GE Site Yearly Performance Evaluation GE Signa Excite HD - 3T 1-Sep-08. Table of Contents

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1 GE Site Yearly Performance Evaluation GE Signa Excite HD T Sep8 Table of Contents Summary and Signature Page 2 Specific Comments Site Information 4 Equipment Information 4 Table Position ccuracy 4 Magnetic Field Homogeneity 4 Slice ccuracy 4 Slice Crosstalk Soft Copy Displays 6 RF Coil Performance Evaluation Coil Inventory List 7 Body Integrated 8 Breast 8 Ch. 9 Cardiac 8 Ch. Head 8 Ch 7 Head Split Top 8 Knee 8 Ch. 2 Knee T/R 2 eurovascular rray 8 Ch. 2 Shoulder Ch. 26 Spine 8 Ch. 28 Torso Wrist ppendix : Magnet Homgeneity Map ppendix B: Slice / Profiles / RF Crosstalk ppendix C: CR Phantom nalysis ppendix D: Explanation of RF Coil Test Format 2 4 4

2 MRI Equipment Evaluation Summary & Signature Page Site ame: GE Site MRP # ddress: Survey Date: City, State, Zip Report Date: MRI Mfg: GE Model: Excite HD Field: 9 9//8 9//8 T MRI Scientist: Moriel essiver, Ph.D. Signature: Equipment Evaluation Tests Pass Fail * /. Magnetic field homogeneity: 2. Slice position accuracy:. Table positioning reproducibility: 4. Slice thickness accuracy:. RF coils' performance: a. Volume QD Coils b. Phase rray Coils c. Surface Coils 6. Interslice RF interference (Crosstalk): 7. Soft Copy Display Evaluation of Site's Technologist QC Program Pass Fail * /. Set up and positioning accuracy: (daily) 2. Center frequency: (daily). Transmitter attenuation or gain: (daily) 4. Geometric accuracy measurments: (daily). Spatial resolution measurements: (daily) 6. Low contrast detectability: (daily) 7. Head Coil (daily) 8. Body Coil (weekly) 9. Fast Spin Echo (F/T) ghosting levels: (daily). Film quality control: (weekly). Visual checklist: (weekly) *See comments page for description of any failures. GE Site GE Excite HD T 2

3 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 good channels and one bad There is no difference between ports & 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 O: Please be sure to read appendix D for an explanation of the format of this document. GE Site GE Excite HD T

4 Site ame: GE Site MRI Equipment Performance Evaluation Data Form Contact Title Phone Fax Equipment Information MRI Manufacturer: GE Model: Twinspeed S: 24 Software: 4._M4_629a Camera Manufacturer: Model: S: Software: PCS Manufacturer: Model: S: Software: CR Phantom umber used: J6. Table Positioning Reproducibility: Table motion out/in: IsoCenter Measured Phantom Center.4 Comment: Out/In.9 Out/In Out/In.4.4 Pass 2. Magnetic Field Homogeneity See appendix for field plots. PSS xial: Coronal: Sagittal: Last Year CF: 27,728,84 This Year CF: 27,727,86 CF Change: cm 2 cm 2 cm GRE :, : & Flip ngle: 4, : 4 mm skip mm, :.4KHz, x28, 2nex Comments: Shim is very good Slice ccuracy : 2mm Matrix: x (Slice # from CR Phantom) ll values in mm (CR) (Site T) (2/8) (2/8) Flip S Calc Target % Error.2%.2%.2% 2.2% F(6) T MEMP GRE % 8.% 4.% Comments: GE Site GE Excite HD T 4

5 4. Slice Crosstalk (RF interference) The following data were obtained using the CR phantom slice thickness wedges to measure the slice profile of three common T weighted sequences when the slice gap varies from 2% down to % (contiguous) s 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 T MEMP sequence is a spin echo sequence with a a 6 flip angle. Both this sequence and the standare sequence shows a drop in the profile once the gap drops below %. The interference is less with the smaller flip angle and longer (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. ll of the slice profiles can be seen in ppendix B. There you can see how the profile is very square while the GREs are more triangular. Flip ngle (cm 2 ) Matrix S # of slices Full x T MEMP x GRE in Phs x 4 Skip Full T MEMP GRE In Phase T Weighted Slice es (mm) Full T MEMP GRE InPhase Slice (mm) GE Site GE Excite HD T

