Search found 486 matches

by Dave Higgins
Fri Feb 22, 2019 11:34 am
Forum: MRI Physics Questions and Answers
Topic: Dark bone spots
Replies: 2
Views: 666

Re: Dark bone spots

It is unlikely that users of this forum can offer advice.
It's all physics here, not clinical (anatomical/radiological) expertise.
Sorry
by Dave Higgins
Wed Nov 15, 2017 8:30 am
Forum: MRI Physics Questions and Answers
Topic: Heating effects of RF pulses
Replies: 4
Views: 4840

Re: Heating effects of RF pulses

You can reduce energy deposition, and therefore heating, with a reduction of flip angle. But this also affects image contrast.
by Dave Higgins
Tue Oct 31, 2017 2:38 pm
Forum: MRI Physics Questions and Answers
Topic: Echo planar Imaging- Echo Train Length
Replies: 6
Views: 4583

Re: Echo planar Imaging- Echo Train Length

No, the effective echo time for EPI is whenever the central k-space line is acquired.
For a single shot EPI, this would be half way along the echo train.
by Dave Higgins
Tue Oct 31, 2017 12:23 pm
Forum: MRI Physics Questions and Answers
Topic: Echo planar Imaging- Echo Train Length
Replies: 6
Views: 4583

Re: Echo planar Imaging- Echo Train Length

Assuming no partial Fourier, yes
by Dave Higgins
Tue Oct 31, 2017 9:36 am
Forum: MRI Physics Questions and Answers
Topic: Echo planar Imaging- Echo Train Length
Replies: 6
Views: 4583

Re: Echo planar Imaging- Echo Train Length

63 x 1 ms? (63 spacings in 64 echo readout)
by Dave Higgins
Fri Oct 27, 2017 3:15 pm
Forum: MRI Physics Questions and Answers
Topic: Shim volumes?
Replies: 1
Views: 1132

Re: Shim volumes?

Balanced SSFP (FIESTA, on GE).
But also think about which body parts or measurements require a good shim. E.g. the heart requires volume shimming (B0) and at 3T RF (B1) volume shimming too.