Table 1. Time-to-peak and valley for different duration breath holds.

	5 seconds	10 seconds	15 seconds	20 seconds	25 seconds
Time-to-peak	8.6±0.9	7.6±1.0	7.7±1.2	7.4±1.2	6.9±1.0
Time-to-valley	8.3±1.2	11.7±1.2	11.9±1.6	10.8±1.8	10.5±1.6

Time-to-peak and time-to-valley in seconds for different duration breath holds with a 30mm Hg target intrathoracic pressure. To normalize for different duration breath holds, time-to-peaks are the time from the end of each breath hold, while time-to-valleys are from the start of each breath hold. Values are mean±standard deviation values across subjects for voxels within the cortical gray-matter ROI.