Abstract
The relationship between gantry angle and the interval length of the scanning plane in computed tomography(CT)was studied with a simple geometrical calculation and the evaluation of clinical images obtained with a human phantom. The change in patient dose was also evaluated under various conditions of gantry angle. When the same table feeding distance was used, it was theoretically and experimentally demonstrated that the interval length of the scanning plane was significantly decreased as the gantry angle increased(e.g.about 10% at twenty-five degrees). Integrated patient dose during the sequence could be changed by various combinations of gantry angle and table feeding distance, and was decreased by setting an optimal interval length of scanning plane according to the gantry angle. We concluded that gantry angle had obvious effects on the interval length of the scanning plane and patient dose, and the new method of increasing the table feeding distance according to the gantry angle might be useful for the improvement of image reproduction and the reduction of patient dose.
