Time

Prog #

Marco Piccirelli¹, ², Roger Luechinger¹, Andrea Kaspar Rutz¹, Veit Sturm³, Klara Landau³, Peter Boesiger¹, Oliver Bergamin³

¹University and ETH Zurich, Zurich, Switzerland; ²University Hospital Zurich, n/a, Switzerland; ³University Hospital Zurich, Switzerland

We studied the local deformation pattern along the horizontal extraocular muscles (EOMs), using CSPAMM Tagging, in seven healthy subjects and in a patient with Duane’s syndrome type 1 (DST1). The optic nerve, the medial, and the lateral rectus muscles were tracked with a mesh algorithm using HARP. The healthy EOM deformation patterns during left-to-right and right-to-left gaze were similar, suggesting that both horizontal muscles are active during smooth pursuit. The anterior and posterior muscle segments of the DST1 EOMs had different contraction and relaxation patterns. CSPAMM with mesh postprocessing differentiated the pathologic from the physiologic EOM local deformation pattern.

Niccolo Fiorentino¹, Jonathan Lin², Michael Guttman², Nicholas Evoy², Silvia Blemker¹, Elliot McVeigh, ²³

¹University of Virginia, Charlottesville, Virginia , USA; ²National Institutes of Health, Bethesda, Maryland, USA; ³Johns Hopkins, Baltimore, Maryland, USA

MRI tagging was used to measure engineering strain in the biceps femoris long head muscle, the most commonly injured hamstrings muscle. Imaging of normal volunteers took place in a 70cm wide bore scanner during flexion-extension of the knee. Engineering strain was defined as the difference in distance between tag lines on the initial tagged image and an image 200 ms post-tagging divided by the distance on the original image. Results were obtained along the muscle’s anterior border (4.8%), along the midline (0.9%), and along the posterior border (4.7%), suggesting strain is not uniform across the biceps femoris long head muscle.

Christine B. Chung¹, Jiang Du¹, Won Bae¹, Sheronda Statum¹, Richard Znamirowski¹, Atsushi Takahashi²

¹University of California, San Diego, San Diego, California , USA; ²GE Healthcare Technologies, Menlo Park, California , USA

The temporomandibular joint (TMJ) is an articulation of anatomic and biomechanical complexity. It is affected by a variety of osseous and soft tissue conditions that alter structure and compromise function. The fibrocartilaginous nature of TMJ tissues comprised largely of short T2 components, make their MR imaging evaluation technically difficult. Ultrashort echo time (UTE) pulse sequences allow signal from short T2 tissue components to be detected. Here we report the application of UTE sequences to imaging and quantification of TMJ of cadaver samples and volunteers on a clinical 3T scanner.

Jiang Du¹, Byung C. Pak¹, Atsushi Takahashi², Richard Znamirowski¹, Sheronda Statum¹, Christine B. Chung¹, Graeme M. Bydder¹

¹University of California, San Diego, San Diego, California , USA; ²GE Healthcare Technologies, Menlo Park, California , USA

Collagen fibers in tendons and enthuses are highly ordered. The protons within the bound water are subject to dipolar interactions which strength depends on the orientation of the fibers to the static magnetic field B0. These dipolar interactions are minimized near 55 degree relative to B0 field, resulting in a increase in T2 and MR signal. Here we applied UTE sequence to quantitatively investigate this signal and T2 dependence on orientation angle on a clinical 3T scanner.

David W. Stanley¹, Manojkumar Saranathan², Anthony T. Vu³, Marilyn B. Wood⁴, Jeffrey R. Bond⁴, John A. Skinner⁴, Matthew A. Frick⁴

¹GE Healthcare, Rochester, Minnesota, USA; ²Global Applied Science Laboratory, GE Healthcare, Rochester, Minnesota, USA; ³GE Healthcare, Waukesha, Wisconsin, USA; ⁴Mayo Clinic, Rochester, Minnesota, USA

Many pathologic, cystic or solid conditions involving the musculoskeletal system are detected on the basis of increased signal on T2-weighted images. Conventional fat suppression techniques such as chemical fat saturation are suboptimal at field strengths of 3T or higher due to B0 and B1 inhomogeneity issues leading to non-uniform fat signal across the imaged FOV.We investigated the clinical performance of a two-point Dixon-based fat-water separation scheme compared to conventional fat suppression techniques in 2D FSE imaging of the lower extremities.

