Calculate the effects of the following pulse sequences on thermal equilibrium magnetization.
(a) In a sample of 1000 atoms,if 50 atoms decay in 5seconds, what is the radioactivity measured in mCi, of the sample?
b) in order to produce a level of radioactivity of 1mCi, how many nuclei of 99mTc (
?
Save your time - order a paper!
Get your paper written from scratch within the tight deadline. Our service is a reliable solution to all your troubles. Place an order on any task and we will take care of it. You won’t have to worry about the quality and deadlines
Order Paper Now= 3.22X10^(-5)s^(-) ) must be present? What mass of the radionuclide does this correspond to?(Avogadro’s number is 6.02X10^(23).
c) A radioactive sample of 99mTc contains 10mCi activity at 9 am.What is the radioactivity of the sample at 3pm on the same day.
2) In a nuclear medicine scan using 99mTc, the image SNR for a 30-min scan was 50:1 for an injected radioactive dose of 1 mCi (3.7X10^(7) disintegrations per second). Imaging began immediately after injection.
a) if the injected dose were doubled to 2mCi, what would be the image SNR for a 30-min scan?
b) if the scan time were doubled to 60min with an initial dose of 1mCi, what would be the image SNR?
3) Assuming that there are 6.7X10^(22) protons in 1cm^(3) of water, what is the magnetization contained within this volume at a magnetic field strength of 1.5T?
4) Calculate the effects of the following pulse sequences on thermal equilibrium magnetization. The final answer should include x,y, and z components of magnetization.
a) 90x (a pulse with tip angle 90 degrees , applied about the x axis).
b)80x.
c) 90x 90y (the second 90 degrees pulse is applied immediately after the first).
d)80x80y
