Arterial and venous time-indexed phase histograms with line scans.

<p>Pixels classified by ATOF as arterial are in red and those as venous in blue. Relative histogram count is represented as brightness. The horizontal axis is time is depicted in heartbeats to facilitate human-piglet comparison. The vertical axis is phase ranging as [−<i>π</i>, <i>π</i>]. There is a consistent arteriovenous phase difference across the bolus passage.