____ imaging invovles a rotating x ray beam
rate of attenuation with a CT varies by
Beam attenuates (ie weakens) as it passes through brain tissue
what is detected with a CT?
used to reconstruct 3d image
advantages to CT
disadvantages to CT
1. ionizing radiation
2. not as good for soft tissue
3. lower spatial resolution
with MRI, Rapid repetitions of ___ enhance gray-white contrast
with MRI, Infrequent RF pulses enhance___
advantages to MRI
1. high spatial resolution
2. no radiation
3. excellent contrast
4. functional/chemical imaing avail.
disadvantages to MRI
1. long study duration
2. no ferromagnetic or electronic devices
3. small as hell -- claustrophobia
with Magnetic resosnance spectroscopy you look at the
chemical structure of the brain
on MRS choline indicates
on MRS, creatine indciates
on MRS, lactate indicates
on MRS, NAA indicates
____ involves measuring water diffusion
DTI: Diffusion Tensor Imaging
DTI: Diffusion Tensor Imaging invovles measuring water diffusion along different orientatations within ___
fMRI in vivo measures
BOLD, blood-oxygen-level dependent, signals at baseline vs.
! experimental conditions
limitations of FMRI includes
spatial and temporal resolution
what does PET involves?
PET: radioactive tracer incorporated into a biologically active molecule (ex. Glucose, oxygen, dopamine transporters)
disadvantages of PET?
1. need a cyclotron to make radioisotope
2. radiation exposure
what are 5 applications of imaging mdoalities?
1. map nml brain development
2. alzheimers disease
3. image guieded neurosurgery
5. pain )in high vs. low sensitvity pts)
advantages of pet?
physiological variables can be determined
to study brain structure what could you use
CT or MRI
what to use when looking at vascualture?
what to use when looking at fiber tracts?
what to use when looking at brain perfusion?
what to use when looking at NT integrity?
what to use when looking at metabolism?
what to use when looking at chemical structure?
elements of ___ atomic numbers show up better on CT
high (ca iron barium lead)