Christopher J Koller

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The variation in exposure factors and patient dose, between seven centres using identical multislice CT scanners, was investigated for six standard examinations. Dose values were compared with each other and the relevant diagnostic reference level (DRL) for each examination. The range in weighted CT dose index (CTDI(w)) values between the seven centres was(More)
The performance of 14 primary clinical display monitor workstations in use in the Radiology Department of a large acute NHS Trust was assessed using the methods and guidelines described by the American Association of Physicists in Medicine Task Group 18. Tests undertaken included the measurement of ambient light, display uniformity, luminance ratio,(More)
A computational technique for assessing patient dose in plain radiography is described allowing a large number of examinations to be assessed and enabling dose optimization to be promoted. Entrance surface dose (ESD) was calculated for more than 1500 standard exposure settings in an initial dose assessment. Validation of the technique showed good agreement(More)
There are currently no national guidelines on appropriate quality assurance (QA) test frequencies for MRI equipment in clinical use. From a random selection of 45 hospitals in England, who were contacted by phone, 35 hospitals agreed to participate in a survey of MRI QA and were sent a questionnaire requesting information on the range and frequency of QA(More)
OBJECTIVE To assess the use of a commercial dose management system (GE DoseWatch; GEMS, Milwaukee, WI) for CT dose management for six common CT examinations. METHODS Data were acquired over several months using GE DoseWatch for six common CT examinations on three CT scanners. The dose length product (DLP) was taken as the dose indicator. The data were(More)
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