a. exploits the presence of random motion
(Brownian motion) of water molecules to produce image contrast
b. a pair of diffusion sensitizing gradients applied
symmetrically around a 180 refocusing RF pulse of a T2-weighted MR sequence.
c. loss of signal is proportional to the degree of
microscopic motion that occurs during the pulse sequence
d. regions of relatively stationary water molecules appear
much brighter than areas with a higher molecular diffusion
e. signal loss is
independent of the strength and duration
of the diffusion sensitizing gradient ( the ‘b-value’.)
3.—e
On diffusion-weighted images,
regions of relatively stationary water molecules appear much brighter than
areas with a higher molecular diffusion. The degree of phase shift and signal
loss depends also on the strength and duration of the diffusion sensitizing
gradient, which is expressed by the ‘b-value’. B-values used for imaging of
acute stroke lie typically around 1000s mm
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 List Price: $67.00 Add to Cart | MCQs NEURO-RADIOLOGYSelf-assessment For FRCR Part 2A,American Board of RdiologyAuthored by Dr Nagendra Kumar SinhaEdition: 1 This MCQ book on neuro-radiology contains 16 TEST PAPERS.Each Test Paper consists of approx.60 MCQs ,so this book contains approx.995 MCQs.Each test paper is designed to cover all the different topics of neuro-radiology.Each test paper is followed by answer with detailed explanations .Most of MCQs answer and explanation can be seen in MRI of The Brain And Spine ,3rd edition,--S.Atlas. |
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