• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1545-1555
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• 2021

Purpose The purpose of this study was to evaluate the rates of unacceptable diagnosis and clinically significant diagnostic discrepancy in radiology sections and imaging modalities through a peer review of teleradiology. Materials and Methods Teleradiology peer reviews in a Korean teleradiology clinic in 2018 and 2019 were included. The peer review scores were classified as acceptable and unacceptable diagnoses and clinically insignificant and significant diagnostic discrepancy. The diagnostic discrepancy rates and clinical significance were compared among radiology sections and imaging modalities using the chi-square test. Results Of 1312 peer reviews, 117 (8.9%) cases had unacceptable diagnoses. Of 462 diagnostic discrepancies, the clinically significant discrepancy was observed in 104 (21.6%) cases. In radiology sections, the unacceptable diagnosis was highest in the musculoskeletal section (21.4%) (p < 0.05), followed by the abdominal section (7.3%) and neuro section (1.3%) (p < 0.05). The proportion of significant discrepancy was higher in the chest section (32.7%) than in the musculoskeletal (19.5%) and abdominal sections (17.1%) (p < 0.05). Regarding modalities, the number of unacceptable diagnoses was higher with MRI (16.2%) than plain radiology (7.8%) (p < 0.05). There was no significant difference in significant discrepancy. Conclusion Peer review provides the rates of unacceptable diagnosis and clinically significant discrepancy in teleradiology. These rates also differ with subspecialty and modality.

• Journal of radiological science and technology
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• v.16 no.1
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• pp.89-94
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• 1993

However, technical advances in ultrasono imaging have had a remarkable impact on the study of biliary system oral cholecystography is a contrast of the gallbladder which is very frequently performed even with the application of Extra Shock Wave Lithotripsy(ESWL) in clinical use. Oral GB requires a stringent preparation if it is to be fully successful and a considerable amount of time to complete all its procedures and its objects of the radiographs. 1) to obtain a firm diagnosis of the presence of gallstones. 2) to essess function of the gallbladder that is, its ability to concentrate and store bile. After a times sequence of X-ray exposures taken in various positions to show the gallbladder to be satisfactorily filled, the patient is given a fatty meal, for instances two eggs or a cup of milk. The gallbladder which is drained by the cystic duct stores and concentrates the bile and is stimulated to contrast and excrete the bile by hormone "cholecystokinin" secreted in the intestinal mucosa. To evaluate the effect of the fatty meal which caused the gallbladder to constrict and empty, and by so doing the contrast medium passes through the cystic and bile ducts which are shown in radiographs exposed from 15-30 minutes after the variety practice of fattymeal, such as soft-boiled 2 eggs, raw 2 eggs, 100g of peanuts, and 200ml of milk. If the concentration of the opaque medium in the gallbladder is adequate, then not only the size, shape and position of the gallbladder will be shown from firms taken at intervals, the rate of concentration of the opaque medium and of the emptying of gallbladder has been measured and analyzed.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.26-32
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• 1992

Minimal deterioration of cerebral perfusion or microanatomical changes were undetectable on conventional Brain CT or MRI. So evaluation of focal functional changes of the brain parenchyme is essential in chronic head injury patients, who did not show focal anatomical changes on these radiological studies. However, the patients who had longstanding neurologic sequelae following head injury, there had been no available imaging modalities for evaluating these patients precisely. Therefore we tried to detect the focal functional changes on the brain parenchyme using $^{99m}Tc-HMPAO$ Brain SPECT on the patients of chronic head injuries. Twenty three patients who had suffered from headache, memory dysfunction, personality change and insomnia lasting more than six months fellowing head injury were included in our cases, which showed no anatomical abnormalities on Brain CT or MRI. At first they underwent psychological test whether the symptoms were organic or not. Also we were able to evaluate the cerebral perfusion changes with $^{99m}Tc-HMPAO$ Brain SPECT in 22 patients among the 23, which five patients were focal and 17 patients were nonfocally diffuse perfusion changes. Thus we can predict the perfusion changes such as local vascular deterioration or functional defects using $^{99m}Tc-HMPAO$ Brain SPECT in the patients who had suffered from post-traumatic sequelae, which changes were undetectable on Brain CT or MRI.

