PURPOSE: This study aimed to compare the possible standard-setting methods for the Korean Radiological Technologist Licensing Examination, which has a fixed cut score, and to suggest the most appropriate method. METHODS: Six radiological technology professors set standards for 250 items on the Korean Radiological Technologist Licensing Examination administered in December 2016 using the Angoff, Ebel, bookmark, and Hofstee methods. RESULTS: With a maximum percentile score of 100, the cut score for the examination was 71.27 using the Angoff method, 62.2 using the Ebel method, 64.49 using the bookmark method, and 62 using the Hofstee method. Based on the Hofstee method, an acceptable cut score for the examination would be between 52.83 and 70, but the cut score was 71.27 using the Angoff method. CONCLUSION: The above results suggest that the best standard-setting method to determine the cut score would be a panel discussion with the modified Angoff or Ebel method, with verification of the rated results by the Hofstee method. Since no standard-setting method has yet been adopted for the Korean Radiological Technologist Licensing Examination, this study will be able to provide practical guidance for introducing a standard-setting process.
Education ; Licensure ; Methods ; Technology, Radiologic

This review article presents the radiological options for management of malignant gastric outflow obstruction distal to the pylorus. We place these options in context with surgical and endoscopic alternatives and recommend their use, particularly in those institutions where endoscopic alternatives may not be readily available.
Duodenal Obstruction ; Pylorus* ; Self Expandable Metallic Stents ; Technology, Radiologic

Equipment Design ; Humans ; Radiography ; instrumentation ; Technology, Radiologic ; X-Rays

In this paper, we analyze the transformer of X-ray high-voltage high-frequency generators and, have designed and implemented a high-voltage insulation testing system for its oil tank using full-bridge series resonant soft switching PFM DC-DC converter.
Electricity ; Equipment Design ; Radiology ; instrumentation ; Technology, Radiologic ; X-Rays

It is difficult to take intraoral radiographs in some patients who are intolerable to place the film in their mouth. For these patients, Newman and Friedman recommended a new technique of extraoral film placement. Here we report various cases that diagnostic imaging was performed in patients using the extraoral periapical technique. This technique was used to obtain the radiographs for the patients with severe gag reflex, pediatric dental patients, and patients with restricted mouth opening. This technique can be recommended as an alternative to conventional intraoral periapical technique in cases where intraoral film placement is difficult to achieve.
Diagnostic Imaging ; Humans ; Hypogonadism ; Mitochondrial Diseases ; Mouth ; Ophthalmoplegia ; Radiography, Dental ; Reflex ; Technology, Radiologic

Imaging modalities have developed in tandem with technical developments in recent years. It is common practice worldwide to establish a medical imaging quality control system in accordance with resources and need. In2003, the Korean governmentinstituted a medical imaging quality control system for high-priced and high-end medical imaging equipment. Magnetic resonance imaging (MRI), computed tomography (CT), and mammography were included in this program. General image quality has continuously improved, but some problems remain. The medical imaging quality control program will be extended to other equipment such as positron emission tomography-CT, simulation CT for radiation treatment, and extracorporeal shockwave lithotripsy. Education programs for equipment control personnel should be improved and the quality control system should be refined.
Diagnostic Imaging* ; Education ; Electrons ; Korea* ; Lithotripsy ; Magnetic Resonance Imaging ; Mammography ; Quality Control ; Technology, Radiologic

The radiation-induced occlusive vasculopathy has been known as the one of the side effects of radiation therary The gamma knife for stereotactic radiosurgery has been used popularly as a valuable adjunctive therapeutic option in some patients with pituitary tumors for its accuracy and effectiveness. But the long term complication of gamma knife have not been revealed until now. In spite of the remarkable improvement in radiologic technology, the side effect of radiation induced vasculaopathy remains an unsolved issue. We experienced the occlusion of intracranial portion of the internal carotid artery in one patient with pituitary adenoma, who had been treated with gamma knife radiosurgery previously.
Carotid Artery, Internal ; Cerebral Infarction* ; Humans ; Pituitary Neoplasms* ; Radiosurgery* ; Technology, Radiologic

The radiation-induced occlusive vasculopathy has been known as the one of the side effects of radiation therary The gamma knife for stereotactic radiosurgery has been used popularly as a valuable adjunctive therapeutic option in some patients with pituitary tumors for its accuracy and effectiveness. But the long term complication of gamma knife have not been revealed until now. In spite of the remarkable improvement in radiologic technology, the side effect of radiation induced vasculaopathy remains an unsolved issue. We experienced the occlusion of intracranial portion of the internal carotid artery in one patient with pituitary adenoma, who had been treated with gamma knife radiosurgery previously.
Carotid Artery, Internal ; Cerebral Infarction* ; Humans ; Pituitary Neoplasms* ; Radiosurgery* ; Technology, Radiologic

PURPOSE: Clinical stage of gastric cancer is currently assessed by computed tomography. Accurate clinical staging is important for the tailoring of therapy. This study evaluated the accuracy of clinical N staging using stomach protocol computed tomography. MATERIALS AND METHODS: Between March 2004 and November 2012, 171 patients with gastric cancer underwent preoperative stomach protocol computed tomography (Jeju National University Hospital; Jeju, Korea). Their demographic and clinical characteristics were reviewed retrospectively. Two radiologists evaluated cN staging using axial and coronal computed tomography images, and cN stage was matched with pathologic results. The diagnostic accuracy of stomach protocol computed tomography for clinical N staging and clinical characteristics associated with diagnostic accuracy were evaluated. RESULTS: The overall accuracy of stomach protocol computed tomography for cN staging was 63.2%. Computed tomography images of slice thickness 3.0 mm had a sensitivity of 60.0%; a specificity of 89.6%; an accuracy of 78.4%; and a positive predictive value of 78.0% in detecting lymph node metastases. Underestimation of cN stage was associated with larger tumor size (P<0.001), undifferentiated type (P=0.003), diffuse type (P=0.020), more advanced pathologic stage (P<0.001), and larger numbers of harvested and metastatic lymph nodes (P<0.001 each). Tumor differentiation was an independent factor affecting underestimation by computed tomography (P=0.045). CONCLUSIONS: Computed tomography with a size criterion of 8 mm is highly specific but relatively insensitive in detecting nodal metastases. Physicians should keep in mind that computed tomography may not be an appropriate tool to detect nodal metastases for choosing appropriate treatment.
Humans ; Lymph Nodes ; Neoplasm Metastasis ; Neoplasm Staging ; Retrospective Studies ; Sensitivity and Specificity ; Stomach ; Stomach Neoplasms ; Technology, Radiologic

In this paper, a seriesly connected three phase bipolar symmetrical voltage multiplier (VM) is proposed, which is a novel VM for X-ray power supply. It consists of three single phase bipolar symmetrical VM, which are connected in series at their smoothing columns. The charging and discharging process occurs six times in a cycle and the frequency of the output voltage ripple is six times as large as the drive signal frequency. The proposed VM has three times larger output voltage and three times smaller ripple factor as compared to single phase bipolar symmetrical VM, and smaller voltage drop and faster dynamic response than those of the series connected three phase symmetrical VM. The simulation is provided to show the feasibility of proposed VM.
Electric Power Supplies ; Equipment Design ; Radiography ; instrumentation ; Technology, Radiologic ; instrumentation ; X-Rays