GE Site Yearly Performance Evaluation GE Signa Excite HD ...simplyphysics.com/Sample_reports/GE_ExciteHD_3T_Report.pdf · Site Name ACR Magnet # Active Coil Description Model Rev

Summary and Signature Page 2

Specific Comments 3

Site Information 4

Equipment Information 4

Table Position Accuracy 4

Magnetic Field Homogeneity 4

Slice Thickness Accuracy 4

Slice Crosstalk 5

Soft Copy Displays 6

RF Coil Performance Evaluation

Coil Inventory List 7

Body - Integrated 8

Breast - 8 Ch. 9

Cardiac - 8 Ch. 15

Head 8 Ch 17

Head Split Top 18

Knee - 8 Ch. 20

Knee T/R 21

Neurovascular Array - 8 Ch. 23

Shoulder - 3 Ch. 26

Spine - 8 Ch. 28

Torso 31

Wrist 32

35

40

43

50

GE Site

Appendix C: ACR Phantom Analysis

Appendix D: Explanation of RF Coil Test Format

1-Sep-08

Table of Contents

Appendix A: Magnet Homgeneity Map

Appendix B: Slice Thickness / Profiles / RF Crosstalk

GE Signa Excite HD - 3TYearly Performance Evaluation

Site Name: GE Site MRAP #Address: Survey Date:

City, State, Zip Report Date:MRI Mfg: Model: Field:

MRI Scientist: Moriel NessAiver, Ph.D. Signature:

Pass

Fail

*

N/A

1. Magnetic field homogeneity:2. Slice position accuracy:3. Table positioning reproducibility:4. Slice thickness accuracy:5. RF coils' performance:

a. Volume QD Coilsb. Phase Array Coilsc. Surface Coils

6. Inter-slice RF interference (Crosstalk):7. Soft Copy Display

Pass

Fail

*

N/A

1. Set up and positioning accuracy: (daily)2. Center frequency: (daily)3. Transmitter attenuation or gain: (daily)4. Geometric accuracy measurments: (daily)5. Spatial resolution measurements: (daily)6. Low contrast detectability: (daily)7. Head Coil SNR (daily)8. Body Coil SNR (weekly)9. Fast Spin Echo (FSE/TSE) ghosting levels: (daily)

10. Film quality control: (weekly)11. Visual checklist: (weekly)

*See comments page for description of any failures.

9/5/08

3T

Evaluation of Site's Technologist QC Program

Equipment Evaluation Tests

GE Excite HD

MRI Equipment Evaluation Summary & Signature Page

00139-05

9/1/08

GE Site GE Excite HD 3T 2

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

NOTE: Please be sure to read appendix D for an explanation of the format of this document.

Specific Comments and Recommendations

The breast coil has an effectively dead channel. When using bilateral mode, 7 channels were good, one bad. When

using EITHER the left side or the right side only, there were 3 good channels and one bad.

There is no difference between ports A & B (if the coil can use either.)

The magnet homogeneity is good.

The display console is good and there is good agreement between the screen and the film.

Everything else looks fine.


Site Name: GE Site

Equipment InformationMRI Manufacturer: Model: SN: Software:

Camera Manufacturer: Model: SN: Software:PACS Manufacturer: Model: SN: Software:

ACR Phantom Number used:

1. Table Positioning Reproducibility:Table motion out/in:

Measured Phantom Center

2. Magnetic Field Homogeneity See appendix A for field plots.

Last Year CF: This Year CF: CF Change:GRE TR: 500, TE: 10 & 15 Flip Angle: 45, FOV: 40

5 mm skip 5 mm, BW: 10.4KHz, 256x128, 2nex

Axial: Comments:

Coronal:Sagittal:

3. Slice Thickness AccuracyFOV: 250mm Matrix: 256x256 (Slice #1 from ACR Phantom) All values in mm

NSA

1111114

Comments:

8.0%

5.61 12.2%FSE(16) 3000 5 -10.4%

SE (20/80) 2000 80

MRI Equipment Performance Evaluation Data Form

1234 14.0_M4_629a

Title eMailFax

Out/In Out/In

Contact

-0.40 -0.41-0.40

Phone

IsoCenter Out/In

5.2%5.2%

Pass

% Error

-0.39

-1498

PASS

127,727,086

Sequence TR Target

0.17 0.24 0.32 Shim is very good.0.09 0.16

500 20 90

90

5.40

SE (Site T1) 500 90

T1 MEMP SE 650 10 632.1 80 4.80

5

5

580 90 4.48

5.26

-4.0%GRE 200

SE (20/80) 2000 20 90

5

5.26 5

Comment:

5

5.2%14

CalcTE Flip

5.26SE (ACR)

GE Twinspeed

J0061

127,728,584

0.280.16 0.26 0.40

15 cm 20 cm 25 cm


4. Slice Crosstalk (RF interference)

Sequence Type TR TE Flip Angle

FOV (cm2)

Matrix NSA Thickness # of slices

SE Min Full 400 12 90 25 256x256 1 5 11

T1 MEMP 650 10 63 25 256x256 1 5 11

GRE in Phs 200 2.1 80 25 256x256 4 5 11

Skip SE Min Full T1 MEMP GRE In-

Phase

0 4.94 5.13 4.57

0.2 5 5.17 4.58

0.5 5.03 5.19 4.7

1 5.21 5.32 4.89

1.5 5.33 5.38 4.81

2 5.43 5.41 4.76

2.5 5.45 5.44 4.82

5 5.46 5.41 4.9110 5.46 5.4 4.8

The following data were obtained using the ACR phantom slice thickness wedges to measure the slice profile of three

common T1 weighted sequences when the slice gap varies from 200% down to 0% (contiguous) As the slices get closer

together it is expected that the edges of the slices will overlap causing a deterioration of the slice profile. The data shown

below clearly demonstrates this effect. The T1 MEMP sequence is a spin echo sequence with a a 63° flip angle. Both this

sequence and the standare SE sequence shows a drop in the profile once the gap drops below 50%. The interference is less

with the smaller flip angle and longer TR (as expected) The GRE sequence is more complicated to evaluate because the images

were not as sharp and the profile wedges were not well defined. All of the slice profiles can be seen in Appendix B.

There you can see how the SE profile is very square while the GREs are more triangular.

T1 Weighted Slice Thicknesses

4.5

4.75

5

5.25

5.5

0 1 2 3 4 5 6 7 8 9 10

Slice Gap (mm)

Thic

knes

s (m

m) SE Min Full

T1 MEMPGRE In-Phase


5. Soft & Hard Copy Displays

Luminance Meter Make/Model: Tektronix J16 Digital Photometer Cal Expires:

Monitor Description: Efilm workstation

Luminance Measured: Ft. lamberts

SMPTE

Which Monitor

Center of Image

Display

Top Left Corner

Top Right

Corner

Bottom Left

Corner

Bottom Right

CornerMAX MIN Percent

Delta OK?

