“…The increase in point spacing resulted in a considerable reduction in the number of counted points and, therefore, in a reduction of the time required. The mean time needed to estimate EDV with a point spacing of 10,15,20,25,30, and 35 pixels was equal to 3.7, 2.2, 1.6, 1.2, 1.1, and 0.9 min, respectively. The corresponding times for ESV estimation were 2.0, 1.1, 1.0, 0.9, 0.9, and 0.8 min, respectively.…”