![]() ![]() Peristaltic motion can be reduced with the intravenous injection of an anti-spasmodic (e.g. Flow effects can be reduced by using gradient moment nulling of the first order of flow, gradient moment rephasing or flow compensation, depending of the MRI system. The artifacts can be reduced by using breath holding, cardiac synchronization or respiratory compensation techniques: triggering, gating, retrospective triggering or phase encoding artifact reduction. Motion artifacts can be flipped 90° by swapping the phase//frequency encoding directions. ![]() These artifacts appear in the phase encoding direction, independent of the direction of the motion. an elevator), loose connections anywhere, pulse timing variations, as well as sample motion. Causes of motion artifacts can also be mechanical vibrations, cryogen boiling, large iron objects moving in the fringe field (e.g. The nature of the artifact depends on the timing of the motion with respect to the acquisition. Movement of the object being imaged during the sequence results in inconsistencies in phase and amplitude, which lead to blurring and ghosting. respiration, cardiac motion and blood flow, eye movements and swallowing) and minor subject movements. Patient motion is the largest physiological effect that causes artifacts, often resulting from involuntary movements (e.g. Motion, phase encoded motion, instability, smearingĬompensation techniques, more averages, anti spasmodic Please note that there are different common names for this artifact. Searchterm ' Motion Artifact' was also found in the following services: Result : Searchterm ' Motion Artifact ' found in 5 terms and 19 definitions ġ - 5 (of 24) next Result Pages : “The results of this study suggest that the goal of reducing motion artifacts, and the related image degradation, represents an opportunity to improve efficiency, reduce costs, and improve imaging services,” wrote Andre and colleagues.2 3 5 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Software that can correct for motion would be valuable, as would efforts to reduce sequence acquisition time. Still, the potential costs of MRI motion artifacts are likely to be significant anywhere, and the authors suggested greater attention should be paid to this problem. Results across the country could vary widely as well, owing to geographic variability in reimbursement, payer mix, practice patterns, and other factors. The one-week sample of scans is a limitation, as there could be significant week-to-week variance. The authors did note that precise estimates of costs are difficult and that they used a simplified, averaged-cost approach. They suggested this difference stems from the fact that outpatients are presumably healthier and in less acute distress than inpatients.Īfter reviewing institutional data to determine the cost of lost scanner time, Andre and colleagues determined the potential cost to the hospital was $592 per hour in lost revenue due to motion artifacts, equating to an average cost of approximately $115,000 per scanner per year. Once broken down by patient disposition, the authors reported that 7.5 percent of outpatient exams and 29.4 percent of inpatient and/or emergency department exams had significant motion artifacts. A pair of blinded neuroradiologists visually reviewed the scans and used a five-tier scale to measure the presence of motion artifacts, from “none” to “severe.”Īcross 192 completed clinical exams in the sample, nearly one-in-five (19.8 percent) had to be repeated due to motion artifacts. The sample came from April 2014 and included scans from three different scanners. To get an estimate of the significance of this issue, Andre and colleagues retrospectively reviewed one randomly selected week’s work of MR exams conducted at Harborview Medical Center. Despite these challenges, the authors were surprised that few studies have looked at the prevalence or impact of motion artifacts in clinical MR exams. Motion artifacts such as blurring or ring artifacts can affect interpretation, and advanced MR techniques are particularly at risk as they rely on high spatial resolution and greater sequence complexity, noted Andre and colleagues. Their findings were published online in the Journal of the American College of Radiology. Andre, MD, of the University of Washington in Seattle, and colleagues. “These costs may affect much of the global MR community, reducing resource efficiency and the quality of patient care,” wrote authors Jalal B. Just how costly is patient motion? A recent study from Harborview Medical Center in Seattle pegged the potential cost of motion artifacts at $115,000 per scanner per year. Repeated scans take time, and tied up scanners can affect a hospital’s bottom line. When a patient moves during an MRI, it can mean having to redo the scan.
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