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European Radiology

, Volume 26, Issue 6, pp 1879–1888 | Cite as

Assessment of Silent T1-weighted head imaging at 7 T

  • Mauro Costagli
  • Mark R. Symms
  • Lorenzo Angeli
  • Douglas A. C. Kelley
  • Laura Biagi
  • Andrea Farnetani
  • Catarina Rua
  • Graziella Donatelli
  • Gianluigi Tiberi
  • Michela Tosetti
  • Mirco Cosottini
Magnetic Resonance

Abstract

Objectives

This study aimed to assess the performance of a “Silent” zero time of echo (ZTE) sequence for T1-weighted brain imaging using a 7 T MRI system.

Methods

The Silent sequence was evaluated qualitatively by two neuroradiologists, as well as quantitatively in terms of tissue contrast, homogeneity, signal-to-noise ratio (SNR) and acoustic noise. It was compared to conventional T1-weighted imaging (FSPGR). Adequacy for automated segmentation was evaluated in comparison with FSPGR acquired at 7 T and 1.5 T. Specific absorption rate (SAR) was also measured.

Results

Tissue contrast and homogeneity in Silent were remarkable in deep brain structures and in the occipital and temporal lobes. Mean tissue contrast was significantly (p < 0.002) higher in Silent (0.25) than in FSPGR (0.11), which favoured automated tissue segmentation. On the other hand, Silent images had lower SNR with respect to conventional imaging: average SNR of FSPGR was 2.66 times that of Silent. Silent images were affected by artefacts related to projection reconstruction, which nevertheless did not compromise the depiction of brain tissues. Silent acquisition was 35 dB(A) quieter than FSPGR and less than 2.5 dB(A) louder than ambient noise. Six-minute average SAR was <2 W/kg.

Conclusions

The ZTE Silent sequence provides high-contrast T1-weighted imaging with low acoustic noise at 7 T.

Key Points

“Silent” is an MRI technique allowing zero time of echo acquisition

Its feasibility and performance were assessed on a 7 T MRI system

Image quality in several regions was higher than in conventional techniques

Imaging acoustic noise was dramatically reduced compared with conventional imaging

“Silent” is suitable for T1-weighted head imaging at 7 T

Keywords

Magnetic resonance imaging Neuroimaging Technology assessment, Biomedical Patient satisfaction Brain 

Abbreviations

MRI

Magnetic resonance imaging

TE

Time of echo

TI

Time of inversion

TD

Time of delay

ZTE

Zero time of echo

SNR

Signal-to-noise ratio

FSPGR

Fast spoiled gradient-recalled

ROI

Region of interest

WM

White matter

GM

Gray matter

TC

Tissue contrast

WMIV

White matter intensity variability

GMCR

Gray matter cortical ribbon

OT

Other tissues

SAR

Specific absorption rate

TPR

True-positive rate (sensitivity)

SPC

Specificity

PPV

Positive predictive value (precision)

NPV

Negative predictive value

Notes

Acknowledgments

The scientific guarantor of this publication is Mirco Cosottini. Authors #2 and #4 of this manuscript declare relationships with the following companies: GE Healthcare. This study has received funding by the Italian Ministry of Health and the Health Service of Tuscany (RF-2009-1546281), and by the FP7 Marie Curie Actions of the European Commission (FP7-PEOPLE-2012-ITN-316716). No complex statistical methods were necessary for this paper. Institutional review board approval was obtained. Written informed consent was obtained from all subjects in this study. Methodology: assessment/evaluation of technique, performed at one institution.

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Copyright information

© European Society of Radiology 2015

Authors and Affiliations

  • Mauro Costagli
    • 1
    • 2
  • Mark R. Symms
    • 3
  • Lorenzo Angeli
    • 4
  • Douglas A. C. Kelley
    • 5
  • Laura Biagi
    • 2
  • Andrea Farnetani
    • 6
    • 7
  • Catarina Rua
    • 8
  • Graziella Donatelli
    • 9
  • Gianluigi Tiberi
    • 1
    • 2
  • Michela Tosetti
    • 1
    • 2
  • Mirco Cosottini
    • 1
    • 4
  1. 1.Imago7 FoundationPisaItaly
  2. 2.Laboratory of Medical Physics and Biotechnologies for Magnetic ResonanceIRCCS Stella MarisPisaItaly
  3. 3.GE Applied Science LaboratoryPisaItaly
  4. 4.Department of Translational Research and New Technologies in Medicine and SurgeryUniversity of PisaPisaItaly
  5. 5.GE Healthcare TechnologiesSan FranciscoUSA
  6. 6.Engineering DepartmentUniversity of FerraraFerraraItaly
  7. 7.Materiacustica s.r.l.FerraraItaly
  8. 8.Department of PhysicsUniversity of PisaPisaItaly
  9. 9.Neuroradiology Unit, Department of Diagnostic and Interventional RadiologyAzienda Ospedaliero-Universitaria Pisana (AOUP)PisaItaly

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