Console 86.7 77.9 79.2 83 84.5 86.7 77.9 11% Y

Density Ft-Lamber

Film Density

0 0.15 -3.14

5 0.30 -2.67

10 0.48 -2.38

20 1.03 -1.87

30 2.84 -1.51

40 5.47 -1.23

50 9.73 -0.98

60 16.22 -0.78

70 26.80 -0.62

80 42.90 -0.46

90 67.80 -0.34

95 83.40 -0.27

100 86.70 -0.21

Measured Data

4/6/06

% delta =200% x (max-min)/(max+center) (>30% is action limit)

Uniformity

The monitor is excellent and the agreemen between the screen and film is good.

Minimum Brightness must be > 26.24 Ft. Lamberts

LCD & Film Response Curve

0.1

1.0

10.0

100.0

0 20 40 60 80 100% Density

Lo

g F

t-Lam

bert

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

Ideal CurveLCDFilm


Site Name

ACR Magnet #

Coil DescriptionActive Model Rev. Mfg. Date SN Channels

GE Site05 Nickname Signa 3

Coil and Other Hardware Inventory List

Manufacturer

Body Integrated 1

Breast 8 Ch GE 2415544 Sep, 2006 370 8

Cardiac 8 Ch GE 2411986 Oct, 2005 8

Head 8 Ch GE 5147134-2 Aug, 2006 U28780 8

Head Split Top GE 795WH3 Apr, 2006 7953WH3 1

Knee 8ch Invivo 104504 Sep, 2006 U29317 8

Knee T/R Invivo U222191 1

Neurovascular Array 8 Ch USAI 2414390 Sep, 2006 582 8

Shoulder 3 Ch USAI 2414331 May, 2006 321 3

Spine 8 Ch USAI 2415542 Jul, 2006 329 8

Torso USAI 2415410 Dec, 2006 344 8

Wrist HD Mayo Clinic BC-10 3HB10R006 1

7

miriam

Text Box

miriam

Text Box

7

Test Date: 9/1/2008RF Coil Performance Evaluation

Coil: Body IntegratedMfg.:

Mfg. Date:

Model:

Revision:

SN:

Phantom: Body sphere

SequenceSE

TR300

TE20

PlaneT

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 166 R1: 13 R2: 28Coil Mode: Body

The SNR of the Body coil is 4 times higher than last year!

Analysis of Test Image

Coil ID: 907

# of Channels 1

Mean1,0681,068

Max1,1301,132

Min997

1,002

Background

-0.315.8

NoiseSD

9.708.70

Measured Data Calculated ResultsMeanSNR

77.980.4

MaxSNR

82.485.3

Normal-ized

30.431.4

Uni-formity

93.7%93.9%

NoiseType

NEMAAir

LabelN

A

�G�E� �S�i�t�e Signa 3 8


Coil: Breast 8 ChMfg.: GE

Mfg. Date: 9/1/2006

Model: 2415544

Revision:

SN: 370

Phantom: HD Breast Phantom

SequenceSE

TR300

TE20

PlaneT

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 160 R1: 13 R2: 29Coil Mode: HD Breast Port A

Channel #7 is one fourth of what it should be.

Analysis of Composite Image

Measured Data Calculated ResultsAnalysis of Uncombined Images

Coil ID: 901

Channel 1 Channel 2

Composites

Mean53041342944150548348

643

Max1,3951,0051,070999

1,1141,015119

1,476

# of Channels 8

Mean1,4581,457

Max1,8771,875

Min1,0631,063

Background

1.07.6

NoiseSD

2.772.11


372.2452.5

MaxSNR

479.2582.3

Normal-ized

145.4176.8

Uni-formity

72.3%72.4%

NoiseType

NEMAAir

Ch12345678

1.711.421.501.291.251.590.501.88

NoiseSD

NoiseType

AirAirAirAirAirAirAirAir

MeanSNR

% ofMean

203.1190.6187.4224.0264.7199.162.9

224.1

77%72%71%85%

100%75%24%85%

MaxSNR

% ofMax

534.6463.8467.5507.5584.0418.3156.0514.5

92%79%80%87%

100%72%27%88%

Channel 3 Channel 4

Channel 5 Channel 6 Channel 7 Channel 8

LabelNA


miriam

Highlight

miriam

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miriam

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miriam

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Mfg. Date: 9/1/2006

Model: 2415544

Revision:

SN: 370


SequenceSE

TR300

TE20

PlaneC

FOV40

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 160 R1: 12 R2: 29Coil Mode: HD Breast Port A

Channel 7 is 1/4th of what it should be.



Coil ID: 901

Channel 1 Channel 2Composites - NEMA

Mean1,25269263874687262573

1,382

Max1,6111,0211,0031,0401,238997100

1,663

# of Channels 8

Mean1,5671,6721,5681,672

Max1,9801,9341,9851,934

Min1,3981,5041,3981,503

Background

-0.70.111.311.3

NoiseSD

3.593.703.053.04


308.7319.6336.9360.4

MaxSNR

390.1369.7426.5416.9

Normal-ized

173.6179.8189.5202.7

Uni-formity

82.8%87.5%82.6%87.5%

NoiseType

NEMANEMA

AirAir

Ch12345678

2.482.062.131.841.782.280.672.72

NoiseSD

NoiseType


MeanSNR

% ofMean

330.8220.1196.3265.7321.0179.671.4

333.0

99%66%59%80%96%54%21%

100%

MaxSNR

% ofMax

425.7324.8308.6370.4455.8286.697.8

400.7

93%71%68%81%

100%63%21%88%

Channel 3 Channel 4

Channel 5 Channel 6 Channel 7

LabelNNAA

Composites - Air


miriam

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miriam

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miriam

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miriam

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Mfg. Date: 9/1/2006

Model: 2415544

Revision:

SN: 370


SequenceSE

TR300

TE20

PlaneT

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 160 R1: 13 R2: 29Coil Mode: HD Breast Port B




Coil ID: 901

Channel 1 Channel 2

Composites

Mean51440943143848147635

594

Max1,340971

1,044986

1,0641,005

871,399

# of Channels 8

Mean1,4051,404

Max1,8181,816

Min1,0161,018

Background

0.57.4

NoiseSD

9.082.04


109.4451.0

MaxSNR

141.6583.4

Normal-ized

42.7176.2

Uni-formity

71.7%71.8%

NoiseType

NEMAAir

Ch12345678

1.661.411.481.301.211.540.481.82

NoiseSD

NoiseType


MeanSNR

% ofMean

202.9190.1190.8220.8260.5202.547.8

213.9

78%73%73%85%

100%78%18%82%

MaxSNR

% ofMax

529.0451.3462.3497.0576.2427.7118.8503.7

92%78%80%86%

100%74%21%87%

Channel 3 Channel 4


LabelNA


miriam

Highlight

miriam

Highlight

miriam

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miriam

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Mfg. Date: 9/1/2006

Model: 2415544

Revision:

SN: 370


SequenceSE

TR300

TE20

PlaneC

FOV40

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 160 R1: 12 R2: 29Coil Mode: HD Breast Port B




