MRI Map Density Margin Scan - Biophysical Instrumentation VII: NMR Relaxation and MRI Contrast Step by Step

A contrast map is accepted only when the displayed order follows the cited voxel signals. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Contrast maps compare cited voxel signal rows

Each row rebuilds voxel A and voxel B before accepting the same ordering.

\text{map accepted when }S_B>S_A

Three density rows keep B greater than A

The margin can shrink, but the displayed ordering must still follow the cited signals.

\begin{array}{c|c|c}S_A&S_B&S_B-S_A\\5&6&1\\5&8&3\\\frac{15}{2}&8&\frac{1}{2}\\\end{array}

The final row has a one-half signal margin

Voxel A signal is 15/2 and voxel B signal is 8, leaving margin 1/2.

8-\frac{15}{2}=\frac{1}{2}