How can you find out what is going on inside a person' s body without opening the patient up? Regular X-rays can show a lot. CAT scans can show even more. They can give three-dimensional(三维) view of body organs(器官).
What is a CAT scan? CAT stands for Computerized Axial Tomography(层面X线照相术). It is a special X-ray machine that gets a 360 - degree picture of a small area of a patient's body.
Doctors use X-rays to study and examine diseases and injuries within the body. X-rays can find foreign objects inside the body or to take pictures of some organs inside if special things as dyes or special liquids are added to the organs to be X-rayed.
A CAT scanner, however, uses a beam(光束) of X-rays to give a cross-sectional view of a particular part of the body. A fine beam of X-rays is scanned across the body and circled around the patient from many different angles(角度). A computer analyzes(分析) the information from each angle and produces a clear cross-sectional picture on the screen. This picture is then photographed for later use. Several cross-sections, taken one after another, can give a clear "photo" of the entire body or of any body organs. The newest CAT scanners can even give a clear picture of active, moving organs just as a fast-action camera can "stop the action" giving clear pictures of what appear only mistily(模糊) to the eye. And because of the 360 - degree pictures, CAT scans show 3-dimensional views of organs in a manner that was once only seen during surgery or autopsy (examining a dead body).
小题1:According to the first two paragraphs, doctors can see the inside of a patient's body by ______.
A．giving the patient an operation
B．checking body organs
C．getting a 360-degree picture of a small area of a patient's body
D．examining the CAT小题2:From the last paragraph, we can infer that ______.
A．the newest pictures become more misty
B．many pictures can be taken at the same time
C．the information about the scanned patient is not highly valued
D．some pictures of the scanned parts of the body are developed for further examinations in the future小题3:The best title of this passage might be ______.
A．Modern X-ray
B．Three-dimensional View
C．Fast - moving Camera
D．CAT Scan