Coil ID: 901


Mean1,19968863473983160048

1,301

Max1,5411,013987

1,0341,19096563

1,589

# of Channels 8

Mean1,5091,6161,5091,616

Max1,8911,8811,8961,875

Min1,3481,4571,3481,455

Background

-0.3-0.011.011.0

NoiseSD

3.494.203.003.00


305.8272.1329.6353.0

MaxSNR

383.2316.7414.2409.6

Normal-ized

172.0153.1185.4198.6

Uni-formity

83.2%87.3%83.1%87.4%

NoiseType

NEMANEMA

AirAir

Ch12345678

2.442.042.121.821.712.200.642.59

NoiseSD

NoiseType


MeanSNR

% ofMean

322.0221.0196.0266.1318.5178.749.1

329.2

98%67%60%81%97%54%15%

100%

MaxSNR

% ofMax

413.9325.4305.1372.3456.0287.464.5

402.0

91%71%67%82%

100%63%14%88%

Channel 3 Channel 4


LabelNNAA

Composites - Air


miriam

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miriam

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miriam

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miriam

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Mfg. Date: 9/1/2006

Model: 2415544

Revision:

SN: 370


SequenceSE

TR300

TE20

PlaneT

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 160 R1: 13 R2: 29Coil Mode: HD BreastLeft

Channel 3 is dead in both the Left and Right only modes.



Coil ID: 901

Channel 1 Channel 2

Mean46040453

590

Max1,077959129

1,396

# of Channels 8

Mean760760

Max1,5151,517

Min141140

Background

0.24.7

NoiseSD

2.181.74


246.6286.2

MaxSNR

491.5571.3

Normal-ized

96.3111.8

Uni-formity

17.0%16.9%

NoiseType

NEMAAir

Ch1234

1.231.650.561.91

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

245.1160.562.0

202.4

100%65%25%83%

MaxSNR

% ofMax

573.8380.9151.0479.0

100%66%26%83%

Channel 3 Channel 4

LabelNA

Composites


miriam

Highlight

miriam

Highlight

miriam

Highlight

miriam

Highlight



Mfg. Date: 9/1/2006

Model: 2415544

Revision:

SN: 370


SequenceSE

TR300

TE20

PlaneC

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: R1: R2:Coil Mode: HD BreastRight

Channel 3 is dead in both the Left and Right only modes.



Coil ID: 901

Channel 1 Channel 2

Mean52240928

420

Max1,35097594

1,004

# of Channels 8

Mean685684

Max1,4131,413

Min9494

Background

0.34.4

NoiseSD

2.191.52


221.2294.9

MaxSNR

456.3609.2

Normal-ized

86.4115.2

Uni-formity

12.5%12.5%

NoiseType

NEMAAir

Ch1234

1.771.370.551.27

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

193.3195.633.4

216.7

89%90%15%

100%

MaxSNR

% ofMax

499.8466.4112.0518.1

96%90%22%

100%

Channel 3 Channel 4

LabelNA

Composites


miriam

Highlight

miriam

Highlight

miriam

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miriam

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Coil: Cardiac 8 ChMfg.: GE

Mfg. Date: 10/1/2005

Model: 2411986

Revision:

SN:

Phantom: Cardiac phantom

SequenceSE

TR300

TE20

PlaneT

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 169 R1: 13 R2: 29Coil Mode: HD Cardiac Port A

There is no significant difference between Ports A & B



Coil ID: 900

Channel 1 Channel 2

Composites

Mean191209203174194237243178

Max1,7631,4361,3181,5151,4101,6061,6961,330

# of Channels 8

Mean878879

Max2,0122,014

Min287286

Background

-0.312.0

NoiseSD

2.402.75


258.7209.5

MaxSNR

592.9479.9

Normal-ized

101.181.8

Uni-formity

25.0%24.9%

NoiseType

NEMAAir

Ch12345678

1.701.811.831.611.881.941.992.01

NoiseSD

NoiseType


MeanSNR

% ofMean

73.675.772.770.867.680.180.058.0

92%95%91%88%84%

100%100%72%

MaxSNR

% ofMax

679.6519.9472.0616.6491.5542.5558.5433.6

100%77%69%91%72%80%82%64%

Channel 3 Channel 4


LabelNA



Coil: Cardiac 8 ChMfg.: GE

Mfg. Date: 10/1/2005

Model: 2411986

Revision:

SN:

Phantom: Cardiac phantom

SequenceSE

TR300

TE20

PlaneT

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 169 R1: 13 R2: 29Coil Mode: HD Cardiac Port B

There is no significant difference between Ports A & B



Coil ID: 900

Channel 1 Channel 2

Composites

Mean178208193171185232228173

Max1,6431,4241,2551,4901,3521,5801,5961,296

# of Channels 8

Mean845845

Max1,9071,907

Min274275

Background

0.211.0

NoiseSD

2.502.56


239.0216.3

MaxSNR

539.5488.2

Normal-ized

93.484.5

Uni-formity

25.1%25.2%

NoiseType

NEMAAir

Ch12345678

1.611.801.731.581.811.911.851.95

NoiseSD

NoiseType


MeanSNR

% ofMean

72.575.773.170.967.079.680.858.1

90%94%91%88%83%99%

100%72%

MaxSNR

% ofMax

668.7518.4475.4618.0489.5542.1565.3435.5

100%78%71%92%73%81%85%65%

Channel 3 Channel 4


LabelNA



Coil: Head 8 ChMfg.: GE

Mfg. Date: 8/6/2006

Model: 5147134-2

Revision:

SN: U28780

Phantom: Head TLT sphere

SequenceSE

TR300

TE20

PlaneT

FOV36

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 163 R1: 13 R2: 29Coil Mode: 8HRBrain

There is a 7% drop in SNR since last year.



Coil ID: 898

Channel 1 Channel 2

Composites

Mean458492541480438448502426

Max1,1261,2451,3721,2241,1391,1841,1951,030

# of Channels 8

Mean1,5371,536

Max1,9021,902

Min1,1931,192

Background

1.113.3

NoiseSD

3.042.84


357.6354.4

MaxSNR

442.5438.9

Normal-ized

248.3246.1

Uni-formity

77.1%77.1%

NoiseType

NEMAAir

Ch12345678

2.212.302.592.632.202.212.332.07

NoiseSD

NoiseType


MeanSNR

% ofMean

135.8140.2136.9119.6130.5132.8141.2134.9

96%99%97%85%92%94%

100%96%

MaxSNR

% ofMax

333.9354.7347.1305.0339.3351.1336.1326.1

94%100%98%86%96%99%95%92%

Channel 3 Channel 4


LabelNA



Coil: Head Split TopMfg.: GE

Mfg. Date: 4/1/2006

Model: 795WH3

Revision:

SN: 7953WH3

Phantom: ACR

SequenceSE

TR300

TE20

PlaneT

FOV40

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: R1: R2:Coil Mode: Head


Coil ID: 905

# of Channels 1

Mean3,6053,602

Max4,4864,488

Min2,6682,660

Background

2.29.2

NoiseSD

6.825.12


373.8461.0

MaxSNR

465.2574.4

Normal-ized

210.3259.3

Uni-formity

74.6%74.4%

NoiseType

NEMAAir

LabelN

A



Coil: Head Split TopMfg.: GE

Mfg. Date: 4/1/2006

Model: 795WH3

Revision:

SN: 7953WH3

Phantom: Oil filled sphere

SequenceSE

TR300

TE20

PlaneT

FOV36

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 152 R1: 13 R2: 29Coil Mode: Head


Coil ID: 905

# of Channels 1

Mean1,0651,064

Max1,1201,119

Min1,0211,022

Background

0.511.8

NoiseSD

7.326.51


102.9107.1

MaxSNR

108.2112.6

Normal-ized

71.574.4

Uni-formity

95.4%95.5%

NoiseType

NEMAAir

LabelN

A



Coil: Knee 8chMfg.: Invivo

Mfg. Date: 9/1/2006

Model: 104504

Revision:

SN: U29317

Phantom: Knee phantom.

SequenceSE

TR300

TE20

PlaneT

FOV30

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 168 R1: 13 R2: 29Coil Mode: HD TR Knee PA



Coil ID: 912

Channel 1 Channel 2

Composites

Mean695662586426646515521638

Max1,9781,8781,8391,4721,6031,5591,7391,372

# of Channels 8

Mean2,0422,043

Max2,7622,762

Min1,3621,362

Background

-0.314.7

NoiseSD

3.043.06


475.0437.5

MaxSNR

642.5591.5

Normal-ized

475.0437.5

Uni-formity

66.1%66.1%

NoiseType

NEMAAir

Ch12345678

2.432.672.762.432.542.512.532.26

NoiseSD

NoiseType


MeanSNR

% ofMean

187.4162.5139.1114.9166.7134.5134.9185.0

100%87%74%61%89%72%72%99%

MaxSNR

% ofMax

533.4460.9436.6397.0413.6407.0450.4397.8

100%86%82%74%78%76%84%75%

Channel 3 Channel 4


LabelNA



Coil: Knee T/RMfg.: Invivo

Mfg. Date:

Model:

Revision:

SN: U222191

Phantom: 8ch Knee phantom and my wrist bottle in foot.

SequenceSE

TR300

TE20

PlaneT

FOV36

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

Coil Mode: QUADKNEE


Coil ID: 904

Test Images

# of Channels 1

Mean12,4814,24312,4794,240

Max13,9574,79513,9304,798

Min10,8683,77710,8773,765

Background

1.73.112.312.4

NoiseSD

29.1412.496.746.75


302.9240.21213.3411.6

MaxSNR

338.7271.51354.4465.8

Normal-ized

210.4166.8842.6285.9

Uni-formity

87.6%88.1%87.7%87.9%

NoiseType

NEMANEMA

AirAir

LabelN

N

A

A

TX gain: 77 R1: 10 R2: 28



Coil: Knee T/RMfg.: Invivo

Mfg. Date:

Model:

Revision:

SN: U222191

Phantom: 8ch Knee phantom and my wrist bottle in foot.

SequenceSE

TR300

TE20

PlaneS

FOV40

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

Coil Mode: QUADKNEE


Coil ID: 904

Test Images

# of Channels 1

Mean11,8954,09211,8984,090

Max13,4435,27413,4465,275

Min10,8591,76510,8571,766

Background

-2.91.412.811.4

NoiseSD

8.035.746.516.02


1047.6504.21197.7445.2

MaxSNR

1183.9649.81353.5574.2

Normal-ized

589.3283.6673.7250.4

Uni-formity

89.4%50.1%89.3%50.2%

NoiseType

NEMANEMA

AirAir

LabelN

N

A

A

TX gain: 77 R1: 9 R2: 29



Coil: Neurovascular Array 8 ChMfg.: USAI

Mfg. Date: 9/1/2006

Model: 2414390

Revision:

SN: 582

Phantom: Two-piece NVA phantom set.

SequenceSE

TR300

TE20

PlaneT

FOV36

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 165 R1: 13 R2: 30Coil Mode: a HDNV Head



Coil ID: 902

Channel 1 Channel 2

Composites

Mean281236272239216225350301

Max612510534519467459718621

# of Channels 8

Mean835835

Max982982

Min708708

Background

-0.214.0

NoiseSD

2.752.87


214.7190.7

MaxSNR

252.5224.2

Normal-ized

149.1132.4

Uni-formity

83.8%83.8%

NoiseType

NEMAAir

Ch12345678

2.472.232.412.592.352.342.582.28

NoiseSD

NoiseType


MeanSNR

% ofMean

74.669.474.060.560.263.088.986.5

84%78%83%68%68%71%

100%97%

MaxSNR

% ofMax

162.4149.9145.2131.3130.2128.5182.4178.5

89%82%80%72%71%70%

100%98%

Channel 3 Channel 4


LabelNA




Mfg. Date: 9/1/2006

Model: 2414390

Revision:

SN: 582


SequenceSE

TR300

TE20

PlaneS

FOV48

Nx256

Ny256

NSA2

BW15.6

Thickness3

Gap-

TX gain: 177 R1: 13 R2: 29Coil Mode: HDNV Array



Coil ID: 902


Mean563317393544549392396516

Max1,144610767

1,0901,100897705

1,048

# of Channels 8

Mean1,122956

1,121955

Max1,6111,8791,6101,879

Min662644661645

Background

0.90.35.85.8

NoiseSD

1.681.981.191.19


472.3341.5617.3525.9

MaxSNR

678.2671.1886.61034.7

Normal-ized

130.594.3

170.5145.3

Uni-formity

58.2%51.1%58.2%51.1%

NoiseType

NEMANEMA

AirAir

Ch12345678

1.330.921.001.311.050.930.961.01

NoiseSD

NoiseType


MeanSNR

% ofMean

277.4225.8257.5272.1342.6276.2270.3334.8

81%66%75%79%

100%81%79%98%

MaxSNR

% ofMax

563.7434.5502.6545.3686.5632.1481.2680.0

82%63%73%79%

100%92%70%99%

Channel 3 Channel 4


LabelNNAA

Composites - Air




Mfg. Date: 9/1/2006

Model: 2414390

Revision:

SN: 582


SequenceSE

TR300

TE20

PlaneC

FOV48

Nx256

Ny256

NSA1.5

BW15.6

Thickness3

Gap-

TX gain: 177 R1: 13 R2: 29Coil Mode: HDNV Array



Coil ID: 902


Mean213318364191364351387323

Max455738781374772832

1,057712

# of Channels 8

Mean892611891610

Max1,5311,0301,5321,029

Min632157631156

Background

0.50.55.95.8

NoiseSD

1.411.261.221.21


447.4342.9478.6330.4

MaxSNR

767.9578.1822.9557.3

Normal-ized

142.7109.4152.6105.4

Uni-formity

58.4%26.5%58.3%26.3%

NoiseType

NEMANEMA

AirAir

Ch12345678

1.340.931.001.301.050.950.991.02

NoiseSD

NoiseType


MeanSNR

% ofMean

104.2224.1238.596.3

227.2242.1256.2207.5

41%87%93%38%89%95%

100%81%

MaxSNR

% ofMax

222.5520.0511.8188.5481.8573.9699.7457.4

32%74%73%27%69%82%

100%65%

Channel 3 Channel 4


LabelNNAA

Composites - Air



Coil: Shoulder 3 ChMfg.: USAI

Mfg. Date: 5/01/2006

Model: 2414331

Revision:

SN: 321

Phantom: Shoulder sphere

SequenceSE

TR300

TE20

PlaneT

FOV36

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 164 R1: 13 R2: 29Coil Mode: HD SHOULDER

These axial images were acquired at the center of the phantom and NOT at the ‘+’ mark on the coil like last year.



