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



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.


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.


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.


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


Magnetic resonance imaging Neuroimaging Technology assessment, Biomedical Patient satisfaction Brain 



Magnetic resonance imaging


Time of echo


Time of inversion


Time of delay


Zero time of echo


Signal-to-noise ratio


Fast spoiled gradient-recalled


Region of interest


White matter


Gray matter


Tissue contrast


White matter intensity variability


Gray matter cortical ribbon


Other tissues


Specific absorption rate


True-positive rate (sensitivity)




Positive predictive value (precision)


Negative predictive value



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.


  1. 1.
    Bergin CJ, Pauly JM, Macovski A (1991) Lung parenchyma: projection reconstruction MR imaging. Radiology 179:777–781CrossRefPubMedGoogle Scholar
  2. 2.
    Madio DP, Lowe IJ (1995) Ultra‐fast imaging using low flip angles and fids. Magn Reson Med 34:525–529CrossRefPubMedGoogle Scholar
  3. 3.
    Idiyatullin D, Corum C, Park J-Y, Garwood M (2006) Fast and quiet MRI using a swept radiofrequency. J Magn Reson 181:342–349CrossRefPubMedGoogle Scholar
  4. 4.
    Wu Y, Dai G, Ackerman JL et al (2007) Water- and fat-suppressed proton projection MRI (WASPI) of rat femur bone. Magn Reson Med 57:554–567CrossRefPubMedGoogle Scholar
  5. 5.
    Tyler DJ, Robson MD, Henkelman RM et al (2007) Magnetic resonance imaging with ultrashort TE (UTE) PULSE sequences: Technical considerations. J Magn Reson Imaging 25:279–289CrossRefPubMedGoogle Scholar
  6. 6.
    Du J, Bydder M, Takahashi AM, Chung CB (2008) Two-dimensional ultrashort echo time imaging using a spiral trajectory. Magn Reson Imaging 26:304–312CrossRefPubMedGoogle Scholar
  7. 7.
    Qian Y, Boada FE (2008) Acquisition‐weighted stack of spirals for fast high‐resolution three‐dimensional ultra‐short echo time MR imaging. Magn Reson Med 60:135–145CrossRefPubMedGoogle Scholar
  8. 8.
    Du J, Bydder M, Takahashi AM et al (2011) Short T2 contrast with three-dimensional ultrashort echo time imaging. Magn Reson Imaging 29:470–482CrossRefPubMedPubMedCentralGoogle Scholar
  9. 9.
    Weiger M, Pruessmann KP, Hennel F (2011) MRI with zero echo time: hard versus sweep pulse excitation. Magn Reson Med 66:379–389CrossRefPubMedGoogle Scholar
  10. 10.
    Weiger M, Brunner DO, Dietrich BE et al (2013) ZTE imaging in humans. Magn Reson Med 70:328–332CrossRefPubMedGoogle Scholar
  11. 11.
    Grodzki DM, Jakob PM, Heismann B (2012) Ultrashort echo time imaging using pointwise encoding time reduction with radial acquisition (PETRA). Magn Reson Med 67:510–518CrossRefPubMedGoogle Scholar
  12. 12.
    Johnson KM, Fain SB, Schiebler ML, Nagle S (2013) Optimized 3D ultrashort echo time pulmonary MRI. Magn Reson Med 70:1241–1250CrossRefPubMedPubMedCentralGoogle Scholar
  13. 13.
    Weiger M, Stampanoni M, Pruessmann KP (2013) Direct depiction of bone microstructure using MRI with zero echo time. Bone 54:44–47CrossRefPubMedGoogle Scholar
  14. 14.
    Weiger M, Hennel F, Pruessmann KP (2010) Sweep MRI with algebraic reconstruction. Magn Reson Med 64:1685–1695CrossRefPubMedGoogle Scholar
  15. 15.
    Heilmaier C, Theysohn JM, Maderwald S et al (2011) A large-scale study on subjective perception of discomfort during 7 and 1.5 T MRI examinations. Bioelectromagnetics 32:610–619CrossRefPubMedGoogle Scholar
