Electronic Posters : Musculoskeletal Imaging
Click on to view the abstract pdf and click on to view the video presentation.
Reduction of Susceptibility Artifact: Imaging Around Metallic Implants

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 19

14:00 3169.   Distortion Scout in Metal Implants Imaging  
Guobin Li1, Mathias Nittka2, Dominik Paul2, and Wei Jun Zhang1
1Siemens Mindit Magnetic Resonance Ltd., Shenzhen, Guang Dong, China, People's Republic of, 2Siemens Healthcare Sector, Erlangen

In SEMAC and SEMAC-MAVRIC hybrid sequences, additional z-phase encoding steps are used to correct the through-plane distortion. But the preknowledge of the distortion degree is needed to determine the extension factor of the z-phase encoding. In this work, a method to scout the through-plane distortion by applying the readout gradient in slice direction is presented, which can be fully integrated into SEMAC and SEMAC-MAVRIC hybrid sequence.

14:30 3170.   MR Imaging near orthopedic implants using Slice-Encoding for Metal Artifact Correction and Off-Resonance Suppression 
Chiel Johan den Harder1, Ulrike A Blume1, and Clemens Bos2
1MR CTO, Philips Healthcare, Best, Netherlands, 2MR Clinical Science, Philips Healthcare, Best, Netherlands

Slice-Encoding for Metal Artifact Correction (SEMAC) has been proposed for reducing image distortions near metal implants. In SEMAC, the number of through-plane phase encoding steps determines the frequency range for which slice distortions are corrected. Signals with frequencies outside this range will alias in through-plane direction. Here, SEMAC and Off-Resonance Suppression (ORS) are combined to limit signal selection to a confined frequency range and thus prevent back-folding. Phantom and in-vivo experiments show that ORS allows substantial reduction of phase encoding steps to obtain SEMAC images without back-folding. The resulting imaging time reduction supports the clinical utility of SEMAC.

15:00 3171.   MSVAT-SPACE for fast metal implants imaging 
Guobin Li1, Mathias Nittka2, Dominik Paul2, and Lars Lauer2
1Siemens Mindit Magnetic Resonance Ltd., Shenzhen, Guang Dong, China, People's Republic of, 2Siemens Healthcare Sector, Erlangen

SEMAC and MAVRIC are two recently developed techniques to significantly reduce the geometric distortion caused by metallic implants in MR examinations. However, both two methods are suffering from long scan time due to their intrinsic feature of 3D acquisition. In this abstract, the limitations of these two methods in terms of sampling efficiency are analyzed and an improved implementation MSVAT-SPACE is presented to show the higher imaging speed

15:30 3172.   Combined Parallel Imaging and Compressed Sensing on 3D Multi-Spectral Imaging Near Metal Implants 
Kevin M Koch1, and Kevin F King1
1Global Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States

3D Multi-Spectral Imaging (3D-MSI) can significantly reduce susceptibility artifacts near metal implants. In order to reduce these artifacts, 3D-MSI acquires a large amount of spectral and spatially encoded data. With such requirements, it is challenging to acquire high-resolution 3D-MSI images in a clinical environment. Here, we explore the combined effects of data-driven parallel imaging and compressed sensing in improving the resolution capabilities of 3D-MSI near a total knee replacement at 1.5T.

Tuesday May 10th
  13:30 - 15:30 Computer 19

13:30 3173.   Jacobian-Based Correction of 3D-MSI Images Near Implanted Metal Devices 
Kevin M Koch1, Matthew A Koff2, and Hollis G Potter2
1Global Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States, 2Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States

3D-Multi-Spectral Imaging techniques (MAVRIC, SEMAC, and combinations thereof) can substantially reduce image artifacts in the presence of implanted metal. Residual susceptibility artifacts in 3D-MSI techniques are commonly manifested as localized “pileup” artifacts - where many spins are frequency encoded to the same spatial position. Here, we show that spectral information inherent to 3D-MSI acquisitions can be used to construct field maps with sufficient accuracy to combat these residual artifacts through estimation of local gradients and Jacobian intensity correction of shifted pixels. The proposed methods are demonstrated on clinical images at 1.5T of total knee and shoulder replacements composed of cobalt-chromium alloys.

14:00 3174.   POCS-based Compressive Slice Encoding for Metal Artifact Correction 
Wenmiao Lu1, Jun Deng1, Yi Lu2, Garry Gold3, and Brian Hargreaves3
1Nanyang Tech. University, Singapore, SG, Singapore, 2University of Illinois, Urbana Champaign, United States, 3Stanford University, United States

Slice Encoding for Metal Artifact Correction (SEMAC) fully corrects metal-induced artifacts in MR images, which nevertheless suffers from two main problems, namely long scan times and low signal-to-noise ratio. This work presents a new POCS-based reconstruction procedure for SEMAC, which fully exploit the correlation and sparsity in SEMAC-encoded slices. The new reconstruction procedure not only greatly reduces scan times incurred to fully correct metal-induced artifacts but also leads to the improved SNR of SEMAC corrected result.

14:30 3175.   B1 Mapping Near Metallic Implants 
Uchechukwuka Diana Monu1, Pauline W Worters2, Kyunghyun Sung2, Kevin M Koch3, Garry E Gold2, and Brian A Hargreaves2
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Department of Radiology, Stanford University, Stanford, CA, United States, 3Applied Science Lab, GE Healthcare, Waukesha, WI, United States

In MRI, the measurement of RF excitation fields is challenging. Furthermore, B0 inhomogeneities make B1 mapping near metallic implants especially difficult. Currently available B1 mapping methods that are based on gradient echo and spin echo techniques have not been successfully used around metallic implants. This is mostly due to signal loss from increased susceptibility and imaging artifacts near metal. In this work, B1 maps of phantoms were obtained using the standard gradient echo double angle method (DAM) and using the SEMAC DAM on a 1.5T whole-body MR scanner. A good comparison of these maps and matlab simulations carried out to model the error values of the SEMAC DAM, allowed for the SEMAC DAM to be subsequently applied to a metallic implant phantom at both 1.5T and 3T. The flip angle maps obtained show that the proposed technique is a valid approach for tackling the issue of B1 mapping near metallic implants.

15:00 3176.   Magnetic Resonance Imaging of Metal-On-Metal Hip Resurfacing Implants 
Catherine Lee Hayter1, Matthew F Koff1, Kevin F Koch2, Parina Shah1, Edwin P Su3, and Hollis G Potter1,4
1Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States, 2Applied Science Laboratory, General Electric Healthcare, Waukesha, Wisconsin, United States, 3Center for Hip Pain and Preservation, Hospital for Special Surgery, New York, NY, United States, 4Weill Cornell Medical College of Cornell University, New York, NY, United States

Metal-on-metal hip resurfacing is associated with specific complications, including metal hypersensitivity which may manifest as synovitis, bursitis or osteolysis. The purpose of this prospective, observational study was to review patterns of osteolysis and synovitis in symptomatic and asymptomatic individuals following resurfacing. Synovitis was detected in a similar proportion of symptomatic and asymptomatic patients. Osteolysis was only detected in symptomatic individuals. The similarities of the synovitis measurements combined with the lack of correlation with blood chromium and weak correlation with blood cobalt ion levels indicate that additional factors must be considered when determining the long term prognosis of hip resurfacing implants.