Coil ID: 903

Channel 1 Channel 2

Mean518251577

Max1,171436921

# of Channels 3

Mean878878

Max1,5401,539

Min422422

Background

-0.28.1

NoiseSD

3.212.64


193.4217.9

MaxSNR

339.3382.0

Normal-ized

134.3151.3

Uni-formity

43.0%43.0%

NoiseType

NEMAAir

Ch123

2.962.391.86

NoiseSD

NoiseType

AirAirAir

MeanSNR

% ofMean

114.768.8

203.3

56%34%

100%

MaxSNR

% ofMax

259.2119.5324.5

80%37%

100%

Channel 3

LabelNA

Composites



Coil: Shoulder 3 ChMfg.: USAI

Mfg. Date: 5/01/2006

Model: 2414331

Revision:

SN: 321

Phantom: Shoulder sphere

SequenceSE

TR300

TE20

PlaneC

FOV36

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 164 R1: 13 R2: 29Coil Mode: HD SHOULDER



Coil ID: 903

Channel 1 Channel 2

Mean503347560

Max1,7871,287883

# of Channels 3

Mean943943

Max1,8421,841

Min375374

Background

0.08.0

NoiseSD

2.952.62


226.1235.9

MaxSNR

441.6460.5

Normal-ized

157.0163.8

Uni-formity

33.8%33.8%

NoiseType

NEMAAir

Ch123

2.922.391.86

NoiseSD

NoiseType

AirAirAir

MeanSNR

% ofMean

112.995.1

197.3

57%48%

100%

MaxSNR

% ofMax

401.0352.9311.1

100%88%78%

Channel 3

LabelNA

Composites



Coil: Spine 8 ChMfg.: USAI

Mfg. Date: 7/01/2006

Model: 2415542

Revision:

SN: 329

Phantom: Dual 3T spine phantoms

SequenceSE

TR300

TE20

PlaneS

FOV48

Nx256

Ny256

NSA2

BW15.6

Thickness3

Gap-

TX gain: 166 R1: 13 R2: 29Coil Mode: HDCTL123



Coil ID: 899

Channel 1 Channel 2Composites

Mean707549438435325360

Max2,8441,7961,7451,7621,8641,788

# of Channels 8

Mean1,5451,545

Max3,0913,091

Min623622

Background

0.36.5

NoiseSD

1.851.52


590.6666.1

MaxSNR

1181.61332.6

Normal-ized

163.1184.0

Uni-formity

33.5%33.5%

NoiseType

NEMAAir

Ch123456

1.571.291.381.181.391.23

NoiseSD

NoiseType

AirAirAirAirAirAir

MeanSNR

% ofMean

295.1278.9208.0241.6153.2191.8

100%95%70%82%52%65%

MaxSNR

% ofMax

1187.1912.4828.6978.5878.8952.6

100%77%70%82%74%80%

Channel 3

Channel 4 Channel 5

LabelNA

Extra Pics




Mfg. Date: 7/01/2006

Model: 2415542

Revision:

SN: 329


SequenceSE

TR300

TE20

PlaneS

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 167 R1: 13 R2: 29Coil Mode: HDCTL34 PE AP



Coil ID: 899

Channel 1 Channel 2

Mean597560638602

Max2,2911,9692,5101,891

# of Channels 8

Mean1,4301,430

Max3,1263,126

Min502501

Background

-0.67.3

NoiseSD

3.362.14


301.0437.9

MaxSNR

658.0957.2

Normal-ized

117.6171.1

Uni-formity

27.7%27.6%

NoiseType

NEMAAir

Ch1234

1.911.712.111.67

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

204.8214.6198.1236.2

87%91%84%

100%

MaxSNR

% ofMax

786.0754.6779.5742.0

100%96%99%94%

Channel 3 Channel 4

LabelNA

Composites




Mfg. Date: 7/01/2006

Model: 2415542

Revision:

SN: 329


SequenceSE

TR300

TE20

PlaneS

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 167 R1: 13 R2: 29Coil Mode: HDCTL56 PE AP



Coil ID: 899

Channel 1 Channel 2

Mean693688653668

Max2,6682,4032,6932,247

# of Channels 8

Mean1,6051,605

Max3,6233,627

Min513512

Background

0.37.0

NoiseSD

3.512.07


323.4508.1

MaxSNR

730.01148.2

Normal-ized

126.3198.5

Uni-formity

24.8%24.7%

NoiseType

NEMAAir

Ch1234

1.951.771.811.65

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

232.9254.7236.4265.3

88%96%89%

100%

MaxSNR

% ofMax

896.6889.7975.0892.4

92%91%

100%92%

Channel 3 Channel 4

LabelNA

Composites



Coil: TorsoMfg.: USAI

Mfg. Date: 12/1/2006

Model: 2415410

Revision:

SN: 344

Phantom: Two large Torso phantoms... one of which is centered.

SequenceSE

TR300

TE20

PlaneT

FOV48

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 171 R1: 13 R2: 29Coil Mode: 8US TORSOPA



Coil ID: 1774

Channel 1 Channel 2

Composites

Mean266305280297262268295272

Max1,5281,1021,1291,7401,7201,1641,2131,786

# of Channels 8

Mean1,1691,168

Max2,3502,349

Min596593

Background

1.113.8

NoiseSD

3.203.02


258.4253.4

MaxSNR

519.4509.7

Normal-ized

100.999.0

Uni-formity

40.5%40.3%

NoiseType

NEMAAir

Ch12345678

2.212.622.922.132.142.362.671.92

NoiseSD

NoiseType


MeanSNR

% ofMean

78.976.362.891.480.274.472.492.8

85%82%68%98%86%80%78%

100%

MaxSNR

% ofMax

453.1275.6253.4535.3526.7323.2297.7609.6

74%45%42%88%86%53%49%

100%

Channel 3 Channel 4


LabelNA



Coil: Wrist HDMfg.: Mayo Clinic

Mfg. Date:

Model: BC-10

Revision:

SN: 3HB10R006

Phantom: Small wrist bottle.

