a Pathologic Prognosis Stage is assigned to patients in whom surgery is the initial treatment. In a few situations, low Oncotype DX recurrence scores can change the prognostic stage. The radiologists need to understand the importance of the biologic factors that can influence cancer staging.

Study on the Physical Imaging Characteristics by Using Magnetic Resonance Imaging 1.5T (1.5T 자기공명영상을 이용한 물리적 영상 특성에 대한 연구)

  • Min, Jung-Whan;Jeong, Hoi-Woun;Han, Ji-Hyun;Lee, Si-Nae;Park, Jang-Ho;Kim, Ki-Won;Kim, Hyun-Soo
    • Journal of radiological science and technology
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    • v.42 no.5
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    • pp.329-334
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    • 2019
  • This study was purpose to quantitative evaluation of noise power spectrum(NPS) and studied the quantitative evaluation and characteristics of modulation transfer function(MTF) by obtain the optimal edge image by using Coil in magnetic resonance imaging(MRI) equipment through Fujita theory using edge method. The MRI equipment was used (Tim AVANTO 1.5T, Siemense healthcare system, Germany) and the head matrix coil were 12channels(elements) receive coil. The NPS results of showed the best value of 0.004 based on the T2 Nyquist frequency of $1.0mm^{-1}$, and the MTF results of showed that the T1 and T2 values were generally better than the T1 CE and T1 CE FC values. The characteristics of this study were to explain the characteristic method of image quality evaluation in general. To present the quantitative evaluation process and results in the evaluation of MRI image characteristics in radiology.

A Study on Radiation Dose and Image Quality according to CT Table Height in Brain CT (두부 CT 검사 시 테이블 높이에 따른 선량과 화질에 관한 연구)

  • Ki-Won Kim;Joo-Young Oh;Jung-Whan Min;Sang-Sun Lee;Young-Bong Lee;Kyung-Hwan Lim;Yun Yi
    • Journal of radiological science and technology
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    • v.46 no.2
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    • pp.99-106
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    • 2023
  • The height of the table should be considered important during computed tomography (CT) examination, but according to previous studies, not all radiology technologists set the table at the patient's center at the examination, which affects the exposure dose and image quality received by the patient. Therefore, this study intends to study the image quality exposure dose according to the height of the table to realize the optimal image quality and dose during the brain CT scan. The head phantom images were acquired using Philips Brilliance iCT 256. When the image was acquired, the table height was adjusted to 815, 865, 915, 965, 1015, and 1030 mm, respectively, and each scan was performed 3 times for each height. For the exposure dose measurement, optically stimulated luminescence dosimeter (OSLD) was attached to the front, side, eye, and thyroid gland of the head phantom. In the signal to noise ratio (SNR) measurement result, The SNR values for each table height were all lower than 915 mm. As a result of exposure dose, the exposure dose on each area increased as the table height decreased. The height of the table has a close relationship with the patient's radiation exposure dose in the CT scan.

A Study on Characteristic of Image Quality according to CT Table Height in Computed Tomography (컴퓨터단층촬영 검사 시 테이블 높이에 따른 화질 특성에 관한 연구)

  • Ki-Won Kim;Jung-Whan Min;Sang-Sun Lee;Young-Bong Lee;Ki-Jong Lee;Han-Sol Park;Joo-Young Oh
    • Journal of radiological science and technology
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    • v.46 no.4
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    • pp.295-301
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    • 2023
  • In addition to protocol adjustments during CT examinations, the height of the CT table can also affect image quality. Therefore, this study aimed to investigate the change in image quality depending on the height of the table in brain CT, which accounts for a large proportion of CT examinations, by measuring signal to contrast to noise ratio (CNR) and noise power spectrum (NPS) using the head phantom and evaluating them. The head phantom images were acquired using Philips Brilliance iCT 256. When the image was acquired, the table height was adjusted to 815, 865, 915, 965, 1015, and 1030 mm, respectively, and each scan was performed 3 times for each height. The CNR result showed the highest value at 965 mm, which is the height adjacent to the center of the head phantom. NPS showed the lowest NPS at 915 mm, the center of the head phantom in the low frequency region. From these results, it can be seen that the height of the table in CT examination is closely related to the image quality, and it can be seen the characteristics of image quality according to CT table through quantitative evaluation methods such as CNR and NPS.

Current Landscape and Future Perspectives of Abbreviated MRI for Hepatocellular Carcinoma Surveillance

  • Hyo Jung, Park;Nieun Seo;So Yeon Kim
    • Korean Journal of Radiology
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    • v.23 no.6
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    • pp.598-614
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    • 2022
  • While ultrasound (US) is considered an important tool for hepatocellular carcinoma (HCC) surveillance, it has limited sensitivity for detecting early-stage HCC. Abbreviated MRI (AMRI) has recently gained popularity owing to better sensitivity in its detection of early-stage HCC than US, while also minimizing the time and cost in comparison to complete contrast-enhanced MRI, as AMRI includes only a few essential sequences tailored for detecting HCC. Currently, three AMRI protocols exist, namely gadoxetic acid-enhanced hepatobiliary-phase AMRI, dynamic contrast-enhanced AMRI, and non-enhanced AMRI. In this study, we discussed the rationale and technical details of AMRI techniques for achieving optimal surveillance performance. The strengths, weaknesses, and current issues of each AMRI protocol were also elucidated. Moreover, we scrutinized previously performed AMRI studies regarding clinical and technical factors. Reporting and recall strategies were discussed while considering the differences in AMRI protocols. A risk-stratified approach for the target population should be taken to maximize the benefits of AMRI and the cost-effectiveness should be considered. In the era of multiple HCC surveillance tools, patients need to be fully informed about their choices for better adherence to a surveillance program.