Electronic Posters : Musculoskeletal Imaging
Click on to view the abstract pdf and click on to view the video presentation.
Kinematic MR in the Knee & Small Joints/Inflammatory

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 20

14:00 3177.   Dynamic imaging produces different 3D knee kinematic information than static imaging 
Agnes G d'Entremont1,2, Jurek Nordmeyer-Massner3, Clemens Bos4, David R Wilson2,5, and Klaas P Pruessmann3
1Mechanical Engineering, University of British Columbia, Vancouver, BC, Canada, 2Centre for Hip Health and Mobility, Vancouver, BC, Canada, 3Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland, 4Philips Healthcare, Best, Netherlands, 5Orthopaedics, University of British Columbia, Vancouver, BC, Canada

In many in vivo studies, knee kinematics have been assessed using images acquired at a series of static positions over the range of motion, however there may be differences between the kinematics estimated from sequential static poses of the joint and the kinematics of the moving joint. Ten normal subjects were examined using static and dynamic methods. Differences between dynamic and static results were seen for nine of 11 kinematic parameters Dynamic-based 3D kinematics measures provide different information from static 3D measures, and may represent kinematic results closer to those in activities of daily living.

14:30 3178.   Dynamic Imaging of 3d Knee Kinematics using PC-VIPR 
Robert Bradford1, Kevin Johnson2, Oliver Wieben2, and Darryl Thelen1
1Mechanical Engineering, University of Wisconsin - Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin - Madison

Abnormal joint mechanics may contribute to the development of osteoarthritis in individuals with prior knee injuries. We evaluated the potential to use 3D cine-PC VIPR sequence to directly measure knee kinematics. Cyclic, loaded knee flexion-extension was performed while 3D velocity images were collected. Velocity data were numerically integrated to track tibia and femur position and orientation. These kinematic data were coupled with segmented models to visualize knee joint motion and cartilage contact. The results are promising and will be used to assess how well knee reconstructive surgeries are able to restore normal mechanics and thereby mitigate the potential for osteoarthritis.

15:00 3179.   Compression of the knee upon weight loading in healthy and osteoarthritis subjects as measured by MRI and X-ray 
Bradley T. Wyman1, Sebastian Cotofana2, Yanwei Zhang1, Richard B Souza3, M-P Hellio Le Graverand1, Xiaojuan Li3, Sharmila Majumdar3, Thomas M Link3, Felix Eckstein2, and Eric Vignon4
1Pfizer, Groton, CT, United States, 2Paracelsus Medical University, Salzburg, Austria, 3University Califorinia, San Francisco, San Francisco, CA, United States, 4Universite Claude Bernard, Lyon, France

MRI and x-rays were acquired of the knee in weight bearing and non weight bearing conditions in 31 subjects. Eleven had no radiographic osteoarthritis (OA), Kellgren and Lawrence grade (KLG) 0, and 10 subjects each with OA KLG 2, and 3. Joint space width (JSW) was measured from the x-ray and mean medial femoral tibial cartilage thickness (MFTC_ThCtAB) from MRI. The compression in JSW and mean MFTC_ThCtAB under load was not significantly different from zero in KLG 0 subjects but JSW and MFTC_ThCtAB were both greater and significantly different from zero in KLG 2 and 3 subjects.

15:30 3180.   Fast dynamic multislice MRI of the human knee using a motion device 
Daniel Ludwig Weber1,2, Sebastian Klum2, Sai Ramesh Raghuraman2, Joachim Hermann Schrauth1,2, Peter Michael Jakob1,2, and Daniel Haddad1,2
1MRB Research Center for Magnetic Resonance Bavaria eV, Würzburg, Bavaria, Germany, 2Department of Experimental Physics 5 (Biophysics), University of Würzburg, Würzburg, Bavaria, Germany

Knee injuries are among the most common injuries of the musculoskeletal system. Unfortunately, static MRI often does not lead to satisfying diagnoses, especially in difficult cases. We developed a motion device and – in collaboration with Rapid Biomedical – a 16 channel U-shaped coil array to enable dynamic imaging of the knee for a characterization of the complex motion of the knee or therapy monitoring after cartilage or ligament reconstruction. A triggered, segmented, dynamic multislice MRI sequence was used to acquire 4D datasets in 8 minutes which can be visualized as several compartments (femur, tibia, patella, infrapatellar fat pad, cruciate ligaments).

Tuesday May 10th
  13:30 - 15:30 Computer 20


Kinematic evaluation of the wrist is important in the diagnosis and management of wrist pathology. Altered kinematics can lead to unbalanced joint loading and ultimately, osteoarthritis. Unfortunately, dynamic abnormalities of carpal motion are often missed by static imaging. Using fast imaging techniques such as HASTE, data can be rapidly acquired during normal wrist motion and quickly processed into 2D and 3D cine loops. We show that it is feasible to obtain this data at little time cost; this may prove to be an important addition to routine clinical imaging to provide important kinematic information to the clinician.

14:00 3182.   Quantitative assessment of mechanical ankle laxity using MR imaging 
Christian Jürgen Seebauer1, Jens Rump2, Hermann Josef Bail3, Felix Güttler2, Bernd Hamm2, and Ulf Teichgräber2
1Center for Musculoskeletal Surgery, Charité-Universitätsmedizin Berlin, Berlin, Berlin, Germany, 2Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Berlin, Germany, 3Department of Trauma and Orthopedic Surgery, Clinic Nuremberg, Nuremberg, Germany

To date, no reports document the advantages of the combination of MRI and stress examination in the assessment of mechanical ankle instability. In the present study an MR-compatible stress device was developed and tested for MR-safety. Bilateral MRI-stress examinations were performed on 50 volunteers, i.e. 35 healthy subjects (group A) and 15 athletes suffering from chronic ankle instability (group B). Both, the inversion test and the anterior drawer test were performed under axial, coronal, 45° para-axial and sagittal T2W FSE image control. MR images were assessed for the talar-tilt (TT), subtalar-tilt (STT), anterior-talus-translation (ATT), anterior-calcaneus-translation (ACT), lateral-talocalcaneal-translation (MTCT) and the ligaments of the lateral ankle (ATFL, CFL and PTFL).

14:30 3183.   Stress MRI of Ligamentous Stabilizers in Acute and Chronic Acromioclavicular Joint Instabilities 
Marco Vicari1,2, Kaywan Izadpanah3, Norbert P Suedkamp3, Matthias Weigel2, Matthias Honal2, Elisabeth Weitzel3, Elmar Kotter4, Mathias Langer4, and Jan T Winterer4
1MRI R&D, Esaote S.p.A., Genova, Italy, 2Dept. of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 3Dept. of Orthopeadic and Trauma Surgery, University Medical Center Freiburg, Freiburg, Germany, 4Dept. of Radiology, Clinical Radiology, University Medical Center Freiburg, Freiburg, Germany

Currently, clinical evaluation, plain and weighted radiography are the gold standard for acromioclavicular joint injury grading. A detailed injury identification is sometimes lacking and this might explain the high percentage of persisting or recurrent joint instability after conservative or operative treatment. Biomechanical tests have shown the importance of a complete anatomic reconstruction of all ligamentous stabilizers, whose planning requires detailed morphologic information. Since weight-bearing shoulder MRI enables simultaneous acquisition of morphology and functional integrity information of all stabilizers of the acromioclavicular joint, both in acute and chronic injuries, it may improve the injury classification accuracy of borderline cases and, thus, the therapeutic decision making efficacy.