• Journal of radiological science and technology
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• v.24 no.1
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• pp.5-9
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• 2001

Over-density of pancreatic duct tail part on the endoscopic retrograde pancreatogram results from patient's position and inserted air during the study. The aim of this paper is to decide the filter angle to obtain an uniform density. Endoscopic retrograde pancreatography was performed to 234 patients, and angled wedge filter was used differently. They are $10^{\circ}$ (47), $20^{\circ}$ (45), $30^{\circ}$ (50), and $40^{\circ}$ (50). We also did not use wedge filter to 42 patients. We decided reliance degree in 95%. The statistical difference was p<0.05. The patients' sex rate was 1.8 : 1 between 18 and 87 years old(average age 58 years). Their body girth was 18.71 cm on the average. Of total 234 patients, difference of right and left average density was 0.01 by $30^{\circ}$ wedge filter, -0.08 $40^{\circ}$ wedge filter and 0.27 non-wedge filter. These average values of difference density were very significant statistically, and standard deviation also was close to regular distribution. In conclusion, there is a usefulness of angled wedge filter for increasing diagnostic value of pancreatic duct tall part on the endoscopic retrograde pancreatogram.

• Korean Journal of Radiology
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• v.23 no.2
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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.

• Journal of The Korean Radiological Technologist Association
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• v.25 no.1
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• pp.177-191
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• 1999

We conducted a survey into the radiation safety and their vocational consciousness in May in 1998. The population consisted of 273 diagnostic radiotechnologists who have worked in medical institutions in Chonbuk province. The results was as follows; 1. In

• Korean Journal of Radiology
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• v.25 no.3
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• pp.267-276
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• 2024

Objective: To evaluate the diagnostic performance of susceptibility map-weighted imaging (SMwI) taken in different acquisition planes for discriminating patients with neurodegenerative parkinsonism from those without. Materials and Methods: This retrospective, observational, single-institution study enrolled consecutive patients who visited movement disorder clinics and underwent brain MRI and ¹⁸F-FP-CIT PET between September 2021 and December 2021. SMwI images were acquired in both the oblique (perpendicular to the midbrain) and the anterior commissure-posterior commissure (AC-PC) planes. Hyperintensity in the substantia nigra was determined by two neuroradiologists. ¹⁸F-FP-CIT PET was used as the reference standard. Inter-rater agreement was assessed using Cohen;s kappa coefficient. The diagnostic performance of SMwI in the two planes was analyzed separately for the right and left substantia nigra. Multivariable logistic regression analysis with generalized estimating equations was applied to compare the diagnostic performance of the two planes. Results: In total, 194 patients were included, of whom 105 and 103 had positive results on ¹⁸F-FP-CIT PET in the left and right substantia nigra, respectively. Good inter-rater agreement in the oblique (κ = 0.772/0.658 for left/right) and AC-PC planes (0.730/0.741 for left/right) was confirmed. The pooled sensitivities for two readers were 86.4% (178/206, left) and 83.3% (175/210, right) in the oblique plane and 87.4% (180/206, left) and 87.6% (184/210, right) in the AC-PC plane. The pooled specificities for two readers were 83.5% (152/182, left) and 82.0% (146/178, right) in the oblique plane, and 83.5% (152/182, left) and 86.0% (153/178, right) in the AC-PC plane. There were no significant differences in the diagnostic performance between the two planes (P > 0.05). Conclusion: There are no significant difference in the diagnostic performance of SMwI performed in the oblique and AC-PC plane in discriminating patients with parkinsonism from those without. This finding affirms that each institution may choose the imaging plane for SMwI according to their clinical settings.

• Korean Journal of Radiology
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• v.19 no.6
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• pp.1021-1030
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• 2018

Objective: We evaluated the effect of various patient characteristics and time-density curve (TDC)-factors on the test bolus-affected vessel enhancement on coronary computed tomography angiography (CCTA). We also assessed the value of generalized linear regression models (GLMs) for predicting enhancement on CCTA. Materials and Methods: We performed univariate and multivariate regression analysis to evaluate the effect of patient characteristics and to compare contrast enhancement per gram of iodine on test bolus (${\Delta}HUTEST$) and CCTA (${\Delta}HUCCTA$). We developed GLMs to predict ${\Delta}HUCCTA$. GLMs including independent variables were validated with 6-fold cross-validation using the correlation coefficient and Bland-Altman analysis. Results: In multivariate analysis, only total body weight (TBW) and ${\Delta}HUTEST$ maintained their independent predictive value (p < 0.001). In validation analysis, the highest correlation coefficient between ${\Delta}HUCCTA$ and the prediction values was seen in the GLM (r = 0.75), followed by TDC (r = 0.69) and TBW (r = 0.62). The lowest Bland-Altman limit of agreement was observed with GLM-3 (mean difference, $-0.0{\pm}5.1$ Hounsfield units/grams of iodine [HU/gI]; 95% confidence interval [CI], -10.1, 10.1), followed by ${\Delta}HUCCTA$ ($-0.0{\pm}5.9HU/gI$; 95% CI, -11.9, 11.9) and TBW ($1.1{\pm}6.2HU/gI$; 95% CI, -11.2, 13.4). Conclusion: We demonstrated that the patient's TBW and ${\Delta}HUTEST$ significantly affected contrast enhancement on CCTA images and that the combined use of clinical information and test bolus results is useful for predicting aortic enhancement.

