Skip to content

28. SMS InI acquisition

Jump to bottom
Fa-Hsuan Lin edited this page May 22, 2025 · 22 revisions

1. Introduction

These are protocols for simultaneous multi-slice inverse imaging (SMS-InI).

1.1 pulse sequence explained

Slice prescription (left) and pulse sequence diagram (right) of SMS-InI. The acquisition used two slice groups, each of which had two slice sets. Two different slice sets were separated by simultaneous echo refocusing (SER). Adjacent slices within the same slice set were shifted by blipped-CAIPI EPI with 1/3 FOV shift. These shifted slices were then separated by coil sensitivity information. The acquisition time for each slice group was 50 ms.

1.2 reconstructed image comparison

Eight axial slice images from EPI, InI, and SMS-InI. Both EPI and SMS-InI show similar coarse structure feature, while InI is more spatially smooth.

1.3 Signal leakage and time-domain SNR maps

(Left) Maps of signal leakage for SMS-InI and InI with the optimized regularization parameter (10-2λ_1). (Right) Maps of tSNR for SMS-InI and InI with the optimized regularization parameter.

1.4 Visual cortex functional activity demonstration

Significant BOLD signals measured by EPI, InI and SMS-InI elicited by visual stimuli with a large (15.7o; top row) or small (8.1o; middle row) view angle. Maps of statistically significant difference between these two stimuli conditions are shown at the bottom row.

1.5 Sensorimotor cortex functional activity demonstration

Significant BOLD signals were found in the sensorimotor cortices and thalamic areas by EPI and SMS-InI, while InI only detected significant BOLD signal at the sensorimotor area with a much smaller extend.

2. Scanner setup

SMS-InI has been tested on Siemens Skyra and Prisma. You would need a 32-ch or 64-ch head coil array.

2.1 Download

Please download the binaries for VE11C, VE11E, XA30, and XA60 from Siemens Teamplay platform by searching "SMS-InI" in c2p exchange.

2.2 Install

Copy the so and dll files to %CustomerSeq% and the sequence will be visible in DotCockpit.

Create protocol from DotCockpit by dragging the sequence from Default.

3. Protocol

SMS-InI needs to acquire separate reference scan and accelerated scan. The reference scan is used to reconstruct data in the accelerated scan, which is typical the interested fMRI experiment.

3.1 Reference scan (2 segments; takes few sec; size ~ 200M bytes)

  1. Slice = 20
  2. Phaseenc. Dir = R>>L
  3. Fov read = 210mm
  4. TR = 50 ms; TE = 27.5 ms
  5. Flip angle = 25 deg; Fat sat. enabled.
  6. Measurements = 10
  7. Baseresolution = 42
  8. Bandwidth = 3970Hz/px
  9. ReferenceScanbox <---checked

3.2 Accelerated scan (2 segments; takes few minutes; size about a few G bytes)

  1. Slice = 20
  2. Phaseenc. Dir = R>>L
  3. Fov read = 210mm
  4. TR = 50 ms (the whole brain sampling rate is 10Hz = 0.1 sec); TE = 27.5 ms
  5. Flip angle = 25 deg; Fat sat. enabled.
  6. Measurements = 2460 (60 dummyscan+2400scan = 246 sec for example)
  7. Baseresolution = 42
  8. Bandwidth = 3970Hz/px
  9. ReferenceScanbox<---unchecked
  10. To achieve higher scan number, please use “Averages” option. Averages = 1,2,3,..... For example: total 20 min = 20*60 / (0.1sec) = 12000 scans. Set “Measurements = 2000” and “Averages = 6”, let “Measurements” * “Averages” = total scan

3.2 Protocols for VE11E

4. Image reconstruction

4.1 get raw data

Get meas.dat data from TWIX. Advanced user mode must be activated.

Get raw data from the TWIX at MRI console. This program is only available in the advanced user mode.

4.2 reconstruct images

Following the procedure to reconstruct images by Matlab offline.

Clone this wiki locally