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MRI: State of the Art. MR Attractions. MRI 的特點. 非侵入性 MRCP MR Myelography. 無輻射. 任意斷層切面. T2. 組織對比. 信號抑制. MR 血管攝影. No CM Necessary Replacing Diganostic Angio Vasculatures beyond Brain. 安全的造影劑. 最安全 健保給付. Tissue Contrast. TR. 2500 500. TE. 15. 90. T1,T2 & PD.

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Mr attractions
MR Attractions


MRI的特點

  • 非侵入性

    • MRCP

    • MR Myelography

  • 無輻射



T2

組織對比



MR 血管攝影

  • No CM Necessary

  • Replacing Diganostic Angio

  • Vasculatures beyond Brain


安全的造影劑

  • 最安全

  • 健保給付



T1 t2 pd

TR

2500

500

TE

15

90

T1,T2 & PD



Se tse epi
SE, TSE & EPI

SE: 7 min TSE: 2 min EPI: 0,2 s


Echo planar imaging
Echo Planar Imaging

  • Single shot EPI

    • Uncooperative patients

    • Ultra-fast imaging

  • Stroke Imaging

    • Separation of old versus new infarctions

    • Online calculation of Trace & ADC maps

    • Up to 16 b - values: 0 - 4000

  • Perfusion imaging

    • Online calculation of global bolus plots, TTP maps

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?


Restrictions
Restrictions

  • Magnetic Field

    • Safety: 5 Gauss Fringe Field

    • Superconductive Magnet︰Weight, Price

  • Scan Time

  • Know-How

    • Longer Training Time

    • Operation of MR Center


What mri can do

What MRI can do?

  • Images

  • Spectroscopy


Functional mri
Functional MRI

  • Restrictions of Medical Imaging

  • Lesion Detection

  • Function Indicators︰

    • Example -- GPT、GOT

    • Cardiac Function – Myocardial Perfusion

    • Brain Function – Diffusion & Perfusion

  • Images+Functional Studies  functional MRI


Functional mr imaging
Functional MR Imaging

T2W TSE

T2W FLAIR

DWI SE-EPI

rCBV

post Gd T1W SE

PCA - angio


Spectroscopy
Spectroscopy

  • Images vs Spectra

  • OrgansTissuesCellsMolecules

  • Active Metabolism on Tumor

  • Unusual Concentration Metabolites

  • Tumor Phasing

  • Radiotherapy follow-up


Brain tumor
Brain Tumor

Images+Spectroscopy



From Pixel to Images


Mr system components

speed

MR System Components

Receiving Bandwidth

RF system

(coils, pre-amp, etc.)

Gradients

Computer

SNR

flexibility

magnet


1 5 t 160 cm magnet
1,5 T 160 cm magnet


Gradient systems
Gradient systems

„Stronger and faster“

Required for advanced applications like EPI and contrast enhanced MR-Angio

Level of peripheral nerve and muscle stimulation is reached. Searching for compromises regarding amplitude, rise time, FoV, linearity.


Gradient amplifier

Gradient Amplifier

Amplitude: 40 mT/m

Slew Rate: 200 T/m/s

Rise Time: 200 s

Max. 40 cm FOV

  • Voltage:

  • max. 2000 V

  • Current:

  • max. 500 A

  • per axis

  • (1 MW / axis)


Rf amplifier

  • 15 kW Pulse power

  • 600 W average power

  • System control compensates for nonlinearities and phase errors

RF Amplifier


Rf coils
RF - Coils

Using a larger number of local coils, the s/n can be improved significantly in peripheral regions but not in the center of the patient.



Coil family

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+

+

=

+

=

+

+

+

=

Coil Family

Be creative!


Sequence family
Sequence Family

EPI

TGSE

MP RAGE

TSE

turboFLASH

HASTE

PSIF

CISS

DESS

trueFISP

FISP

TIRM

QUEST

FLASH

SSFP

STEAM

IR

GRE

SE

SE


TGSE

True-FISP

3D-TOF-Angio

3D-FLASH

Turbo-FLASH


1H-SVS

PC.Angio

Flow

Koronarien

EPI-Func.

Imaging

Diffusion-EPI


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