6 . Soft & Hard Copy Displays Luminance Meter Make/Model: Tektronix J6 Digital Photometer Monitor Description: Efilm workstation Cal Expires: 4/6/6 Which Monitor Luminance Measured: Ft. lamberts Center of Image Display Top Left Corner Top Right Corner Bottom Left Corner Bottom Right Corner MX MI Percent Delta Console % Y SMP OK? % delta =2% x (maxmin)/(max+center) (>% is action limit) imum Brightness must be > Ft. Lamberts The monitor is excellent and the agreemen between the screen and film is good. Density Ft Lamber Film Density LCD & Film Response Curve Log FtLambert.. Ideal Curve LCD Film % Density GE Site GE Excite HD T 6

7 Coil and Other Hardware Inventory List Site ame GE Site CR Magnet # ickname Signa ctive Coil Description Manufacturer Model Rev. Mfg. Date S Channels Body Integrated Breast 8 Ch GE 2444 Sep, Cardiac 8 Ch GE Oct, 2 8 Head 8 Ch GE 4742 ug, 26 U Head Split Top GE 79WH pr, 26 79WH Knee 8ch Invivo 44 Sep, 26 U297 8 Knee T/R Invivo U2229 eurovascular rray 8 Ch USI 2449 Sep, Shoulder Ch USI 244 May, 26 2 Spine 8 Ch USI 2442 Jul, Torso USI 244 Dec, Wrist HD Mayo Clinic BC HBR6 7

8 Coil: Body Integrated Mfg.: Mfg. Date: Coil ID: 97 Phantom: Body sphere Test Date: 9//28 Model: S: # of Channels 2 T 48 x y.6 S Body TX gain: 66 R: R2: 28 nalysis of Test Image ormalized,68, %,68,2, % The of the Body coil is 4 times higher than last year! G E S i t e Signa 8

9 Coil: Breast 8 Ch Mfg.: GE Mfg. Date: 9//26 Coil ID: 9 Phantom: HD Breast Phantom Test Date: 9//28 Model: 2444 S: 7 # of Channels 8 2 T 48 x y.6 S HD Breast Port TX gain: 6 R: R2: 29 nalysis of Composite Image,48,47,877,87,6, ormalized 72.% 72.4% nalysis of Uncombined Images Ch ,9,,7 999,4, 9, % 72% 7% 8% % 7% 24% 8% % 79% 8% 87% % 72% 27% 88% Channel #7 is one fourth of what it should be. Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 Channel 8 G E S i t e Signa 9

10 Coil: Breast 8 Ch Mfg.: GE Mfg. Date: 9//26 Coil ID: 9 Phantom: HD Breast Phantom Test Date: 9//28 Model: 2444 S: 7 # of Channels 8 2 C 4 x y.6 S HD Breast Port,67,672,68,672,98,94,98,94,98,4,98, nalysis of Composite Image TX gain: 6 R: 2 R2: ormalized 82.8% 87.% 82.6% 87.% nalysis of Uncombined Images Ch , ,82,6,2,,4,28 997, % 66% 9% 8% 96% 4% 2% % % 7% 68% 8% % 6% 2% 88% Channel 7 is /4th of what it should be. Composites Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 G E S i t e Signa

11 Coil: Breast 8 Ch Mfg.: GE Mfg. Date: 9//26 Coil ID: 9 Phantom: HD Breast Phantom Test Date: 9//28 Model: 2444 S: 7 # of Channels 8 2 T 48 x y.6 S HD Breast Port B TX gain: 6 R: R2: 29 nalysis of Composite Image,4,44,88,86,6, ormalized 7.7% 7.8% nalysis of Uncombined Images Ch ,4 97,44 986,64, 87, % 7% 7% 8% % 78% 8% 82% % 78% 8% 86% % 74% 2% 87% Channel 7 is /4th of what it should be. Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 Channel 8 G E S i t e Signa