15:00 3184.   Assessment of length variations of the coracoclavicular ligaments during arm movement from MRI data 
Matthias Honal1, Marco Vicari2, Elisabeth Weitzel3, and Kaywan Izadpanah3
1Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Esaote S. p. A., Genova, Italy, 3Department of Orthopeadic and Trauma Surgery, University Medical Center Freiburg, Freiburg, Germany

The precise analysis of the coracoclavicular ligaments during arm movement may be important for the treatment of acromioclavicular joint disruption. In this study a semi-automatic method based on the registration of MRI images is introduced which allows for the accurate assessment of length variations of the coracoclavicular ligaments for different arm abductions. Points in the ligament insertion regions are manually defined for one arm abduction only and automatically propagated to the other arm abductions with high accuracy. Thus the distance variations between points as a function of the arm abduction can be reliably obtained.

Wednesday May 11th
  13:30 - 15:30 Computer 20

13:30 3185.   MRI of the plantar plate in the painful forefoot of patients with rheumatoid arthritis 
Heidi J Siddle1, Richard J Hodgson2, Anthony C Redmond1,2, Andrew J Grainger2,3, Richard J Wakefield1,2, David A Pickles4, and Philip S Helliwell1
1Section of Musculoskeletal Disease, University of Leeds, Leeds, West Yorkshire, United Kingdom, 2Leeds Musculoskeletal Biomedical Research Unit, Leeds, United Kingdom,3Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom, 4Department of Rheumatology, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom

This study aims to characterise the structural changes in the plantar plates of the lesser (2nd to 5th) MTP joints in 24 patients with rheumatoid arthritis (RA) using 3T MRI. PD FS, T2 FS and T1 post gadolinium sequences were acquired through 96 lesser MTP joints. Images were scored using the RAMRIS and plantar plates were assessed for pathology. Plantar plate pathology was most frequently demonstrated at the 5th MTP joint. A statistically significant relationship was demonstrated between plantar plate pathology and both bone oedema erosion at the lesser MTP joints. There was no significant relationship between synovitis and plantar plate pathology.

14:00 3186.   Dynamic contrast enhanced MRI of the Achilles enthesis in spondyloarthritis 
Richard Hodgson1, Peter Wright2, Andrew J Grainger2, Phillip J O'Connor2, Phillip Helliwell3, Dennis McGonagle3, Paul Emery3, and Matthew D Robson4
1LMBRU, University of Leeds, Leeds, Yorkshire, United Kingdom, 2Leeds Teaching Hospitals NHS Trust, 3University of Leeds, 4University of Oxford

Enthesitis is the hallmark of spondyloarthritis. 23 patients with SpA and 13 healthy volunteers were studied with DCE-MRI of the tendon and the calcaneal bone marrow at the Achilles enthesis. The relative early enhancement rate was significantly greater in SpA patients than healthy volunteers. The EER was significantly higher in patients with power Doppler ultrasound abnormalities. Tendon and bone changes were significantly correlated (R=0.6). In conclusion, DCE-MRI may be useful for assessing changes at the Achilles enthesis in spondyloarthritis.

14:30 3187.   Comparison of MRI of the hand and feet for detecting early arthritis 
Andrew J Grainger1, Richard J Hodgson2, Jackie Nam2, Edith Villeneuve2, and Paul Emery2
1LMBRU, Leeds Teaching Hospitals NHS Trust, Leeds, Yorkshire, United Kingdom, 2University of Leeds

Objective: To determine whether MRI of the feet in patients with suspected arthritis provides additional diagnostic information over and above MRI of the hand alone. Methods: 18 patients with suspected arthritis and anti-CCP antibody underwent MRI of a hand and the feet. Images were assessed for synovitis, marrow edema, erosions and tenosynovitis. Results: 7 patients with non-diagnostic hand MRI showed foot abnormalities. In 5 of these cases the foot imaging was suggestive of rheumatoid arthritis. Conclusion: Imaging the feet in patients with suspected arthritis may provide additional information where hand imaging is non-diagnostic.

15:00 3188.   Magnetisation Transfer Contrast imaging of Synovitis in Arthritis. 
Carole Burnett1, Andrew Grainger1, Anthony Redmond1,2, and Richard Hodgson1,2
1LMBRU, Chapel Allerton Hospital, Leeds, United Kingdom, 2Leeds University, United Kingdom

Synovitis is an important feature of rheumatoid and osteoarthritis and is well assessed by MRI. Previous work suggested Magnetisation Transfer Contrast may be helpful in the assessment of synovitis. Currently, the gold standard for assessing synovitis with MRI requires intravenous contrast agents which are associated with discomfort, cost and potential patient complications. The aim of this study was to compare magnetisation transfer imaging with T1 weighted imaging after administration of intravenous contrast for quantification of synovitis.

Thursday May 12th
  13:30 - 15:30 Computer 20

13:30 3189.   The Value of 3D eTHRIVE in the Diagnosis of Early Rheumatoid Arthritis of the Hand at 3T 
Kazuyuki Ohgi1, Masatoshi Hotta1, Satoshi Doishita1, Akinori Harada1, Akiyoshi Yamashita1, Hiroyuki Yokote1, Shunji Tsukuda1, and Tetsuhisa Yamada1
1Department of Radiology, Japanese Red-Cross Medical Center, Shibuya-ku, Tokyo, Japan

Early diagnosis is essential in patients with RA. This study illustrates the usefulness of 3D eTHRIVE in MR diagnosis of RA of the hand at 3T. 3D eTHRIVE can provide useful information by eliminating partial volume effect and by yielding excellent fat saturation, and has a potential of playing important roles in the diagnosis of RA.

14:00 3190.   In Vivo 19F MRI for Sensitive Assessment of Arthritis: Antiinflammatory Action of A2A Receptor Activation 
Ulrich Flögel1, Lisa Galbarz1, Zhaoping Ding1, Ali El-Tayeb2, Christoph Jacoby1, Peter van Lent3, Christa Müller2, and Jürgen Schrader1
1Institute for Cardiovascular Physiology, Heinrich Heine University, Düsseldorf, NRW, Germany, 2PharmaCenter Bonn, 3Radboud University Nijmegen

Since arthritis is associated with persistent high levels of inflammation, the present study made use of the underlying autoimmune response to sensitively monitor the development of arthritis. For this purpose, we used emulsified perfluorocarbons (PFCs) which are preferentially phagocytized by monocytes/macrophages and readily detected by 19F MRI. This approach was employed to assess the therapeutical feasibility of adenosine A2A receptor activation. The results (i) show that PFCs can serve as MRI contrast agent for the early detection of arthritis, thereby permitting a more timely therapeutic intervention, and (ii) provide in vivo evidence for site-specific A2A stimulation as novel antiinflammatory therapy.

14:30 3191.   Iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) of the wrist and finger at 3TMRI: comparison with chemical shift selective fat suppression images 
Takatoshi Aoki1, Yoshiko Yamashita1, Hiroyuki Takahashi1, Yoshiko Hayashida1, Hodaka Oki1, Shigeru Hibino2, Atsushi Nozaki2, Kazuyoshi Saito3, Yoshiya Tanaka3, and Yukunori Korogi1
1Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Fukuoka, Japan, 2GE Healthcare Japan, 3First department of Internal Medicine, University of Occupational and Environmental Health School of, Kitakyushu, Fukuoka, Japan

A main challenge of clinical musculoskeletal imaging with maintaining high SNR is uniform fat suppression in areas of B0 inhomogeneity. Our purpose is to compare IDEAL with chemical shift selective fat-suppressed T1-weighted spin-echo (FS-CHESS-T1-SE) images for MR imaging of the hand and finger at 3.0T MR system. Eight healthy volunteers and 8 rheumatoid arthritis patients were examined with both sequences. Image quality and lesion delineation was better on IDEAL than on FS-CHESS-T1-SE images. IDEAL compensates for the effects of field inhomogeneities, providing uniform fat suppression of the hand and finger than did FS-CHESS-T1-SE sequence.

