Initial experience with volume CT scanning.

A new method of CT is proposed: "volume scanning," produced by continuous table incrementation during continuous scanning. This approach was successfully implemented on a commercially available third generation scanner with continuous measuring system and slip ring technology (Somatom Plus; Siemens AG, Erlangen, F.R.G.). Different phantoms were scanned with volume scanning at different table incrementation speeds and with conventional scanning with standard sequential table incrementation. Comparison of the results showed that in volume scanning, a table incrementation speed equal to the slice thickness per second provides the optimal compromise between acquisition volume and level of artifact production. Different reconstruction parameters available were tested for optimal artifact reduction. A 240 degrees reconstruction angle offered the best results. Experiments on geometrical distortion and contrast resolution revealed hardly any difference between volume scans and conventional scans. Up to now volume scanning has been used in 20 patients. Images obtained in the thoracic, pelvic, and upper abdominal region show exceptionally sharp anatomical detail with minimal artifacts. Volume scanning opens new possibilities in fast sequential dynamic contrast studies in the abdomen and chest.