Focused Ultrasound Sonications of Tumor Model in Head Phantom under MRI Monitoring: Effect of Skull Obstruction on Focal Heating
Journal of Medical Physics,
Journal Year:
2025,
Volume and Issue:
50(1), P. 38 - 45
Published: Jan. 1, 2025
This
study
presents
the
outcomes
of
a
series
magnetic
resonance
imaging
(MRI)-guided
focused
ultrasound
(MRgFUS)
sonications
performed
on
an
anatomically
accurate
head
phantom
with
embedded
tumor
simulator
to
evaluate
effectiveness
partial
and
complete
ablation
obstruction
from
thin
polymer
skull
mimics.
The
was
subjected
single
grid
using
single-element
concave
transducer
integrated
MRI-compatible
(FUS)
robotic
system.
All
experiments
were
carried
out
in
high-field
MRI
scanner
utilizing
proton
frequency
thermometry
T2-weighted
(T2-W)
turbo
spin
echo
(TSE)
induced
thermal
effects.
FUS
transmission
through
1-mm
thick
three-dimensional-printed
mimics
compared
unobstructed
sonication
circular
aperture
model.
T2-W
TSE
demonstrated
sharp
contrast
between
hyperintense
lesions.
Complete
coverage
achieved
robotic-assisted
without
mimic,
as
well
resin
mimic
intervening
beam.
With
lowest
attenuation
among
tested
polymers,
resulted
approximately
20%
reduction
focal
temperature
change
sonication,
yet
still
facilitated
beam
focusing,
raising
ablative
levels.
provides
preliminary
evidence
for
potential
application
biocompatible
implant
temporarily
replace
portion
facilitating
MRgFUS
inoperable
tumors
transducer.
tumor-embedded
proven
effective
testing
oncological
protocols
equipment.
Language: Английский
Focused ultrasound heating in brain tissue/skull phantoms with 1 MHz single-element transducer
Journal of Ultrasound,
Journal Year:
2023,
Volume and Issue:
27(2), P. 263 - 274
Published: July 30, 2023
Abstract
Purpose
The
study
aims
to
provide
insights
on
the
practicality
of
using
single-element
transducers
for
transcranial
Focused
Ultrasound
(tFUS)
thermal
applications.
Methods
FUS
sonications
were
performed
through
skull
phantoms
embedding
agar-based
tissue
mimicking
gels
a
1
MHz
spherically
focused
transducer.
3D
printed
with
Acrylonitrile
Butadiene
Styrene
(ABS)
and
Resin
thermoplastics
having
exact
bone
geometry
healthy
volunteer.
temperature
field
distribution
during
after
heating
was
monitored
in
3
T
Magnetic
Resonance
Imaging
(MRI)
scanner
MR
thermometry.
effect
skull’s
thickness
intracranial
investigated.
Results
A
single
sonication
at
focal
acoustic
intensities
close
1580
W/cm
2
60
s
free
heated
up
agar
phantom
ablative
temperatures
reaching
about
90
°C
(baseline
37
°C).
ABS
strongly
blocked
ultrasonic
waves,
resulting
zero
increase
within
phantom.
Considerable
achieved
skull,
but
it
remained
hyperthermia
levels.
Conversely,
tFUS
mm
showed
enhanced
penetration
heating,
70
°C.
Conclusions
demonstrated
poorer
performance
terms
compared
owing
its
higher
attenuation
porosity.
thin
provided
an
efficient
window
delivering
deep
areas.
results
such
studies
could
be
particularly
useful
accelerating
establishment
wider
range
Language: Английский