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8/9/2019 PENN PET 240 H
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U Medical Systems Inc
PENN PET Model 240 H
WHOLE BODY POSITRON SCANNER BASED ON
LARGE AREA POSITION SENSITIVE DETECTORS
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WHY PENN PET
The
PENN PET
scanner was designed with clinical imaging
in
mind. It therefore offers
a combination of features not commonly found
in
PET instruments.
Equal resolution all 3 directions
combined with fine axial sampling
allows reslicing into coronal, sagittal
and oblique sections.
Large axial field of view
12 8
cm
and no gantry motion, such as wobbling,
permits gated cardiac imaging and fast
dynamic studies without sampling
problems.
Reslicing along major axis of the heart
64
transverse slices and 2 mm spacing
gives superior quantitative accuracy by
eliminating partial volume effect.
Equal resolution
in
XYZ and 2 mm sampling
Superior energy resolution
of sodium iodide detector material
allows use of large acceptance angle
without septa for hig h sensitivity and
low scatter fraction.
6 crystals and
240
photomultipliers
result in a scanner with clinically important
features at an affordable price.
400
r - - - - - - - - - - - - - - -
300
>
o
200
u
100
200 300 400 500
60 0
ENERGY keV)
10 energy resolution
SPHERE CENTERED SLICE
SPHERE LOCATED BETWEEN SLICES
10000
10000
2 mm slices PENNPET
8000
8000
6 mm slices
>
6000
6000
u
lOOO
2
mm
slices
4000
PENN.PET
2000
2000
,
,
,
0
_ _ _ _ I
0
40
20 30
40
AXIAL DISTANCE mm)
Axial profile through 10 mm sphere with 2mm samples PENN-PET) and with a system having 6 mm slice
separation demonstrating better quantitative accuracy with 2
mm
slices.
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SYSTEM DES RIPTION
DETE TORS
6 large-area posit ion-sensit ive
Nal TI) detectors
high spatial resolution along both
axes 5-6 mm)
high energy resolution 10 FWHM
at5 keV
good coincidence timing
nanosec
FWHM)
pulse shortening and local centroid
calculation for high count rates
S NNER
large patient port suitable for body
imaging 50 cm diameter)
12.8 cm axial field of view with
continuous axial sampling
completely stationary gantry - no
need for complicated wobbling
mechanism
compact design to minimize space
requirements
,
DATA ACQUISITION SYSTEM
separate terminal for acquisit ion
nearscanner
acquisition is controlled by a
pre-processor - frees host
computer during data collection
high speed sorting into project
ion matrices
provisions for dynamic or gated
data acquisition
compact electronics rack - no
need for separate equipment
room
IM GE DISPL Y
Unix-based display and data
analysis software
transverse, sagit tal, coronal and
oblique sections
variable image format, multiple
windows
2-D and 3-D image display and
analysis using regions or
volumes-of-i nterest
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U
Medical Systems Inc.
UGM Medical Systems is dedicated to providing its customers with PET instrumentation
tai lored to clinical use. UGM operates under the direction of Dr Gerd Muehllehner, one
of the leading physicists in PET with over 20 years of experience in Nuclear Medicine
instrumentation. The efforts of Dr.
Muehllehner
and his associates
over
the last 15
years have been aimed at bringing the advantages of continuous position-sensitive
detectors to PET, first through research based at the University of Pennsylvania and
now at UGM Medical Systems.
Sodium Iodide Nal TI Detectors
P T
Until now, commercially available PET scanners have used detectors composed of many
discrete
or
block-type Bismuth Germanate BGO) crystals. While BGO crystals have
certain attractive properties,
their
scintillation light output and
therefore
energy
resolution) is insufficient for use in large-area continuous detectors. To gain the
advantage of
continuous
scintil lation detectors, UGM has chosen to use sodium iodide,
Nal TI), one of
the
most luminescent scintil lators known, and the mainstay of
single-photon
Nuclear
Medicine
in
the form of the
Anger
camera. By using Nal TI)
detectors, the P NN P T can not only provide continuous axial sampling, but can also
obtain the energy resolution necessary for good scatter rejection without extensive
detector
shielding, thereby leading to higher sensitivity.
