VOA常速英语2007年-Study Says CT Scans Raise Cancer Risks

By Carolyn Presutti
Washington
07 December 2007
 

CT scans, also known as CAT scans, have long served as lifesaving tools to expose deadly diseases. But a new study finds that CT scans might also cause diseases. VOA's Carolyn Presutti has the story.

 

C.J. Sutphin, 5, has received numerous CT scans. He has seven brain tumors. Now his mother has to choose between continuing the scans or heeding¹ a new report that says the scans are harmful for children like C.J.

CT scans, also known as CAT scans, give doctors a peek² at what is going on inside the human body. They take three-dimensional images that can help detect cancer. But a report in The New England Journal of Medicine warns that scans could eventually cause cancer and that one in three scans is unnecessary.

Dr. David Brenner is co-author of the study says, "When someone comes into the emergency room for example with a pain in the belly³ or chronic⁴ headaches, they will automatically get a CT scan even before the physician has examined the patient. We would question whether that is appropriate."

Brenner's study claims that the radiation from CT scans will cause nearly two percent of all cancers in the next few decades.

The authors base their figures on Japanese atomic bomb survivors⁵. The survivors demonstrated increased cancer risks after receiving the same amount of radiation as several CT scans.

CT scans use considerably⁶ higher doses of radiation than regular X-rays. But the study found that three out of four doctors surveyed underestimated the dosage and did not make the connection between the cumulative⁷ radiation and cancer risks.

At risk most are children like CJ, whose tinier bodies are more sensitive to radiation.

Dr. Raymond Sze ("Z") is chief of radiology at Children's National Medical Center in Washington, D.C. explains, "Kids are different. They are smaller. There are certain organs such as the thymus, the gonads, that are more sensitive in kids. Having said that though, the take home for me is to have your care done in a hospital that specializes in children. We decrease dosage. We target our therapies. We do not use excessive technique."

Dr. Sze let's the patient know what's happening, "Ok bud. We are going to take the some pictures."

These pictures take less than a second, eliminating the need for anesthesia to prevent the child from moving. That is why the numbers of pediatric CT scans have risen considerably. The study says one million pediatric scans a year are unneeded, putting those kids at higher risk for cancer.

But after reviewing the study, C.J.'s mom, Kathy Sutphin, says the benefits outweigh⁸ the danger. "Without CT, we wouldn't be able to know if the shunts are malfunctioning⁹ or what the tumors are doing. So I think they are very helpful.

The authors agree CT scans are a valuable medical tool, but patients should make certain the scan is justified¹⁰ and the radiation levels are weight and height appropriate.

1 heeding   

v.听某人的劝告，听从( heed的现在分词 )

参考例句：

• This come of heeding people who say one thing and mean another! 有些人嘴里一回事，心里又是一回事，今天这个下场都是听信了这种人的话的结果。 来自辞典例句
• Her dwarfish spouse still smoked his cigar and drank his rum without heeding her. 她那矮老公还在吸他的雪茄，喝他的蔗酒，睬也不睬她。 来自辞典例句

2 peek   

vi.偷看，窥视；n.偷偷的一看，一瞥

参考例句：

• Larry takes a peek out of the window.赖瑞往窗外偷看了一下。
• Cover your eyes and don't peek.捂上眼睛，别偷看。

3 belly   

n.肚子，腹部；(像肚子一样)鼓起的部分，膛

参考例句：

• The boss has a large belly.老板大腹便便。
• His eyes are bigger than his belly.他眼馋肚饱。

4 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

5 survivors   

幸存者，残存者，生还者( survivor的名词复数 )

参考例句：

• The survivors were adrift in a lifeboat for six days. 幸存者在救生艇上漂流了六天。
• survivors clinging to a raft 紧紧抓住救生筏的幸存者

6 considerably   

adv.极大地；相当大地；在很大程度上

参考例句：

• The economic situation has changed considerably.经济形势已发生了相当大的变化。
• The gap has narrowed considerably.分歧大大缩小了。

7 cumulative   

adj.累积的，渐增的

参考例句：

• This drug has a cumulative effect.这种药有渐增的效力。
• The benefits from eating fish are cumulative.吃鱼的好处要长期才能显现。

8 outweigh   

vt.比...更重，...更重要

参考例句：

• The merits of your plan outweigh the defects.你制定的计划其优点胜过缺点。
• One's merits outweigh one's short-comings.功大于过。

9 malfunctioning   

出故障

参考例句：

• But something was malfunctioning in the equipment due to human error. 但由于人为的错误，设备发生故障了。 来自超越目标英语 第4册
• Choke coils are useful for prevention of malfunctioning electronic equipment. 扼流圈对于防止电器设备的故障很有帮助。 来自互联网

10 justified   

a.正当的，有理的

参考例句：

• She felt fully justified in asking for her money back. 她认为有充分的理由要求退款。
• The prisoner has certainly justified his claims by his actions. 那个囚犯确实已用自己的行动表明他的要求是正当的。