philips site 2-mar-08 table of contents philips intera 1.5t yearly

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

Body Sense Coil 9

Breast Coil 10

Head and Neck 11

Head Sense 12

Knee/Foot Quadrature 14

Shoulder Array - Large 16

Shoulder Array - Small 18

Spine - Synergy 20

Surface - C-1 23

Surface - C-3 24

Surface - C-4 25

Surface - E-1 26

Synergy Flex-M 27

Wrist Coil - High Res. 29

32

37

39

46

Philips Site

Appendix C: ACR Phantom Analysis

Appendix D: Explanation of RF Coil Test Format

2-Mar-08

Table of Contents

Appendix A: Magnet Homgeneity Map

Appendix B: Slice Thickness / Profiles / RF Crosstalk

Philips Intera 1.5TYearly Performance Evaluation

Site Name: Philips 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 Display8. Hard 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.

3/17/08

1.5T

Evaluation of Site's Technologist QC Program

Equipment Evaluation Tests

Philips Intera

MRI Equipment Evaluation Summary & Signature Page

6266-01

2/18/08

Philips Site Philips Intera 1.5T 2

1.

2.

3.

4.

5.

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

Specific Comments and Recommendations

The following warning was often seen: "Batteries of Magnet Emergency Rundown Unit are Low - Contact Philips

Service" Edwin says this is a known issue and the batteries are actually fine. How are we sure?

The wrist coil has one totally dead channel and one weak channel.

Overall image quality looks good.

The film response is very good. The monitor's response curve is good in the middle but it dims a little too fast at

the high end. The 5% is also rather difficult to see at the low end.

In general, the shim is very good. As can be seen in Appendix A, there is a small region in the Inferior Right region

that has slightly less homogeneity (still within spec).


Site Name: Philips 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

10 mm skip 10 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

111232

Comments:

-3.0%

5.00 0.0%TSE(15) 4000 5 7.8%

SE 450 15

SE 400 15 69

10540 11.1.4.1

MRI Equipment Performance Evaluation Data Form

Chief Tech.

TitleOwner

eMail

Out/In Out/In

Contact

0.35 0.340.2

Phone

IsoCenter Out/In

0.8%0.6%

Pass

% Error

0.38

NA

PASS

63902931

Sequence TR Target

0.2 0.4 0.6 In general, the shim is very good. As can be seen in Appendix A, 0.2 0.2

SE (20/80) 2000 90SE (ACR) 500 20 90

Calc

100 90 5.39

TE Flip

5.035.04

90

20 5

5

54.85

Comment:

5

-2.8%SE (20/80) 2000 80 90 4.86 5

Philips Intera

2449

N/A

0.3 there is a small region in the Inferior Right region that has slightly less0.2 0.4 0.5 homogeneity (still within spec)

15 cm 20 cm 25 cm


4. Slice Crosstalk (RF interference)

Sequence Type TR TE

FOV (cm2)

Matrix NSA Thickness # of slices Slice Measured

SE 69° 400 15 25 256x256 2 5 11 6

SE 90° 400 15 25 256x256 2 5 11 6

Skip SE 69° SE 90°

0 4.34 4.410.2 4.45 4.530.5 4.6 4.611 4.76 4.83

1.5 4.86 4.92 4.84 4.92

2.5 4.85 4.945 4.86 4.9510 4.85 4.95

All of the slice profiles can be seen in Appendix B.

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

T1 weighted sequences, a Spin Echo with either 69° pr 90° flip angle, 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

sequences is the lower flip angle has a slightly smaller thickness as would be expected.

a deterioration of the slice profile. The data shown below clearly demonstrates this effect. Once the slice gap reaches

30% (SE) of the slice thickness, the measured slice profile begins to drop. The main difference between the two

T1 Weighted Slice Thicknesses

4.25

4.5

4.75

5

5.25

0 1 2 3 4 5 6 7 8 9 10Slice Gap (mm)

Thic

knes

s (m

m)

SE 69°SE 90°


5. Soft & Hard Copy Displays

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

Monitor Description: LCD

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 Fair

DensityFt-

Lamberts

Film from

scanner

Film from

Camera

0 0.02 -2.99 -2.98

5 0.06 -2.56 -2.57

10 0.33 -2.35 -2.22

20 1.62 -1.92 -1.72

30 3.78 -1.58 -1.42

40 7.00 -1.3 -1.14

50 10.4 -1.08 -0.92

60 14.8 -0.87 -0.71

70 20.2 -0.67 -0.55

80 26.5 -0.48 -0.38

90 33.2 -0.3 -0.26

95 39.3 -0.22 -0.19

100 39.6 -0.13 -0.13

Measured Data

4/6/06

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

Uniformity

The film response is very good. The monitor's response curve is good in the middle but it dims a little too fast at

the high end. The 5% is also rather difficult to see at the low end.