12 Coil: Breast 8 Ch Mfg.: GE Mfg. Date: 9//26 Coil ID: 9 Phantom: HD Breast Phantom Test Date: 9//28 Model: 2444 S: 7 # of Channels 8 2 C 4 x y.6 S HD Breast Port B,9,66,9,66,89,88,896,87,48,47,48,4 nalysis of Composite Image TX gain: 6 R: 2 R2: ormalized 8.2% 87.% 8.% 87.4% nalysis of Uncombined Images Ch , ,,4, 987,4,9 96 6, % 67% 6% 8% 97% 4% % % % 7% 67% 82% % 6% 4% 88% Channel 7 is /4th of what it should be. Composites Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 G E S i t e Signa 2

13 Coil: Breast 8 Ch Mfg.: GE Mfg. Date: 9//26 Coil ID: 9 Phantom: HD Breast Phantom Test Date: 9//28 Model: 2444 S: 7 # of Channels 8 2 T 48 x y.6 S HD BreastLeft TX gain: 6 R: R2: 29 nalysis of Composite Image 76 76,, ormalized 7.% 6.9% nalysis of Uncombined Images Ch , , % 6% 2% 8% % 66% 26% 8% Channel is dead in both the Left and Right only modes. Channel Channel 2 Composites Channel Channel 4 G E S i t e Signa

14 Coil: Breast 8 Ch Mfg.: GE Mfg. Date: 9//26 Coil ID: 9 Phantom: HD Breast Phantom Test Date: 9//28 Model: 2444 S: 7 # of Channels 8 2 C 48 x y.6 S HD BreastRight TX gain: R: R2: nalysis of Composite Image ,4, ormalized 2.% 2.% nalysis of Uncombined Images Ch , 97 94, % 9% % % % 9% 22% % Channel is dead in both the Left and Right only modes. Channel Channel 2 Composites Channel Channel 4 G E S i t e Signa 4

15 Coil: Cardiac 8 Ch Mfg.: GE Mfg. Date: //2 Coil ID: 9 Phantom: Cardiac phantom Test Date: 9//28 Model: S: # of Channels 8 2 T 48 x y.6 S HD Cardiac Port TX gain: 69 R: R2: 29 nalysis of Composite Image ,2 2, ormalized 2.% 24.9% nalysis of Uncombined Images Ch ,76,46,8,,4,66,696, % 9% 9% 88% 84% % % 72% % 77% 69% 9% 72% 8% 82% 64% There is no significant difference between Ports & B Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 Channel 8 G E S i t e Signa

16 Coil: Cardiac 8 Ch Mfg.: GE Mfg. Date: //2 Coil ID: 9 Phantom: Cardiac phantom Test Date: 9//28 Model: S: # of Channels 8 2 T 48 x y.6 S HD Cardiac Port B TX gain: 69 R: R2: 29 nalysis of Composite Image 84 84,97, ormalized 2.% 2.2% nalysis of Uncombined Images Ch ,64,424,2,49,2,8,96, % 94% 9% 88% 8% 99% % 72% % 78% 7% 92% 7% 8% 8% 6% There is no significant difference between Ports & B Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 Channel 8 G E S i t e Signa 6

17 Coil: Head 8 Ch Mfg.: GE Mfg. Date: 8/6/26 Coil ID: 898 Phantom: Head TLT sphere Test Date: 9//28 Model: 4742 S: U2878 # of Channels 8 2 T 6 x y.6 S 8HRBrain TX gain: 6 R: R2: 29 nalysis of Composite Image,7,6,92,92,9, ormalized 77.% 77.% nalysis of Uncombined Images Ch ,26,24,72,224,9,84,9, % 99% 97% 8% 92% 94% % 96% % % 98% 86% 96% 99% 9% 92% There is a 7% drop in since last year. Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 Channel 8 G E S i t e Signa 7

