Non-uniform magnitude. Non-uniform magnitude modulation during data acquisition for (T1, T2*) values of (120, 20); (13, 5); and (5, 2) ms. Top row: normalised signal for each phase-encode line acquired with a centric interleaved order (parallel imaging with R=2). Middle row: the magnitude modulation effects simulated on a homogenous disk. Bottom row: line signal profile across the centre of the disk along the phase-encode direction. The arrows point to the blurred edge of the disk.