Non-alcoholic
fatty
liver
disease
and
the
risk
of progression
to steatohepati
tis,
cirrhosis
and
hepatocellular
carcinoma
have
been
identified
as
major
public
health
concerns.
We
have
demonstrated
the
feasibility
and
potential
value
of measuring
liver
fat
content
by
magnetic
resonance
imaging
(MRI)
in a large
population
in this
study
of 4,949
participants
(aged
45–
73
years)
in the
UK
Biobank
imaging
enhancement
. Despite
requirements
for
only
a single
(

3min)
scan
of each
subject,
liver
fat
was
able
to be
measured
as
the
MRI
proton
density
fat
fraction
(PDFF)
with
an
overall
success
rate
of 96.4%.
The
overall
hepatic
fat
distribution
was
centred
between
1–2%,
and
was
highly
skewed
towards
higher
fat
content.
The
mean
PDFF
was
3.91%,
and
median
2.11%.
Analysis
of PDFF
in conjunction
with
other
data
fields
available
from
the
UK
Biobank
Resource
showed
associations
of increased
liver
fat
with
greater
age,
BMI,
weight
gain,
high
blood
pressure
and
Type
2 diabetes.
Subjects
with
BMI
less
than
25
kg/m
2
had
a low
risk
(5%)
of high
liver
fat
(PDFF
>
5.5%),
whereas
in the
higher
BMI
population
(
>
30
kg/m
2
) the
prevalence
of high
liver
fat
was
approximately
1 in 3. These
data
suggest
that
population
screening
to identify
people
with
high
PDFF
is possible
and
could
be
cost
effective.
MRI
based
PDFF
is an
effective
method
for
this.
Finally,
although
cross
sectional,
this
study
suggests
the
utility
of the
PDFF
measuremen
t within
UK
Biobank,
particularly
for
applications
to elucidating
risk
factors
through
associations
with
prospec-
tively
acquired
data
on
clinical
outcomes
of liver
diseases,
including
non-alcoholic
fatty
liver
disease.