![]() The order in which images are acquired was modified to avoid intense activation of the digital plate quickly followed by another acquisition. ![]() Working with the vendor, Mayo staff devised strategies that have helped to mitigate the artifact problem - but at a cost of reduced machine efficiency. "Otherwise, we would have never gotten this strange artifact." "This is when we realized the vendors were actually doing something actively," Walz-Flannigan said. Lag artifacts typically do not appear in images acquired 60 seconds after their onset, but intense opacities did persist sporadically for up to 15 minutes after image acquisition on a particular DR unit at Mayo because of a manufacturer's unsuccessful attempt to use a subtraction technique to eliminate the phenomenon. Highly opaque objects depicted in a DR image will reappear less densely in one or more subsequent images. All images courtesy of Alisa Walz-Flannigan, PhD. The most visible artifact is directly posterior to the lumbar spine. Outline of the patient's neckline and lead marker from a swimmer’s view of a shoulder study are seen (with inverse opacity) in this lumbar spine image taken two minutes later. The trapped charges produce a double exposure, making the next image in a series either difficult or impossible to read. Ghosting seems to arise from an inability to deactivate detector plate phosphors that were energized on a completed image before later image acquisitions are performed. "This could have led to wrong-side labeling," she said. Walz-Flannigan pointed to instances where the shadows of lead laterality markers positioned on a patient during an earlier procedure reappear as artifacts on subsequent images. In an interview with, Walz-Flannigan discussed the implications of image lag artifact, a problem linked to DR detector design, and backscatter artifact, an issue primarily associated with inadequate radiation shielding for wireless digital detectors.Īrtifacts due to image lag (also referred to as ghosting) have raised safety concerns. ![]() Mayo's experience varied with the different makes and models of DR equipment. Similar problems have not affected Mayo's CR systems because of essential differences in detector design between the CR and DR systems. Specific equipment models in the study included DRX-1 from Carestream Health, Definium 8000 from GE Healthcare, DigitalDiagnost from Philips Healthcare, and Axiom Aristos MX from Siemens Healthcare. 156-161).Īrtifacts featured in the Mayo paper were produced by flat-panel DR detectors with an amorphous silicon thin-film transistor array, coupled to a phosphor layer of either cesium iodide or gadolinium oxysulfide. "These are things users need to be aware of, especially things that could jeopardize patient safety," said Alisa Walz-Flannigan, PhD, lead researcher on the study ( AJR, January 2012, Vol. But DR's recent growth means that many facilities are encountering artifacts that are novel to the technology. Imaging facilities are shifting to DR equipment due to its inherent workflow efficiencies compared to analog x-ray, or even computed radiography (CR). The group described its experience with DR artifacts and how to correct for them. Janu- New forms of image artifacts can compromise the performance of digital radiography (DR) equipment, say researchers from the Mayo Clinic in Rochester, MN, in the January issue of the American Journal of Roentgenology. Image artifacts degrade digital radiography performance By James Brice, contributing writer
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