CT成像的依据是（）
A.横断面图像观察的特性
B.X线的吸收衰减特性
C.探测器的模数转换功能
D.多幅照相成像原理
E.多方位成像技术
参考答案：B
解析：CT与常规X线检查比较，虽然它们都以X线作为能源，但两者的成像依据和成像方式截然不同。X线透视、摄影是以被照体的密度、厚度及原子序数的差异对X线的吸收不同为成像依据，透过X线射入荧屏或胶片直接成像。CT则是以X线的吸收衰减特性为成像依据，成像方式是数据重建。
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| Professor Green, known to the world as a scientist, is not only absent-minded but short-sighted as well. His mind is always busy 1 scientific problems and seldom notices what is going on 2 him. One fine day recently, he went 3 a walk in the countryside, but as 4 he has a book in his hand. When he went out , he began to read his book . He hadn't gone far 5 he run into a big cow and fell down. In the fall, he had lost his glasses, without which he couldn't see anything. He thought he had hit his head 6 a fat lady. "I'm sorry, Madam." He said politely 7 searching for his glasses. As soon as he had 8 , he realized his mistake. Soon he was fixing his mind on his book 9 and paid no attention to anything else. He had scarcely been walking for five minutes when he fell over again, _10 both his book and his glasses. This time he got very angry, seizing his umbrella, he gave the "cow" a wild blow. Then, after finding his glasses, he realized with horror that he made a second mistake. A large fat woman was fleeing from him in a horror. | ||||
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