  16. 16.
    Cosottini M, Frosini D, Biagi L et al (2014) Short-term side-effects of brain MR examination at 7 T: a single-centre experience. Eur Radiol 24:1923–1928CrossRefPubMedGoogle Scholar
  17. 17.
    Glover GH, Pauly JM (1992) Projection reconstruction techniques for reduction of motion effects in MRI. Magn Reson Med 28:275–289CrossRefPubMedGoogle Scholar
  18. 18.
    Madio DP, Gach HM, Lowe IJ (1998) Ultra-fast velocity imaging in stenotically produced turbulent jets using RUFIS. Magn Reson Med 39:574–580CrossRefPubMedGoogle Scholar
  19. 19.
    Kelley DAC, McKinnon GC, Sacolick LI et al (2014) Optimization of a Zero Echo Time (ZTE) Sequence at 7T with Phased Array Coils. Proceedings of International Society for Magnetic Resonance in Medicine ISMRMGoogle Scholar
  20. 20.
    Weiger M, Brunner DO, Wyss M et al (2014) ZTE Imaging with T1 Contrast. Proceedings of International Society for Magnetic Resonance in Medicine ISMRMGoogle Scholar
  21. 21.
    Hurley AC, Al-Radaideh A, Bai L et al (2010) Tailored RF pulse for magnetization inversion at ultrahigh field. Magn Reson Med 63:51–58PubMedGoogle Scholar
  22. 22.
    Wrede KH, Johst S, Dammann P et al (2012) Caudal image contrast inversion in MPRAGE at 7 Tesla: problem and solution. Acad Radiol 19:172–178CrossRefPubMedGoogle Scholar
  23. 23.
    O'Brien KR, Magill AW, Delacoste J et al (2014) Dielectric pads and low- B1+ adiabatic pulses: complementary techniques to optimize structural T1 w whole-brain MP2RAGE scans at 7 tesla. J Magn Reson Imaging 40:804–812CrossRefPubMedGoogle Scholar
  24. 24.
    Belaroussi B, Milles J, Carme S et al (2006) Intensity non-uniformity correction in MRI: existing methods and their validation. Med Image Anal 10:234–246CrossRefPubMedGoogle Scholar
  25. 25.
    Van de Moortele P-F, Akgun C, Adriany G et al (2005) B(1) destructive interferences and spatial phase patterns at 7 T with a head transceiver array coil. Magn Reson Med 54:1503–1518CrossRefPubMedGoogle Scholar
  26. 26.
    Vaughan JT, Garwood M, Collins CM et al (2001) 7T vs. 4T: RF power, homogeneity, and signal-to-noise comparison in head images. Magn Reson Med 46:24–30CrossRefPubMedGoogle Scholar
  27. 27.
    Dietrich O, Raya JG, Reeder SB et al (2007) Measurement of signal‐to‐noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters. J Magn Reson Imaging 26:375–385CrossRefPubMedGoogle Scholar
  28. 28.
    Tannús A, Garwood M (1997) Adiabatic pulses. NMR Biomed 10:423–434CrossRefPubMedGoogle Scholar
  29. 29.
    Sacolick LI, Wiesinger F, Hancu I, Vogel MW (2010) B1 mapping by Bloch-Siegert shift. Magn Reson Med 63:1315–1322CrossRefPubMedPubMedCentralGoogle Scholar
  30. 30.
    Kelley DAC, McKinnon GC, Sacolick LI et al (2014) Depiction of Multiple Sclerosis Lesions with Zero Echo Time (ZTE) Imaging at 7T. Proceedings of International Society for Magnetic Resonance in Medicine ISMRMGoogle Scholar
  31. 31.
    Tourdias T, Saranathan M, Levesque IR et al (2014) Visualization of intra-thalamic nuclei with optimized white-matter-nulled MPRAGE at 7T. NeuroImage 84:534–545CrossRefPubMedPubMedCentralGoogle Scholar
  32. 32.
    Costagli M, Kelley DAC, Symms MR et al (2014) Tissue Border Enhancement by inversion recovery MRI at 7.0 Tesla. Neuroradiology 56:517–523CrossRefPubMedGoogle Scholar
  33. 33.
    De Ciantis A, Barkovich AJ, Cosottini M et al (2015) Ultra-high-field MR imaging in polymicrogyria and epilepsy. AJNR Am J Neuroradiol 36:309–316CrossRefPubMedGoogle Scholar
  34. 34.