15:00 3192.   Progression of an antigen-induced arthritis model in rat assessed by MRI 
Lindsey Alexandra Crowe1, Frank Tobalem1, David Tchernin2, Benedicte M-A Delattre1, Kerstin Grosdemange1, Marije Koenders3, Wim B van den Berg3, and Jean-Paul Vallée1
1Division of Radiology, Geneva University Hospitals, University of Geneva, Faculty of Medicine, Foundation for Medical Researchers, Geneva, Switzerland, 2Division of Radiology, Geneva University Hospitals, Geneva, Switzerland, 3Department of Rheumatology, Rheumatology Research and Advanced Therapeutics, Radboud University Nijmegen Medical Center, Netherlands

In-vivo MR imaging of intra and extra-articular oedema by T2 STIR MRI enables serial assessment of the progression of an antigen-induced arthritis (AIA) model in rat. Images were scored for the stage of the disease by consent of 3 readers after blinding. All left control knees scored zero for oedema and bone erosion, unlike diseased right knees that showed a rapid peak in extra-articular oedema, followed by intra-articular oedema and finally bone erosion.

Electronic Posters : Musculoskeletal Imaging
Click on to view the abstract pdf and click on to view the video presentation.
MSK: 7T & Beyond MRI

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 21

14:00 3193.   High resolution imaging of the sacroiliac joints in ankylosing spondylitis patients at 7 Tesla 
Maartje E Vossen1, Wouter M Teeuwisse1, Monique Reijnierse1, Desiree M van der Heijde2, Nadine B Smith1, and Andrew G Webb1
1Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Rheumatology, Leiden University Medical Center

High spatial resolution images of the SI joints have been acquired at 7 Tesla in both volunteers and patients sufferenting from sacroilitis. Very small cortical erosions can be visualized with an in-plane resolution of 0.5 x .5 mm. Water/fat imaging using a three-point Dixon method was shown to differentiate between fatty infiltration and edema in a second patient.

14:30 3194.   MR Imaging of the Lower Extremities at 7 Tesla: Initial Experience with a 15 Channel Coil 
Michael Bock1, Florian Meise1, Titus Lanz2, Reiner Umathum1, Lydia Schuster3, Lars Gerigk3, Armin M Nagel1, Ann-Kathrin Homagk1, and Wolfhard Semmler1
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2RAPID Biomedical GmbH, Rimpar, Germany, 3Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany

MR imaging of the knee has been demonstrated at 7 Tesla, but the full potential of the high field strength has so far not been exploited due to the lack of multi-channel receive coils. In this work we present preliminary data acquired with a 15 channel extremty coil which demonstrates that MR imaging of the knee region is feasible with parallel imaging at 7 Tesla in clinically acceptable imaging times.

15:00 3195.   The Comparison of the Performance of MRI Clinical Sequences for Ankle Imaging at 3T vs 7T 
Vladimir Juras1,2, Goetz Welsch1, Ladislav Valkovic2, Pavol Szomolanyi1,2, Iris-Melanie Nöbauer-Huhmann1, Ivan Frollo2, and Siegfried Trattnig1
1Department of Radiology, Medical University of Vienna, Vienna, Austria, Austria, 2Department of Imaging Methods, Institute of Measurement Science, Bratislava, Slovakia

The aim of this study was to investigate the performance of the clinical MR sequences in in-vivo ankle imaging at ultrahigh-field (7 Tesla) MR. As a key parameter SNR and CNR of different structures were used with 3 sequences (3D-GRE, 2D-SE, 2D-TSE). Significantly better performance of clinical MR sequences in ankle joint imaging at 7T in comparison to 3T was observed. The substantial benefit from ultrahigh-field could be demonstrated.

15:30 3196.   Magnetic Resonance Imaging of the Knee at 3 and 7 Tesla – comparison using dedicated multi-channels coils and optimized 2D and 3D protocols 
Goetz Hannes Welsch1,2, Vladimir Juras1, Pavol Szomolanyi1, Tallal Charles Mamisch3, Peter Baer4, Claudia Kronnerwetter1, Friedrich Frank Hennig2, Hiroyuki Fujita5, and Siegfried Trattnig1
1Medical University of Vienna, Vienna, Vienna, Austria, 2Department of Trauma Surgery, University of Erlangen-Nuremberg, Erlangen, Bavaria, Germany, 3University of Berne, 4Siemens Healthcare, 5Quality Electrodynamics

Aim of this study was to compare the quantitative and qualitative performance of a routine 8-channel knee coil at 3T and a new 28-channel knee coil at 7T. Compared to an optimized 3T protocol, at 7T, i)the resolution was increased whereas keeping the same examination time and ii)the examination time was reduced whereas keeping the spatial resolution the same. CNR as well as the subjective quality revealed better results for both 7T measurements compared to the 3T measurements, documenting the possible superiority of 7T MRI in the knee joint compared to 3T in the presence of a dedicated multi-channel coil.

Tuesday May 10th
  13:30 - 15:30 Computer 21

13:30 3197.   High Resolution MRI of the Wrist at 7 Tesla Detects Subregional Variation in Trabecular Bone Micro-architecture in Healthy Subjects 
Gregory Chang1, Ligong Wang1, Guoyuan Liang2, Graham C Wiggins1, Punam K Saha2, and Ravinder R Regatte1
1NYU Langone Medical Center, New York, NY, United States, 2University of Iowa, Iowa City, Iowa, United States

High resolution 7 Tesla MRI can detect subregional variations in trabecular bone micro-architecture of the wrist in healthy subjects. These differences may explain differences in individuals' bone quality and fracture risk.

14:00 3198.   Comparison of a 28 Channel Phased-Array Coil and a Circularly Polarized Coil for Morphologic Imaging and T2 Mapping of Knee Cartilage at 7 Tesla 
Gregory Chang1, Ding Xia1, Graham C Wiggins1, Guillaume Madelin1, Christian Glaser1, Matthew Finnerty2, Hiroyuki Fujita2, and Ravinder R Regatte1
1NYU Langone Medical Center, New York, NY, United States, 2Quality Electrodynamics, Mayfield Village, Ohio, United States

This in vivo study on 10 healthy subjects compares the performance of a 28 channel phased array coil and a circularly polarized coil for morphologic magnetic resonance imaging and T2 mapping of knee cartilage at 7 Tesla. Signal-to-noise ratio and contrast-to-noise ratio are higher with the 28 channel coil, favoring its use for future studies of osteoarthritis or other knee pathology.

14:30 3199.   Skeletal muscle diffusion tensor imaging of the human forarm at 7T 
Martijn Froeling1,2, Johannes M Hoogduin3,4, Dennis W.J. Klomp3, Klaas Nicolay1, Gustav J Strijkers1, and Aart J Nederveen2
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, 2Department of Radiology, Academic Medical Center, Amsterdam, Netherlands, 3Imaging Division, University Medical Center Utrecht, Utrecht, Netherlands, 4Brain Division, University Medical Center Utrecht, Utrecht, Netherlands

Data acquisition at high field increases the signal allowing for higher spatial resolution. In this study demonstrate the feasibility of DTI of skeletal muscle at 7T maximizing the spatial resolution.

