Download Improvement of image quality for 3D high resolution MRI of Dental

Improvement of image quality for 3D high resolution MRI of Dental
and Maxillo-Mandibular Structures by an optimized 14+1 receive
coil array and positioning system
Alexandre T. Assaf1, Ralf Smeets1, Max Heiland1, Jens Fiehler2, Jan Sedlacik2
1
2
Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg Eppendorf, University of Hamburg,
Hamburg, Germany
Department of Diagnostics and Interventional Neuroradiology, University Medical Center Hamburg Eppendorf,
University of Hamburg, Hamburg, Germany
Abstract
Introduction and objectives: MRI is known to visualize soft tissues with great detail
and contrast. It allows assessing maxillo-mandibular pathologies before disease
progression can cause distinct destruction of osseous structures. Despite first proves
of concepts and further developments, till today, regular use in dentistry or oralmaxillofacial surgery isn’t first choice, although accelerated image acquisition allows
high spatial resolution with sufficient signals to noise ratio and reasonable scan
times. We designed, manufactured and tested a multi element receive coil array and
positioning system, optimized for 3D high-resolution dental and maxillo-mandibular
MRI with superior patient comfort.
Methods:
Three healthy volunteers were scanned with this newly created 14+1 coil array and
positioning system, consisting of a curved 23x15 cm2, 14 element phased array coil,
mounted between two pillars. Central beam is positioned directly above the upper lip.
Outer wings of the phase array coil are highly flexible and can be adapted perfectly to
the facial anatomy. One butterfly coil element provides additional coverage and
support of the lower jaw. MRI imaging parameters were fsT2w, T1w, and weT1w.
Results and discussion:
All volunteers reported high comfort at all times. 3D isotropic image data of all three
sequences were of high quality and post processing allowed reconstruction of
different views, e.g. panoramic reconstruction. The visibility of dental and oromandibular structures was excellent, especially at high-resolution weT1w data.
FsT2w data showed great visibility of the dental pulp. Furthermore, salivary glands
and ducts were depicted in great detail and superb delineation against surrounding
structures.
Conclusion:
The optimized MRI coil and positioning system for dental and oral-maxillofacial
imaging allows high-quality 3D high-spatial-resolution imaging with reasonable scan
times at 3T. It is easy to handle and provides high patient comfort, since imaging
artifacts due to movement or failing to complete the exam jeopardize the diagnostic
value of MRI examination.
Acknowledgment:
The authors thank Mr. Daniel Kutzner, Mr. Arun Khokale, Mr. Dirk Schulze, Turgay Celik, (NORAS),
Daniel Gareis (NORAS), and Mr. Reinhard E. Friedrich (OMFS) for their great work and helpful
discussions and comments on the design and the production of the coil and positioning system.