To maintain the countrate capability, the large-area detectors
in
the P NN P T use
pulse-clipping to shorten the scintillation response of the detectors, thereby increasing
the rate at which the detectors can handle photon interactions. Pulse-clipping has
enabled the
PENN-PET
detectors to operate successfully at count rates of over 2 million
counts per second, a factor of 10 improvement over the best comparable single-photon
device. Furthermore, instead of calculat ing the event using all photomult ip liers in a
crystal, the
P NN P T
detectors only use the photomultipliers in the immediate vicinity
of the scintil lation to posit ion the event, cal led the local centroid . This avoids
interference of signals from other scintillations which may occur in the same crystal
nearly simultaneously. The result is a continuous detector with all the features that
have made it the detector of choice in Nuclear Medicine, but with the count rate
capability necessary for PET.
REFERENCES:
The PENN-PET Model 240 H is based on the design described
in
the following publications:
1
Karp JS, Muehllehner G Mankoff DA, et al: Continuous slice PENN-PET: A positron tomograph with
volume imaging capabil ity. J Nucl Med to be published).
2 Muehllehner G Karp JS, Mankoff DA, et al: Design and performance of a new positron tomograph.
IEEE Trans Nucl Science, 35:670-674, 1988.
3
Mankoff DA, Muehllehner
G
Karp JS: The high count rate performance of a two-dimensionally
position-sensitive detector for positron emission tomography. Phys Med Bioi,
34:437-456 1989.
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PROVEN CLINIC L PERFORM NCE
The
PENN PET s nner
is well suited for a wide variety of clinical procedures. High
resolution equil ibrium images of the brain using O have been used in the study of
Alzheimer s disease tumor detection and staging and the assessment of the severity
of stroke. Ca rd ia c PET has been used in the evaluation of tissue viabili ty for choosing
treatment options and assessing treatment eff icacy. The fine axial resolution and 2mm
slice spacing is particularly effective in neuroreceptor studies.
Normal FDG brain scan
FDG cardiac scan of patient with myocardial
infarction. Papillary muscles are visualized
on these diastolic gated images.
FDG scan of patient with Alzheimers disease
Dynamic study using F-18 spiperone in a
baboon. Each row shows several slices
different rows represent different times.
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8/9/2019 PENN PET 240 H
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WESTERN
BIOMEDICAL RESEARCH
4815
Mr.
Pt.EASANT DR
FLAGSTAFF,
AZ
86004
602
527-9428
. v l
PERFORM NCE
SPECIFICATIONS
PENN-PET
MODEL
240-H
G NTRY
Pa t i en t aper tu re :
Gantry
t lt
motor ized
t r ans l a t i on
50 cm
/- 15 degrees
for
pa t i en t couch
.
.
DETECTORS
mate r i a l :
s i ze :
usefu l
ax i a l f i e ld of view
length
th ickness
Number
of
de tec to r s
Photomul t ip l iers per
de tec to r
Detec to r
separa t i on
In t r in s i c
s pa t i a l r e so lu t ion FWHM):
t ransverse
ax i a l
Detec to r t iming r e so lu t ion FWHM):
SYSTEM
Sl ice spac ing in
a l l t h ree di rec t ions :
Sl ice t h i ckness increment
se l e c t ab l e
a f t e r
data acqu i s i t ion
Sl ice
separa t i on : over lap o r c on tig uo us
Number
of
s l i c e s :
Fie ld of view:
t r ansver se
axia l
Spa t i a l Resolu t ion FWHM):
t r ansver se
a t 0
from center
t r ansver se a t 10 cm
ax i a l a t 0 from cen te r
axia l
a t 10 cm
NaI Tl
14 cm
50
cm
2.5 cm
6
40
85 cm
5.2
mm
6 .2
mm
3 nsec
d
2
mm
2
mm
64
50 cm
12.8
cm
5.5 mm
6.5 mm
5.8 mm
8 .5
mm
Volume
s en s i t i v i t y :
rand om s an d
s c a t t e r sub t rac t ed
photopeak only
200
keY th reshold
Energy r e sou l t ion FWHM @ 5l lkeV
S c att er f ra c tio n :
18
cm
dia . /photopeak
18
cm dia/250 keV
th reshold
70,000 CPS/uC i/ cc
140 ,000 CPS/uC i/ cc
10
15
25
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