This paper is published as part of a Special Issue entitled “NMR of the Musculoskeletal System”.
Quantitative MRI for the assessment of bone structure and function†
Article first published online: 31 OCT 2006
Copyright © 2006 John Wiley & Sons, Ltd.
NMR in Biomedicine
Volume 19, Issue 7, pages 731–764, November 2006
How to Cite
Wehrli, F. W., Song, H. K., Saha, P. K. and Wright, A. C. (2006), Quantitative MRI for the assessment of bone structure and function. NMR Biomed., 19: 731–764. doi: 10.1002/nbm.1066
- Issue published online: 31 OCT 2006
- Article first published online: 31 OCT 2006
- Manuscript Accepted: 1 MAY 2006
- Manuscript Revised: 25 APR 2006
- Manuscript Received: 26 JAN 2006
- National Institutes of Health. Grant Numbers: RO1 AR41443, RO1 AR40671, RO1 AR49553, RO1 AR53156
- trabecular bone;
Osteoporosis is the most common degenerative disease in the elderly. It is characterized by low bone mass and structural deterioration of bone tissue, leading to morbidity and increased fracture risk in the hip, spine and wrist–all sites of predominantly trabecular bone. Bone densitometry, currently the standard methodology for diagnosis and treatment monitoring, has significant limitations in that it cannot provide information on the structural manifestations of the disease. Recent advances in imaging, in particular MRI, can now provide detailed insight into the architectural consequences of disease progression and regression in response to treatment. The focus of this review is on the emerging methodology of quantitative MRI for the assessment of structure and function of trabecular bone. During the past 10 years, various approaches have been explored for obtaining image-based quantitative information on trabecular architecture. Indirect methods that do not require resolution on the scale of individual trabeculae and therefore can be practiced at any skeletal location, make use of the induced magnetic fields in the intertrabecular space. These fields, which have their origin in the greater diamagnetism of bone relative to surrounding marrow, can be measured in various ways, most typically in the form of R2′, the recoverable component of the total transverse relaxation rate. Alternatively, the trabecular network can be quantified by high-resolution MRI (µ-MRI), which requires resolution adequate to at least partially resolve individual trabeculae. Micro-MRI-based structure analysis is therefore technically demanding in terms of image acquisition and algorithms needed to extract the structural information under conditions of limited signal-to-noise ratio and resolution. Other requirements that must be met include motion correction and image registration, both critical for achieving the reproducibility needed in repeat studies. Key clinical applications targeted involve fracture risk prediction and evaluation of the effect of therapeutic intervention. Copyright © 2006 John Wiley & Sons, Ltd.