Minimum Brightness must be > 26.24 Ft. Lamberts

LCD & Film Response Curve

0.0

0.1

1.0

10.0

100.0

0 20 40 60 80 100% Density

Lo

g F

t-Lam

bert

-4

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

Ideal CurveLCDFilmFilm


Site Name

ACR Magnet #

Coil DescriptionActive Model Rev. Mfg. Date SN Channels

Philips Site01 Nickname Achieva

Coil and Other Hardware Inventory List

Manufacturer

Body - Integrated QD Philips Jan, 2004 1

Body Sense Coil Philips 4522 131 5575 Apr, 2003 3000097431 4

Breast Coil Philips 4522 131 17226 Mar, 2004 300033255 1

Head and Neck Philips 4522 131 5271/86 Jun, 2002 4892890/000623 3

Head Quadrature Philips 4522 131 39008 Mar, 2004 300035099 1

Head Sense Invivo 4522 132 14003 Mar, 2003 000108 6

Knee/Foot Quadrature Med. Advances 4522 132 14021 Jan, 2004 38378 1

Shoulder Array - Large MRI Devices 102271 Oct, 2004 U17964 4

Shoulder Array - Small MRI Devices 102270 Oct, 2004 U17999 4

Spine - Synergy 131 4522 131 4927 Mar, 1998 2606370/S 5

Surface - C-1 Philips 9896 030 02032 Feb, 2004 001756 1

Surface - C-3 Philips 9896 030 05011 Feb, 2004 001612 1

Surface - C-4 Philips 9896 030 05021 Nov, 2003 000383 1

Surface - E-1 Philips 4522 131 66952 May, 2001 457040/00293 1

Syn. Multi Connect IGC Med. Advances 1Px1 Oct, 2003 36962/09

Syn. Multi-Connect Philips 1Px1 Mar, 2002 32513/01

Synergy Flex-M Philips 4522 131 66562 Mar, 2004 300035170 2

Synergy Multi-Connect IGC Med. Advances 1Px1 Jan, 2004 38874/09

Wrist Coil - High Res. MRI Devices 105003 Aug, 2005 U24216 4

7

Test Date: 3/2/2008RF Coil Performance Evaluation

Coil: Body - Integrated QDMfg.: Philips

Mfg. Date: 1/1/2004

Model:

Revision:

SN:

Phantom: 32 cm GE sphere (used on pillows without table.)

SequenceSE

TR300

TE20

PlaneT

FOV53

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Body-QD

Analysis of Test Image

Coil ID: 1562

Test Images

# of Channels 1

Mean148148

Max194193

Min118118

Background

0.18.0

NoiseSD4.904.58

Measured Data Calculated ResultsMeanSNR

21.421.2

MaxSNR

28.027.6

Normal-ized

9.29.1

Uni-formity

75.6%75.9%

NoiseType

NEMAAir

LabelN

A

Philips Site Intera 8


Coil: Body Sense CoilMfg.: Philips

Mfg. Date: 4/1/2003

Model: 4522 131 5575

Revision:

SN: 3000097431

Phantom: Philips Body disk

SequenceSE

TR300

TE20

PlaneT

FOV53

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Body Synergy

The first composite image used CLEAR hence a greater signal uniformity.

Analysis of Composite Image

Measured Data Calculated ResultsAnalysis of Uncombined Images

Coil ID: 1531

Channel 1 Channel 2

Composites

Mean447455510440

Max1,0271,0451,0931,120

# of Channels 4

Mean1,191738737

Max1,4051,1471,147

Min770383379

Background

0.40.24.1

NoiseSD

5.933.792.80


142.0137.7172.5

MaxSNR

167.6214.0268.4

Normal-ized

61.159.274.2

Uni-formity

70.8%50.1%49.7%

NoiseType

NEMANEMA

Air

Ch1234

4.294.923.763.66

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

68.360.688.978.8

77%68%

100%89%

MaxSNR

% ofMax

156.9139.2190.5200.5

78%69%95%

100%

Channel 3

LabelNclr

NA

Channels

Channel 4



Coil: Breast CoilMfg.: Philips

Mfg. Date: 3/1/2004

Model: 4522 131 17226

Revision:

SN: 300033255

Phantom: 2 1 liter bottles with pad between them

SequenceSE

TR300

TE20

PlaneC

FOV30

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Breast (linear)


Coil ID: 1538

Test Images

# of Channels 1

Mean1,2281,236

Max1,3241,331

Min1,0931,099

Background

-8.08.6

NoiseSD

6.234.75


139.4170.5

MaxSNR

150.3183.6

Normal-ized

187.1228.8

Uni-formity

90.4%90.5%

NoiseType

NEMAAir

LabelN

A



Coil: Head and NeckMfg.: Philips

Mfg. Date: 6/1/2002

Model: 4522 131 5271/86

Revision:

SN: 4892890/000623

Phantom: ACR Phantom in Head, 3 liter bottle in neck

SequenceSE

TR300

TE20

PlaneT

FOV40

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Head/Neck HAP



Coil ID: 1529

Channel 1 Channel 2

Composites

Mean

1,067449495

Max

1,1301,0741,174

# of Channels 3

Mean999999

1,0181,018

Max1,1621,1641,1641,167

Min777774823823

Background

0.26.6-0.26.8

NoiseSD

4.834.805.004.67


146.3136.4144.0142.8

MaxSNR

170.1158.9164.6163.8

Normal-ized

110.4103.0108.7107.8

Uni-formity

80.1%79.9%82.8%82.7%

NoiseType

NEMAAir

NEMAAir

Ch

HAP

4.772.871.45

NoiseSD

NoiseType

AirAirAir

MeanSNR

% ofMean

146.6102.5223.7

0%66%46%

100%

MaxSNR

% ofMax

155.2245.2530.6

0%29%46%

100%

Channel 3

LabelNheadAheadNneckAneck

Channels

Channel 4



Coil: Head SenseMfg.: Invivo

Mfg. Date: 3/1/2003

Model: 4522 132 14003

Revision:

