improve coverage and maintain the signal from blood flowing within the larger volume in MRI
Added by Jessica N.
Step 1
Step 1: Use a larger or multi-channel RF coil designed to cover the larger volume of interest, ensuring better sensitivity and uniform signal reception from the blood flow region. Show more…
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The size of a voxel (usually given in cubic mm) defines the spatial resolution of an imaging experiment. Let's assume that the signal strength in a single (isotropic, i.e. all edges have the same length) voxel is proportional to the number of molecules in it. A high spatial resolution is preferable, so one wants to reduce the voxel size. How does the signal change if the edge of the voxel is reduced by 20%/50%/80%? Hint: Reduction in signal = [1 - (1 - reduction%)^3] If you solve this equation, the answers are 0.488, 0.875, and 0.992 for 20%, 50%, and 80%. However, if the voxel is reduced, shouldn't the signal increase?
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Magnetic resonance imaging (MRI) is a medical technique for producing "pictures" of the interior of the body. The patient is placed within a strong magnetic field. One safety concern is what would happen to the positively and negatively charged particles in the body fluids if an equipment failure caused the magnetic field to be shut off suddenly. An induced emf could cause these particles to flow, producing an electric current within the body. Suppose the largest surface of the body through which flux passes has an area of 0.027 m2 and a normal that is parallel to a magnetic field of 1.4 T. Determine the smallest time period during which the field can be allowed to vanish if the magnitude of the average induced emf is to be kept less than 0.015 V.
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Magnetic resonance imaging (MRI) is a medical technique for producing pictures of the interior of the body. The patient is placed within a strong magnetic field. One safety concern is what would happen to the positively and negatively charged particles in the body fluids if an equipment failure caused the magnetic field to be shut off suddenly. An induced emf could cause these particles to flow, producing an electric current within the body. Suppose the largest surface of the body through which flux passes has an area of 0.042 m2 and a normal that is parallel to a magnetic field of 3.59 T. Determine the smallest time period during which the field can be allowed to vanish if the magnitude of the average induced emf is to be kept less than 0.031 V.
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