1 of 11

Week 9 Section

3D Imaging, Lab Report

2 of 11

Multiple 2D Slices: Multislice

3D Imaging

Lab Report

Dead time waiting for signal to recover …

3 of 11

Multiple 2D Slices: Multislice

3D Imaging

Lab Report

Interleave N slices!

4 of 11

Multiple 2D Slices: Hadamard Encoding

3D Imaging

Lab Report

First Excitation

Second Excitation

Can invert to solve for slice images

5 of 11

Multiple 2D Slices: Hadamard Encoding

3D Imaging

Lab Report

First Excitation

Second Excitation

Why simultaneously excite two slices?

6 of 11

Multiple 2D Slices: Hadamard Encoding

3D Imaging

Lab Report

First Excitation

Second Excitation

SNR boost by

7 of 11

Multiple 2D Slices: 3D Volume

3D Imaging

Lab Report

Can combine multi-slice, hadamard, and parallel imaging along slice dimension

8 of 11

3D K-space

3D Imaging

Lab Report

Can acquire 3D data instead

9 of 11

3D K-space

3D Imaging

Lab Report

Faster encoding by using efficient sampling schemes

10 of 11

2D Multiple Slices vs 3D K-space Imaging

3D Imaging

Lab Report

  • Gaps in slice direction usually

​

  • Long/high SAR pulses needed for good slices

​

  • Less use of gradients

​

  • Can make use of dead time (T2 weighted long TR)

​

  • Lots of control over contrast (T1w, T2w, etc)

​

  • Simpler reconstruction

​

  • No XYZ gaps

​

  • Short/low SAR RF pulses

​

  • Efficient use of gradient encoding

​

  • Can’t make use of dead time

​

  • Less control over contrast (GE, mix T1 & T2, etc)

​

  • Complex reconstruction

11 of 11

Lab Report Office Hours!

3D Imaging

Lab Report