NOTE
The conflicting recommendations for age to  start   mammography are the result  of  differing   views
of  “harm   versus  benefit“    studies.Mammography may be  a   screening   test    for breast  cancer  when    performed   on
asymptomatic    women.  Screening   typically   uses    2   views   of  each    breast:
craniocaudal    and lateral.    The patient is  encouraged  to  lean    in  toward  the
device  to  image   as  much    of  the breast  tissue  as  possible.
Recommended age to  start   mammograms  varies  among   medical
organizations,  ranging from    age 40−50.
Start   screening   at  age 40  gives   potentially earlier cancer  diagnosis
(benefit)   but at  the cost    of  higher  false-positives with    unnecessary follow-
up  testing and anxiety (harms).    False-negatives occur   more    in  younger
women   and those   with    denser  breasts.
Start   screening   at  age 50  gives   fewer   false-negatives (benefit)   but at  a
cost    of  potentially later   diagnosis   (harm).
The best    strategy    is  for doctors to  assess  individual  patient risk    and
engage  in  shared  decision-making with    the patient.
Mammography may also    be  performed   because of  a   breast  complaint   (e.g.,
breast  mass,   nipple  discharge,  abnormal    screening   mammogram); in  those
cases   many    images  are taken,  some    under   higher  magnification   to  better
visualize   the target  area.
Risks:  ionizing    radiation   exposure    0.7 mSv (about  the same    that    the average
person  receives    from    background  radiation   in  three   months  [1  Rad =   10
mSv])