18 Coil: Head Split Top Mfg.: GE Mfg. Date: 4//26 Coil ID: 9 Phantom: CR Test Date: 9//28 Model: 79WH S: 79WH # of Channels 2 T 4 x y.6 S Head TX gain: R: R2: nalysis of Test Image ormalized,6 4,486 2, %,62 4,488 2, % G E S i t e Signa 8

19 Coil: Head Split Top Mfg.: GE Mfg. Date: 4//26 Coil ID: 9 Phantom: Oil filled sphere Test Date: 9//28 Model: 79WH S: 79WH # of Channels 2 T 6 x y.6 S Head TX gain: 2 R: R2: 29 nalysis of Test Image ormalized,6,2, %,64,9, % G E S i t e Signa 9

20 Coil: Knee 8ch Mfg.: Invivo Mfg. Date: 9//26 Coil ID: 92 Phantom: Knee phantom. Test Date: 9//28 Model: 44 S: U297 # of Channels 8 2 T x y.6 S HD Knee P TX gain: 68 R: R2: 29 nalysis of Composite Image 2,42 2,4 2,762 2,762,62, ormalized 66.% 66.% nalysis of Uncombined Images Ch ,978,878,89,472,6,9,79, % 87% 74% 6% 89% 72% 72% 99% % 86% 82% 74% 78% 76% 84% 7% Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 Channel 8 G E S i t e Signa 2

21 Coil: Knee T/R Mfg.: Invivo Mfg. Date: Coil ID: 94 Phantom: 8ch Knee phantom and my wrist bottle in foot. Test Date: 9//28 Model: S: U2229 # of Channels 2 T 6 x y.6 S QUDKEE TX gain: 77 R: R2: 28 nalysis of Test Image ormalized 2,48,97, % 4,24 4,79, % 2,479,9, % 4,24 4,798, % Test Images G E S i t e Signa 2

22 Coil: Knee T/R Mfg.: Invivo Mfg. Date: Coil ID: 94 Phantom: 8ch Knee phantom and my wrist bottle in foot. Test Date: 9//28 Model: S: U2229 # of Channels 2 S 4 x y.6 S QUDKEE TX gain: 77 R: 9 R2: 29 nalysis of Test Image ormalized,89,44, % 4,92,274, %,898,446, % 4,9,27, % Test Images G E S i t e Signa 22

23 Coil: eurovascular rray 8 Ch Mfg.: USI Mfg. Date: 9//26 Coil ID: 92 Phantom: Twopiece V phantom set. Test Date: 9//28 Model: 2449 S: 82 # of Channels 8 2 T 6 x y.6 S a HDV Head TX gain: 6 R: R2: nalysis of Composite Image ormalized 8.8% 8.8% nalysis of Uncombined Images Ch % 78% 8% 68% 68% 7% % 97% % 82% 8% 72% 7% 7% % 98% Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 Channel 8 G E S i t e Signa 2

24 Coil: eurovascular rray 8 Ch Mfg.: USI Mfg. Date: 9//26 Coil ID: 92 Phantom: Twopiece V phantom set. Test Date: 9//28 Model: 2449 S: 82 # of Channels 8 2 S 48 x y.6 S 2 HDV rray,22 96,2 9,6,879,6, nalysis of Composite Image TX gain: 77 R: R2: ormalized 8.2%.% 8.2%.% nalysis of Uncombined Images Ch , ,9, 897 7, % 66% 7% 79% % 8% 79% 98% % 6% 7% 79% % 92% 7% 99% Composites Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 G E S i t e Signa 24

25 Coil: eurovascular rray 8 Ch Mfg.: USI Mfg. Date: 9//26 Coil ID: 92 Phantom: Twopiece V phantom set. Test Date: 9//28 Model: 2449 S: 82 # of Channels 8 2 C 48 x y.6 S. HDV rray ,,,2, nalysis of Composite Image TX gain: 77 R: R2: ormalized 8.4% 26.% 8.% 26.% nalysis of Uncombined Images Ch , % 87% 9% 8% 89% 9% % 8% % 74% 7% 27% 69% 82% % 6% Composites Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 G E S i t e Signa 2

