Operating instructions

HeartView CT
151
ACV on/off
On the Trigger tabcard, ACV (Adaptive Cardio Volume
reconstruction) can be switched on/off by you. With
ACV off, single segment reconstruction is performed
for all heart rates. Data acquired in one heart cycle is
used for the reconstruction of each image, and the
temporal resolution is independent of the heart rate.
Example: The temporal resolution is 187 ms for 0.37 s
gantry rotation time. With ACV on, the system auto-
matically switches between single segment and two
segment reconstruction depending on the patient’s
heart rate. For heart rates below 65 bpm at 0.37 s gan-
try rotation time, single segment reconstruction is per-
formed. For heart rates exceeding 65 bpm, two seg-
ment reconstruction is performed, using scan data
acquired in two subsequent heart cycles to improve
temporal resolution. With ACV on, temporal resolution
is constant for heart rates below 65 bpm (94 ms for
0.37 s gantry rotation time).
Temporal resolution as a function of the patient’s heart
rate is shown in the figure below. We recommend
switching ACV on.