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Fig. 2. Flow-related signal loss in the carotid and basillary arteries (T2 axial study of the brain). [1]Flow can manifest as either an altered intravascular signal (flow enhancement or flow-related signal loss), or as flow-related artifacts (ghost images or spatial misregistration).
Displacement artifacts (also known as misregistration and oblique flow artifacts) occur when there is a time difference between the phase and frequency encoding. These artifacts are highest when the flow direction is within the slice plane (most prominent in the heart and aorta for biological flows) [ 10 ]
Velocity encoding (VENC), measured in cm/s, is directly related to the properties of the bipolar gradient. The VENC is used as the highest estimated fluid velocity in PC-MRI. Underestimating VENC leads to aliasing artifacts, as any velocity slightly higher than the VENC value has the opposite sign phase shift.
Requirements traceability is a sub-discipline of requirements management within software development and systems engineering.Traceability as a general term is defined by the IEEE Systems and Software Engineering Vocabulary [1] as (1) the degree to which a relationship can be established between two or more products of the development process, especially products having a predecessor-successor ...
This artifact can be a consequence of environmental factors or the human body (such as blood flow, implants, etc.). Ghosting is a multidimensional artifact that occurs in the MRI in the phase-encoded direction (short axis of the image) after applying the Fourier transform.
SWI uses a fully flow compensated, long echo, gradient recalled echo (GRE) pulse sequence to acquire images. This method exploits the susceptibility differences between tissues and uses the phase image to detect these differences. The magnitude and phase data are combined to produce an enhanced contrast magnitude image.
The stated reason for the new taxes was to stop the flow of migrants and fentanyl into the US, although relatively little fentanyl comes to the US through Canada.
In econometrics, which focuses on computing relationships between related variables, an artifact is a spurious finding, such as one based on either a faulty choice of variables or an over-extension of the computed relationship. Such an artifact may be called a statistical artifact.