• Imaging Science in Dentistry
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• v.52 no.2
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• pp.181-186
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• 2022

Purpose: This study aimed to investigate inter-observer reliability among observers with different levels of proficiency and the diagnostic imaging reliability of cone-beam computed tomography (CBCT) images of the retromolar canal. Materials and Methods: CBCT images of 307 patients were assessed for the presence of retromolar canals(RMCs) by 3 observers independently. Diagnoses were made twice by each observer at intervals of more than 3 weeks. Interobserver reliability was assessed using the kappa coefficient. One observer had no experience in diagnosis using CBCT images. Therefore, a specialist in diagnostic imaging explained the CBCT images for interpretation and practiced diagnostic imaging together with this observer, while the other observer interpreted the images independently. Thereafter, the observers re-evaluated the images. Results: The interobserver kappa coefficients (including bilateral RMCs) calculated at the first reading were low, ranging from 0.21 to 0.61. Their values ranged from 0.95 (right side) to 1.00 (left side) after one-on-one practice with a diagnostic imaging specialist, while the values ranged from 0.65 (right side) to 0.66 (left side) without one-on-one practice. Conclusion: Diagnostic accuracy was improved through diagnostic imaging practice. To improve the anatomical interpretation of images, it is important to practice diagnostic imaging with a specialist in diagnostic imaging. One-on-one instruction about diagnostic imaging was an effective method of training.

• The Korean Journal of Nuclear Medicine
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• v.20 no.2
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• pp.101-104
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• 1986

• Proceedings of the KOSOMBE Conference
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• v.1994 no.05
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• pp.3-6
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• 1994

• Proceedings of the KSMRM Conference
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• 1996.10a
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• pp.75-75
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• 1996

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.311-311
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• 1999

• Korean Journal of Radiology
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• v.23 no.3
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• pp.295-297
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• 2022

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3407-3412
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• 2015

Background: The aim of this study was to evaluate and compare the accuracy of diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) value, and time-intensity curve (TIC) type analysis derived from dynamic contrast-enhanced MR imaging (DCE-MRI) in differentiating benign from malignant adnexal masses. Materials and Methods: 47 patients with 56 adnexal masses (27 malignant and 29 benign) underwent DWI and DCE-MRI examinations, prior to surgery. DWI signal intensity, mean ADC value, and TIC type were determined for all the masses. Results: High signal intensity on DWI and type 3 TIC were helpful in differentiating benign from malignant adnexal masses (p<0.001). The mean ADC value was significantly lower in malignant adnexal masses (p<0.001). An ADC value< $1.20{\times}10^{-3}mm^2/s$ may be the optimal cutoff for differentiating between benign and malignant tumors. The negative predictive value for low signal intensity on DWI, and type 1 TIC were 100%. The pairwise comparison among the receiver operating characteristic (ROC) curves showed that the area under the curve (AUC) of TIC was significantly larger than the AUCs of DWI and ADC (p<0.001 for comparison of TIC and DWI, p<0.02 for comparison of TIC and ADC value). Conclusions: DWI, ADC value and TIC type derived from DCE-MRI are all sensitive and relatively specific methods for differentiating benign from malignant adnexal masses. By comparing these functional MR techniques, TIC was found to be more accurate than DWI and ADC.

• 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.