SN: 000108

Phantom: ACR Phantom

SequenceSE

TR300

TE20

PlaneT

FOV40

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: SENSE-Head Port #1

This is normally an 8 channel coil, not a 6. channels 2 and 5 are actually 2 coils combined each.The results from Ports #1 & 2 are virtually identical.The first composite image used CLEAR hence a greater signal uniformity.



Coil ID: 1528

Channel 1 Channel 2

Composites

Mean366403356405404346

Max1,0871,1081,0531,1771,1281,037

# of Channels 6

Mean1,437859859

Max1,5171,1391,140

Min1,304597597

Background

-0.1-0.13.5

NoiseSD

4.392.422.44


231.5251.0230.7

MaxSNR

244.4332.9306.2

Normal-ized

174.8189.5174.2

Uni-formity

92.4%68.8%68.7%

NoiseType

NEMANEMA

Air

Ch123456

3.022.183.123.282.263.08

NoiseSD

NoiseType

AirAirAirAirAirAir

MeanSNR

% ofMean

79.4121.174.880.9

117.173.6

66%100%62%67%97%61%

MaxSNR

% ofMax

235.9333.1221.2235.2327.1220.6

71%100%66%71%98%66%

Channel 3

Channel 4 Channel 5 Channel 6

LabelN CL

NA



Coil: Head SenseMfg.: Invivo

Mfg. Date: 3/1/2003

Model: 4522 132 14003

Revision:

SN: 000108

Phantom: ACR Phantom

SequenceSE

TR300

TE20

PlaneT

FOV40

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: SENSE-Head Port #2

This is normally an 8 channel coil, not a 6. channels 2 and 5 are actually 2 coils combined each.The results from Ports #1 & 2 are virtually identical.



Coil ID: 1528

Channel 1 Channel 2

Composites

Mean369401359404402347

Max1,0951,1051,0641,1751,1221,040

# of Channels 6

Mean1,434856856

Max1,5111,1261,126

Min1,300596595

Background

-0.5-0.33.4

NoiseSD

4.342.402.42


233.7252.2231.8

MaxSNR

246.2331.8304.9

Normal-ized

176.4190.4175.0

Uni-formity

92.5%69.2%69.1%

NoiseType

NEMANEMA

Air

Ch123456

3.032.243.103.172.193.07

NoiseSD

NoiseType

AirAirAirAirAirAir

MeanSNR

% ofMean

79.8117.375.983.5

120.374.1

66%98%63%69%

100%62%

MaxSNR

% ofMax

236.8323.3224.9242.9335.7222.0

71%96%67%72%

100%66%

Channel 3

Channel 4 Channel 5 Channel 6

LabelN CL

NA



Coil: Knee/Foot QuadratureMfg.: Med. Advances

Mfg. Date: 1/1/2004

Model: 4522 132 14021

Revision:

SN: 38378

Phantom: 3 liter bottle in Knee, wrist phantom in foot

SequenceSE

TR300

TE20

PlaneT

FOV40

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Knee/Foot


Coil ID: 1526

Test Images

# of Channels 1

Mean1,094994

1,4021,403

Max1,4701,0201,4701,471

Min959957

1,3691,370

Background

-0.78.0-0.78.0

NoiseSD

5.084.444.684.44


152.3146.7211.9207.1

MaxSNR

204.6150.5222.1217.1

Normal-ized

115.0110.7159.9156.3

Uni-formity

79.0%96.8%96.4%96.4%

NoiseType

NEMAAir

NEMAAir

LabelN

A

N

A



Coil: Knee/Foot QuadratureMfg.: Med. Advances

Mfg. Date: 1/1/2004

Model: 4522 132 14021

Revision:

SN: 38378

Phantom: 3 liter bottle in Knee, wrist phantom in foot

SequenceSE

TR300

TE20

PlaneS

FOV40

Nx256

Ny256

NSA2

BW28.096

Thickness3

Gap-

Coil Mode: Knee/Foot NPW

No phase wrap is used to eliminate wrap around of ghost into phantom.


Coil ID: 1526

Test Images

# of Channels 1

Mean687687

1,2241,224

Max925925

1,3381,340

Min212213

1,2061,207

Background

-0.24.6-0.24.6

NoiseSD

3.042.662.932.68


159.8169.2295.4299.3

MaxSNR

215.2227.9323.0327.7

Normal-ized

85.390.3

157.7159.8

Uni-formity

37.3%37.4%94.8%94.8%

NoiseType

NEMAAir

NEMAAir

LabelN

A

N

A



Coil: Shoulder Array - LargeMfg.: MRI Devices

Mfg. Date: 10/1/2004

Model: 102271

Revision:

SN: U17964

Phantom: Breast coil phantom

SequenceSE

TR300

TE20

PlaneT

FOV36

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: SMC-MRI-D 2345 (Shoulder)



