Image Markers for Evaluation of Bone & Spine
 

Room 717 A/B

13:30-15:30

Chairs: John C. Waterton and Felix W. Wehrli


Time

Prog #

 
13:30 534. Multi-Center MRI Reproducibility of Cancellous Bone Microstructure at the Distal Radius

Bryon R. Gomberg1, Pamela Seaman1, Michael Kleerekoper1

1MicroMRI Inc., Philadelphia, Pennsylvania, USA

Metabolic bone diseases cause small changes to bone quality over long times. Combined with the difficulty in finding naÔve patients, the large numbers of patients needed for clinical investigations requires multi-center recruitment and data collection. This study evaluates the multi-center reproducibility and accuracy of commercial technology we have developed for microscopic bone imaging. We found that the multicenter data is as reproducible as previously reported from single centers, and the accuracy across centers falls within the measurement error. This information allows researchers to use the existing validation data to establish sample size estimates for future large studies.

13:42 535. Geodesic Topological Analysis of Trabecular Bone Micro-Architecture of High-Spatial Resolution Magnetic Resonance Images

Julio Carballido-Gamio1, Markus B. Huber1, Roland Krug1, Felix Eckstein2, 3, Sharmila Majumdar1, Thomas M. Link1

1University of California, San Francisco, San Francisco, California , USA; 2Ludwig-Maximilians-Universitšt, Munich, Germany; 3Paracelsus Medical Private University, Salzburg, Austria

In this work Geodesic Topological Analysis or GTA is presented as a new trabecular bone analysis quantification technique. New apparent trabecular bone parameters derived from GTA are also presented: apparent trabecular bone volume distribution (app.Tb.V.D.), apparent trabecular bone junction space (app.Tb.J.Sp.), and apparent trabecular bone distance to junction (app.Tb.D.J). The performance of the proposed methodology is evaluated in terms of its ability in discriminating vertebral fractures based on high-spatial resolution MR images of the calcaneus of 30 specimens. Area under the curve values of the receiver-operator curve analysis showed moderate accuracy demonstrating the potential of the new technique.

13:54 536. Quantification of Bone Water in the Human Tibia in Vivo by Ultra-Short TE Radial MRI at 3T

Aranee Techawiboonwong1, Hee Kwon Song2, Catherine E. Jones2, Mary B. Leonard3, Felix W. Wehrli2

1University of Pennsylvania School of Medicine , Philadelphia, USA; 2University of Pennsylvania School of Medicine, Philadelphia, USA; 3Children's Hospital of Philadelphia, Philadelphia, USA

Most of bone water (BW) resides in the microscopic pores of the lacuno-canalicular system. These short-T2 water protons can be quantified by MRI using ultra-short echo-time (UTE) imaging techniques therefore providing an indirect measurement of cortical bone porosity which is known to affect bone strength. Here we developed and evaluated a method based on UTE MRI to quantify BW content as a new metric of bone quality in human cortical bone in vivo. A pilot study in three groups of women showed BW to be a more sensitive discriminator than clinical bone mineral density.

14:06 537. Vertebra Bone Mineral Density Reduction is Associated with Vertebra Blood Perfusion Reduction: Dynamic Contrast Enhanced MRI Study in a Rat Orchiectomy Model

Yi Xiang Wang1, H Zhou, 12, Y F. Zhang3, T Kwok3, D K. Yeung3, L Qin3, G E. Antonio3, J F. Griffith3

1The Chinese University of Hong Kong, Prince of Wales Hospital , Shatin, People's Republic of China; 2First Affiliated Hospital of Zhejiang University, Hangzhou, People's Republic of China; 3The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, People's Republic of China

Recent clinical studies have shown that both in male and female human subjects vertebral marrow blood perfusion is significantly decreased in the osteoporotic subjects as demonstrated by MRI derived blood perfusion parameters. In a group of matured male rats, the current study demonstrated that vertebra bone mineral density decreased by 16.6% and MRI maximum enhancement decreased by 17% at 4 weeks post- bilateral orchiectomy. The results showed it is feasible to reproduce the clinical observations that a decease of vertebra bone mineral density is associated with a decease of vertebra blood perfusion in this male rat osteoporosis model.

