At the moment, we still assume a connection with the markers and not a malfunction.When using parallel imaging techniques the high signal from a marker close to a coil element cannot fully be resolved and ghosts may occur shifted by half of the fov in the accelerated encoding direction.In this situation, when using for example caipirinha sequences with a sliceshiftfactor and acceleration in 2 directions (slice and phase encoding direction), the folding artifacts may occur whose position is shifted by half of the field of view in 2 directions.This can be very difficult to identify since the appear not on the same slice in the original acquired, main orientation, and the artifact can easily be confused with a lesion.Siemens is conducting a thorough investigation of the reported events.As this event is under investigation, a final root cause has not yet been determined.A supplement report will be filed upon completion of the investigation.
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Siemens has completed an investigation of the reported event.The root cause was determined to be the usage of the markers and not a malfunction.When using parallel imaging techniques, the high signal from a marker close to a coil element cannot fully be resolved and ghosts occur shifted by half of the fov in the accelerated encoding direction.In the used setup with caipirinha sequences with a slice shift factor and acceleration in 2 directions (slice and phase encoding direction), the folding artifacts may occur whose position is shifted by half of the field of view in 2 directions.This can be very difficult to identify as they appear not on the same slice in the original acquired, main orientation, and the artifact can easily be confused with a lesion.If the mr system is combined with other systems or components, it must be ensured that the planned combination does not affect the safety of patients, personnel, or the environment as stated in the ifu magnetom vida, magnetom sola instruction for use (ifu) chapter 2.2.6: interference with mr image quality.If the user uses not qualified accessories the responsibility lies with the user.For rt planning purposes, siemens healthineers provides a predefined protocol set, the rt dot engine.The radiotherapy (rt) planning of the rt dot engine offers protocols to be used with an external laser bridge.Therefore, the workflow does not assume the use of external markers.These markers can cause hyperintense signal, with the possibility of known side effects.To avoid this issue the following work around is recommended: please use only grappa with acceleration in pe direction.The ghost should than appear only in the main orientation which is directly displayed.Position the marker as far away from the coil as possible.Check the lesion in an mpr view.Ghosts from markers are much better to identify.In addition, the wrong lesions have an identical shape and size as the applied markers.In principle, we always recommend checking a different contrast (e.G.A conventional 2d acquisition) and previous examinations without markers.In all cases, the setup needs to be tested on phantoms before used in patients.No further actions are to be taken as there is no negative awareness regarding the quality and performance of the system.
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