전산화단층촬영에 있어서 X-선 흡수계수의 신뢰도에 관한 실험적 연구 = An Experimental Study on Reliability of Attenuation Values in CT Scan

다국어 초록 (Multilingual Abstract)

For evaluation of reliability of CT numbers, one ovoid and three round phantoms, which were filled with pure water and different in their diameters, were scanned under various conditions with five whole body and four head CT scanners.
The results were as follows:
1. The ovoid phantom similar to human body in size and shape scanned with whole body scanners revealed stable and relatively correct CT numbers throughout entire of phantom.
2. CT numbers were generally higher in phantoms of round and smaller types.
3. There was definite tendency to show higher CT numbers at peripheral zone of phantoms.
4. With increase of kVp, CT numbers were decreased.
5. By the change in mA and slice thickness, some CT scanners were influenced, but the others were not.
6. CT numbers were not influenced by scan time.
7. CT numbers were not influenced by position of phantom in the aperture of gantry of CT scanner.
8. The bone density had no influence upon CT numbers at the region distant more than 1㎝. In two CT scanners, CT numbers were significantly increased within 1㎝ to bone density higher than 455 Hounsfield Unit.
9. CT scanners from different manufacturers showed different results, but those of same model from same manufacturer revealed similar results.