Coil ID: 1539

Channel 1 Channel 2

Mean542804638503

Max1,0351,002947925

# of Channels 4

Mean799799

Max1,1071,106

Min389389

Background

0.12.8

NoiseSD

2.101.93


269.1271.3

MaxSNR

372.8375.5

Normal-ized

250.8252.8

Uni-formity

52.0%52.0%

NoiseType

NEMAAir

Ch1234

2.304.792.291.96

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

154.4110.0182.6168.2

85%60%

100%92%

MaxSNR

% ofMax

294.9137.1271.0309.3

95%44%88%

100%

Channel 3 Channel 4

LabelNA

Composites



Coil: Shoulder Array - LargeMfg.: MRI Devices

Mfg. Date: 10/1/2004

Model: 102271

Revision:

SN: U17964


SequenceSE

TR300

TE20

PlaneS

FOV36

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-




Coil ID: 1539

Channel 1 Channel 2

Mean388518823391

Max1,0941,2111,2931,174

# of Channels 4

Mean534534

Max1,1011,101

Min188187

Background

0.32.3

NoiseSD

1.891.67


199.8209.5

MaxSNR

412.0432.0

Normal-ized

186.2195.3

Uni-formity

29.2%29.0%

NoiseType

NEMAAir

Ch1234

2.273.514.861.98

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

112.096.7

111.0129.4

87%75%86%

100%

MaxSNR

% ofMax

315.8226.1174.3388.6

81%58%45%

100%

Channel 3 Channel 4

LabelNA

Composites



Coil: Shoulder Array - SmallMfg.: MRI Devices

Mfg. Date: 10/1/2004

Model: 102270

Revision:

SN: U17999


SequenceSE

TR300

TE20

PlaneT

FOV36

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-




Coil ID: 1561

Channel 1 Channel 2

Mean560715595929

Max1,1001,019870

1,299

# of Channels 4

Mean669669

Max971970

Min292291

Background

0.52.0

NoiseSD

1.571.47


301.4298.2

MaxSNR

437.4432.4

Normal-ized

280.9277.9

Uni-formity

46.2%46.2%

NoiseType

NEMAAir

Ch1234

1.974.811.703.88

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

186.397.4

229.4156.9

81%42%

100%68%

MaxSNR

% ofMax

365.9138.8335.4219.4

100%38%92%60%

Channel 3 Channel 4

LabelNA

Composites



Coil: Shoulder Array - SmallMfg.: MRI Devices

Mfg. Date: 10/1/2004

Model: 102270

Revision:

SN: U17999


SequenceSE

TR300

TE20

PlaneS

FOV36

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-


Channel #2 is a little lower than normal for this coil... but.. it could be related to phantom position. I don’t think it is significant enough of a difference to merit action at this time.



Coil ID: 1561

Channel 1 Channel 2

Mean347451

1,021251

Max930

1,0471,603849

# of Channels 4

Mean441441

Max851850

Min198198

Background

0.31.6

NoiseSD

1.321.20


236.3240.8

MaxSNR

455.9464.2

Normal-ized

220.2224.4

Uni-formity

37.8%37.8%

NoiseType

NEMAAir

Ch1234

1.732.834.761.39

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

131.4104.4140.6118.3

94%74%

100%84%

MaxSNR

% ofMax

352.3242.4220.7400.3

88%61%55%

100%

Channel 3 Channel 4

LabelNA

Composites



Coil: Spine - SynergyMfg.: 131

Mfg. Date: 3/1/1998

Model: 4522 131 4927

Revision:

SN: 2606370/S

Phantom: Philips Body Disk

SequenceSE

TR300

TE20

PlaneS

FOV53

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Spine Coil 1&2



Coil ID: 1525

Mean257288

Max824929

# of Channels 5

Mean423424

Max825824

Min133133

Background

-0.71.7

NoiseSD

2.001.35


149.6205.8

MaxSNR

291.7400.0

Normal-ized

64.388.5

Uni-formity

27.8%27.8%

NoiseType

NEMAAir

Ch12

1.171.41

NoiseSD

NoiseType

AirAir

MeanSNR

% ofMean

143.9133.9

100%93%

MaxSNR

% ofMax

461.5431.8

100%94%

LabelNA

Composites Channel 1 Channel 2




Mfg. Date: 3/1/1998

Model: 4522 131 4927

Revision:

SN: 2606370/S


SequenceSE

TR300

TE20

PlaneS

FOV53

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-




Coil ID: 1525

Mean312340

Max1,0071,131

# of Channels 5

Mean555556

Max1,0621,070

Min146145

Background

-1.42.3

NoiseSD

3.341.74


117.5209.4

MaxSNR

224.9403.0

Normal-ized

50.590.0

Uni-formity

24.2%23.9%

NoiseType

NEMAAir

Ch23

1.491.59

NoiseSD

NoiseType

AirAir

MeanSNR

% ofMean

137.2140.1

98%100%

MaxSNR

% ofMax

442.9466.1

95%100%

LabelNA





Mfg. Date: 3/1/1998

Model: 4522 131 4927

Revision:

SN: 2606370/S


SequenceSE

TR300

TE20

PlaneS

FOV53

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-




Coil ID: 1525

Mean184351

Max561

1,078

# of Channels 5

Mean319318

Max563561

Min126125

Background

0.61.2

NoiseSD

1.010.99


223.4210.5

MaxSNR

394.2371.3

Normal-ized

96.090.5

Uni-formity

36.6%36.4%

NoiseType

NEMAAir

Ch45

0.961.50

NoiseSD

NoiseType

AirAir

MeanSNR

% ofMean

125.6153.3

82%100%

MaxSNR

% ofMax

382.9470.9

81%100%

LabelNA




Coil: Surface - C-1Mfg.: Philips

Mfg. Date: 2/1/2004

Model: 9896 030 02032

Revision:

SN: 001756

Phantom: PIQT

SequenceSE

TR300

TE20

PlaneC

FOV45

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: C1 Ports 1 & 2


Coil ID: 1533

Test Images

# of Channels 1

Mean1,3181,3081,3201,307

Max1,6081,5941,6051,595

Min914905908898

Background

10.16.812.46.8

NoiseSD

5.493.84

10.233.86


169.8223.291.3

221.9

MaxSNR

207.1272.0111.0270.8

Normal-ized

101.3133.154.4

132.3

Uni-formity

72.5%72.4%72.3%72.0%

NoiseType

NEMAAir

NEMAAir

LabelN P1

A P1

N P2

A P2




Mfg. Date: 2/1/2004

Model: 9896 030 05011

Revision:

SN: 001612

Phantom: PIQT

SequenceSE

TR300

TE20

PlaneC

FOV45

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: C3


Coil ID: 1530

Test Images

# of Channels 1

Mean1,004995

Max1,6041,587

Min465461

Background

8.46.1

NoiseSD

10.423.48


68.1187.4

MaxSNR

108.9298.8

Normal-ized

40.6111.8

Uni-formity

44.9%45.0%

NoiseType

NEMAAir

LabelN

A




Mfg. Date: 11/1/2003

Model: 9896 030 05021

Revision:

SN: 000383

Phantom: PIQT

SequenceSE

TR300

TE20

PlaneT

FOV45

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: C4


Coil ID: 1532

Test Images

# of Channels 1

Mean845838

Max1,6061,597

Min343339

Background

6.76.0

NoiseSD

6.263.39


95.5162.0

MaxSNR

181.4308.7

Normal-ized

56.996.6

Uni-formity

35.2%35.0%

NoiseType

NEMAAir

LabelN

A



Coil: Surface - E-1Mfg.: Philips

Mfg. Date: 5/1/2001

Model: 4522 131 66952

Revision:

SN: 457040/00293

Phantom: 3 liter bottle

SequenceSE

TR300

TE20

PlaneT

FOV36

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: E1


Coil ID: 1534

Test Images

# of Channels 1

Mean874868

Max1,0561,051

Min475473

Background

5.67.9

NoiseSD

5.734.36


107.9130.5

MaxSNR

130.3158.0

Normal-ized

100.5121.6

Uni-formity

62.1%62.1%

NoiseType

NEMAAir

LabelN

A



Coil: Synergy Flex-MMfg.: Philips

Mfg. Date: 3/1/2004

Model: 4522 131 66562

Revision:

SN: 300035170


SequenceSE

TR300

TE20

PlaneT

FOV40

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Synergy Flex M



Coil ID: 1535

Mean402464

Max892926

# of Channels 2

Mean832830

Max995989

Min618614

Background

1.94.3

NoiseSD

4.743.53


124.1154.1

MaxSNR

148.5183.6

Normal-ized

93.7116.3

Uni-formity

76.6%76.6%

NoiseType

NEMAAir

Ch12

2.653.14

NoiseSD

NoiseType

AirAir

MeanSNR

% ofMean

99.496.8

100%97%

MaxSNR

% ofMax

220.6193.3

100%88%

LabelNA




Coil: Synergy Flex-MMfg.: Philips

Mfg. Date: 3/1/2004

Model: 4522 131 66562

Revision:

SN: 300035170


SequenceSE

TR300

TE20

PlaneS

FOV40

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Synergy Flex M



Coil ID: 1535

Mean431315

Max1,089841

# of Channels 2

Mean625624

Max849846

Min313314

Background

0.93.8

NoiseSD

3.973.17


111.3129.0

MaxSNR

151.2174.9

Normal-ized

84.097.4

Uni-formity

53.9%54.1%

NoiseType

NEMAAir

Ch12

3.522.72

NoiseSD

NoiseType

AirAir

MeanSNR

% ofMean

80.275.9

100%95%

MaxSNR

% ofMax

202.7202.6

100%100%

LabelNA




Coil: Wrist Coil - High Res.Mfg.: MRI Devices

Mfg. Date: 8/1/2005

Model: 105003

Revision:

SN: U24216

Phantom: Wrist Phantom

SequenceSE

TR300

TE20

PlaneT

FOV14

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Wrist

Channel 2 is dead, channel 4 is very sick.



