Recent content by BobP

thanks

Why does increasing the kVp in x-ray production increase the number of x-ray photons if the number of electrons produced by the cathode is unchanged? thanks

Thank you. very detailed answer. very grateful

Sorry. When I say "basically the same" I mean a high SNR = high NECR... so they are linearly related...but I clarified this issue with my lecturer.. He said PET has a higher SNR and a higher NECR :)

If I produce an anti-particle (e.g: positron) in a reaction MUST I produce a non-anti particle too (e.g: neutrino)...is this a rule? thanks

Well my lecturer said that SNR is basically the same as NECR. So it have a lower SNR and a higher NECR :)

My question was based on a misunderstanding of the difference between frequency of the RF pulse and Larmor frequency. I foolishky assumed they were the same which is why I was confused. However problem is now fixed :) Thanks for your help though :)

The NEC is the true count rate of a theoretical image without any scatter or random events which would give the same statistical quality image as a real image which includes scatter and randoms.

The magnetic moment of protons precesses at a frequency ω0=γB0 about the static magnetic field. In order to move the magnetisation vector into the transverse plane the RF pulse must be applied at a frequency ω0. However, as B1 (the field strength of the RF pulse) is << B1 how is this possible...

Not according to my lecturer...

In PET, 2D PET scanners have a superior SNR to 3D PET scanners as the influence of scatter and random events is lowered by the septa between detector rings. However, the NECR (noise-equivalent count rate), which is linearly proportional to SNR, is higher in 3D PET scanners. These two facts seem...

My course is entire lecture-based and we were told we didn't need books. as they are so expensive I didn't buy any. I did a google search but couldn't find anything Having said that I realized I probably got two things in the working the wrong way around but the answer is still N? right...

thanks :)

Thank you for your help :)

I see. well thank you for the confirmation but as I have a very limited knowledge of calculus it seems like it'll be a long time before I can prove why the bottom image is correct. Thanks again for your help though :)