WHICH ONE DOESN’T FIT? THAT’S MORE LIKE IT.
Dec 23, 2015
WHICH ONE DOESN’T FIT?
THAT’S MORE LIKE IT.
RADIATION DOSAGE
CXR= 1/100 Background Radiation
Background Radiation/yr Sea level = 3 milli Sieverts
100 milli Rem = 1 milli Sievert
LARGEST STUDY GROUP OF
RADIATION HEALTH EFFECTS IS THE HIROSHIMA BOMB SURVIVORS
• There is an excess cancer risk seen in large groups of Hiroshima survivors.
• Doses from 50 to 100 milli Sieverts can produce cancer in humans.
TYPICAL EFFECTIVE DOSE VALUES
Imaging Examination (mSv)
LINEAR – NO THRESHOLD RISK CURVE
CT DOSE IS IN RANGE OF HIROSHIMA BOMB SURVIVORS DOSE
There is an excess cancer risk seen in large groups of Hiroshima survivors.
Statistically CT scans WOULD increase risk of cancer.
PERSPECTIVE
300/1000 die normally from cancer by age 80.
301/1000 of CT patients would die from cancer.
So out of our 1 million people 300,000 would get cancer by normal risk.. and the 1 million receiving a CT would produce a cancer group of 301,000.
TAKE HOME MESSAGE
Benefit of diagnostic information from CT Scan is far greater that radiation risk, if there is an appropriate indication
ALARA : Pediatric Radiology: Image Gently
Be especially careful in children, pregnant patients, thoracic imaging in young women, Repetitive scans
Whole body CT screening is inappropriate
Lung cancer screening –value ? Data being released