SequenceSE

TR300

TE20

PlaneT

FOV15

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-

TX gain: 151 R1: 11 R2: 29Coil Mode: HD WristCoil


Coil ID: 1775

# of Channels 1

Mean8,3528,345

Max8,8728,879

Min7,4977,470

Background

6.734.1

NoiseSD

22.0718.31


267.6298.7

MaxSNR

284.3317.8

Normal-ized

1070.51194.7

Uni-formity

91.6%91.4%

NoiseType

NEMAAir

LabelN

A




Mfg. Date:

Model: BC-10

Revision:

SN: 3HB10R006


SequenceSE

TR300

TE20

PlaneC

FOV20

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-



Coil ID: 1775

# of Channels 1

Mean6,0946,096

Max8,7258,731

Min1,5331,532

Background

-2.319.3

NoiseSD

15.8510.52


271.9379.7

MaxSNR

389.3543.9

Normal-ized

611.8854.4

Uni-formity

29.9%29.9%

NoiseType

NEMAAir

LabelN

A




Mfg. Date:

Model: BC-10

Revision:

SN: 3HB10R006


SequenceSE

TR300

TE20

PlaneS

FOV20

Nx256

Ny256

NSA1

BW15.6

Thickness3

Gap-



Coil ID: 1775

# of Channels 1

Mean6,0696,071

Max8,5268,532

Min1,5131,515

Background

-2.119.4

NoiseSD

18.0010.38


238.4383.3

MaxSNR

335.0538.6

Normal-ized

536.5862.4

Uni-formity

30.1%30.2%

NoiseType

NEMAAir

LabelN

A


-20

-20

0

0

0

0

0

20

20

20

-40

-40

-20

-20

-20

-20

0

0

0

0

0

0

0

0

20

2020

40

Superior

Inferior

Rig

ht

Left

Cor

onal

Superior

Inferior

Ant

eriro

r

Pos

terio

r

Sag

ittal

Anterior

Posterior

Rig

ht

LeftAxi

al

AxialDIAMETER MIN MAX RANGE PPM MEAN STDEV

10 -8.3 5.2 13.5 0.11 -1.40 3.215 -14.3 7.4 21.6 0.17 -2.58 5.120 -22.2 8.5 30.7 0.24 -4.39 7.125 -32.6 8.6 41.2 0.32 -7.05 9.728 -45.2 8.6 53.7 0.42 -9.21 11.630 -58.1 8.6 66.7 0.52 -10.87 13.1

Appendix A: Magnet Homogeneity Field Maps GE Site - Signa 3Excite HD 1.5T - 3 central planes

Measured September 1, 2008

CoronalDIAMETER MIN MAX RANGE PPM MEAN STDEV

10 -1.3 4.9 6.2 0.05 0.87 1.315 -2.2 9.2 11.4 0.09 1.94 2.320 -5.1 15.1 20.1 0.16 3.43 3.825 -11.6 23.6 35.2 0.28 5.39 5.828 -18.0 38.5 56.5 0.44 6.84 7.630 -25.4 56.2 81.6 0.64 7.93 9.1

SagittalDIAMETER MIN MAX RANGE PPM MEAN STDEV

10 -5.5 5.1 10.6 0.08 0.83 2.115 -11.2 9.1 20.3 0.16 0.50 3.720 -18.0 14.5 32.5 0.26 -0.00 5.825 -26.8 23.7 50.5 0.40 -0.66 8.428 -34.2 37.3 71.5 0.56 -1.13 10.530 -44.1 52.6 96.8 0.76 -1.46 12.2

miriam

Text Box

35

Appendix A: Magnet Homogeneity Field Maps GE Site - Signa 3

Excite HD 1.5TMeasured September 1, 2008

GE Site - Signa 3 - Axial Field Plot - 9/1/08

0.00

0.25

0.50

0.75

1.00

1.25

1.50

-9 -6 -3 0 3 6 9cm from Isocenter (S/I)

pp

m

10cm15cm20cm25cm28cm30cm

FOV Diameter

GE Site - Signa 3 - Coronal Field Plot - 9/1/08

0.00

0.25

0.50

0.75

1.00

1.25

1.50

-9 -6 -3 0 3 6 9

cm from Isocenter (P/A)

pp

m


FOV Diameter

GE Site - Signa 3 - Sagittal Field Plot - 9/1/08

0.00

0.25

0.50

0.75

1.00

1.25

1.50

-9 -6 -3 0 3 6 9cm from Isocenter (R/L)