• Journal of Yeungnam Medical Science
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• v.6 no.2
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• pp.79-90
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• 1989

Computerized Tomography is now well established and important noninvasive method of diagnosting mediastinal mass lesions because of its superior imaging of their size, location and internal composition. Authors ana lysed and present CT findings of 30 surgically proven mediastinal tumors and cysts that were studied and treated at the Yeungnam University Hospital during recent 6 years. The most common tumor was thymona(9 cases), and teratoma(6 cases), lymphoma(6 cases), bronchogenic cyst(4 cases), neurogenic tumor (4 cases), pericardial cyst(1 case) were next in order of frequency. There were 5 cases of thymoma showing homogenous solid density mass, 2 cases were malignant thymoma and myasthenia gravis was present in 2 cases. A case of thymolipoma and a case of thymic carcinoma were included. All teratomas were cystic masses but pathognomic fat, and calcified density were seen only in 4 cases. 5 cases were located in anterior mediastinum and 1 case was in posterior mediastinum. Lymphoma(3 Hodgkin's and 3 non-Hodgkin's) appeared as irregular lobulated mass in anterior mediastinum. Neurogenic tumor(2 ganglioneuroma and 2 neurilemmoma) appeared as homogenous density mass located in posterior mediastinum. Among the 4 bronchogenic cysts, 2 were located in retrotracheal area, 1 was located in subcarinal and 1 was in parathoracic area. One case of pericardial cyst was oval shaped cystic mass located in left pericardiac border.

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.1-8
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• 1997

뇌성마비는 뇌 발달시기중 초기의 장애로 인하여 운동기능과 자세의 이상 등을 초래하는 질환으로 임상적으로 여러 유형으로 나누어진다. 뇌성마비 환자중에서 MRI 상 롤란도야의 이상소견을 보이는 경우 특이한 임상적 특징을 나타낸다고 보고되어있다. 본 논문에서는 이들을 대상으로 하여 뇌 단일광자컴퓨터촬영에서 나타나는 뇌혈류 이상 소견과 MRI 소견, 그리고 임상양상들을 비교해보고자 하였다. 임상적으로 뇌성마비로 진단된 80여명의 환자중 MRI상 롤란도야에 저산소성 뇌질환의 소견을 보인 7명을 대상으로 하였다. 이들에게 5-10mCi의 Tc-99m-ECD를 정맥주사후 뇌 단일광자컴퓨터촬영을 하였다. 뇌 단일광자컴퓨터촬영상에서는 특히 뇌피질, 선조체, 시상, 뇌간 및 소뇌의 혈류이상 소견을 분석하였고, 이를 MRI 소견 및 임상증상과 비교하였다. 모든 환자들은 만삭 또는 만삭에 가깝게 태어났고, 주산기 아사가 여섯명의 환자에서 있었다. 임상적으로는 긴장성 사지마비로 나타났다. Tc-99m ECD를 이용한 뇌 단일광자 컴퓨터촬영상 롤란도야의 혈류감소는 모두에서 확연하게 나타났다 MRI상에서 롤란도야의 이상소견은 5명에서는 확실하게 나타났고, 2명에서는 의심되었다. MRI상에서 이상소견을 보인 것보다 더 광범위한 부분에서 뇌단일광자컴퓨터촬영상 이상소견이 보였다. 결론적으로, 롤란도야에서 이상소견을 보인 환자는 임상적, 구조적, 그리고 기능적으로 특이한 소견을 보였다. Tc-99m-ECD를 이용한 뇌 단일광자컴퓨터촬영은 매우 민감하게 반영하였고, MRI보다 뇌의 더 광범위한 부위에서 이상소견을 보였다.