26 Coil: Shoulder Ch Mfg.: USI Mfg. Date: //26 Coil ID: 9 Phantom: Shoulder sphere Test Date: 9//28 Model: 244 S: 2 # of Channels 2 T 6 x y.6 S HD SHOULDER TX gain: 64 R: R2: 29 nalysis of Composite Image ,4, ormalized 4.% 4.% nalysis of Uncombined Images Ch , % 4% % % 7% % These axial images were acquired at the center of the phantom and OT at the + mark on the coil like last year. Channel Channel 2 Composites Channel G E S i t e Signa 26

27 Coil: Shoulder Ch Mfg.: USI Mfg. Date: //26 Coil ID: 9 Phantom: Shoulder sphere Test Date: 9//28 Model: 244 S: 2 # of Channels 2 C 6 x y.6 S HD SHOULDER TX gain: 64 R: R2: 29 nalysis of Composite Image 94 94,842, ormalized.8%.8% nalysis of Uncombined Images Ch ,787, % 48% % % 88% 78% Channel Channel 2 Composites Channel G E S i t e Signa 27

28 Coil: Spine 8 Ch Mfg.: USI Mfg. Date: 7//26 Coil ID: 899 Phantom: Dual T spine phantoms Test Date: 9//28 Model: 2442 S: 29 # of Channels 8 2 S 48 x y.6 S 2 HDCTL2 TX gain: 66 R: R2: 29 nalysis of Composite Image,4,4,9, ormalized.%.% nalysis of Uncombined Images Ch ,844,796,74,762,864, % 9% 7% 82% 2% 6% % 77% 7% 82% 74% 8% Composites Channel Channel 2 Channel Extra Pics Channel 4 Channel G E S i t e Signa 28

29 Coil: Spine 8 Ch Mfg.: USI Mfg. Date: 7//26 Coil ID: 899 Phantom: Dual T spine phantoms Test Date: 9//28 Model: 2442 S: 29 # of Channels 8 2 S 48 x y.6 S HDCTL4 PE P TX gain: 67 R: R2: 29 nalysis of Composite Image,4,4,26, ormalized 27.7% 27.6% nalysis of Uncombined Images Ch ,29,969 2,, % 9% 84% % % 96% 99% 94% Channel Channel 2 Composites Channel Channel 4 G E S i t e Signa 29

30 Coil: Spine 8 Ch Mfg.: USI Mfg. Date: 7//26 Coil ID: 899 Phantom: Dual T spine phantoms Test Date: 9//28 Model: 2442 S: 29 # of Channels 8 2 S 48 x y.6 S HDCTL6 PE P TX gain: 67 R: R2: 29 nalysis of Composite Image,6,6,62, ormalized 24.8% 24.7% nalysis of Uncombined Images Ch ,668 2,4 2,69 2, % 96% 89% % % 9% % 92% Channel Channel 2 Composites Channel Channel 4 G E S i t e Signa

31 Coil: Torso Mfg.: USI Mfg. Date: 2//26 Coil ID: 774 Phantom: Two large Torso phantoms... one of which is centered. Test Date: 9//28 Model: 244 S: 44 # of Channels 8 2 T 48 x y.6 S 8US TORSOP TX gain: 7 R: R2: 29 nalysis of Composite Image,69,68 2, 2, ormalized 4.% 4.% nalysis of Uncombined Images Ch ,28,2,29,74,72,64,2, % 82% 68% 98% 86% 8% 78% % % 4% 42% 88% 86% % 49% % Channel Channel 2 Channel Channel 4 Composites Channel Channel 6 Channel 7 Channel 8 G E S i t e Signa

32 Coil: Wrist HD Mfg.: Mayo Clinic Mfg. Date: Coil ID: 77 Phantom: Small wrist bottle. Test Date: 9//28 Model: BC S: HBR6 # of Channels 2 T x y.6 S HD WristCoil TX gain: R: R2: 29 nalysis of Test Image ormalized 8,2 8,872 7, % 8,4 8,879 7, % G E S i t e Signa 2