    Pusey E, Lufkin RB, Brown RK et al (1986) Magnetic resonance imaging artifacts: mechanism and clinical significance. Radiographics 6:891–911CrossRefPubMedGoogle Scholar
  35. 35.
    Van de Moortele P-F, Auerbach EJ, Olman C et al (2009) T1 weighted brain images at 7 Tesla unbiased for Proton Density, T2 contrast and RF coil receive B1 sensitivity with simultaneous vessel visualization. NeuroImage 46:432–446CrossRefPubMedPubMedCentralGoogle Scholar
  36. 36.
    Dale AM, Fischl B, Sereno MI (1999) Cortical surface-based analysis. I. Segmentation and surface reconstruction. NeuroImage 9:179–194CrossRefPubMedGoogle Scholar
  37. 37.
    Fischl B, Sereno MI, Dale AM (1999) Cortical surface-based analysis. II: Inflation, flattening, and a surface-based coordinate system. NeuroImage 9:195–207CrossRefPubMedGoogle Scholar
  38. 38.
    Ueno K, Cheng K (2014) Model-Free Spatial Intensity Non-Uniformity Correction Algorithm for MR Images. Proceedings of International Society for Magnetic Resonance in Medicine ISMRMGoogle Scholar
  39. 39.
    Jenkinson M, Bannister P, Brady M, Smith S (2002) Improved optimization for the robust and accurate linear registration and motion correction of brain images. NeuroImage 17:825–841CrossRefPubMedGoogle Scholar
  40. 40.
    Klauschen F, Goldman A, Barra V et al (2009) Evaluation of automated brain MR image segmentation and volumetry methods. Hum Brain Mapp 30:1310–1327CrossRefPubMedGoogle Scholar
  41. 41.
    Jenkinson M, Beckmann CF, Behrens TEJ et al (2012) FSL. NeuroImage 62:782–790CrossRefPubMedGoogle Scholar
  42. 42.
    van Osch MJP, Webb AG (2014) Safety of ultra-high field MRI: what are the specific risks? Curr Radiol Rep 2:1–8Google Scholar
  43. 43.
    Marques JP, Kober T, Krueger G et al (2010) MP2RAGE, a self bias-field corrected sequence for improved segmentation and T1-mapping at high field. NeuroImage 49:1271–1281CrossRefPubMedGoogle Scholar
  44. 44.
    Nishimura DG (1990) Time‐of‐flight MR angiography. Magn Reson Med 14:194–201CrossRefPubMedGoogle Scholar
  45. 45.
    Ashburner J, Friston KJ (2000) Voxel-based morphometry--the methods. NeuroImage 11:805–821CrossRefPubMedGoogle Scholar
  46. 46.
    Whitwell JL (2009) Voxel-based morphometry: an automated technique for assessing structural changes in the brain. J Neurosci 29:9661–9664CrossRefPubMedGoogle Scholar
  47. 47.
    Fischl B, Rajendran N, Busa E et al (2008) Cortical folding patterns and predicting cytoarchitecture. Cereb Cortex 18:1973–1980CrossRefPubMedPubMedCentralGoogle Scholar
  48. 48.
    Gatehouse PD, Bydder GM (2003) Magnetic resonance imaging of short T2 components in tissue. Clin Radiol 58:1–19CrossRefPubMedGoogle Scholar
  49. 49.
    Pruessmann KP, Weiger M, Scheidegger MB, Boesiger P (1999) SENSE: sensitivity encoding for fast MRI. Magn Reson Med 42:952–962CrossRefPubMedGoogle Scholar
  50. 50.
    Griswold MA, Jakob PM, Heidemann RM et al (2002) Generalized autocalibrating partially parallel acquisitions (GRAPPA). Magn Reson Med 47:1202–1210CrossRefPubMedGoogle Scholar
  51. 51.
    Tiberi G, Costagli M, Stara R, Cosottini M (2013) Electromagnetic characterization of an MR volume coil with multilayered cylindrical load using a 2-D analytical approach. J Magn Reson 230:186–197CrossRefPubMedGoogle Scholar
  52. 52.
    Tiberi G, Fontana N, Costagli M et al (2015) Investigation of maximum local specific absorption rate in 7 T magnetic resonance with respect to load size by use of electromagnetic simulations. Bioelectromagnetics 36:358–366CrossRefPubMedGoogle Scholar

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

Personalised recommendations