Biomaterial Database

X-ray machine calibration: a study of failure rates. 1994

O L Pirtle

Richmond Imaging Associates, Houston, Texas.

Inaccurate calibrations can seriously affect the technique chart and, ultimately, affect patient exposure and the diagnostic quality of radiographs. Texas regulations require that several quality control tests, including kV accuracy, timer accuracy, mAs linearity and reproducibility, be performed on all x-ray units. This article reports the results of those tests for radiographic x-ray machines in nonhospital facilities. Of the 161 machines tested, 30% failed one or more tests. The most commonly failed test was kV accuracy, while failure of mAs linearity was the second most frequently failed test.

UI	MeSH Term	Description	Entries
D011786	Quality Control	A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)	Control, Quality,Controls, Quality,Quality Controls
D011829	Radiation Dosage	The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).	Sievert Units,Dosage, Radiation,Gray Units,Gy Radiation,Sv Radiation Dose Equivalent,Dosages, Radiation,Radiation Dosages,Units, Gray,Units, Sievert
D011834	Radiation Monitoring	The observation, either continuously or at intervals, of the levels of radiation in a given area, generally for the purpose of assuring that they have not exceeded prescribed amounts or, in case of radiation already present in the area, assuring that the levels have returned to those meeting acceptable safety standards.	Monitoring, Radiation
D011859	Radiography	Examination of any part of the body for diagnostic purposes by means of X-RAYS or GAMMA RAYS, recording the image on a sensitized surface (such as photographic film).	Radiology, Diagnostic X-Ray,Roentgenography,X-Ray, Diagnostic,Diagnostic X-Ray,Diagnostic X-Ray Radiology,X-Ray Radiology, Diagnostic,Diagnostic X Ray,Diagnostic X Ray Radiology,Diagnostic X-Rays,Radiology, Diagnostic X Ray,X Ray Radiology, Diagnostic,X Ray, Diagnostic,X-Rays, Diagnostic
D002138	Calibration	Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.	Calibrations
D004868	Equipment Failure	Failure of equipment to perform to standard. The failure may be due to defects or improper use.	Defects, Equipment,Device Failure,Failure, Equipment,Malfunction, Equipment,Medical Device Failure,Misuse, Equipment,Device Failure, Medical,Device Failures, Medical,Failure, Medical Device,Failures, Medical Device,Defect, Equipment,Device Failures,Equipment Defect,Equipment Defects,Equipment Failures,Equipment Malfunction,Equipment Malfunctions,Equipment Misuse,Equipment Misuses,Failure, Device,Failures, Device,Failures, Equipment,Malfunctions, Equipment,Misuses, Equipment
D006268	Health Facilities	Institutions which provide medical or health-related services.	Facilities, Health,Facility, Health,Health Facility
D013781	Texas	State bounded on the north by Oklahoma, on the east by Arkansas and Louisiana, on the south by Mexico, and on the west by New Mexico.
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D015203	Reproducibility of Results	The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.	Reliability and Validity,Reliability of Result,Reproducibility Of Result,Reproducibility of Finding,Validity of Result,Validity of Results,Face Validity,Reliability (Epidemiology),Reliability of Results,Reproducibility of Findings,Test-Retest Reliability,Validity (Epidemiology),Finding Reproducibilities,Finding Reproducibility,Of Result, Reproducibility,Of Results, Reproducibility,Reliabilities, Test-Retest,Reliability, Test-Retest,Result Reliabilities,Result Reliability,Result Validities,Result Validity,Result, Reproducibility Of,Results, Reproducibility Of,Test Retest Reliability,Validity and Reliability,Validity, Face