33 Coil: Wrist HD Mfg.: Mayo Clinic Mfg. Date: Coil ID: 77 Phantom: Small wrist bottle. Test Date: 9//28 Model: BC S: HBR6 # of Channels 2 C 2 x y.6 S HD WristCoil TX gain: 2 R: R2: 29 nalysis of Test Image ormalized 6,94 8,72, % 6,96 8,7, % G E S i t e Signa

34 Coil: Wrist HD Mfg.: Mayo Clinic Mfg. Date: Coil ID: 77 Phantom: Small wrist bottle. Test Date: 9//28 Model: BC S: HBR6 # of Channels 2 S 2 x y.6 S HD WristCoil TX gain: R: R2: 29 nalysis of Test Image ormalized 6,69 8,26, % 6,7 8,2, % G E S i t e Signa 4

35 ppendix : Magnet Homogeneity Field Maps GE Site Signa Excite HD.T central planes Measured September, 28 xial Right 2 nterior Left xial DIMER MI MX RGE PPM ME STDEV Posterior Coronal Right 2 Superior 4 2 Left Coronal DIMER MI MX RGE PPM ME STDEV Inferior Sagittal nteriror 2 2 Superior 2 2 Posterior Sagittal DIMER MI MX RGE PPM ME STDEV Inferior

36 ppendix : Magnet Homogeneity Field Maps GE Site Signa Excite HD.T Measured September, 28 Diameter cm cm 2cm 2cm 28cm cm GE Site Signa xial Field Plot 9//8..2. ppm cm from Isocenter (S/I) Diameter cm cm 2cm 2cm 28cm cm GE Site Signa Coronal Field Plot 9//8..2. ppm cm from Isocenter (P/) Diameter cm cm 2cm 2cm 28cm cm GE Site Signa Sagittal Field Plot 9//8..2. ppm cm from Isocenter (R/L)

37 xial Field Plots 2 2 H9 2 2 H8 2 2 H H H H H H H Isocenter F F F 2 2 F4 2 2 F 2 2 F6 2 F7 2 F8 2 F9 xial Field Plots

38 Coronal Field Plots Isocenter P P P P P P P7 2 2 P8 2 P9 Coronal Field Plots

39 Sagittal Field Plots R R R R R R R R R Isocenter L L L L L L L L L9 Sagittal Field Plots

40 ppendix B: RF Slice Profiles and Crosstalk Spin Echo / = 4/2 = 9.2 KHz nex = Scan time: :4 sk Upper=6.28 Lower=. sk Upper=6.4 Lower=2.84 sk 2. Upper=6.4 Lower= Slice =.46 Slice =.46 Slice =.4 sk 2 Upper=6.4 Lower=2.8 sk. Upper=.8 Lower=. sk. Upper=.9 Lower= Slice =.4 Slice =. Slice =.2 sk. Upper=2.29 Lower=48.4 sk.2 Upper=.4 Lower=48.6 sk. Upper=.94 Lower= Slice =. 6. Slice =. Slice =4.94 Slice thickness as a function of slice gap Slice Slice

41 ppendix B: RF Slice Profiles and Crosstalk Spin Echo T MEMP / = 6/ FLIP = 6 = 9.2 KHz nex = Scan time: 2:47 MEMP SK Upper=. Lower=2.6 MEMP SK Upper=.78 Lower=2. MEMP SK 2. Upper=.78 Lower= Slice =.4 Slice =.4 Slice =.44 MEMP SK 2 Upper=.9 Lower=2.6 MEMP SK. Upper=.66 Lower=2.4 MEMP SK. Upper=4.87 Lower= Slice =.4 Slice =.8 Slice =.2 MEMP SK. Upper=.6 Lower=. MEMP SK.2 Upper=. Lower=.2 MEMP SK. Upper=2.94 Lower= Slice =.9 6. Slice =.7 Slice =. Slice thickness as a function of slice gap Slice Slice