Coil ID: 1541

Channel 1 Channel 2

Mean7124

348147

Max7876

400178

# of Channels 4

Mean1,2941,294

Max1,3981,397

Min1,1681,172

Background

-0.018.4

NoiseSD

8.9811.27


101.975.2

MaxSNR

110.181.2

Normal-ized

628.0463.7

Uni-formity

91.0%91.2%

NoiseType

NEMAAir

Ch1234

4.913.834.814.68

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

95.00.747.420.6

100%1%50%22%

MaxSNR

% ofMax

105.01.054.524.9

100%1%52%24%

Channel 3 Channel 4

LabelNA

Composites


miriam

Highlight

miriam

Highlight

miriam

Highlight

miriam

Highlight



Mfg. Date: 8/1/2005

Model: 105003

Revision:

SN: U24216


SequenceSE

TR300

TE20

PlaneC

FOV20

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Wrist




Coil ID: 1541

Channel 1 Channel 2

Mean7905

583153

Max1,497

101,518303

# of Channels 4

Mean923923

Max1,6011,602

Min126127

Background

0.111.2

NoiseSD

3.927.31


166.582.7

MaxSNR

288.8143.6

Normal-ized

502.8249.8

Uni-formity

14.6%14.7%

NoiseType

NEMAAir

Ch1234

4.753.354.224.56

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

109.01.090.522.0

100%1%83%20%

MaxSNR

% ofMax

206.52.0

235.743.5

88%1%

100%18%

Channel 3 Channel 4

LabelNA

Composites


miriam

Highlight

miriam

Highlight

miriam

Highlight

miriam

Highlight



Mfg. Date: 8/1/2005

Model: 105003

Revision:

SN: U24216


SequenceSE

TR300

TE20

PlaneS

FOV20

Nx256

Ny256

NSA1

BW28.096

Thickness3

Gap-

Coil Mode: Wrist




Coil ID: 1541

Channel 1 Channel 2

Mean6545

449165

Max1,313

111,244354

# of Channels 4

Mean782782

Max1,3431,343

Min129129

Background

-0.38.7

NoiseSD

3.045.76


181.989.0

MaxSNR

312.4152.8

Normal-ized

549.3268.6

Uni-formity

17.5%17.5%

NoiseType

NEMAAir

Ch1234

3.773.332.884.55

NoiseSD

NoiseType

AirAirAirAir

MeanSNR

% ofMean

113.71.0

102.223.8

100%1%90%21%

MaxSNR

% ofMax

228.22.2

283.151.0

81%1%

100%18%

Channel 3 Channel 4

LabelNA

Composites


miriam

Highlight

miriam

Highlight

miriam

Highlight

miriam

Highlight

0

0

0

20

0

0

20

20

-20

-20

0

0

000

20

Superior

Inferior

Rig

ht

Left

Cor

onal

CoronalDIAMETER MIN MAX RANGE PPM MEAN STDEV

10 0 7 6 0.1 3.1 1.515 0 10 10 0.2 3.7 2.320 0 14 15 0.2 4.5 3.425 -1 20 21 0.3 5.6 4.528 -3 24 27 0.4 6.4 5.230 -4 29 33 0.5 6.9 5.8

Superior

Inferior

Ant

eriro

r

Pos

terio

r

Sag

ittal

SagittalDIAMETER MIN MAX RANGE PPM MEAN STDEV

10 1 9 8 0.1 5.9 1.615 -2 11 14 0.2 5.9 2.720 -7 15 23 0.4 5.8 4.125 -13 19 33 0.5 5.8 5.728 -17 24 42 0.7 5.9 6.830 -20 28 49 0.8 5.9 7.5

Anterior

Posterior

Rig

ht

LeftAxi

al

AxialDIAMETER MIN MAX RANGE PPM MEAN STDEV

10 0 9 8 0.1 4.8 1.815 -2 11 13 0.2 4.2 3.020 -7 15 22 0.4 3.2 4.525 -15 22 37 0.6 1.9 6.428 -22 27 49 0.8 0.9 7.930 -27 33 60 1.0 0.1 9.1

Appendix A: Magnet Homogeneity Field MapsPhilips Intera 1.5T - 3 central planes

Measured March 2, 2008

miriam

Text Box

32

Appendix A: Magnet Homogeneity Field MapsPhilips Intera 1.5T

Measured March 2, 2008

Philips Site - Intera - Axial Field Plot - 3/2/08

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

-9 -6 -3 0 3 6 9

cm from Isocenter (S/I)

pp

m10cm15cm20cm25cm28cm30cm

FOV Diameter

Philips Site - Intera - Coronal Field Plot - 3/2/08

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

-9 -6 -3 0 3 6 9cm from Isocenter (P/A)

pp

m

10cm15cm20cm25cm28cm30cm

FOV Diameter

Philips Site - Intera - Coronal Field Plot - 3/2/08

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

-9 -6 -3 0 3 6 9

cm from Isocenter (R/L)

