What causes zipper artifact MRI?
Zipper-like artifacts oriented in the frequency-encode direction are usually caused by stimulated echoes from imperfect slice-selection profiles or improper RF-transmitter adjustments. Increasing interslice gap may minimize them, but a call to the service engineer is usually in order.
How do you get rid of zipper artifact MRI?
Causes and remedies
- make sure the MR scanner room-door is shut during imaging.
- remove all electronic devices from the patient prior to imaging.
- if the artifact persists despite all nearby electronic equipment being turned off, it is possible that the RF shielding is compromised.
What is zipper artefact?
Zipper artifacts are a type of MRI artefact where one or more spurious bands of electronic noise extends across the image. There are various causes for zipper artifacts in images and no single solution exists. These artefacts can be related to hardware or software problems either of the scanner itself or the shielding.
How do you reduce ghosting artifact on MRI?
Physical restraint , breath-hold Reducing the patient’s movements sometimes requires using physical restraint (compression devices) or sedation (or general anesthetic). Breath-hold sequences with scan time less than 30 seconds can be used to eliminate respiratory artifacts.
What is T2 and flair Hyperintensities?
Focal hyperintensities in the subcortical white matter demonstrated by T2-weighted or FLAIR images are a common incidental finding in patients undergoing brain MRI for indications other than stroke. They are indicative of chronic microvascular disease.
What is coherent noise in MRI?
This test (termed “Coherent Noise” per GE Healthcare) is de- signed to detect the presence of external electromagnetic frequencies inside the MR scan room that are within the op- erational bandwidth of the MR system electronics, and thus have the potential to interfere with the diagnostic quality of the MR imaging.
What is magic angle artifact?
The magic angle is an MRI artifact which occurs on sequences with a short TE (less than 32ms; T1W sequences, PD sequences and gradient echo sequences).
Do all VA panels have ghosting?
VA panel monitors, in particular, have very slow pixel transitions from dark to gray or bright shades (rise time), which results in a lot of visible ghosting (i.e. trailing) artifacts behind fast-moving objects when a lot of dark pixels are involved in the scene.
What is imaging ghosting?
Ghost imaging, often called cloning, is a software-driven data backup process that copies the contents of a computer hard disk in a single compressed file or set of files, referred to as an image.