1.Research of Establishing of Standard Radiation Qualities and Radiation Conditions for Use in the Determination and Characteristics of Medical Diagnostic X-ray Equipment.
Shibing XIE ; Xin ZHANG ; Guangyong HU ; Xintao ZHANG
Chinese Journal of Medical Instrumentation 2018;42(6):453-454
The standard of YY/T 0481-2004 Medical diagnostic X-ray equipment-Radiation conditions for use in the determination and characteristics has been revised and replaced in 2012. This paper first introduces the key technical problems to be solved in establishing standard radiation quality and radiation conditions by comparing the main changes of the two versions standards, including the expression of radiation quality and radiation conditions, the measurement of X-ray tube voltage, and the measuring of the practical peak voltage. Then it introduces a procedure for establishing standard radiation quality and radiation conditions.
Radiation Dosage
;
Radiography
;
Reference Standards
3.Image Quality Improvement after Implementation of a CT Accreditation Program.
You Sung KIM ; Seung Eun JUNG ; Byung Gil CHOI ; Yu Ri SHIN ; Seong Su HWANG ; Young Mi KU ; Yeon Soo LIM ; Jae Mun LEE
Korean Journal of Radiology 2010;11(5):553-559
OBJECTIVE: The purpose of this study was to evaluate any improvement in the quality of abdominal CTs after the utilization of the nationally based accreditation program. MATERIALS AND METHODS: Approval was obtained from the Institutional Review Board, and informed consent was waived. We retrospectively analyzed 1,011 outside abdominal CTs, from 2003 to 2007. We evaluated images using a fill-up sheet form of the national accreditation program, and subjectively by grading for the overall CT image quality. CT scans were divided into two categories according to time periods; before and after the implementation of the accreditation program. We compared CT scans between two periods according to parameters pertaining to the evaluation of images. We determined whether there was a correlation between the results of a subjective assessment of the image quality and the evaluation scores of the clinical image. RESULTS: The following parameters were significantly different after the implementation of the accreditation program: identifying data, display parameters, scan length, spatial and contrast resolution, window width and level, optimal contrast enhancement, slice thickness, and total score. The remaining parameters were not significantly different between scans obtained from the two different periods: scan parameters, film quality, and artifacts. CONCLUSION: After performing the CT accreditation program, the quality of the outside abdominal CTs show marked improvement, especially for the parameters related to the scanning protocol.
*Accreditation
;
Humans
;
*Quality Improvement
;
Radiography, Abdominal/*standards
;
Republic of Korea
;
Retrospective Studies
;
Tomography, X-Ray Computed/*standards
4.Optimizing Imaging Quality and Radiation Dose by the Age-Dependent Setting of Tube Voltage in Pediatric Chest Digital Radiography.
Hui GUO ; Wen Ya LIU ; Xiao Ye HE ; Xiao Shan ZHOU ; Qun Li ZENG ; Bai Yan LI
Korean Journal of Radiology 2013;14(1):126-131
OBJECTIVE: The quality and radiation dose of different tube voltage sets for chest digital radiography (DR) were compared in a series of pediatric age groups. MATERIALS AND METHODS: Forty-five hundred children aged 0-14 years (yr) were randomly divided into four groups according to the tube voltage protocols for chest DR: lower kilovoltage potential (kVp) (A), intermediate kVp (B), and higher kVp (C) groups, and the fixed high kVp group (controls). The results were analyzed among five different age groups (0-1 yr, 1-3 yr, 3-7 yr, 7-11 yr and 11-14 yr). The dose area product (DAP) and visual grading analysis score (VGAS) were determined and compared by using one-way analysis of variance. RESULTS: The mean DAP of protocol C was significantly lower as compared with protocols A, B and controls (p < 0.05). DAP was higher in protocol A than the controls (p <0.001), but it was not statistically significantly different between B and the controls (p = 0.976). Mean VGAS was lower in the controls than all three protocols (p < 0.001 for all). Mean VGAS did not differ between protocols A and B (p = 0.334), but was lower in protocol C than A (p = 0.008) and B (p = 0.049). CONCLUSION: Protocol C (higher kVp) may help optimize the trade-off between radiation dose and image quality, and it may be acceptable for use in a pediatric age group from these results.
Adolescent
;
Age Factors
;
Analysis of Variance
;
Child
;
Child, Preschool
;
Humans
;
Infant
;
Infant, Newborn
;
Pediatrics/*standards
;
Prospective Studies
;
*Radiation Dosage
;
Radiation Protection/standards
;
Radiographic Image Enhancement/*standards
;
Radiography, Thoracic/*standards
5.Computed tomographic characteristics of acute thoracolumbar intervertebral disc disease in dogs.
Changyun LIM ; Oh Kyeong KWEON ; Min Cheol CHOI ; Jihye CHOI ; Junghee YOON
Journal of Veterinary Science 2010;11(1):73-79
Forty canine patients with a presumptive diagnosis of the intervertebral disc herniation at the thoracolumbar region were imaged. A neurological examination was performed and all patients were classified under four grades by the examination. The degrees of attenuation of the herniated disc material were measured in Housefield units (HU) in each image. The ratio of the area to herniated disc material and the height to disc material were measured. The clinical grade was correlated with the area ratio of the herniated disc material to the spinal cord, but not correlated with the height ratio of that. In the patients with epidural hemorrhage at surgery, HUs of the herniated disc material was lower than those with no epidural hemorrhage at surgery. Non-contrast computed tomography scans of the spine can be useful in diagnosing acute intervertebral disc disease in chondrodystrophoid breeds, evaluating patient status and identifying concurrent epidural hemorrhage.
