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Clinical Application of Balanced Steady-State Free

Precession Technique in Neuroradiology

Yueh-hsun LuHsiu-mei WuJiing-feng LimgWan-yuo Guo Cheng-yen Chang

Taipei Veterans General Hospital, TaiwanNational Yang-Ming University, Taiwan

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Properties of b-SSFP

•Total coherent steady-state magnetization

•Image contrast is given by T2/T1 ratio high signal of fluid and fat, and low signal of soft tissues

•Within a certain range, field inhomogeneity induced dephasing will be nearly completely refocused at TE=TR/2 (~SE)

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Balanced Steady-State Free Precession

Scheffler Eur Radiol 2003 13:2409–2418

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Clinical Application in Neuroradiology•Ventriculocisternography•MR myelography with brachial

plexus injury•CSF leakage•Delineation of intracranial cystic

lesion

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•Ventriculocisternography

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Obstructive hydrocephalus

Ventriculocisternography

Presurgical Evaluation for Hydrocephalus

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•MR myelogram and brachial plexus image

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Brachial Plexus Imaging

T2WI Axi FIESTA

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Brachial Plexus Injury

31y/o M, Post Motorcycle Accident

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CSF Leakage

•Traumatic cause•Iatrogenic cause

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Post Traumatic CSF Leakage

T2WICT with bone window

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Post Traumatic CSF Leakage

Axi 3D FIESTA COR 3D FIESTA

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Post TSA CSF Rhinorrhea

3D FIESTA 1mmTR/TR/FA: 4.88/1.38/65•2D FSE T2WI

2mm

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3D FIESTA 1mmTR/TR/FA: 4.88/1.38/65

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•Delineation of cystic lesion

•Demonstration of normal structure

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Diagnosis and Delineation of Arachnoid Cyst

3-month-boy, Arachnoid cyst with hydronephrosis

FLAIR DWI 3D b-SSFP

61/M, right trigeminal neuralgia for 3 years

Delineation of Epidermoid Cyst

77/M vertigo attacks in recent weeks

Delineation of Cranial Nerves: CN 7th and 8th

Detection and Delineation of Small Intracannalicular Acoustic Neuroma

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Discussion•The quality of image is somehow

machine and parameter dependent. Magnetic inhomogeneity will cause artifacts, such as banding artifact.

•Flip angle effect and section aliasing effect.

•Proper selection of TR/TE/Flip angle would improve the quality of image.

α=70 ° α=50 ° α=30 °

AJNR 26:1170–1173, May 2005

flip angle effect alone is an important factor that presents an obvious tradeoff between image contrast and aliasing artifacts in 3D SSFP MR ventriculocisternography.

Section Aliasing Artifacts

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Conclusion•b-SSFP offers the highest SNR per unit

time of all other imaging sequences.•The dynamic equilibrium of b-SSFP is

insensitive to flow or motion.• It can provide the high resolution of

ventriculocystography for delineation of CSF space lesion, cranial nerve, intradural cervical nerve roots and detection of CSF leakage.

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Thank You For Your Attention

The 101 Building, Taipei, Taiwan

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Imaging of Membranous Labyrinth

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Imaging of 3D Membranous Labyrinth

75y/o m, TR/TE 6.9x1.7, 0.4mm, 14x14cm 488x256

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Artifacts of b-SSFP

•Banding artifact•Section aliasing artifact•Acquisition artifact•Susceptibility artifact

Banding Artifact

FIESTA C

FOV 20x20 cm 182 slices

TR/TE/a: 5.49/1.47/65NEX:2

Matrix 448x256Slice thickness: 1.4 0.7 cm

FOV 24x24 cm 232 slices

TR/TE/a: 5.63/1.37/65NEX:2

Matrix 448x256Slice thickness: 1.4 0.7 mm