According to the Seimen's website, when imaging just the heart:
50 %* lower dose at typical heart rates compared with today’s most dose-efficient, single source CT scanners.Whole body scans will be much, much more radiation...
5.5 msv at 80 bpm.**
Depends on system configuration. *Results may vary. Data on file.** Typical regular heart rate of 80 bpm, 12 cm scan range, male patient, small ECG-Pulsing window.