15:00 3200.   Sodium (23Na) MR Imaging at 7 T for the Evaluation of Repair Tissue Quality in Patients after Two Cartilage Repair Procedures 
Stefan Zbyn1,2, David Stelzeneder1, Goetz Hannes Welsch1,3, Lukas L. Negrin4, Vladimir Juras1,5, Pavol Szomolanyi1,5, Ronald Dorotka2, and Siegfried Trattnig1
1Department of Radiology, Medical University Vienna, Vienna, Austria, 2Department of Orthopaedic Surgery, Medical University Vienna, Vienna, Austria, 3Department of Trauma Surgery, University Hospital of Erlangen, Erlangen, Germany, 4Department of Trauma Surgery, Medical University Vienna, Vienna, Austria, 5Department of Imaging Methods, Institute of Measurement Science - SAS, Bratislava, Slovakia

The aim was to apply gradient-echo sequence optimized for sodium imaging at 7T for the evaluation of repaired tissue glycosaminoglycan (GAG) content in the patients after bone marrow stimulation (BMS) and matrix-associated autologous chondrocyte transplantation (MACT) treatment of articular cartilage. Significantly lower GAG content was found in the repaired tissue in comparison to the native cartilage in both treatment groups and significantly lower GAG content was observed in BMS repair tissue in comparison to MACT repair tissue. Our results suggest that the MACT treatment provides higher GAG content and therefore higher quality repair tissue in comparison to the BMS techniques.

Wednesday May 11th
  13:30 - 15:30 Computer 21

13:30 3201.   Detection of Fast Decaying Lactate in Human Skeletal Muscle after Exercise by 7T 1H MRS 
Jimin Ren1, Ivan Dimitrov1,2, Changho Choi1, A Dean Sherry1,3, and Craig R Malloy1,4
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 2Philips Medical Systems, Cleveland, Ohio,3Department of Chemistry, University of Texas at Dallas, Richardson, Texas, United States, 4VA North Texas Health Care System, Dallas, Texas, United States

Lactate plays a crucial role in energy homeostasis in body. Elevated lactate can be an important marker of mitochondria disease, poor prognosis in acutely ill patients, or nutritional deficiency of thiamine. Lactate measurement by proton MRS is usually done by detecting the methyl resonance. In muscle, overlapping signals from lipids poses challenge to the effectiveness of this approach. Here we demonstrate that STEAM-based sequence with long echo time at 7T allows detection of lactate methine signal in exercised muscle in vivo. It is found that lactate decays very fast (half time 1.4 min) following 10 minutes of hand open-close exercise.

14:00 3202.   Population-averaged 7T 1H MRS Determination of Metabolites in Human Skeletal Muscle at Rest 
Jimin Ren1, Ivan Dimitrov1,2, Craig R Malloy1,3, and A Dean Sherry1,4
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 2Philips Medical System, Cleveland, Ohio, United States, 3VA North Texas Health Care System, Dallas, Texas, United States, 4Department of Texas at Dallas, University of Texas at Dallas, Richardson, Texas, United States

Proton MRS offers many advantages for detection of a number of muscle metabolites. However, quantitative and reliable measurement of muscle metabolites can be quite challenging due to multiple factors intrinsic to MRS and skeletal muscle itself. We present here an optimized 1H MRS acquisition protocol, termed “muscle module”, for acquisition of high-quality spectra for easy data analysis. This muscle module is based on a STEAM sequence, with data acquisition at two different echo-times, TE 140 and 280 ms, without applying water-suppression pulses. Its advantage in spectral resolution enhancement and quantitative analysis is demonstrated in a large population (n = 80).

14:30 3203.   Phosphocreatine and Acetylcarnitine in Skeletal Muscle During Exercise at 7T by Interleaved 31P and 1H-MRS 
Katja Heinicke1,2, Jackson Green1,2, Ivan Dimitrov3,4, Sergey Cheshkov3, Jimin Ren3, Craig R. Malloy3, and Ronald G. Haller1,2
1Neuromuscular Center, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, United States, 2Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States, 3Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, 4Philips Medical Systems, Cleveland, OH, United States

31P-MRS provides insight into muscle energy metabolism, and 1H-MRS offers direct measurement of intramyocellular lipid concentration and the concentration of acetylcarnitine which is important for characterizing mitochondrial function and integrity. The objective of this pilot study was to evaluate the feasibility of interleaved 1H and 31P-MRS measurements in human skeletal muscle during exercise in a 7 Tesla whole body magnet. This study demonstrates that, it is possible to obtain consecutive high resolution 1H-MRS and 31P-MRS spectra in response to exercise. The rate of recovery of high energy phosphates in skeletal muscle post exercise is much faster than recovery of acetylcarnitine.

15:00 3204.   Comparison of 31P-MRS at 3T and 7T for localized and non-localized acquisition 
Wolfgang Bogner1, Marek Chmelik1, Siegfried Trattnig1, and Stephan Gruber1
1Department of Radiology, Medical University of Vienna, Vienna, Austria

For phosphorus magnetic resonance spectroscopy (31P-MRS) the SNR of surface coil localized fully relaxed 31P spectra was reported to be almost doubled between 3T vs 7T in the human calf muscle. These studies did not consider differences in the sensitive volume of coils. Localized 31P-MRS allows unbiased comparison of spectral quality between different field strength. We found that the reported SNR gain for surface coil localized 31P-MRS was significantly underestimated. In our study localized 31P-MRS showed an ~3.2 times higher SNR at 7T than at 3T with identical measurement parameters, while surface coil localized 31P-MRS showed only an increase by a factor of ~2.

Thursday May 12th
  13:30 - 15:30 Computer 21

13:30 3205.   In vivo 31P diffusion tensor spectroscopy of human calf muscle 
Hermien E. Kan1, Sebastian Aussenhofer1, Andrew Webb1, Aranee Techawiboonwong2, and Itamar Ronen1
1Radiology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands, 2Department of Electrical Engineering, Mahidol University, Nakornpathom, Thailand

Assessment of diffusive properties of phosphorous metabolites using diffusion tensor spectroscopy (DTS) has so far been limited to animal studies. 31P DTS of the phosphocreatine signal could provide a useful method to probe intracellular space in humans, as it is not present in the same compartment as the adipose tissue that influences DTI measurements of skeletal muscle. In this study, we show, for the first time in humans, that it is feasible to obtain ADC and FA values of different skeletal muscles in the human calf using 2D 31P DT CSI and a newly developed coil design for 7T.

14:00 3206.   T1-rho dispersion in human OA cartilage specimens using HRMAS Spectroscopy at 11.7T 
Keerthi Shet1, Hikari Yoshihara2, Joe Schooler2, John Kurhanewicz2, Michael Ries2, and Xiaojuan Li2
1Radiology, University of California, San Francisco, San Francisco, CA, United States, 2University of California, San Francisco

HRMAS NMR spectroscopy was used to quantify T1-rho and T2 relaxation times and examine the T1-rho dispersion characteristics of human OA cartilage specimens. T2 of water in cartilage showed a bi-exponential decay, with the shorter component significantly higher in OA cartilage. A mono-exponential decay was a better fit to T1-rho of control cartilage as against a bi-exponential decay for OA-cartilage. The longer T1-rho component of OA cartilage was found to be significantly higher than the T1-rho of healthy cartilage which can be attributed to proteoglycan degeneration in OA cartilage.

