问题 问答题 简答题

肺动静瘘的MRI表现有哪些?

答案

参考答案:

在MRI上表现为圆形、椭圆形、不规则形或分叶状,边缘清楚,壁较薄,由于流空效应,其内的血液表现为低信号,但应用梯度回波快速成像技术,其内的血液则可表现为高信号,如动静脉瘘内血流较慢,TWI上呈中等信号,信号不均匀,TWI上呈高信号,MRI多方位成像有时可显示动静脉瘘的输入动脉及引流静脉。WI上呈中等信号,信号不均匀,TWI上呈高信号,MRI多方位成像有时可显示动静脉瘘的输入动脉及引流静脉。

阅读理解

请品读以下短文,判断句子正(T)误(F)。

     Dogs are friends of man. They work for us. They hunt (狩猎) with us. They play with us. But once,

all over the world, dogs are wild (野生的).

     Dogs go back to the Stoen Age. All dogs had the same ancestor (祖先). It is believed that this

ancestor was much like a wolf (狼). Other animals like the fox, came from this ancestor, too.

     Thousands of years ago, man began to tame (驯服) the wild dogs . When the dogs were tame, they

were trained (训练). The strong dogs became working animals. They were trained to pull heavy loads

(担子). They learned to keep watch over the sheep and other animals. Working dogs had other jobs,

too.

     Some dogs were not strong. But they could help man hunt for game. Other dogs were best as pets.

At first, there were only a few kinds of dogs. Today there are more than 100 kinds.

( )1. The word in the story that means an animal far back in another animal's family is ancestor.

( )2. The story make us believe that Man has helped change animals.                              

( )3. The strong dogs turned into foxes.                                                          

( )4. Dogs are pets from the beginning.                                                          

( )5. Dogs and man have been friends for a long time.                                            

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