pp

m

10cm15cm20cm25cm28cm30cm

FOV Diameter

miriam

Text Box

33

0

0

H9

0

0

0

20

H8

0

0

0

20

H7

-200

0

0

20

H6

-200

0

0

20

H5

-200

0

0

0

20

H4

-200

0

00

20

H3

-200

0

0

0

0

20

H2

-20

-20

0

0

000

20

H1

-20

-20

0

0

0

0

0

0

20

Isocenter

-20

-20

0

00

0

0

0

20

F1

-20

-20

0

00

0

0

0

20

F2

-20

-20

0

00

0

0

0

F3

-20

-20

0

00

0

0

0

F4

-200

00

0

0

0

F5

0

0

0

0

0

F6

0

0

0

0

F7

0

0

00

F8

0

0

0

F9

Axial Field Plots

miriam

Text Box

34

00

20

A9

0

20

A8

0

0

20

A7

0

0

20

20

A6

0

20

20

A5

0

0

20

20

A4

0

20

20

20

A3

0

0

2020

20

A2

0

0

20

20

A1

0

0

20

Isocenter

0

0

0

0

P1

0

0

20

P2

0

0

0

20

P3

0

0

20 20

P4

00

20

P5

00

20

P6

0

0

20

P7

00

20

P8

00

20

P9

Coronal Field Plots

miriam

Text Box

35

-20

0

0

0

20

L9

-20

0

0

0

2040

L8

-20

0

0

0

2040

L7

-20

0

0

0

20

20

40

L6

-20

0

0

0

2040

L5

-20

0

0

2040

L4

-20

0

0

20

L3

-20

0

0

20

L2

0

0

0

20

L1

0

0

0

20

Isocenter

0

0

0

20

R1

0

0

0

20

20

R2

0

0

0

20

20

R3

0

0

0

20

20

R4

0 0

20

20

R5

0

0

20

20

R6

0

0

20

20

R7

0

0

20

R8

0

0

20

20R9

Sagittal Field Plots

miriam

Text Box

36

Appendix B: RF Slice Profiles and Crosstalk

0 50 100 1500

20

40

60

80

100

Upper=48.79 Lower=48.16

Slice Thickness=4.85

RF Xtalk SE 69 sk 10

0 50 100 1500

20

40

60

80

100



RF Xtalk SE 69 sk 5.0

0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




Slice thickness as a function of slice gap

0 2 4 6 8 10Slice Gap

4.004.25

4.50

4.75

5.00

5.255.50

Slic

eT

hick

ness

Spin Echo : Flip = 69°TR/TE = 400/15BW = 14.4 KHznex = 2Scan time: 3:25

miriam

Text Box

37

Appendix B: RF Slice Profiles and Crosstalk

0 50 100 1500

20

40

60

80

100



RF Xtalk SE 90 sk 10

0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




0 50 100 1500

20

40

60

80

100




Slice thickness as a function of slice gap

0 2 4 6 8 10Slice Gap

4.004.25

4.50

4.75

5.00

5.255.50

Slic

eTh

ickn

ess

Spin Echo : Flip = 69°TR/TE = 400/15BW = 14.4 KHznex = 2Scan time: 3:25

miriam

Text Box

38

0.9 0.9 0.9 0.9 0.90.9 0.9 0.9 0.9 0.951.0 51.4 50.0 51.0 55.049.7 49.5 47.3 49.1 52.95.03 5.04 4.86 5.00 5.391.5 1.5 1.5 1.5 1.6190.1 190.1 190.1 190.1 189.7189.7 189.7 189.7 189.7 189.6

190.5 190.6 190.6 190.5 189.9189.8 189.8 189.8 189.8 189.7190.2 190.1 190.1 190.2 190.1

23456789

190.3 190.3 190.3 190.3 190.3

1481 1488 888 1494 8541530 1529 913 1547 8931313 1334 794 1350 76992.4% 93.2% 93.0% 93.2% 92.5%

0.1% 0.2% 0.1% 0.2% 0.1%262 256 238 258 315

9 9 8 10 6

10 10 10 10 1010 10 10 10 1038 39 38 40 35

0.1 0.2 0.1 0.1 0.4-1.4 -1.4 -1.4 -1.4 -1.2

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

9 10 10 10 9

2930

Slice Location #11Wedge (mm)Slice Position Error

±±

±±

4.7 5.65 5.1 7.49 3.9 4.69 4.7 5.81 3.1 2.825.1 5.65 3.9 4.14 3.2 2.77 5.1 5.79 2.8 2.6

8.1 8.09 7.7 7.73 4 4.6 8 7.12 3.9 4.66

5.9 5.62 7.6 5.76 5.4 3.84 6.8 6.86 4.5 5.12

Test Date: 3/2/2008

146.6

ACR T1 ACR PD ACR T2 Site T1 Site T2

Philips Site AchievaHead SenseCoil Used:

= + = -= +

= + = -= +

±±

±±

±±

±±

±±

±±

±±

±±

Calculated value 5.0±0.7

miriam

Text Box

39

TestID: 256Magnet ID: Coil ID: 1528

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)

14.4

ScanTime

(min:sec)

2:09

PhaseMatrix

StudyDescription

ACR T1

256

256

256

Dual Echo SE

Dual Echo SE

SE

TSE(15)