14:30 3207.   Multiparametric assessment of healthy and OA articular cartilage under loading at 17.6 T 
Jose G Raya1, Gerd Melkus2, Silvia Adam-Neumair3, Kevin Dunham4, Olaf Dietrich3, Maximilian F Reiser3, Reinhard Putz3, Peter M Jakob5, and Christian Glaser4
1Radiology, New York University Langone Medical Center, New York, NY, United States, 2University of California, San Francisco, 3University of Munich, 4New York University Langone Medical Center, 5University of Wuerzburg

The aim of this work was to characterize the functionality of human healthy and OA articular cartilage using a multiparametric approach (T2, T1, ADC, FA and water volume fraction). Samples of healthy (n=10) and OA (n=3) patellar cartilage were MRI examined at 17.6T (resolution=50×100μm2) native, under loading (strain=26%) and 4h after relaxation (n=5 healthy, n=1 OA). Differences in MRI parameters between the native and loading examinations were larger in absolute value and extension in OA than in the healthy samples. After 4h relaxation, healthy samples returned to their native values, whereas the OA sample demonstrated signs of the indentation.

15:00 3208.   A newly strictly non-invasive experimental device allowing repeated MR investigations of exercising hindlimb mouse muscles at ultra-high field (11.75T) 
Julien GONDIN1, Christophe VILMEN1, Patrick J. COZZONE1, Guillaume DUHAMEL1, and David BENDAHAN1
1Centre de Résonance Magnétique Biologique et Médicale (CRMBM) - UMR CNRS 6612, Faculté de Médecine - Université de la Méditerranée, Marseille, France
We have constructed a strictly non-invasive experimental setup adapted to an ultra-high field MR system and report in the present work the results of MRI investigation and force production measurements in exercising hindlimb mouse muscles at ultra-high field. This newly strictly non-invasive device allowed highly reproducible measurements of both force production and muscle activation (T2 changes) in exercising hindlimb mouse muscles within an ultra-high field magnet. Our setup appears as a suitable tool for future ultra-high field functional MR investigations of exercising hindlimb mouse muscles.

Electronic Posters : Musculoskeletal Imaging
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Ultrashort TE: MSK Applications

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 22

14:00 3209.   Free and bound water quantification of cortical bone 
Jiang Du1, Won Bae1, Hermida Juan2, Eric Diaz1, Christine Chung1, Darryl DLima2, and Graeme Bydder1
1Radiology, University of California, San Diego, San Diego, California, United States, 2Scripps Reseach Institution

Bone water occurs at various locations and in different states. It is associated with the mineral phase, bound to the organic matrix, and a significant fraction occurs in more or less free form in the microscopic pores of the Haversian and the lacuna-canalicular systems. A measure of free water concentration can potentially provide a surrogate measure of bone porosity, while a measure of bound water reflects collagen content. Here we propose to use bi-component analysis of UTE images to quantify T2* and fractions of the free and bound water components in cortical bone.

14:30 3210.   Preliminary Results on Bone Perfusion Measurement using Dynamic Contrast Enhanced Ultrashort TE Imaging 
Olivier M Girard1, Jiang Du1, Robert F Mattrey1, and Graeme M Bydder1
1Department of Radiology, University of California, San Diego, CA, United States

Dynamic Contrast Enhanced MRI has been applied for micro-vascular characterization of various tissues such as brain lesions and tumors. So far its application to bone perfusion characterization has been limited to bone marrow studies due to the lack of detectable signal from cortical bone, which has extremely short T2 and therefore cannot be detected by conventional gradient echo sequences. Ultrashort echo time (UTE) sequences offer an opportunity to measure signal from cortical bone. In this preliminary study we report on the kinetic analysis of dynamic UTE imaging data of cortical bone acquired on healthy volunteers using a clinical 3T MR scanner.

15:00 3211.   Ultrashort echo time MRI for quantification of tendon disease in spondyloarthritis. 
Richard J Hodgson1, Nikesh Menon2, Andrew J Grainger2, Philip O'Connor2, Dennis McGonagle3, Philip Helliwell3, Paul Emery3, and Matthew D Robson4
1LMBRU, University of Leeds, Leeds, Yorkshire, United Kingdom, 2Leeds Teaching Hospitals NHS Trust, 3University of Leeds, 4University of Oxford

There is increasing interest in quantifying tendon disease in spondyloarthritis. Ultrashort echo time and gradient echo images were acquired from the Achilles tendon of 24 patients and 14 healthy volunteers. Signal intensities at different echo times before and after intravenous gadolinium were normalized to the signal intensity on unenhanced UTE images. Ratios were significantly greater in patients with spondyloarthritis compared to controls. This was most marked on the ratio of the image acquired at TE=2ms to the UTE image. These measurements are straightforward, reproducible and fast and may be useful as potential quantitative biomarkers of tendon disease in spondyloarthritis.

15:30 3212.   1H Relaxation Properties of Achilles Tendons Measured by 3D-UTE at 3T and 7T: a Feasibility Study 
Vladimir Juras1,2, Stefan Zbyn1, Vladimir Jellus3, Pavol Szomolanyi1,2, Ivan Frollo2, and Siegfried Trattnig1
1Department of Radiology, Medical University of Vienna, Vienna, Austria, Austria, 2Department of Imaging Methods, Institute of Measurement Science, Bratislava, Slovakia, 3Siemens AG, Erlangen, Germany

Proton NMR relaxation properties (T2*) in human Achilles tendon were assessed in vivo at 3T and 7T field strength. 3D-UTE sequence (capable of minimum TE=0.07ms) was used with the set of 8 different TE {min 0.07 ms, max 4.00 ms}. T2* were found to be statistically significantly different between two field strengths in the most of the selected anatomical regions. Bulk T2* was 0.98+/-0.08ms (3T) and 0.41+/-0.10 (7T). T2 may prospectively serve as a marker for diagnosis of early tendon diseases.

Electronic Posters : Musculoskeletal Imaging
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MRI of Articular Cartilage - Osteoarthritis

Tuesday May 10th
Exhibition Hall  13:30 - 15:30 Computer 23

13:30 3213.   Assessment of T1lower case Greek rho and T2 mapping as biomarkers of denaturalization in articular cartilage with osteoarthritis: comparison with pathological results after total knee replacement 
Yukihisa Takayama1, Masamitsu Hatakenaka1, Takashi Yoshiura1, Hidetoshi Tsushima2, Ken Okazaki2, Kei Nishikawa3, Makoto Obara4, Yukihide Iwamoto2, and Hiroshi Honda1
1Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan, 2Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan, 3Radiology Center, Kyushu University Hospital, Fukuoka, Fukuoka, Japan, 4Philips Electronics Japan, Tokyo, Japan

We retrospectively compared T1ƒÏ and T2 mapping with pathological results in osteoarthritis patients and analyzed their detectability of an early stage of denatured articular cartilage and correlations to the severity of denaturalization. Both mappings are useful to detect mild and moderate denaturalization prior to thinning of the articular cartilage and to assess the severity of denatured articular cartilage. In particular, T1ƒÏ mapping is more sensitive than T2 mapping to detect early-stage denaturalization and to assess the severity of denaturalization.

14:00 3214.   T2, T1p, and Sodium MRI of Articular Cartilage in Patients with Osteoarthritis Treated with Arthritis Relief Plus Cream 
Hillary Jayne Braun1, Melissa A Vogelsong1,2, Ernesto Staroswiecki1,3, Brian A Hargreaves1, Neal Bangerter4, Eric Han5, Jill Fattor6, Anne L Friedlander7, Omer Shah8, Jacquie M Beaubien9, and Garry Evan Gold1
1Radiology, Stanford University, Stanford, CA, United States, 2UCSF School of Medicine, 3Electrical Engineering, Stanford University, 4Electrical Engineering, Brigham Young University, 5GE Healthcare Global Applied Sciences Laboratory, Menlo Park, CA, 6Stanford Center on Longevity, Stanford University, Stanford, CA, 7VA Palo Alto Healthcare Center, Palo Alto, CA, 8Georgetown University School of Medicine, 9Psychology, Stanford University, Stanford, CA

Arthritis Relief Plus (ARP) Cream has been previously shown to relieve joint pain. In this study, MRI was used to evaluate the knees of eight (5 experimental, 3 placebo) osteoarthritic patients before and after a twelve-week course of topical ARP Cream application. T2, T1ρ, and sodium imaging techniques were used to assess the macromolecule content of cartilage. Significant decreases in T1ρ relaxation times and increases sodium signal in the medial femoral condyle regions of the experimental group suggests there may be a benefit to ARP Cream application. However, results should be interpreted with caution due to the small sample size.

