Exam 30: Magnetic Resonance Imaging

Problems associated with installing MRI units are: 1)stray radio waves. 2)weight. 3)effects on electronics.

Standard pulse sequences show blood flow with a _____ signal compared with surrounding tissues.

Spin-spin relaxation (T2) is the release of energy by excited nuclei:

Generally MRI is considered safe; however, there are some hazards, which would include:

MRI depends on interactions with:

Spin lattice relaxation (T1) is the release of energy by excited nuclei:

There are a variety of magnet types that can be used for MRI. Resistive and superconductive magnets are both:

When the RF pulse is applied and the protons absorb the energy, the result is the protons orient to:

The absorption of RF energy is referred to as:

MRI has been useful for imaging many areas of the body, particularly the brain, because of:

MR spectroscopy is used to look at:

A possible patient reaction to rapid venting of the supercooled liquid gases in a superconductive magnet into the examination room would be:

Gadolinium is a contrast agent used for MRI because it has paramagnetic properties. Compared with iodine contrast, it is:

Compared with CT image acquisition, MRI can obtain images:

Hydrogen is used for imaging in MRI because it:

The rates of relaxation (T1 and T2) of a hydrogen nucleus depend on the:

The MRI signal is generated in the receiving antenna by:

The wobbling motion of the proton when it is placed in a strong magnetic field is called:

Proton density helps determine signal strength; however, it cannot be used alone because of the:

Strong MRI signals are represented by _____ in the image.