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

Humans ; Pneumoconiosis ; diagnostic imaging ; Radiography, Thoracic ; standards ; X-Ray Film

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

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

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

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

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

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

No abstract available.
*Advisory Committees ; Antineoplastic Combined Chemotherapy Protocols/*therapeutic use ; Female ; Humans ; Neoplasm Recurrence, Local/*radiography ; Ovarian Neoplasms/*radiography ; Radiology/*standards

OBJECTIVE: To devise a new method to measure the amount of soft tissue in pulmonary ground-glass opacity nodules, and to compare the use of this method with a previous volumetric measurement method by use of a phantom study. MATERIALS AND METHODS: Phantom nodules were prepared with material from fixed normal swine lung. Forty nodules, each with a diameter of 10 mm, were made with a variable mean attenuation. The reference-standard amount of soft tissue in the nodules was obtained by dividing the weight by the specific gravity. The imaging data on the phantom nodules were acquired with the use of a 16-channel multidetector CT scanner. The CT-measured amount of soft tissue of the nodules was calculated as follows: soft tissue amount = volume x (1 + mean attenuation value / 1,000). The relative percentage error (RPE) between the CT-measured amount of the soft tissue and the reference-standard amount of the soft tissue was also measured. The RPEs determined with use of the new method were compared with the RPEs determined with the current volumetric measurement method by the use of the paired t test. RESULTS: The CT-measured amount of soft tissue showed a strong correlation with the reference-standard amount of soft tissue (R(2) = 0.996, p < 0.01). The mean RPE of the CT-measured amount of soft tissue in the nodules was -7.79 +/- 1.88%. The mean RPE of the CT-measured volume was 114.78 +/- 51.02%, which was significantly greater than the RPE of the CT-measured amount of soft tissue (p < 0.01). CONCLUSION: The amount of soft tissue measured by the use of CT reflects the reference-standard amount of soft tissue in the ground-glass opacity nodules much more accurately than does the use of the CT-measured volume.
Animals ; Lung Neoplasms/*radiography ; Phantoms, Imaging ; Reference Standards ; Swine ; *Tomography, X-Ray Computed