14:18 538. Quantitative Water and Fat Suppressed Proton Projection MRI (WASPI) Measurement of Bone Matrix Density Differentiates Normal, Osteoporotic and Osteomalacic Bone

Haihui Cao1, 2, Jerome L. Ackerman, 23, Ara Nazarian, 24, Brian D. Snyder, 24, Guangping Dai, 23, Melvin Glimcher1, 2, Yaotang Wu1, 2

1Children's Hospital, Boston, Massachusetts, USA; 2Harvard Medical School, Boston, Massachusetts, USA; 3Massachusetts General Hospital, Boston, Massachusetts, USA; 4Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA

Bone matrix density is important for evaluating the degree of bone mineralization in the study and diagnosis of metabolic bone diseases.  Quantitative water and fat suppressed proton projection MRI (WASPI) was utilized to measure bone matrix densities of normal, osteoporotic, and osteomalacic rat bone specimens.  Osteoporotic trabecular bone matrix density was much lower than in the normal and osteomalacic states, while cortical bone matrix density was not significantly altered. This method offers the potential, for the first time, of a noninvasive clinical means to differentiate osteoporosis from osteomalacia.

14:30 539. Manganese-Enhanced Magnetic Resonance Microscopy of Mineralization Rates

Ingrid E. Chesnick1, Jose A. Centeno2, Todor I. Todorov3, Alan E. Koenig3, Kimberlee Potter1

1Armed Forces Institute of Pathology Annex, Rockville, Maryland, USA; 2Armed Forces Institute of Pathology, Washington, District Of Columbia, USA; 3USA Geological Survey, Denver, Colorado , USA

Manganese can be employed to sensitize the Magnetic Resonance Microscopy (MRM) technique to the deposition of bone in mineralizing tissues. In this work, manganese-enhanced MRM was used to establish that the mineralizing activity of organ-cultured calvariae is much higher after 1 day in culture compared to 22 days in culture. It was also discovered that different regions of the embryonic skull mineralize at different rates. These results support the application of Mn-enhanced MRM to the study of different treatment paradigms on mineralization rates.

14:42 540. Bone Susceptibility Quantification: In Vivo Feasibility with MR Source QUantification by Inverting the Dipole Field

Ludovic de Rochefort1, Ryan Brown1, Martin R. Prince1, Yi Wang1

1Weill Medical College of Cornell University, New York, New York, USA

Bone mineral density is an important parameter for evaluating osteoporosis and other bone diseases. To avoid invasive biopsy and exposure to ionizing radiation, there have been several works using MRI to quantify bone density. One approach makes use of the susceptibility difference between the various constituents of bone tissue, which is linked to its composition. Here we show the in vivo feasibility of MR-SQUID (Magnetic Resonance Source QUantification by Inverting the Dipole field) to measure bone magnetic susceptibility by fitting the observed field shifts to a field model built from segmented signal intensity images.

14:54 541. MR Diffusion Measurements Are Sensitive in Detecting the Effect of Age and Loading on the Response of Intervertebral Discs

Ron N. Alkalay1, Carl-Fredrik Westin2

1Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA; 2Brigham and Women's Hospital, Boston, Massachusetts, USA

The aim of this MR study was to contrast the ability of diffusion and T2 weighted protocols to detect the affect of age and mechanical loading on the discís anatomy. L2-L3 discs, obtained from human donors aged 39 and 72 yrs. underwent T2Map and Diffusion MR measurement protocols in an unloaded state and once exposed to 800N compressive load.  Both methods were able to delineate the anatomy of the tissue and the loss in definition due to age.  Under applied compression, diffusion measures demonstrated increased sensitivity in detecting the differences in the mechanical response of the disc, independent of age.

15:06 542. New MRI Methods for the Monitoring of the Intervertebral Disc Ablation

Galit Saar1, Yoram Zilberman2, Hadassah Shinar1, Gadi Pelled2, Dan Gazit2, Gil Navon1

1Tel Aviv University, Tel Aviv, Israel; 2Hebrew University - Hadassah Medical Campus, Jerusalem, Israel

MRI contrasts such as T2, MTR, dipolar echo refocusing, as well as 2H double quantum filter were used to monitor early changes occurring after nucleus pulpous ablation of IVD.  In the ablated disc the clear distinction between nucleus and annulus is lost, T2 is significantly shorter and 1/Tdipol, a measure of the contribution of the dipolar interaction to the transverse relaxivity, as well as MTR, are larger. These results indicate the spread of the collagen fibers into the inner part of the ablated disc providing a baseline for future work on disc degeneration and repair.

15:18 543. MR Spectroscopy in Intact and Degenerated Bovine Intervertebral Disc

Jin Zuo1, Ehsan Saadat2, Xiaojuan Li1, Sharmila Majumdar1

1Univ. of California, San Francisco, San Francisco, California , USA; 2Univ. of California, San Francisco, San Francisco, California , USA

Intervertebral Disc Disease (IVDD) is a leading cause of lumbar spine-related lower-back pain. A new technique using single voxel MR spectroscopy was developed for the quantification of the concentration of metabolites in the intervertebral disc to detect disc degeneration. The study tested the feasibility of the method in bovine intervertebral discs and examined the changes in concentration of metabolites as a result of papain-induced degeneration of bovine discs  in vitro.