2000

2000

450

4000

20

80

15

100

25

25

24

24

1

1

1

1

11

11

11

11

5

5

5

5

5

5

5

5 384

256

256

256

300

1

1

2

3

11.6

11.6

14.4

28

8:32

8:32

3:51

4:00

ACR PD

ACR T2

Site T1

Site T2

Sequence parameters Test Date: 3/2/2008

Test ID 256

Philips Site Achieva

Head Sense

195

Coil Used:

miriam

Text Box

40

Appendix C: ACR Phantom Analysis ACR T1

0 50 100 150 2000

100

200

300

Upper=50.98

Lower=49.70Slice Thickness=5.03

0 10 20 30 40 500

1000

2000

3000

4000

5000

Diff.= 1.49

0 45 90 135 180184

186

188

190

192

194

196

189.7

189.7

190.1

190.1

189.5189.7

03/02/08 TR: 499 TE: 20.0

0 45 90 135 180184

186

188

190

192

194

196

189.8

190.2

190.5

190.3

189.6189.8

03/02/08 TR: 499 TE: 20.0

Max:1530 Min:1313 PIU: 92.4%

Mean:1481

Mean 8.1S.D. 8.09

Mean 5.9S.D. 5.62

Mean 4.7S.D. 5.65

Mean 5.1S.D. 5.65

0 10 20 30 40 500

1000

2000

3000

4000

5000

Diff.= 0.12

0 50 100 150 200 2500

500

1000

1500

2000

146.6

Sagital Length High Contrast Resolution Slice Thickness Slice Position - Inferior

Axial Diameters - #1 Axial Diameters - #5 Uniformity & Ghosting - #7 Slice Position - Superior

Low Contrast - #8 Low Contrast - #9 Low Contrast - #10 Low Contrast - #11

miriam

Text Box

41

Appendix C: ACR Phantom Analysis ACR PD

0 50 100 150 2000

100

200

300

Upper=51.37


0 10 20 30 40 500

1000

2000

3000

4000

5000

Diff.= 1.56

0 45 90 135 180184

186

188

190

192

194

196

189.7

189.7

190.1

190.1

189.5189.7

03/02/08 TR:2000 TE: 20.0

0 45 90 135 180184

186

188

190

192

194

196

189.8

190.1

190.6

190.3

189.6189.8

03/02/08 TR:2000 TE: 20.0

Max:1529 Min:1334 PIU: 93.2%

Mean:1488

Mean 7.7S.D. 7.73

Mean 7.6S.D. 5.76

Mean 5.1S.D. 7.49

Mean 3.9S.D. 4.14

0 10 20 30 40 500

1000

2000

3000

4000

5000

Diff.= 0.16

High Contrast Resolution Slice Thickness Slice Position - Inferior



miriam

Text Box

42

Appendix C: ACR Phantom Analysis ACR T2

0 50 100 150 2000

50

100

150

200

Upper=50.03


0 10 20 30 40 500

500

1000

1500

2000

2500

3000

Diff.= 1.52

0 45 90 135 180184

186

188

190

192

194

196

189.7

190.0

190.1

190.1

189.5189.7

03/02/08 TR:2000 TE: 80.0

0 45 90 135 180184

186

188

190

192

194

196

189.8

190.1

190.6

190.3

189.6189.8

03/02/08 TR:2000 TE: 80.0

Max:913 Min:794 PIU: 93.0%

Mean:888

Mean 4.0S.D. 4.60

Mean 5.4S.D. 3.84

Mean 3.9S.D. 4.69

Mean 3.2S.D. 2.77

0 10 20 30 40 500

500

1000

1500

2000

2500

3000

Diff.= 0.14




miriam

Text Box

43

Appendix C: ACR Phantom Analysis Site T1

0 50 100 150 2000

50

100

150

200

250

300

Upper=51.04


0 10 20 30 40 500

1000

2000

3000

4000

5000

Diff.= 1.48

0 45 90 135 180184

186

188

190

192

194

196

189.7

189.8

190.1

190.1

189.7189.9

03/02/08 TR: 450 TE: 15.0

0 45 90 135 180184

186

188

190

192

194

196

189.8

190.2

190.5

190.3

189.8190.0

03/02/08 TR: 450 TE: 15.0

Max:1547 Min:1350 PIU: 93.2%

Mean:1494

Mean 8.0S.D. 7.12

Mean 6.8S.D. 6.86

Mean 4.7S.D. 5.81

Mean 5.1S.D. 5.79

0 10 20 30 40 500

1000

2000

3000

4000

5000

Diff.= 0.12




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Appendix C: ACR Phantom Analysis Site T2

0 50 100 150 2000

50

100

150

200

Upper=54.97


0 10 20 30 40 500

500

1000

1500

2000

2500

Diff.= 1.64

0 45 90 135 180184

186

188

190

192

194

196

189.6

189.8

189.7

190.1

189.7189.9

03/02/08 TR:4000 TE: 100.0

0 45 90 135 180184

186

188

190

192

194

196

189.7

190.1

189.9

190.3

189.9190.0

03/02/08 TR:4000 TE: 100.0

Max:893 Min:769 PIU: 92.5%

Mean:854

Mean 3.9S.D. 4.66

Mean 4.5S.D. 5.12

Mean 3.1S.D. 2.82

Mean 2.8S.D. 2.60

0 10 20 30 40 500

500

1000

1500

2000

2500

3000

Diff.= 0.41




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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 of28.1 KHz (a 1 pixel fat/water chemical shift). The FOV was varied depending on the size of the coil and thephantom used. All of the parameters used for each test can be found on each page immediately below thecoil 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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philips site 2-mar-08 table of contents philips intera 1.5t yearly

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