SMS‐InI setup
The simultaneous multi-slice inverse imaging (SMS-InI) integrates the state-of-the-art blipped-CAIPI-EPI and simultaneous echo refocusing (SER) in image acquisition and regularized reconstruction in order to achieve high spatiotemporal resolution with high computational efficiency. The aim of this page is to demonstrate how to use SMS-InI pulse sequence with either blip down or blip up phase encoding scheme.
In this method, there are two different options available for phase encoding: blip down and blip up, and the k-space sampling is accomplished through a linear trajectory (i.e. either top-bottom or bottom-top depending on the phase encoding scheme selected). There are also 2 slice-selective radio-frequency excitation pulses implemented for a multi-slice data acquisition. The timing diagram of the pulse sequence is shown for blip down phase encoding scheme:
The most recent version of the pulse sequence provides the option of two different phase encoding schemes, blip down and blip up. The desired phase encoding scheme can be selected through the "PE direction" drop down menu on the UI special card, as shown on following figure, where, "Standard" stands for the blip down, and "Inverted" stands for the blip up phase encoding schemes.
The offline reconstruction requires both a "reference scan" and "accelerated scans". The reference scan can be performed by selecting the "Reference Scan" check box on the UI special card. While the same slice prescription is essential for both scans, the reference scan can be acquired for smaller number of bold measurements. Other imaging parameters are the same for both scans.
Suggested protocols for both scans can be found in section 5.
The pulse sequence source code can be requested here.