pp

m


FOV Diameter

miriam

Text Box

36

Axial Field Plots

-20

0

00

20

H9

-20

0

0

0

20

H8

-200

0

0

20

H7

-40

-20

-20

0

0

00

20

H6

-60-40

-40

-20

-20

-20

-20

0

0

0

0

H5

-60-40

-40

-20

-20-20 -20

0

0

0

0

0

H4

-60

-40-40

-40

-20

-20

-20

-20

0

0

0

0

0

H3

-60

-40

-40

-40

-20

-20

-20-20

0

0

0

00

0

H2

-40

-40

-40

-20

-20

-20

-20

0

0

0

0

0

0

H1

-40

-40

-20

-20

-20

-20

0

0

0

0

0

0

Isocenter

-40-20

-20

0

0

0

0

F1

-40-20

-20

0

0

0

0

F2

-40-20

-20

0

0

0

0

F3

-200

0

0

20

F4

-200

0

0

20

F5

-200

0

0

20

F6

0

00

20

F7

-20

0

0

0F8

-20

0

0

0F9

Axial Field Plots

miriam

Text Box

37

Coronal Field Plots

0

0

20

20

20

A9

0

0

20

20

20

A8

00

20 20

2040

A7

00

20

20

20

20

40

A6

0

0 0

20

20

20

20

40

A5

0

0

20

20

20

40

A4

0

0

0

0

20

20

20

A3

0

0

0

20

20

20

20

A2

0

0

20

20

20

40A1

0

0

20

2020

40Isocenter

0

0

20

2020

20 40P1

0

0

20

20

20

20

40

P2

00

20

20

20

20P3

0 0

20

20

20

P4

0

0

20

20

40

P5

0

0

20

20

40

P6

0

0

20

20

40

P7

00

0

20

20

P8

0 0

0

20

P9

Coronal Field Plots

miriam

Text Box

38

Sagittal Field Plots

-20

-20

0

0

20 40R9

-20

-20

00

0

0

2040

R8

-20

-20

00

0

0

20

40

R7

-20

-20

0

0

0

0

2040

R6

-20

-20

0

0

0

0

20

R5

-20

-20

00

0

0

20

20

R4

-20

-20

00

0

0

20

2040R3

-20

-20

00

0

0

20

20

2040R2

-20

-20

0

0

0

0

20

2020R1

-20

-20

0

0

0

0

0

20

20

20

Isocenter

-20

-20

0

0

0

0

0

20

2040L1

-20

-20

0

0

0

0

020L2

-20

-20

0

0

0

0

20L3

-40

-20

-20

0

0

0

0

20

L4

-40

-20

-20

0

0

0

0

20

L5

-40

-20

-20

0

0

0

0

20

L6

-40

-20

-20

0 0

0

0

20

L7

-40

-20

-20

0

0

0

0

20

L8

-40-2

0

-20

0

0

0

20

L9

Sagittal Field Plots

miriam

Text Box

39

Appendix B: RF Slice Profiles and Crosstalk

0 50 100 1500

20

40

60

80

100

Upper=56.28 Lower=53.01

Slice Thickness=5.46

SE sk 10

0 50 100 1500

20

40

60

80

100



SE sk 5

0 50 100 1500

20

40

60

80

100



SE sk 2.5

0 50 100 1500

20

40

60

80

100



SE sk 2

0 50 100 1500

20

40

60

80

100



SE sk 1.5

0 50 100 1500

20

40

60

80

100



SE sk 1.0

0 50 100 1500

20

40

60

80

100



SE sk 0.5

0 50 100 1500

20

40

60

80

100



SE sk 0.2

0 50 100 1500

20

40

60

80

100



SE sk 0.0

Slice thickness as a function of slice gap

0 2 4 6 8 10Slice Gap

4.0

4.5

5.0

5.5

6.0

Slic

eTh

ickn

ess

Spin EchoTR/TE = 400/12BW = 19.23 KHznex = 1Scan time: 1:43

miriam

Text Box

40


0 50 100 1500

20

40

60

80

100



MEMP SK 10

0 50 100 1500

20

40

60

80

100



MEMP SK 5

0 50 100 1500

20

40

60

80

100



MEMP SK 2.5

0 50 100 1500

20

40

60

80

100



MEMP SK 2

0 50 100 1500

20

40

60

80

100



MEMP SK 1.5

0 50 100 1500

20

40

60

80

100



MEMP SK 1.0

0 50 100 1500

20

40

60

80

100



MEMP SK 0.5

0 50 100 1500

20

40

60

80

100



MEMP SK 0.2

0 50 100 1500

20

40

60

80

100



MEMP SK 0.0


0 2 4 6 8 10Slice Gap

4.0

4.5

5.0

5.5

6.0

Slic

eTh

ickn

ess

Spin Echo - T1 MEMPTR/TE = 650/10FLIP = 63°BW = 19.23 KHznex = 1Scan time: 2:47

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0 50 100 1500

20

40

60

80

100



InPhs sk 10

0 50 100 1500

20

40

60

80

100



InPhs sk 5

0 50 100 1500

20

40

60

80

100



InPhs sk 2.5

0 50 100 1500

20

40

60

80

100



InPhs sk 2

0 50 100 1500

20

40

60

80

100



InPhs sk 1.5

0 50 100 1500

20

40

60

80

100



InPhs sk 1.0

0 50 100 1500

20

40

60

80

100



InPhs sk 0.5

0 50 100 1500

20

40

60

80

100



InPhs sk 0.2

0 50 100 1500

20

40

60

80

100



InPhs sk 0.0


0 2 4 6 8 10Slice Gap

4.0

4.5

5.0

5.5

6.0

Slic

eTh

ickn

ess

GRE - In PhaseTR/TE = 200/2.1FLIP = 80°BW = 83.32 KHznex = 4Scan time: 3:25

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1.0 1.0 1.0 0.9 0.91.0 1.0 1.0 0.9 0.952.2 52.4 54.9 51.9 45.653.1 52.8 57.4 53.3 44.05.26 5.26 5.61 5.26 4.48-1.2 -1.2 -1.1 -1.2 -1.3191.1 191.1 191.1 191.1 191.0191.1 191.1 191.2 191.1 191.4

190.9 190.9 190.9 190.9 190.8191.0 191.0 191.0 190.9 191.2190.8 190.8 190.8 190.9 191.2

23456789

190.6 190.6 190.5 190.6 190.6

4412 4606 2363 4525 17015119 5299 2762 5272 20793140 3303 1538 3112 119376.0% 76.8% 71.5% 74.2% 72.9%

0.6% 0.5% 0.5% 0.0% 0.2%352 342 200 341 132

10 10 8 10 0

10 10 10 10 1010 10 10 10 1040 40 36 40 29

-1.9 -1.8 -1.9 -1.9 -2.1-0.7 -0.6 -0.8 -0.7 -0.8

Sagittal Locator1 Length of phantom, end to end (mn 148± 2)

Slice Location #1(SE 500/20) (SE 2000/20) (SE 2000/80) (Site T1) (Site T2)

= calculated field

Resolution

Slice Thickness(fwhm in mm)

(1.10, 1.00, 0.90 mm)

TopBottom

Wedge (mm)

Diameter (mm) (190±2)

10111213

Slice Location #5

Diameter (mm) (190±2)

Slice Location #714151617181920212223

Signal(mean only)

Big ROIHighLow

Uniformity (>87.5%)

Background Noise Top Bottom

LeftRight

(mean ±std dev)

Ghosting Ratio (<2.5%) SNR (no spec)

2425262728

Slice Location #8Slice Location #9Slice Location #10Slice Location #11

1.4%2.5%3.6%5.1%

Total # of Spokes (>=9)

Low Con Detectability

10 10 8 10 9

2930

Slice Location #11Wedge (mm)Slice Position Error

±±

±±

21.7 11.16 24.8 12.47 23.9 11.87 25.1 13.51 26.7 13.2024.1 13.94 26.8 14.43 24.2 11.73 26.1 13.02 26.6 12.67

51.8 16.93 54.1 17.94 39.9 17.34 26.1 14.80 28.5 14.58

48.2 17.19 40.1 16.82 32.5 15.41 21.3 14.85 30.7 15.11

Test Date: 9/1/2008

148.4

ACR T1 ACR PD ACR T2 Site T1 Site T2

GE Site Signa 3Head Split Top

The low uniformity is expected because I did not use any homogeneity correction.

Coil Used:

= + = -= +

= + = -= +

±±

±±

±±

±±

±±

±±

±±

±±

Calculated value 5.0±0.7

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TestID: 339Magnet ID: Coil ID: 905

PulseSequence

(ETL)

SE

TR(ms)

500

TE(ms)

20

FOV(cm)

25

PhaseSampleRatio

1

Numberof

Slices

11

Thick-ness(mm)

5

SliceGap

5

NSA(Nex)

256

FreqMatrix

2561

BandWidth(kHz)

19.2

ScanTime

(min:sec)

2:09

PhaseMatrix

StudyDescription

ACR T1

256

256

256

Dual Echo SE

Dual Echo SE

SE

FSE(20)

2000

2000

400

3617

20

80

12

123

25

25

24

24

1

1

1

1

11

11

11

11

5

5

5

5

5

5

5

5 256

256

256

256

256

1

1

1

2

19.2

19.2

19.2

31.2

8:32

8:32

1:43

1:32

ACR PD

ACR T2

Site T1

Site T2

Sequence parameters Test Date: 9/1/2008

Test ID 339

GE Site Signa 3

Head Split Top

112

Coil Used:

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Appendix C: ACR Phantom Analysis ACR T1

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Appendix C: ACR Phantom Analysis ACR PD

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Appendix C: ACR Phantom Analysis ACR T2

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Appendix C: ACR Phantom Analysis Site T1

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Appendix C: ACR Phantom Analysis Site T2

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Appendix D:Explanation of RF Coil Testing Report

IntroductionThe primary goal of RF coil testing is to establish some sort of base line for tracking coil performance overtime. The most common measure is the Signal to Noise Ratio or SNR. In addition, we can look at overallsignal uniformity, ghosting level (or better - lack of ghosting) and in the case of phased array coils we lookat the SNR of each and every channel and at symmetry between channels. Unfortunately, there is no singlebest method for measuring SNR. Below I explain the different methods used and the rationale for each.

