Fat and water molecules oscillate differently within the magnetic field, causing them to show up differently during the encoding. Inherent physical artifactsĬhemical-shift artifacts occur during the frequency encoding of the MRI process. Gradient moment nulling can also be applied to try to correct flow artifacts. Using saturation bands can minimize this artifact, saturating the slice upstream so the blood will not produce a signal. Due to the nature of GRE sequences, blood flow will produce a bright signal. Using faster sequences and respiratory-ordered phase encoding can help eliminate artifacts, as can navigator echo gating to track the motion of the diaphragm to time image acquisition.įlow artifacts are also common, especially in gradient echo (GRE) sequences. This periodic motion cannot be avoided, and can cause artifacts.
You may need antispasmodic medications for some patients.Īll patients will continue to breathe, have heartbeats, and blood flow during the exam. Make sure the patient is comfortable prior to beginning the sequence, and advise them when it is especially important remain still. Recognizing that these ghost images are due to motion can help radiologists diagnose patients more accurately.īecause motion can make the images harder to read, patients should be advised to hold still during the exam. Motion artifacts typically show up as blurring or ghosting, especially in the phase-encoding direction. Patient motion – intentional or not – cause artifacts on the MRI image.
Artifact meaning medical software#
Finally, the hardware and software involved in constructing MRI images can cause artifacts. Artifacts can arise from the inherent physics of the MRI, such as the presence of metal or chemical shift. Physiologic artifacts are caused by patient movement, including breathing, heartbeat, and blood flow.
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Learning to recognized common artifacts and how to avoid them improves the diagnostic properties of MRI.Īrtifacts can be categorized into three main types. These artifacts can mimic pathologies, leading to improper diagnoses. Sometimes, structures appear in the MRI imaging that is not anatomically present. These images can be used to diagnose a wide variety of health conditions, making reading these images a critical part of a radiologist’s training. Magnetic resonance imaging uses magnetic fields and radio waves to form images of the body.
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