Animals
;
Dog Diseases/*pathology/radiography
;
Dogs
;
Intervertebral Disk Displacement/radiography/*veterinary
;
Lumbar Vertebrae/*pathology/radiography
;
Retrospective Studies
;
Thoracic Vertebrae/*pathology/radiography
;
Tomography, X-Ray Computed/methods/standards/*veterinary
6.Study on revising the criteria of classification of hazard conditions of productive dust.
Zhi-ming WANG ; Mian-zhen WANG ; Ya-jia LAN ; Jing-dong LIU ; Fu-rong WU ; Su-jun FAN ; Geng-wen CHEN ; Xiao-he CHEN ; Jian-sheng LI
Chinese Journal of Industrial Hygiene and Occupational Diseases 2004;22(1):33-35
OBJECTIVETo provide scientific basis data for revising the national hygiene criteria of "Classification of hazard conditions of productive dust" (GB5817-86).
METHODSThe data of the retrospective study and the field survey data were analyzed with correlation and regression analysis. The product of total dust concentration of respiratory exposure (mg/m(3)), total ventilation during exposure (m(3)/d per psrson), and level of free SiO(2) in dust (%) was the respiratory exposure dose of free SiO(2) (mg per day per person) which was used as dose criteria value of classification of hazard degree of dust.
RESULTSUsing free SiO(2) exposure dose and the dose-effect relationship, the hazard degrees of the dust were divided into 5 grades: 0, I, II, III, IV (0 - 8.0, 8.1 - 12.0, 12.1 - 16.0, > 24.1 mg per day per person).
CONCLUSIONThe exposure dose of free SiO(2) is closely related to the pathogenesis of silicosis. Using the exposure dose of free SiO(2) as the classification indicator of hazard degree of dust is reliable, simple and easy to execute.
China ; Dust ; analysis ; Hazardous Substances ; analysis ; Humans ; Lung ; diagnostic imaging ; pathology ; Occupational Exposure ; standards ; Radiography ; Retrospective Studies ; Safety Management ; standards
7.Multidetector CT Urography in Imaging of the Urinary Tract in Patients with Hematuria.
Michael M MAHER ; Mannudeep K KALRA ; Stefania RIZZO ; Peter R MUELLER ; Sanjay SAINI
Korean Journal of Radiology 2004;5(1):1-10
This review article comprehensively discusses multidetector CT urography protocols and their role in imaging of the urinary tract in patients with hematuria.
Hematuria/etiology/*radiography
;
Human
;
Incidental Findings
;
Sensitivity and Specificity
;
Tomography, X-Ray Computed/*methods/standards
;
Urinary Tract/abnormalities
;
Urography/methods/standards
;
Urologic Diseases/complications/congenital/radiography
8.Perfusion Magnetic Resonance Imaging: A Comprehensive Update on Principles and Techniques.
Geon Ho JAHNG ; Ka Loh LI ; Leif OSTERGAARD ; Fernando CALAMANTE
Korean Journal of Radiology 2014;15(5):554-577
Perfusion is a fundamental biological function that refers to the delivery of oxygen and nutrients to tissue by means of blood flow. Perfusion MRI is sensitive to microvasculature and has been applied in a wide variety of clinical applications, including the classification of tumors, identification of stroke regions, and characterization of other diseases. Perfusion MRI techniques are classified with or without using an exogenous contrast agent. Bolus methods, with injections of a contrast agent, provide better sensitivity with higher spatial resolution, and are therefore more widely used in clinical applications. However, arterial spin-labeling methods provide a unique opportunity to measure cerebral blood flow without requiring an exogenous contrast agent and have better accuracy for quantification. Importantly, MRI-based perfusion measurements are minimally invasive overall, and do not use any radiation and radioisotopes. In this review, we describe the principles and techniques of perfusion MRI. This review summarizes comprehensive updated knowledge on the physical principles and techniques of perfusion MRI.
Arteries/chemistry
;
Brain Neoplasms/radiography
;
Contrast Media/diagnostic use
;
Humans
;
Magnetic Resonance Imaging/standards/*trends
;
Spin Labels
;
Stroke/radiography
10.Gastric Cancer Screening and Diagnosis.
The Korean Journal of Gastroenterology 2009;54(2):67-76
Gastric cancer is the most common cancer in Korea and has overall survival rate of around 50%. Gastric cancer detected in early stage can be cured by endoscopic resection or less invasive surgical treatment and the subsequent prognosis is excellent. National cancer screening program for gastric cancer has been available for several years. The evaluation for efficacy of our screening strategy is strongly needed in terms of mortality reduction and cost-effectiveness. Accurate diagnosis and staging evaluation is important for proper management and prediction of a patient's prognosis. It is recommended to understand the advantages and limitations of currently available guidelines and diagnostic modalities. The 7th edition of gastric cancer staging system from AJCC may have significant effect on our knowledge and patient management.
*Early Detection of Cancer
;
Humans
;
Medical Records/standards
;
Neoplasm Staging
;
Stomach Neoplasms/*diagnosis/pathology/radiography