BrainStat procedure tips

Acquisition timing is critical for images post processed in Brainstat. If the contrast injection is early, modify your acquisition timing to acquire baseline phases before peak contrast uptake.

Image legend for the Optimal acquisition, Early bolus arrival and Scan phases end before complete washout:

• A = pre-enhancement steady state
• B = bolus arrival should be greater than the Skip Image value
• C = peak contrast uptake
• D = bolus departure
• E = end of acquisition should be greater than C + 3 washin phases [3 x (C-B)].

Optimal acquisition

In this example, the curve indicates the bolus arrival after the steady state is reached. Steady state is set using the Skip Images setting (default of 5). The acquisition must not end before adequate washout has occurred. If the acquisition ends before washout occurs, there is no adjustment that can be made in Brainstat.

Early bolus arrival

In this example, the bolus arrived before the steady state is achieved resulting in rejected pixels and inaccurate fittings. Setting the Skip Image value to 1 leads to inaccurate maps because the pre-enhancement baseline is inaccurate. Setting the Skip Image value to 2 could cause rejected pixels because the bolus arrival is at the same time as the steady state. In effect, this is a bad data set.

Scan ends early

In this example, the scan ended before complete washout could occur. No Brainstat adjustments can be made for this acquisition. Adjust the number of phases in your protocol to allow for adequate washout time.