14:30 3215.   The Relationship between Knee Cartilage MR T2 and Morphology in Subjects from the Incidence and Control Cohorts of the Osteoarthritis Initiative 
Gabby B. Joseph1, Thomas Baum1, Julio Carballido-Gamio1, Lorenzo Nardo1, Warapat Virayavanich1, Hamza Alizai1, Michael C. Nevitt2, John A Lynch2, Charles E. McCulloch2, Sharmila Majumdar1, and Thomas M. Link1
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States

The purpose of this study is to 1) compare the prevalence of focal knee abnormalities, the mean cartilage MR T2 relaxation time, and the spatial distribution of cartilage MR T2 relaxation times between subjects from the control and incidence cohorts of the OAI, and 2) determine the relationship between MR cartilage T2 parameters and cartilage morphology. The results indicate no significant difference in the prevalence of knee abnormalities (cartilage lesions, BME, meniscus lesions) between the incidence and control groups; however, T2 parameters (mean T2, GLCM contrast, and GLCM variance) were significantly elevated in the incidence group.

15:00 3216.   T2 relaxation time reveals early cartilage changes after one-year and two-year follow-up in subjects at risk for osteoarthritis: data from Osteoarthritis Initiative 
Annamari Herronen1, Eveliina Lammentausta2, Risto O Ojala3, and Miika T Nieminen1,2
1Department of Medical Technology, University of Oulu, Oulu, Finland, 2Department of Diagnostic Radiology, Oulu University Hospital, 3Deaconess Institute of Oulu

T2 relaxation time mapping is a potential biomarker to follow biochemical changes in articular cartilage in OA progression. Forty-one subjects at risk for OA from the incidence cohort of the Osteoarthritis Initiative were studied at baseline, one-year and two-year follow-up. T2 relaxation time in the medial and lateral weight-bearing compartments of the femur was elevated after one and two years as compared to baseline, while the radiography-based KL-score remained zero at each time-point. The present results are very promising in view of predicting OA in subjects at risk for the disease.

Wednesday May 11th
  13:30 - 15:30 Computer 23

13:30 3217.   In Vivo Sodium and Proton T1rho MR Imaging of Human Knee Cartilage at 3T 
Chan Hong Moon1, Jung-Hwan Kim1, Tiejun Zhao2, Xiang He1, Bum-Woo Park1, and Kyongtae Ty Bae1
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2MR Research Support, Siemens Healthcare, Pittsburgh, PA, United States

We achieved consistent T2, T1rho, and sodium concentration measurements in knee cartilages from normal subjects using an in-house dual-tuned knee coil and in-house sequences at 3T. We believe MR-based physiological and metabolic measures of knee cartilage may play an important role as imaging biomarkers for early detection of knee ostheoarthritis.

14:00 3218.   Does the scanner make a difference? Interscanner variability of tibial cartilage T2 relaxation time – A comparison of three 1.5T and one 3T scanner of one manufacturer 
Annie Horng1, Sabine Weckbach2, Mike Notohamiprodjo2, Malte Münkel2, Jürgen Weber2, Maximilian F. Reiser2, and Christian Glaser3,4
1Department of Clinical Radiology, University Hospitals LMU Munich - Campus Grosshadern, Munich, Bavaria, Germany, 2University Hospitals LMU Munich - Campus Grosshadern, 3Center of Biomedical Imaging, NYULMC, New York, New York, United States, 4Department of Clinical Radiology, University Hospitals LMU Munich - Campus Grosshadern, Munich, Germany

Interscanner variability of T2 in healthy tibial cartilage between three different 1.5T and a 3T scanner of one manufacturer shows significant variability within the same individuum with approximately 7% for global and 9.4% for layer-based values. This appears sufficient to differentiate between healthy and diseased cartilage which may show elevated values up to 70-180%. It still may limit the ability to detect subtle changes under intervention and in follow-up studies. Therefore to reduce measurement error and increase sensitivity to change, not only scanners from the same vendor but identical scanner types within the product lines of a vendor are recommendable.

14:30 3219.   Experimental Investigation into the Relationship between T2* and T2 in Cartilages at 3T 
Yongxian Qian1, Ashley A Williams2, Constance R. Chu2, and Fernando E. Boada1
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, United States

When voxel size is decreased (or image resolution is increased), the impact of encoding gradient and B0-field inhomogeneity on T2* time is decreased and as a result, T2* time is supposed to be closer to T2 value. This work, however, shows that T2* in cartilage explants from human knees does not approach to T2 value when increasing image resolution. The reason for this might be that inhomogeneous microenvironment in tissue dominates local field and T2* values.

15:00 3220.   Quantitative cartilage degeneration associated with spontaneous osteoarthritis in a guinea pig model 
Matthew Fenty1, Victor Babu Kassey1, George Dodge2, Ari Borthakur1, and Ravinder Reddy1
1CMROI, Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2McKay Orthopaedics Labs, Department of Orthopaedic Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA, United States

Osteoarthritis (OA) is a common and painful condition with a multi-factorial etiology of the musculoskeletal system affecting more than 50% of the U.S. population over 65. Degeneration of the articular cartilage, which is believed to be a primary factor in the development of OA, is a slow process and typically takes decades to have full thickness loss. Dunkin-Hartley guinea pigs have been shown to develop OA with the earliest stage of detection manifesting as early as three to four months of age. T1lower case Greek rhoMRI has been shown to correlate with cartilage proteoglycan content. However, there have been no T1lower case Greek rho MRI studies in the Dunkin-Hartley guinea pig model with naturally occurring joint disease that closely mimics human OA. The aim of this study is to quantify age-dependent cartilage degeneration via T1lower case Greek rho MRI with verification by histopathology measurements.

Electronic Posters : Musculoskeletal Imaging
Click on to view the abstract pdf and click on to view the video presentation.
Cartilage - Contrast Enhanced Imaging

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 24

14:00 3221.   A New Approach to Analyze dGEMRIC Measurements in Femoroacetabular Impingement 
Riccardo Lattanzi1,2, Anna Krigel3, Catherine Petchprapa2, Artem V Mikheev2, Kevin Dunham2, Soterios Gyftopoulos2, Tallas Charles Mamisch4, Young Jo Kim5, Henry Rusinek2, Michael Recht2, and Christian Glaser1,2
1Center for Biomedical Imaging, New York University Langone Medical Center, New York, NY, United States, 2Radiology, New York University Langone Medical Center, New York, NY, United States, 3New York University School of Medicine, New York, NY, United States, 4Clinical Research, University of Bern, Bern, Switzerland, 5Orthopedic Surgery, Children's Hospital, Boston, MA, United States

Corrective surgical procedures can delay osteoarthritis for patients with femoroacetabular impingement (FAI) if hip articular cartilage degeneration is diagnosed in its early stages. Delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) is used for the detection of early biochemical changes in articular cartilage. A single threshold value for all cases may not be indicated to discriminate between normal and abnormal cartilage in dGEMRIC T1 maps. A method is proposed to standardize dGEMRIC measurements in order to remove the effect of inter- and intra-patient variability. Comparison with arthroscopic findings showed 66% accuracy in assessing anterior-superior, superior and posterior-superior cartilage in 10 FAI patients.