42 ppendix B: RF Slice Profiles and Crosstalk GRE In Phase / = 2/2. FLIP = 8 = 8.2 KHz nex = 4 Scan time: :2 InPhs sk Upper=4.9 Lower=2.84 InPhs sk Upper=4.4 Lower=.89 InPhs sk 2. Upper=4.4 Lower= Slice =4.8 Slice =4.9 Slice =4.82 InPhs sk 2 Upper=4.7 Lower=.24 InPhs sk. Upper=42.9 Lower=4.74 InPhs sk. Upper=4.47 Lower= Slice =4.76 Slice =4.8 Slice =4.89 InPhs sk. Upper=4.26 Lower=.44 InPhs sk.2 Upper=4.9 Lower=.7 InPhs sk. Upper=4.8 Lower= Slice = Slice =4.8 Slice =4.7 Slice thickness as a function of slice gap Slice Slice

43 GE Site Signa Coil Used: Head Split Top Sagittal Locator Length of phantom, end to end (mn 48± 2) 2 Slice Location # Resolution (.,.,.9 mm) Slice (fwhm in mm) Wedge (mm) Diameter (mm) (9±2) Slice Location # Diameter (mm) (9±2) Top Bottom Slice Location #7 4 6 Signal (mean only) Big ROI High Low 7 (>87.%) (mean ±std dev) Top Bottom Left Right 22 2 Ghosting Ratio (<2.%) (no spec) Calculated value.±.7 Low Con Detectability Slice Location #8 Slice Location #9 Slice Location # Slice Location # Total # of Spokes (>=9) Slice Location # Wedge (mm) Slice Position Error = + =.4% 2.%.6%.% = + = 48.4 The low uniformity is expected because I did not use any homogeneity correction. Test Date: 9//28 = calculated field ( /2) ( 2/2) ( 2/8) (Site T) (Site T2) CR T CR PD CR T2 Site T Site T % 76.8% 7.% 74.2% 72.9% 2.7 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±.4 2. ± ±..6%.%.%.%.2%

44 GE Site Signa parameters Test Date: 9//28 Coil Used: Head Split Top Test ID 9 Study Descrip tion Pulse (ETL) (ms) (ms) (cm) Phase Sample Ratio umber of Slices (mm) Slice S (ex) Freq Matrix Phase Matrix Band Width (khz) Scan Time (min:sec) CR T :9 CR PD Dual Echo :2 CR T2 Dual Echo :2 Site T :4 Site T2 F(2) :2 Magnet ID: 2 Coil ID: 9 TestID: 9

45 ppendix C: CR Phantom nalysis CR T

46 ppendix C: CR Phantom nalysis CR PD

47 ppendix C: CR Phantom nalysis CR T2

48 ppendix C: CR Phantom nalysis Site T

49 ppendix C: CR Phantom nalysis Site T2

50 ppendix D: Explanation of RF Coil Testing Report Introduction The primary goal of RF coil testing is to establish some sort of base line for tracking coil performance over time. The most common measure is the Signal to Ratio or. In addition, we can look at overall signal uniformity, ghosting level (or better lack of ghosting) and in the case of phased array coils we look at the of each and every channel and at symmetry between channels. Unfortunately, there is no single best method for measuring. Below I explain the different methods used and the rationale for each. One needs to measure the signal in the phantom (either mean or peak or both) and then divide that by the back noise. Measuring the signal is fairly straightforward, the noise can be more problematic. The simplest method is to measure the standard deviation () in the back air. However, MRI images are the magnitude of complex data. The noise in the underlying complex data is Gaussian but it follows a Rician distribution when the magnitude is used. The true noise can be estimated by multiplying the measured by.26. During the reconstruction process, most manufacturers perform various additional operations on the images, This could include geometric distortion correction, low pass filtering of the kspace data resulting in low signal at the edge of the images, RF coil intensity correction (PURE, CLER, SCIC, etc), and other processing during the combination of phased array data and parallel imaging techniques. ll of these methods distort the back noise making it impossible to obtain an accurate (and reproducible) estimate of the image noise in the air region. The alternative is to use a method which I shall refer to as the (ational Electrical Manufacturers ssociation) method. The signal in the phantom area is a sum of the proton signal and noise. Once the signal to noise ratio exceeds :, the noise in the magnitude image is effectively Gaussian. To eliminate the proton signal, you acquire an image twice and subtract them. The measured in the phantom region should now be the true times the square root of 2. When determining the using the method, calculate the mean signal of the average of the two source images then divide by.77 x the 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 transmit and receive, be identical with both scans. ny ghosting in the system is not likely to repeat exactly for both scans and will cause a much higher. Finally, the phantom needs to be resting in place prior to the scan long enough for motion of the fluid to have died down. Depending on the size and shape of the phantom, this could take any where from to 2 minutes. One of the most common causes of ghosting is vibration from the helium coldhead. The best way to eliminate this artifact is to turn off the cold head, which will increase helium consumption. Because this vibration is periodic, the ghosting is usually of an over 2 (/2) nature. The affect inside the signal region of the phantom can be minimized by using a that is twice the diameter of the phantom (measured in the PE direction.) If the noise is to be measured in the air, then be sure to OT make measurements to either side of the phantom in the PE direction. Scan parameters also significantly affect measured. For most of the testing performed in this document I used a simple Spin Echo with a of, a of 2 and a slice thickness of mm and a receiver of.6 KHz. The was varied depending on the size of the coil and the phantom used. ll of the parameters used for each test can be found on each page immediately below the coil description. 2

