Chemical Shift Artifact in Medical Imaging

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Which artifact causes the misplacement of signal from fat in the image?

Partial volume artifact

Motion artifact

Chemical shift artifact (correct)

Aliasing artifact

What can chemical shift artifact create in areas where fat and water interface?

Signal superimposition

Signal enhancement

Both signal voids and signal superimposition (correct)

Signal voids

What is the appearance of chemical shift artifact in the image?

Signal blurring

Signal enhancement

Signal loss (correct)

Signal distortion

What is the artifact often referred to as?

Bas-relief artifact Signup and view all the answers

What is the cause of chemical shift artifact?

Different chemical environments of fat and water Signup and view all the answers

What is the difference in the precessional frequencies between magnetic moments in fat and water called?

Chemical shift Signup and view all the answers

What is the overall appearance of chemical shift artifact in the image?

Embossed effect Signup and view all the answers

What does fat consist of?

Hydrogen arranged with a chain of carbon atoms Signup and view all the answers

What is the term used to describe triglyceride fat molecules as a result of self-shielding?

Self-shielding Signup and view all the answers

What is the term used to describe the lowering of the Larmor frequency of the magnetic moments of hydrogen nuclei in fat?

Chemical shift Signup and view all the answers

Which unit is used to express the amount of chemical shift?

Parts per million (ppm) Signup and view all the answers

What is the value of the chemical shift between fat and water?

3.5 ppm Signup and view all the answers

At 1.5 T, what is the difference in precessional frequency between fat and water?

220 Hz Signup and view all the answers

At 1.0 T, what is the difference in precessional frequency between fat and water?

147 Hz Signup and view all the answers

At lower field strengths (0.5 T or less), what is the difference in precessional frequency between fat and water?

Lower and usually insignificant Signup and view all the answers

What causes chemical shift artifact in MRI images?

Difference in frequency between fat and water Signup and view all the answers

What determines the bandwidth of each pixel in an MRI image?

Receive bandwidth Signup and view all the answers

At a field strength of 1.5 T, how many pixels apart are fat and water protons mapped if the individual frequency range of each pixel is 125 Hz?

3.52 pixels Signup and view all the answers

At an FOV of 240 mm and 256 frequency columns, what is the pixel size?

0.93 mm Signup and view all the answers

At a receive bandwidth of 32 KHz and 256 frequency pixels, what is the bandwidth of each pixel?

250 Hz Signup and view all the answers