14:30 3222.   Contrast agent diffusion in dGEMRIC: exploring Donnan equlibrium in vitro and in vivo 
Eveliina Lammentausta1,2, Eliot H Frank3, Zana Hawezi2, Alan J Grodzinsky3, and Leif E Dahlberg2
1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, 2Joint and Soft Tissue Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden,3MIT, Cambridge, MA, United States

Human femoral head cartilage was used to measure T1 relaxation time at constant intervals after exposure to Gd-DTPA2- until ten hours and to determine the depth-wise diffusion characteristics and fixed charge density in cartilage assuming Donnan equilibrium. This information was applied into a dynamic in vivo dGEMRIC data to estimate the evolution of Gd concentration of synovial fluid until two hours after intravenous injection of Gd-DTPA2-. The results suggest that Gd concentration is never in true equilibrium within the cartilage in vivo. To improve in vivo dGEMRIC, careful analysis by time and depth should be considered.

15:00 3223.   Depth-wise relaxivity of Gd-DTPA2- and Gd-DTPA-BMA in human femoral head cartilage 
Eveliina Lammentausta1,2, Samo Lasic3, Daniel Topgaard3, Olle Söderman3, and Leif E Dahlberg2
1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, 2Joint and Soft Tissue Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden,3Department of Physical Chemistry, Lund University, Lund, Sweden

The aim of the current study was to investigate the depth-wise variation of relaxivity in human femoral head articular cartilage using anionic and nonionic contrast agent. The relaxivities were nearly identical, with mean value of 3.8 1/mM/s for both contrast agents, showing similar values through the entire cartilage depth.

15:30 3224.   Optimization of a 3D Phase-Sensitive IR protocol for DGEMRIC technique. 
Michael Durkan1, Jerzy Szumowski2, Dawson Brown1, Dennis Crawford1, Erwin Schwarz2, and Katrina Heiles3
1Orthopaedics & Rehabilitation, Oregon Health & Science University, Portland, Oregon, United States, 2Radiology, Oregon Health & Science University, Portland, OR, United States, 3Hewlett Packard, United States

Phase-sensitive reconstruction of 3D IR images for DGEMRIC technique doubles the dynamic range of data which decreases the number of TI times needed for fitting T1 relaxation maps. We will demonstrate that 3D IR can be optimized with four TI points fit to 3-Parameter inversion recovery function. Using the phase-sensitive reconstruction method for optimized DGEMRIC exams result in total acquisition times less than 10 minutes. Short exam time combined with reliable T1-map calculation makes this approach a clinically attractive implementation of DGEMRIC technique.

Tuesday May 10th
  13:30 - 15:30 Computer 24

13:30 3225.   Early and Delayed Contrast Enhancement MRI of the knee 
Wei Li1, Ewa Gliwa1, and Pottumarthi V Prasad1
1Radiology, NorthShore University HealthSystem, Evanston, IL, United States

Recent studies had indicated that neo-angiogenesis at the bone-cartilage interface could lead to differences in early enhancement in subjects with OA. In this study, we have evaluated the relationship between the early enhancement in the bone vs. cartilage in healthy subjects and those with OA. We also evaluated any potential correlation between the early and delayed enhancement phases. We did observe a significant correlation between the enhancement in bone and cartilage. Our data suggest minimal differences in the early enhancement in cartilage between subject with OA and controls. There was only a weak correlation between early and delayed enhancement phases.

14:00 3226.   Signal polarity restoration in IR sequence for T1-mapping in the DGEMRIC technique. 
Jerzy Szumowski1, Michael Durkan2, Katrina Heiles3, Dawson Brown2, Erwin Schwarz2, and Dennis Crawford2
1Radiology, Oregon Health & Science University, Portland, OR, United States, 2Oregon Health & Science University, 3Hewlett-Packard

We present a reconstruction algorithm that restores image signal polarity in IR sequence and effectively doubles the dynamic range of data used for T1 curve fitting in the DGEMRIC technique. We applied this reconstruction algorithm with 3D IR gradient-echo sequence for T1 mapping, validated the technique in a phantom study and performed T1-map calculations in post osteochondral allograft transplant (OAT) patients and non-symptomatic volunteers. The proposed algorithm significantly improves reliability of T1 relaxation time fits to an inversion-recovery 3-parameter function. The algorithm can be applied to any 2D or 3D IR acquisition sequence used in conjunction with the DGEMRIC technique.

14:30 3227.   The effects of B1 inhomogeneity correction for 3D-Variable Flip Angle T1 measurements in hip-dGEMRIC at 3T and 1.5T 
Carl Siversson1, Jenny Chan2, Carl Johan Tiderius3, Tallal Charles Mamisch4, Jonas Svensson1, and Young jo Kim2
1Department of Radiation Physics, Lund University, Malmö, Sweden, 2Department of Orthopaedics, Children's Hospital Boston, Boston, MA, United States, 3Department of Orthopaedics, Lund University, Malmö, Sweden, 4Department of Orthopaedics, University of Bern, Bern, Switzerland

3D Variable Flip Angle (3D-VFA) is a T1 quantification method commonly used in delayed Gadolinium enhanced MRI of cartilage (dGEMRIC). Since 3D-VFA is sensitive to B1 variations a technique for correcting for this was recently introduced. In this work 15 hips were studied at 1.5T and 15 hips at 3T using this technique. The T1 data was calculated both with and without utilizing the B1 correction. It was concluded that B1 inhomogeneities in vivo are about twice as high at 3T compared to 1.5T. At 3T B1 correction is essential, while at 1.5T it appears to be of minor influence.

15:00 3228.   Histological Correlation with MRI findings to monitor Gene Therapy in an “In Vivo” Equine Model 
Maria Isabel Menendez1,2, Daniel J Clark1, Michelle Carlton3, David C Flanigan4, Guang Jia1, Steffen Sammet5, Steven Weisbrode6, Alicia L Bertone7, and Michael V Knopp5
1Radiology, OSU Imaging Core Lab Wright Center of Innovation in Biomedical Imaging, The Ohio State University, Columbus, Ohio, United States, 2Clinical Veterinary Sciences, College of Veterinary Medicine, Columbus, Ohio, United States, 3Radiology, Wright Center of Innovation in Biomedical Imaging, The Ohio State University,4Orthopedics, The Ohio State University Medical Center, Columbus, Ohio, United States, 5Radiology, OSU Imaging Core Lab Wright Center of Innovation in Biomedical Imaging, The Ohio State University, Columbus, Ohio, 6Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, 7Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio

Using MRI as a serial non-invasive technique to evaluate healing of surgically created large osteochondral defects in a weight-bearing femoral condyle in response to percutaneous direct injection of adenoviral (Ad) vectors containing coding regions for either human bone morphogenetic proteins 2 (BMP-2) or -6. Four osteochondral defects were drilled (n=20 defects). Direct injection of Ad-BMP-2, Ad-BMP-6, Ad- green fluorescence protein (GFP), or saline into the defect was performed. Quantitative magnetic resonance imaging (qMRI) and computed tomography (CT) were serially performed at 12, 24, and 52 weeks. At 52 weeks, histomorphometry and microtomographic analyses were performed to correlate and assess final subchondral bone and cartilage repair tissue quality.