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MRI Artifacts
  
Ultrasound Imaging Artifacts Open this link in a new window
Artifact Reduction
- Motion
Gating 
Synchronization of imaging with a phase of the cardiac or respiratory cycles.
A variety of means for detecting these cycles can be used, such as the ECG, peripheral pulse, chest motion, etc. The synchronization can be prospective or retrospective.

• View the DATABASE results for 'Gating' (67).Open this link in a new window

Gradient Moment Nulling 
Gradient moment nulling used as motion artifact suppression technique (MAST) reduces constant velocity motion distortion in standard spin echo or gradient echo pulse sequences. It is an adjustment to zero at the echo time (TE) of the net moments of the amplitude of the waveform of the magnetic field gradients with time. The zeroth moment is the area under the curve. The first moment is the 'center of gravity' etc.
The aim is to minimize the phase shifts acquired by the transverse magnetization of excited nuclei moving along the gradients (including the effect of refocusing radio frequency pulses), particularly for the reduction of image artifacts due to motion.

• View the DATABASE results for 'Gradient Moment Nulling' (7).Open this link in a new window

Phase Encoding Artifact Reduction 
(PEAR) Each phase of the respiratory cycle coincides with the collection of phase encoded data. The low order phase encoded data, with is highly sensitive to motion, is collected towards the end of exhalation and beginning of inspiration. The high order data, which is less sensitive, is collected over the remaining part of each respiratory cycle.

• View the DATABASE results for 'Phase Encoding Artifact Reduction' (3).Open this link in a new window

Respiratory Trigger 
Respiratory triggering is a type of respiratory motion commonly used with fast imaging techniques. Images are acquired during the expiration phase. With this type of technique, the scan time is based on the selected TR per respiratory cycle and the patient's breathing patterns.

• View the DATABASE results for 'Respiratory Trigger' (4).Open this link in a new window

Shimadzu Motion Artifact Reduction Technique 
(SMART) Movement of the chest and abdominal wall also causes blurring and ghosting in the images due to variation of signal during data collection. Using SMART averaging is one way of reducing these artifacts but is not always possible or effective enough.

• View the DATABASE results for 'Shimadzu Motion Artifact Reduction Technique' (2).Open this link in a new window

  Artifacts - Reduction Index - Cardiac Motion top

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 [last update: 2024-02-26 03:41:00]