问题 单项选择题 B型题

层厚大于层间距的扫描是()

A.重叠扫描

B.靶扫描

C.薄层扫描

D.图像堆积扫描

E.高分辨率扫描

答案

参考答案:A

解析:高分辨率扫描是一种采用较薄的扫描层厚(1~2mm)和采用高分辨率图像重建算法的扫描技术,获得的是高分辨率的扫描图像,对肺部的弥漫性、间质性病变和小结节显示得更加清晰。重叠扫描是指层厚大于层距,使相邻的扫描层面之间有部分重叠的扫描方法,可减少部分容积效应,一般只用于感兴趣区的局部扫描,以提高小病灶检出的机会。靶扫描是对兴趣区局部放大后再进行扫描的方法,可提高空间分辨力,主要用于小器官和小病灶的显示。图像堆积扫描是利用多个薄层扫描图像,通过图像叠加功能进行重建图像的检查方法,可改善信噪比,减少伪影,可用于颅底部的CT检查,有助于发现脑干和颅后窝的病变。薄层扫描是指层厚小于5mm的扫描方法,可减少部分容积效应。

阅读理解

阅读理解。

     What is the hottest topic at your school recently? In Hangzhou Yongjin Middle School, it's money.

     The school held an activity called "Making Money" last weekend. About 200 Junior l and Junior 2

students were divided int0 30 teams. They went out to make money by selling things.

     What did they choose to sell? Some sold newspapers; some chose bottled water; some sold

environmentally-friendly shopping bags and bamboo baskets.

     Hu Qing's team decided to sell some useful books in front of the Children Activity Center. They thought

parents would like to buy the books for their children. But unfortunately, they met urban management

officers (城管). The officers asked them to leave. "We played hide-and- seek (捉迷藏) with the officers

for the whole morning," said Hu. "Finally we had to give up."

      Wang Bing and her team sold ice cream in a square. They didn't meet any officers. But few people

were interested in what they were selling. The team then put up a board saying "For Country Kids". It

worked. More people came to their stall (小摊). A foreigner even gave them 100 yuan. "He didn't want

any change. He said he wanted to help the children," said Wang. "We were touched." Later that day they

gave the 100 yuan and more to the "Project Hope" office.

     Meng Zhaoxiang and his team were luckier. They sold all their cakes in four hours, spending 39.5

yuan and getting back 80 yuan. They made 40.5 yuan. "It was not easy to make the money," said Meng.

"Some people just looked. Others just tasted but didn't buy. Now I know how hard it is for our parents

to make the money we need to lead happy lives."

1. In Hangzhou Yongjin Middle School,what the students talk more about is _____. [ ]

A. the officers

B. the kind foreigner

C. the activity called "Making Money"

D. the money they made last weekend

2. _____ took part in the activity. [ ]

A. All the students

B. Some teachers

C. About 200 students of the three grades

D. Part of Junior l and Junior 2 students

3. Hu Qing's team finally gave up because _____.[ ]

A. the parents didn't like to buy the books

B. the Children Activity Center was too crowded

C. the officers didn't allow them to sell anything there

D. the team played the game of hide-and-seek the whole morning

4. Why did more people come to Wang Bing's stall at last? [ ]

A. The team put up a magic board.

B. A foreigner came up and helped them.

C. The people liked to help country kids.

D. The people were interested in their ice cream.

5. According to the passage the students learn _____. [ ]

A. it's impossible for them to make money

B. it's not easy for their parents to make money

C. it's very important for them to make a living

D. it's necessary for school to hold more activities in the future

判断题