TRADITIONAL POSTER - ismrm

Poster Sessions
data using the multi-echo pulse sequence. Reconstructed conductivity images using the harmonic Bz algorithm show good contrast among different parts of
the subcutaneous adipose tissue, muscle, synovial capsule, and bone inside the knee
Imaging Metal with Magnets
Hall B Thursday 13:30-15:30
891. Reduction of Metal Artifacts in Patients with Hip Joint Implants by Using Optimized Imaging
Protocols
Sven Månsson 1 , Gunilla Müller 2 , Daniel Alamidi 3 , Jonas Svensson 1 , Markus Müller 2
1 Medical Radiation Physics, Lund University, Malmö, Sweden; 2 Radiology, Lund University, Malmö, Sweden; 3 Radiation Physics,
University of Gothenburg, Gothenburg, Sweden
Metal-on-metal hip resurfacing implants are suitable for young, active patients. However, there are indications that these implants fail more frequently than
traditional implants. An early diagnosis of prosthetic failure would be facilitated by artifact-reducing MRI protocols. The purpose of this study was to
investigate to which extent metal artifacts can be reduced, in the worst case of a stainless steel implant, by optimizing routine imaging protocols. The result
on a patient with hip joint implant showed that metal artifacts can be substantially reduced, thereby permitting anatomical details to be visualized closer to
the implant.
892. MAVRIC Imaging Near Metal Implants with Improved Spatial Resolution and Reduced Acquisition
Time
Kevin M. Koch 1 , Matthew F. Koff 2 , Hollis G. Potter 2 , Kevin F. King 1
1 Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States; 2 Hospital for Special Surgery, New York, United States
A variety of enhancements to the MAVRIC technique are described and demonstrated to produce minimal artifact images with sub-millimeter resolution in
the near vicinity of total joint replacements. Clinically feasible scan times are achieved by using k-space corner-cutting, partial Fourier, and autocalibrated
parallel imaging undersampling acquisition strategies. MAVRIC images are shown to dramatically reduce susceptibility artifacts while maintaining
diagnostically relevant spatial resolution when compared to established 2D-FSE arthroplasty images.
893. MRI Near Metallic Implants Using SEMAC: Initial Clinical Experience
Garry E. Gold 1 , Shreyas S. Vasanawala 2 , Wenmiao Lu 3 , Christina A. Chen 2 , Weitian Chen 4 , John M.
Pauly 5 , Kim Butts Pauly 2 , Stuart B. Goodman, Brian A. Hargreaves 2
1 Radiology, Bioengineering, Orthopaedic Surgery, Stanford University, Stanford, CA, United States; 2 Radiology, Stanford University,
Stanford, CA, United States; 3 Electrical and Electronic Engineering, Nanyang Tech., Singapore; 4 Applied Science Laboratory, GE
Healthcare, Menlo Park, CA, United States; 5 Electrical Engineering, Stanford University, Stanford, CA, United States
MRI around metallic implants such as total joint replacements has been limited due to artifacts. Recently a new method for reducing artifact near metal
called Slice Encoding for Metal Artifact Correction (SEMAC) was described. This work compares the clinical performance of SEMAC versus 2D-FSE in
an initial population of symptomatic patients with metal implants. Clinical management was changed in a substantial number of cases.
Foot to Mouth
Hall B Monday 14:00-16:00
894. High Spatial Resolution 3D MRI of the Larynx Using a Dedicated TX/RX Phased Array Coil at 7.0T
Tobias Frauenrath 1 , Wolfgang Renz 2 , Jan Rieger 1 , Andreas Goemmel 3 , Christoph Butenweg 3 , Thoralf
Niendorf 1,4
1 Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany; 2 Siemens Medical Solutions ,
Germany; 3 Chair of Structural Statics and Dynamics, RWTH, Aachen, Germany; 4 Experimental and Clinical Research Center
(ECRC), Charité Campus Buch, Humboldt University, Berlin, Germany
MRI holds great potential for elucidating laryngeal and vocal fold anatomy together with the assessment of physiological processes associated in human
phonation. However, MRI of human phonation remains very challenging due to the small size of the targeted structures, interfering signal from fat, air
between the vocal folds and surrounding muscles and physiological motion. These anatomical/physiological constraints translate into stringent technical
requirements in balancing, scan time, image contrast, immunity to physiological motion, temporal resolution and spatial resolution. Motivated by these
challenges and limitations this study is aiming at translating the sensitivity gain at ultra-high magnetic fields for enhanced high spatial resolution 3D imaging
of the larynx and vocal tract. To approach this goal a dedicated two channel TX/RX larynx coil is being proposed.
895. Real-Time Imaging of the Temporomanibular Joint Motion Based on Golden Ratio Radial MRI
Andreas Johannes Hopfgartner 1 , Olga Tymofiyeva 1 , Philipp Ehses 1 , Kurt Rottner 2 , Julian Boldt 2 , Ernst-
Jürgen Richter 2 , Peter Michael Jakob 1
1 Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; 2 Prosthodontics, Dental School, University of
Würzburg, Würzburg, Bavaria, Germany
Static or pseudo-dynamic MRI of the TMJ does not allow for full analysis of the disc deformation and displacement during the mandibular motion. The
purpose of this study was to develop a dynamic MRI technique for measurement of the TMJ with an arbitrary reconstruction window. The method uses a
radial trajectory with a constant azimuthal profile spacing of 111.246°. Two kinds of measurements were performed: opening and closing of the mouth and