时间:2019-02-12 作者:英语课 分类:VOA标准英语2010年(四)月


英语课

Scientists at the U.S. Food and Drug Administration disagree about the risks from CT scans given during virtual colonoscopies. Doctors who favor the procedure say it is less invasive and more cost effective than a conventional colonoscopy. Those against it say the CT scans expose patients to too much radiation.


Colon 1 cancer is one of the world's deadliest diseases, but it often has no symptoms in the early stages. That's why doctors urge adults over 50 to have a colonoscopy to detect any possible cancer.


Conventional colonoscopy is performed with a long, flexible tube called a colonoscope that is equipped with a tiny fiber-optic video camera and light at the end. The colonoscope is inserted into a patient's colon. Doctors can see the images from the colonoscope on a video monitor. They can also remove any abnormal growths or polyps during the procedure.


 


A less invasive procedure known as a virtual colonscopy is done with a CT scan that passes x-rays through a patient's abdomen 2.


Dr. Mahadevappa Mahesh, a professor of Radiology and Medicine at Johns Hopkins University School of Medicine, says virtual colonoscopies can save the lives of many patients. "(A) lot of the time patients (are) not coming to the clinic after they talk to their doctors (about conventional colonoscopy). They see the invasiveness involved. They get scared. They might not get anything done. They might end up getting cancer," he said. Virtual colonoscopy as a screening tool is quite effective thats one of the reason why national cancer Institute recommends this as one of the screening device."


If growths or polyps are found during a virtual colonscopy, then a conventional colonoscopy must be done to remove them.

But some doctors say the CT scan exposes patients unnecessarily to harmful radiation, as much radiation as a patient might receive from 400 chest x-rays.


Dr. Julian Nicholas is a scientist, formerly 3 with the Food and Drug Administration (FDA). He says arguments for virtual colonoscopy are not sound. "There was an absence of sufficient valid 4 scientific evidence that the use of CT devices for colorectal cancer is both safe and effective," he said.


Dr. Nicholas says before he left the FDA, he and other scientists warned against the routine use of CT scans. "FDA physicians and scientists were ridiculed 5 and chastized for raising the bugaboo (fearful image) of radiation."


Dr. Jeffrey Shuren from the FDA agrees that patients may not be fully 6 aware of the risks involved in a virtual colonoscopy.

"What we assure is that the technologies that do come on the market are safe and effective, but whether or not they should be used on a given case, a given patient, is a decision that is made by the individual practitioner," he said.


But with 70 million CT scans being performed in the U.S. every year, the government is under pressure to make an official recommendation on how much radiation is safe during a CT scan.


This report is narrated 7 by Carol Pearson.

 



n.冒号,结肠,直肠
  • Here,too,the colon must be followed by a dash.这里也是一样,应当在冒号后加破折号。
  • The colon is the locus of a large concentration of bacteria.结肠是大浓度的细菌所在地。
n.腹,下腹(胸部到腿部的部分)
  • How to know to there is ascarid inside abdomen?怎样知道肚子里面有蛔虫?
  • He was anxious about an off-and-on pain the abdomen.他因时隐时现的腹痛而焦虑。
adv.从前,以前
  • We now enjoy these comforts of which formerly we had only heard.我们现在享受到了过去只是听说过的那些舒适条件。
  • This boat was formerly used on the rivers of China.这船从前航行在中国内河里。
adj.有确实根据的;有效的;正当的,合法的
  • His claim to own the house is valid.他主张对此屋的所有权有效。
  • Do you have valid reasons for your absence?你的缺席有正当理由吗?
v.嘲笑,嘲弄,奚落( ridicule的过去式和过去分词 )
  • Biosphere 2 was ultimately ridiculed as a research debade, as exfravagant pseudoscience. 生物圈2号最终被讥讽为科研上的大失败,代价是昂贵的伪科学。 来自《简明英汉词典》
  • She ridiculed his insatiable greed. 她嘲笑他的贪得无厌。 来自《简明英汉词典》
adv.完全地,全部地,彻底地;充分地
  • The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气,然后全部呼出。
  • They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。
v.故事( narrate的过去式和过去分词 )
  • Some of the story was narrated in the film. 该电影叙述了这个故事的部分情节。 来自《简明英汉词典》
  • Defoe skilfully narrated the adventures of Robinson Crusoe on his desert island. 笛福生动地叙述了鲁滨逊·克鲁索在荒岛上的冒险故事。 来自《现代汉英综合大词典》
学英语单词
actinide
African crakes
agatha
alert data
amino-modified silicone oil
automatic record changer
avi cable
bergnas
bounded quantification
braits
bundesamts
buzzs
canales diploici
catharsius
chrysiasis
collapsible bulwark
come-on
computer telex exchange system
DBF (design basis fire)
deep weathering
Dilepididae
double loaded corridor type
down shot
duff ... up
elect.
emulating
end milling machine
equivalent eccentric
erythronic acid lactone
exclusive submap
floating point feature instruction
folia nelumbinis
forechoose
forndose form
fraudulent conveyance
front vault
geostrophic component
googlish
Halafian
have someone's shirt out
height adjustment pad
high frequency seal(ing)
high-frequency electric welded steel pipe
hobos
hornowls
hot-film
hydroa febrile
hyperstaticity
intermittent movement projector
invigorating qi for consolidating superficies
juddered
lamp current
lang.
life-work
loosenings
Methylophilaceae
microminiaturises
multiple-star
natica andoi
non-compute delay
numerically controlled machine tool
one-gene-one-function hypothesis
organic stabilizer
pandya
parallax stereogram
perice
permanent magnet meter
phosphorescent bacteria
possible illegle act
present a proposal to
pseudofaeces
purification loop
re breathing
readeress
rediffusion station
reel-to-reel machine
rhumb-line course
rintje
roentgenkymogram
rolled steel for welded structure
routine of experiment
sagari
sand phloxes
sarcoptess
semivitrification
shila
single-leg manometer
skew boat conformation
status report frame
telescopic jib crane
tremoured
two element air ejector
underdrain system
unity of invention
usse
valley meander gorge
Vauxhall
war-time medicine
whethersoever
wordstrings
writings on the wall
zero-offsets