Essential Mr i Charts

8/12/2019 Essential Mr i Charts

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MSU RADIOLOGY

ESSENTIALMRI CHARTS


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MRI Acronyms MRI Acronyms

GE Phillips Sequence Type Siemens Toshiba

ASSET SENSEParallel Acquisition

TechniquesiPAT SPEEDER

SENSE SENSE Image-Based Algorithm mSENSE SENSE

- - K-space Based Algorithm Grappa -

SE SE Spin Echo (SE) SE SE

GRASE GRASE

Turbo Gradient Spin Echo

(GRASE)

TurboGSE

TGSE Hybrid EPI

FSE (Fast SpinEcho)

TSE (TurboSpin Echo)

Turbo Spin Echo/FastSpin Echo (TSE/FSE)

TSE (TurboSpin Echo)

FSE (Fast SpinEcho)

Echo TrainLength (ETL)

Turbo Factor Number of Echoes Turbo FactorEcho Train

Length (ETL)

Single-ShotFSE

Single-ShotTSE

Single-Shot TSE/FSE HASTE FASE

Echo Spacing Echo Spacing Time Between Echoes Echo Spacing Echo Spacing

FrFSE DRIVETSE/FSE with 90 Flip-

Back PulseRESTORE FSE T2 pulse

NEX NSA Averages Averages NSA

Receive Band-width (kHz)

Fat/WaterShift (Pixel)

BandwidthBandwidth

(Hz/Px)Bandwidth

Smart Prep-Fluoro -

TriggeredBolusTrak

Contrast Bolus Timing/Flouro-Triggering

CARE Bolus Visual Prep


Trigger Delay,

TD

Trigger Delay,

TDDelay after R Wave

Trigger Delay,

TD

Trigger Delay,

TD

Gap Gap Distance Between SlicesDistanceFactor

Gap

FOV (cm) FOV (mm) Field of View FOV (mm) FOV

Anti-AliasingFrequency

Oversampling Frequency Oversampling Oversampling

Frequency

WrapSuppression

Flow CompFlow Comp,

FlagGradient Moment Nulling

Flow Comp/

GMRFlow Comp

1/2NEX,Fractional NEX

Half Scan Half Fourier Imaging Half Fourier Half Fourier

Cardiac Gated/

Triggering

ECG

TriggeredImage Sync with ECG ECG Triggered Cardiac Gated

TI TI Inversion Time (msec) TI TI

MTC MTCMagnetization Transfer

ConstantMTC, MTS SORS-STC

Walking Sat Travel Rest Moving Sat Pulse Travel Sat BFAST

Partial Echo Partial Echo Partial Echo AsymmetricEcho

MatchedBandwidth

Localizer PlanScan Patient Orientation Localizer Locator


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Fat Sat/ChemSat

SPIR, SPAIR Prep Pulse - Chemically Fat Sat Fat Sat

SAT REST Prep Pulse - Spatially Presat Presat

Ramped Pulse TONE Ramped RF Pulse TONE ISCE

Partial FOVRectangular

FOV Rectangular FOV

FOV Phase/Rectangular

RectangularFOV

TR, TE TR, TERepetition Time, Echo

Time (in msec)TR, TE TR, TE

Respiratory

Triggering

Respiratory

TriggeringRespiratory Gating

Respiratory

Gating

Respiratory

Gating

Flip Angle Flip Angle RF Pulse in Gradient Echo Flip Angle Flip Angle

AcquisitionTime

AcquisitionTime

Scan Measurement TimeAcquisition Time,

TAAcquisition

Time

Views perSegment

Views perSegment

Segmented K-Space Lines/Segments Segments

Off CenterFOV

Off CenterFOV

Shifting Slices Off Center Off Center FOVPhase andFrequency

Shift

POMP SIMEX Simultaneous Excitat ion Simultaneous

Excitation QuadScan

IntersegmentDelay

TD Time Delay/Block K-Space Time Delay TD

Variable Band-width

Water FatShift

Variable Bandwidth Optimized Band-width

MatchedBandwidth

- Proset Water Excitation Water Excitation -

MRI Acronyms Arterial to VenousTransition Times

Anatomic

Region

Time in

SecondsIntracranial 5 sec.Cervical 4-8 sec.

Pulmonary 4-8 sec.

Renal 10 sec.

Abdominal 10-12 sec.

Pelvic 10-30 sec.

Peripheral Vessels Up to 60 sec.***Transition Times based on vessels that are clear of pathology andare lying within normal tissue.


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Average Arrival Times ofContrast in ceMRA

MRI Formulas

Vessel Arrival Time

Superior Vena Cava 0-8 seconds

Pulmonary Artery 6-10 seconds

Carotid Artery 7-12 secondsAortic Arch 9-14 seconds

Descending Aorta 13-20 seconds

Femoral Artery 15-20 seconds

Hepatic Artery 19-30 seconds

Trifurcation 20-30 seconds

Palmer Arch 20-40 seconds

Portal Veins 30-45 seconds

Hepatic Veins 40-55 seconds

***Arrival times based on normal, pathology-free, anatomy.

SNR

Mean of Tissue/Standard Deviation =Signal to Noise Ratio

Place a small ROI within the tissue to establish the Mean Value. A large ROI inthe background will determine the Standard Deviation.

