Operating instructions

504
Specials
Radiation exposure to patients
CARE Vision applies continuous exposure at moder-
ate mA levels.
Due to the potentially long scan times and the lim-
ited scan volume, the dose for certain slices may
increase to levels significantly higher than those
known from standard CT applications.
The patient’s exposure levels is usually estimated by
CTDIvol.
This unit is designed to give the average dose in the
scanned volume.
Before starting the scan, the dose rate (CTDIvol in
mGy per second) is displayed on the monitor.
During the CARE Vision scan, the accumulated dose
(CTDI vol) reflecting the patient exposure is dis-
played on the monitor. The display scale ranges from
zero to 3000 mGy.
If the table is shifted during the examination, the
accumulated dose will be distributed to different
slices and will be lower than indicated by the display.
When a new scan is loaded, the dose display starts
again from zero.