FIGURE 1.
Respiratory motion curves (self-gating signal) of different breathing patterns on dynamic T1WI. The x axis indicates the time (second), and the y axis is unitless. Scan was done with GRASP simultaneously with gadoxetic acid administration at time point zero. A, Respiratory curve showing a normal breathing rhythm without transient motion in a 71-year-old man without any subjective symptoms. B, Alteration of respiratory motion frequency was observed for 27.1 seconds (from 10.5–37.6 seconds after gadoxetic acid administration) in a 51-year-old man and was regarded as transient motion (arrows). The patient had neither alteration of vital signs nor subjective symptoms. C, Respiratory graph showing an irregular breathing pattern in a 75-year-old woman with liver cirrhosis. Figure 1 can be viewed online in color at www.investigativeradiology.com.