SNROne needs to measure the signal in the phantom (either mean or peak or both) and then divide that by thebackground noise. Measuring the signal is fairly straightforward, the noise can be more problematic. Thesimplest method is to measure the standard deviation (SD) in the background ‘air’. However, MRI imagesare the magnitude of complex data. The noise in the underlying complex data is Gaussian but it follows aRician distribution when the magnitude is used. The true noise can be estimated by multiplying the mea-sured SD by 1.526.

During the reconstruction process, most manufacturers perform various additional operations on the images,This could include geometric distortion correction, low pass filtering of the k-space data resulting in lowsignal at the edge of the images, RF coil intensity correction (PURE, CLEAR, SCIC, etc), and other pro-cessing during the combination of phased array data and parallel imaging techniques. All of these methodsdistort the background noise making it impossible to obtain an accurate (and reproducible) estimate of theimage noise in the air region. The alternative is to use a method which I shall refer to as the NEMA(National Electrical Manufacturers Association) method. The signal in the phantom area is a sum of theproton signal and noise. Once the signal to noise ratio exceeds 5:1, the noise in the magnitude image iseffectively Gaussian. To eliminate the proton signal, you acquire an image twice and subtract them. Themeasured SD in the phantom region should now be the true SD times the square root of 2. When determin-ing the SNR using the NEMA method, calculate the mean signal of the average of the two source imagesthen divide by .7071 x the SD measured in the same area as the mean signal.

Unfortunately, this doesn’t always work. It is absolutely imperative that the RF channel scalings, both trans-mit and receive, be identical with both scans. Any ghosting in the system is not likely to repeat exactly forboth scans and will cause a much higher SD. Finally, the phantom needs to be resting in place prior to thescan long enough for motion of the fluid to have died down. Depending on the size and shape of the phan-tom, this could take any where from 5 to 20 minutes.

One of the most common causes of ghosting is vibration from the helium cold-head. The best way to elimi-nate this artifact is to turn off the cold head, which will increase helium consumption. Because this vibra-tion is periodic, the ghosting is usually of an N over 2 (N/2) nature. The affect inside the signal region ofthe phantom can be minimized by using a FOV that is twice the diameter of the phantom (measured in thePE direction.) If the noise is to be measured in the air, then be sure to NOT make measurements to eitherside of the phantom in the PE direction.

Scan parameters also significantly affect measured SNR. For most of the testing performed in this documentI used a simple Spin Echo with a TR of 300, a TE of 20 and a slice thickness of 3mm and a receiver BW of15.6 KHz. The FOV was varied depending on the size of the coil and the phantom used. All of the parame-ters used for each test can be found on each page immediately below the coil description.

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Report LayoutEach page of this report lists the data from a single test. The top third of the page describes the coil andphantom information, followed by the scan parameters used. The middle third contains the numbers mea-sured and calculated results. This section will contain one table if the coil being tested is a single channelcoil (i.e. quadrature or surface coils) and two tables if it is a multi-channel phased array coil. The entries inthe table will be described further below. The bottom section contains a few lines of comments (ifnecessary), a picture of the coil with the phantom as used for the testing and one or more of the images thatwere used for the measurements.

There is usually one image for each composite image measurement and one image for each separate channelmeasurement. Each image shows the ROI (red line) where the mean signal was measured and two smallerROIs (green lines) where the signal minimum and maximum was found. In the top left corner of each imageis the mean signal in the large ROI. The bottom left corner contains the large ROI’s area (in mm2). The topright corner contains two numbers a mean and a standard deviation. If the NEMA method was used, thenthe top right corner will list the mean and SD of the large ROI (labeled ROI M and ROIsd) applied to thesubtraction image. If the noise was measured in the background air the the numbers are labeled Air M andAirSD.

Data TablesThe meaning of most of the entries in the data table are should be self evident with a few exceptions. Thefirst column in each table is labeled “Label”. In the composite analysis, this field may be empty or containsome sort of abbreviation to identify some aspect of the testing. Some possibilities are the letter N forNEMA, A for Air, L for Left, R for Right, C for CLEAR, NoC for No CLEAR. In the Uncombined Imagetable, the label usually contains the channel number or similar descriptor. The column labeled “Noise Type”will be either Air or SubSig which stands for Subtracted Signal, i.e. the NEMA method. Both tables containa column for Mean SNR and Max SNR which are the Mean or Max signal divided by the SD of the noisescaled by either 1.526 (Air) or 0.7071 (NEMA).

Composite Image Table: The final two columns in this table are “Normalized” and “Uniformity”. It can berather difficult to compare the performance of different coils particularly if different scan parameters areused. (Of course, it’s even more difficult from one scanner to another.) I have standardized most of my test-ing to use a spin echo with a TR/TE of 300/20msec and a thickness of 3 mm. The FOV changes to depend-ing on the size of the phantom used although I try to use a FOV that is at least twice the diameter of thephantom as measured in the PE direction. For one reason or another, a change may be made in the scanparameters (either accidentally or intentionally such as turning on No Phase Wrap to eliminate aliasing, etc.).In order to make it easier to compare SNR values I calculate a “Normalized” SNR value. This value is theo-retically what the SNR would be if a FOV of 30cm, 256x256 matrix, 1 average, receiver BW of 15.6 KHzand slice thickness of 3mm had been used. Obviously, the final number is affected by the T1/T2 values ofthe phantoms used as well as details of the coil and magnet field strength but it can be useful in certain situa-tions.

The “Uniformity” value is defined by the ACR as 1 - (max-min)/(max+min). This is most important whenlooking at volume coils or for evaluating the effectiveness of surface coil intensity correction algorithms(such as PURE, CLEAR or SCIC).

Uncombined Image Table: This table has two columns labeled “% of Mean” and “% of Max”. When ana-lyzing multi-channel coils it is important to understand the relationship between the different channels, theinherent symmetry that usually exists between channels. In a 8 channel head or 4 channel torso phased arraycoil, all of the channels are usually have about the same SNR. These two columns list how the SNR (eitherMean or Max) of each channel compares to the SNR of the channel with the maximum value.

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Documents

GE Site Yearly Performance Evaluation GE Signa Excite HD ...simplyphysics.com/Sample_reports/GE_ExciteHD_3T_Report.pdf · Site Name ACR Magnet # Active Coil Description Model Rev