Bandwidth Con-version (Hz/Px

to kHz)

(Hz per Pixel/Base Resolution) / 2000 = kHz

EXAMPLE: 130 hz/px X 256 (freq.) = 33,33333,333/2000 = 16.021 kHz

In-Plane Pixel

(phase)

FOVp/Np

FOVp - FOV in the Phase DirectionNP - Number of Phase Encoding Steps

In-Plane Pixel(frequency)

FOVf/Nf

FOVf - FOV in the Frequency DirectionNf - Number of Frequency Encoding Steps

SNRImprovement

(SNR 1 - SNR 2)/SNR 2 x 100 = % of Improvement

Comparison of SNR between two sequences; establish an SNR for each se-quence and plug the values into the above formula. Positive results indicate

SNR1>SNR2. Negative results reflect SNR1


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Gadolinium Dose Chart

BodyWeight

kg 12 14 16 18 20 22 24 26 28 30 40 50 60 70 80 90 100 110 120 130

lb 26 31 35 40 44 49 53 57 62 66 88 110 132 154 176 198 2 20 243 265 287

Pediatric

mL 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 8 10 12 14 16 - - - - -

Adult

mL - - - - - - - - - - 8 10 12 14 16 18 20 22 24 26

Volume based on .2 mL/kg as recommended by vendor inserts(Magnevist, Omniscan and Prohance).


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In and Out ofPhase TE Values

Parameter Trade-Offs

0.5T 1.0T 1.5T 3.0T

In-PhaseTE

13.8 6.9 4.6 2.3

27.6 13.8 9.2 4.6

20.7 13.8 6.9

27.6 18.4 9.2

23 11.5

Out-of-Phase TE

6.9 3.45 2.3 1.15

20.7 10.35 6.9 3.45

17.25 11.5 5.75

24.15 16.1 8.0520.7 10.35

Condition SNRSpatial

ResolutionTime

TR Increase -

TE Increase - -

NEX-NSA-Averages

Increase -

SliceThickness

Increase -

PhaseResolution

Increase

FrequencyResolution

Increase -

FOV Increase -

ReceiveBandwidth

Increase - -

^

^^

^

^^

^

^

^

V

V

V

V

V

V


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Parameter Trade-Offs

Condition SNR RBW

Increase Decrease Increase Decrease Increase Decrease

T1 - -

PD - -

T2- -

Slice Number

Scan Time - -

SNR

Resolution - - - - - -

Flow Artifact - -

MagneticSusceptibility

- - - -

RBW - - - -

Chemical

Shift - - - -Minimum TE - - - -

V

V

V V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V V

V

V

V

V

V

V

V

V

V V

V

V

V

V

V

V

V

V

V

V

Hertz per

Pixel @ 256kHz @ 256

Hertz per

Pixel @ 512

kHz @

512

32 4.096 32 8.192

64 8.0192 64 16.384

96 12.288 96 24.576

128 16.384 128 32.768

160 20.48 160 40.96

248 31.744 248 63.488

496 63.488 496 126.976

RBW Conversion

(Hertz per Pixel X Base Resolution) / 2000 = kHz


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Tissue T1 @ 1.5T T2 @ 1.5T TI @ 1.5T T1 @3 .0T T2 @ 3.0T TI @ 3.0T

Blood 1200 150 828 1380 135 952

Bone Marrow 1013 - 699 1165 - 804

Cartilage 1060 - 731 1219 - 841

CorpusCallosum

- 120 - - 108 -

CFS 3000 510 2070 3450 459 2381

Fat 259 160 179 298 144 206

Fluid 2850 - 1967 3278 - 2262

Grey Matter 921 100 635 1059 90 731

Kidney (cortex) 966 70 667 1111 63 767

Kidney (marrow) 1320 - 911 1518 - 1047

Liver 570 50 393 656 45 453

Muscle 1130 50 780 1300 45 897

Pons - 110 - - 99 -

Spleen 1026 - 708 1180 - 814

White Matter 786 90 542 904 81 624

T1, T2 & Inversion Time Values TOF Parameter Trade-Offs

Temporal

Resolution of:TR

Increase

Flip AngleIncrease

Slice ThinkIncrease

TEIncrease

Fast Moving

Blood

Slow Moving

Blood

BackgroundTissue - -

V

V

V V

V

V

V

V V

V

l i C


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MRI

T1

MRI

T2

X-Ray &

CT

Enhancement

with Gadolinium

Infarct Dark Bright Dark Moderate

Bleed Bright Bright Bright No

Tumor Dark Bright Dark Yes

MS Dark Bright Dark Yes (acute)

MRI T1 MRI T2 X-Ray & CT

Dense Bone Dark Dark Bright

Air Dark Dark Dark

Fat Bright Bright Dark

Water Dark Bright Dark

Abnormal Tissue Contrast Normal Tissue Contrast


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Vessel

Velocity

(cm/sec)

Middle Cerebral Artery 62 12

Anterior Cerebral Artery 52 12

Posterior Cerebral Artery 42 10

Internal Carotid Siphon 54 13

Vertebral Artery 36 9

Basilar Artery 42 10

Internal Iliac Artery 119 21

Common Femoral Artery 114 24

Superficial Femoral Artery 90 13

Superficial Germal Artery(distal) 93 14

Popliteal Artery 69 13

Thoracic Aorta 100 - 175

Common Carotid Artery 80 - 120

Internal Carotid Artery 80 - 120

Average Velocity Encoding Valuesin Phase Contrast Angiography

***Velocity Measurements based on normal vascular anatomy

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