
67-1
67.1 Introduction
Medical imaging has advanced considerably since the discovery of x-rays by Wilhelm Conrad Röntgen
in 18
95
. To
day,
in ad
dition
to th
e
co
ntinued
us
e
of x-
rays
fo
r
me
dical
di
agnosis,
th
ere
ar
e
im
aging
me
thods
th
at
us
e
so
und
(u
ltrasound),
ma
gnetic
e
lds
an
d
ra
dio
wa
ves
(m
agnetic
re
sonance
im
aging
[MRI]), and radionuclides (nuclear medicine). Both projection imaging and cross-sectional imaging are
ro
utinely
us
ed
cl
inically
. i
s
ch
apter
wi
ll
de
scribe
th
e
pr
inciples
be
hind
th
e
va
rious
im
aging
mo
dali-
ties
c
urrently
i
n
u
se
a
nd
t
he
v
arious
m
easurements
r
outinely
m
ade
w
ith
t
hem
.
67.2 Image Information Content
e vast majority of i ...