| 摘要 |
In computerized tomographic scanning systems it is desirable to reduce the scanning time required. Therefore, it is desirable that the radiation source/radiation detector system not be stopped and subsequently accelerated again for each absorption measurement. The present system continuously rotates and the source is continuously turned on, the output signal of each radiation detector being applied via a low-pass filter to a sample-and-hold circuit having a sampling frequency which is about twice as high as the limit frequency of the low-pass filter. Better accuracy is obtained than with known scanners having discontinuous movement or a flashing radiation source. |