51 Report Layout Each page of this report lists the data from a single test. The top third of the page describes the coil and phantom information, followed by the scan parameters used. The middle third contains the numbers measured and calculated results. This section will contain one table if the coil being tested is a single channel coil (i.e. quadrature or surface coils) and two tables if it is a multichannel phased array coil. The entries in the table will be described further below. The bottom section contains a few lines of comments (if necessary), a picture of the coil with the phantom as used for the testing and one or more of the images that were used for the measurements. There is usually one image for each composite image measurement and one image for each separate channel measurement. Each image shows the ROI (red line) where the mean signal was measured and two smaller ROIs (green lines) where the signal minimum and maximum was found. In the top left corner of each image is the mean signal in the large ROI. The bottom left corner contains the large ROI s area (in mm 2 ). The top right corner contains two numbers a mean and a standard deviation. If the method was used, then the top right corner will list the mean and of the large ROI (labeled ROI M and ROIsd) applied to the subtraction image. If the noise was measured in the back air the the numbers are labeled M and. Data Tables The meaning of most of the entries in the data table are should be self evident with a few exceptions. The first column in each table is labeled. In the composite analysis, this field may be empty or contain some sort of abbreviation to identify some aspect of the testing. Some possibilities are the letter for, for, L for Left, R for Right, C for CLER, oc for o CLER. In the Uncombined Image table, the label usually contains the channel number or similar descriptor. The column labeled will be either or SubSig which stands for Subtracted Signal, i.e. the method. Both tables contain a column for and which are the or signal divided by the of the noise scaled by either.26 () or.77 (). Composite Image Table: The final two columns in this table are ormalized and. It can be rather difficult to compare the performance of different coils particularly if different scan parameters are used. (Of course, it s even more difficult from one scanner to another.) I have standardized most of my testing to use a spin echo with a / of /2msec and a thickness of mm. The changes to depending on the size of the phantom used although I try to use a that is at least twice the diameter of the phantom as measured in the PE direction. For one reason or another, a change may be made in the scan parameters (either accidentally or intentionally such as turning on o Phase Wrap to eliminate aliasing, etc.). In order to make it easier to compare values I calculate a ormalized value. This value is theoretically what the would be if a of cm, x matrix, average, receiver of.6 KHz and slice thickness of mm had been used. Obviously, the final number is affected by the T/T2 values of the phantoms used as well as details of the coil and magnet field strength but it can be useful in certain situations. The value is defined by the CR as (maxmin)/(max+min). This is most important when looking at volume coils or for evaluating the effectiveness of surface coil intensity correction algorithms (such as PURE, CLER or SCIC). Uncombined Image Table: This table has two columns labeled and. When analyzing multichannel coils it is important to understand the relationship between the different channels, the inherent symmetry that usually exists between channels. In a 8 channel head or 4 channel torso phased array coil, all of the channels are usually have about the same. These two columns list how the (either or ) of each channel compares to the of the channel with the maximum value.