SPHP

TWIST is a time-resolved MR angiographic sequence which can be used for two purposes:

1. Timing Bolus

2. Diagnostic angiogram

1. TWIST TIMER

This is a LOW spatial resolution sequence with temporal resolution of 1 second. 

Set up a THICK, STRAIGHT CORONAL slab to cover the vessel of interest for timing purposes.

Number of measurements will equal the number of seconds the timing run will be .

Inject small amount of contrast for timing run and start sequence SIMULTANEOUSLY.

Images will not be displayed until the entire sequence is finished, so do not stop sequence prematurely.

2. TWIST ANGIOGRAM

This is a HIGH spatial resolution (and ISOTROPIC) sequence with temporal resolution ~5-7 seconds.

Set up a THICK, STRAIGHT CORONAL slab to cover the vessels of interest.

Number of measurements is the number of angiograms spaced at the temporal resolution.

Run sequence. Phases will be in the bottom left of the screen (for ex. 1/8, 2/8, 3/8...). Wait for first phase to finish (the MASK), then inject contrast on "2". 

Images will not be displayed until the entire sequence is finished, so do not stop sequence prematurely.

Plan off AXIAL BRIGHT BLOOD scouts.

Scroll up and down to ensure that portions of the vessels are not excluded

The following are representative MIP images from each phase (the dynamic angiographic images are too much to display here)