Taylor Handley¹, Chen Lin¹, Robert Choplin¹, Kenneth Buckwalter¹

¹Indiana University School of Medicine, Indianapolis, Indiana, USA

This purpose of this paper is to measure the T1 and T2 relaxation times of three different gadolinium contrast agents, gadobenate dimeglumine (MultiHance),  gadoteridol (ProHance), and Gd-DTPA (Magnevist) when mixed with iodinated contrast media for MR arthrography at 0.7T, 1.5T and 3.0T. T1 and T2 maps were generated for different concentrations of gadolium agents and magnetic field strengths to generate a generalized curve fit using a least squares regression model. Although the greatest T1 relaxation was found with the gadobenate dimeglumine mixture, it was much less than what might be expected.

Joëlle Karine Barral¹, Neal K. Bangerter¹, Bob S. Hu², Dwight George Nishimura¹

¹Stanford University, Stanford, California , USA; ²Palo Alto Medical Foundation, Palo Alto, California , USA

The requirements of very high resolution and adequate SNR in clinically feasible scan times make clinical skin imaging challenging. To evaluate the feasibility of skin imaging as a clinical modality, high-resolution versions of three pulse sequences - spoiled GRE, alternated balanced SSFP, and FLASE - were compared on a 3T system. The main skin layers were identified will all sequences.

R. Dana Carpenter¹, Jean Brilhault¹, Sharmila Majumdar¹, Michael D. Ries¹

¹University of California, San Francisco, California , USA

Patellofemoral kinematics were measured in vivo in controls and in patients with two different types of total knee implants (Genesis II and Journey, both manufactured by Smith & Nephew Orthopedics, Inc.). Patients were imaged with their knees in full extension and in flexion while a compressive load was applied to the foot using an MR-compatible loading device. Knee flexion angle, patellofemoral contact area, contact centroid, medial/lateral patellar tilt, and medial/lateral patellar shift were measured after registering the images from the two different positions. The results suggest that important differences in patellofemoral kinematics may exist among the three groups.

Ute Goerke¹, Patrick John Bolan¹, Can Akgun¹, Gregor Adriany¹, Carl Snyder¹, Pierre-Francois van de Moortele¹, Lance DelaBarre¹, Noam Harel¹, Tommy Vaughan¹, Kamil Ugurbil¹, ², Jutta Ellermann

¹Radiology/University of Minnesota Medical School, Minneapolis, USA; ²Max-Planck-Institute for Biological Cybernetics, Tuebingen, Germany

Muscoloskeletal (MSK) imaging aims at visualizing small details of anatomical structures, such as the characterization of cartilage degradation by its thickness and molecular composition. The contrast and high SNR attainable in a high-resolution image has therefore the potential of providing better quantification of morphology and pathophysiological changes. Initial results demonstrate that high resolution in knee imaging can be achieved taking advantage of the gain in SNR at ultrahigh 7 T. Examples obtained with a dedicated transmit-receive radiofrequency coil driven by a multi-channel are shown. This setup permits B1-shimming to compensate for B1-inhomogeneity often observed at ultrahigh magnetic fields.

Mike Notohamiprodjo¹, Annie Horng, Jose Garcia del Olmo Raya, Wolfgang Horger, Jaeseok Park, Christoph Trumm, Maximilian Reiser, Christian Glaser

¹University Hospitals Munich, Munich, Germany

The purpose of this study was to evaluate a moderately T2-weighted 3D-TSE-fs-sequence (SPACE) for high-resolved MRI of the knee at 3T. Ten volunteers were examined. An isotropic (resolution 0.5³mm³) SPACE was acquired and reformatted into axial, sagittal and coronal sections of 0.5mm, 1mm and 2mm slice thickness (SPACE_0.5mm, SPACE_1mm, SPACE_2mm). As reference standard 2D-TSE-fs-sequences were used. SPACE_1mm yields comparable SNR to 2D-TSE-fs and appears, despite lower CNR, superior in depicting relevant small ligamentous and meniscal structures. Our preliminary results suggest that free isotropic reconstructions of SPACE could become a valuable tool in diagnostic work-up of the knee.