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Ch. 17 Study Guide

Terms in this set (26)

Hydrogen in fat is bound in many different ways, and this causes the fat peak to be broader and less intense.
A. True
B. False
A. True
Free water protons and fat protons have a resonance frequency separation of 3.5 ppm.
A. True
b. False
A. True
Water proton spin different frequency than fat. This difference at 1.5 T and higher, the frequency difference can result in a significant artifact.
A. True
B. False
A. True
The direction of the chemical shift is always along the direction of the phase-encoded gradient magnetic field, BR
A. True
B. False
B. False
Water makes up approximately _______ of all tissue molecules, hydrogen is only approximately ______ of all tissue atoms.
A. 80%, and 60% respectively
B. 60% and 80% respectively
C. 80gm, and 60 gm respectively
D. 60gm, and 80 gm respectively
A. 80%, and 60% respectively
Following are the three-compartment model which is the simplest and all that is necessary for the magnetization transfer (MT) except for one ________
A. Water protons
B. micromolecular proton
C. Fat protons
D. macromolecular proton
B. micromolecular proton
The parts per million (ppm) scale shows that ppm is a relative value compared with the standard molecule _______.
A. Hydrogen
B. Nitrogen
C. tetramethylsilane (TMS)
D. Carbon
C. tetramethylsilane (TMS)
On the proton magnetic resonance spectrum water protons are shifted downfield ________ ppm and those of fat, ______ppm.
A. 7.4, & 2.1 respectively
B. 2.2, &1.2 respectively
C. 1.2, & 4.7 respectively
D. 4.7, &1.2 respectively
D. 4.7, &1.2 respectively
Fat and water protons exhibit ______ resonant peaks and relatively _______ T2, on the order of _______ of milliseconds.
A. narrow, long, and tens respectively
B. wide, short, and hundreds respectively
C. narrow, short, and tens respectively
D. wide, long, and hundreds respectively
A. narrow, long, and tens respectively
The term chemical shift relates principally to a change in:
A. spin density
B. relaxation times
C. nuclear mass
D. larmor frequency
D. larmor frequency
A nuclear species may exhibit more than one peak in an NMR spectrum because of its:
A. nuclear structure
B. electron configuration
C. molecular configuration
D. mass distribution
C. molecular configuration
A hydrogen NMR spectrum may have many peaks because each nucleus has slightly different:
A. spin density
B. relaxation time
C. nuclear mass
D. larmor frequency
D. larmor frequency
The NMR spectrum is related to ______ structure.
A. nuclear
B. electron shell
C. molecular
D. organ
C. molecular
The change in resonant frequency among similar atoms in the same molecule is due to slight change in:
A. the static magnetic field
B. spin density
C. relaxation time
D. the local magnetic field
D. the local magnetic field
A change in resonant frequency for similar atoms in a given molecule is caused by:
A. spin density
B. relaxation time
C. electron cloud
D. nuclear structure
C. electron cloud
If an NMR spectrum contained just two peaks, that would indicate two:
A. spin densities
B. relaxation times
C. different nuclei
D. types of bound atoms
D. types of bound atoms
The more peaks there are in an NMR spectrum the more different types of ______ there will be.
A. nuclear configuration
B. bound nuclei
C. nuclear species
D. nuclear relaxation
B. bound nuclei
The shift or separation of peaks in an NMR spectrum increases with increasing:
A. spin density
B. relaxation time
C. gyromagnetic ratio
D. Bo
D. Bo
The finest separation of peaks in an NMR spectrum will be contained at _______ magnetic field strength.
A. high
B. intermediate
C. low
D. variable
A. high
A 1.0 T magnet said to have homogeneity of +/- 10ppm. This represents:
A. +/- 10 T
B. +/- 10 mT
C. +/- 10 µT
D. +/- 10 nT
C. +/- 10 µT
The number of uniquely bound nuclei in NMR spectrum is related to:
A. the number of peaks
B. the area under the peaks
C. the height of the peaks
D. the parts per million
A. the number of peaks
The fine structure contained in an individual peak of an NMR spectrum is due to:
A. J-coupling
B. Mo
C. Bo
D. R-coupling
A. J-coupling
J-coupling is independent of:
A. Bo
B. Mo
C. SD
D. T1, or T2
A. Bo
J-coupling is dependant on:
A. Mo
B. Bo
C. nearby electrons
D. nearby nuclei
D. nearby nuclei
If an NMR spectrum has 8 peaks of varying heights. The height of each is related to the:
A. number of spins
B. spin relaxation
C. longitudinal relaxation
D. transverse relaxation
A. number of spins
In the ethanol spectrum, the number of peaks is the related to the:
A. spin quantum number
B. different bonding of hydrogen
C. different longitudinal relaxation
D. different transverse relaxation
B. different bonding of hydrogen
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