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Vertical
Bore Imaging, 3-Axes Gradient Probes
NB
and WB MRI Probes (with gradients and RF) |
5
mm to 12 mm Imaging
Probes
- Highest
S/N
- 350
G/cm at 2.3% duty cycle,
water
cooled
- Quick,
convenient, multi-X tuning
- For
magnets up to 900 MHz
- 5,
8, 10, or 12 mm RF Coils
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Our
MRI probes are designed for high-field magnets
with 40 to 72 mm
inside the RT shims. The MRI probe includes the
26-40 gradient coil and 1H or 1H/X,
rf Litz coils. The probe permits highest
gradients at highest fields.
The MRI probe is normally provided with conventional top "NMR-tube" access.
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Partially
assembled 3 axis gradient coils
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Parameter
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Model
26-40
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Units
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Cooling
method
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Water
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Diameter
di for 4%
local deviation
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14
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mm
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Length zi for 4%
local deviation
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17
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mm
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Diameter
di for 10%
local deviation
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18
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mm
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Length zi for 10%
local deviation
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22
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mm
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Nearest Gradient
Null point
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15.4
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mm
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Outside
diameter, do
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39.6
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mm
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Coil
half-length, h1
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36.1
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mm
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RF
shield diameter,dS
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26
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mm
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Clear
bore, di
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23.6
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mm
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Max
inductance, L
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37
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μH
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Max
DC resistance, RE
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1.4
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Ω
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Min
gradient gain, α
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48
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mT/Am
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Max
shielding error at
1.5 d0
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0.4
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%
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Min
slew rate, GS = αV/L, at
1 V
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1,189
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T/m/s
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Continuous
current, IRMS
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A
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Continuous
gradient, GC
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53
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G/cm
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Peak
Voltage
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120
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V
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Approx.
EPI Acoustic Noise, 7 T
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70
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dBa
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Rise
time to GC for
100 V
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4.6
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μs
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Total
mass
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0.4
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kg
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In the
table above, the performance for the X and Y axes are each
as indicated above, and the Z axis is typically better in slew
rate, continuous gradient, and volume of linear region.
Local
deviation (or differential linearity) is defined as the rms
deviation from the mean gradient over the specified diameter, di,
and length, zi, of the
cylindrical sample region. The half-length h1 is
the distance from the center to the closer of the two external
end surfaces. Eddy currents from the internal RF shield are
negligible. The gradient slew rate GS is
the instantaneous rate of change in gradient when a 1 V step
is applied. The continuous current ratings are true continuous
ratings for a single axis with no time limit and adequate cooling.
Derate the current 30% when all three axes are driven simultaneously.
*
For additional gradient specifications – See
MRI 3 Axis Gradient coils
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RF
Litz Volume
Coils For Vertical Bore NB or WB Probes
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RF Coil
I.D.
(mm)
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Shield
Diameter
(mm)
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Tuning
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1H
MHz
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Mod.
Load
τ 90 ( μs)
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Heavy
Load
τ 90 ( μs)
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1H
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31 P
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1H
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31 P
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10
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26
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1H/X
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500
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9
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12
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10
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14
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12
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26
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1H
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500
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9
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-
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12
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-
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10
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26
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1H/X
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600
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11
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13
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12
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15
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12
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26
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1H
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800
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10
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-
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16
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-
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For
the above coils, the length of homogeneous region is 80%
of the coil ID. Coils with a multi-x channel normally
tune 31P through 13C simply by changing
plug-in capacitors. All coils feature simple tuning, high
B1 homogeneity, external rf shield,
and susceptibility matching near the sample region.
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Effectiveness
of the litzcage coil:
Effectiveness of the litzcage coil can be seen in the 50
micron resolution of the Mouse brain and Baby Atlantic Sharpnose
Shark tail below.
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Mouse
brain at 750 MHz, 50-micron
resolution
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Baby Atlantic sharpnose
shark,
50-micron
resolution
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Both
images were taken using a 21 mm CP Litzcage rf
coil at 750 MHz inside a Doty vertical bore imaging probe.
Images
courtesy of Dan Plant, University of Florida, Brain Institute.
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Preprint
available– RF
Coil Technology for Small-Animal MRI.
Download
a preprint of “RF Coil Technology for Small-Animal MRI”,
by F. David Doty, George Entzminger, Jatin Kulkarni, Kranti Pamarthy
and John P. Staab, published in [NMR Biomed. 2007; 20: 304-325,
published online in Wiley Interscience, at www.interscience.wiley.com,
DOI: 10.1002/nbm.1149].
Download
750 MHz Imaging Poster
Please
contact sales with
questions or quote requests.
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