protocol the user may still enter a desired value for the enhancement threshold expressed either as hu value or a percent increase from baseline and manually start the scan just as in the current smartprep once the enhancement level for the monitor roi s reaches the user entry hu value or the increase translated to hu from the baseline value the scan acquisition will switch from the monitor phase to the scan phase automatically anticipated auto trigger may provide the function of predicting either the time to reach the desired enhancement threshold or the approach to the peak of the enhancement curve approach 1 based on slope change in time intensity hu curve the slope of hu value enhancement over time may be calculated from the two most recently acquired data points fig3 illustrates that this slope can be used to predict the amount of time it will take to reach the user entered threshold target once the percentage error between the predicted and actual values of enhancement is within 10 the transition to scan phase will be initiated when the predicted time to reach the threshold equals the diagnostic delay time as used herein the u201c diagnostic delay time u201d is the time between a user pressing the scan button and when the scan data is first acquired additionally in the automated.