Quantitative high-resolution magnetic resonance imaging reveals structural implications of renal osteodystrophy on trabecular and cortical bone

Authors

  • Felix W. Wehrli PhD,

    Corresponding author
    1. Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania
    • Department of Radiology, University of Pennsylvania Medical Center, 3400 Spruce St., 1 Founders Pavilion, Philadelphia, PA 19104
    Search for more papers by this author
  • Mary B. Leonard MD,

    1. Department of Pediatrics, Epidemiology and Biostatistics, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania
    Search for more papers by this author
  • Punam K. Saha PhD,

    1. Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania
    Search for more papers by this author
  • Bryon R. Gomberg PhD

    1. Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania
    2. Department of Radiology, Hadassah Medical School, Jerusalem, Israel
    Current affiliation:
    1. Department of Radiology, Hadassah Medical School, Jerusalem, Israel
    Search for more papers by this author

Abstract

Purpose

To explore the potential role of micro-magnetic resonance imaging (μ-MRI) for quantifying trabecular and cortical bone structural parameters in renal osteodystrophy (ROD), a multifactorial disorder of bone metabolism, traditionally evaluated by bone biopsy.

Materials and Methods

Seventeen hemodialysis patients (average PTH level = 502 ± 415 μg/liter) were compared with 17 age-, gender-, and body mass index (BMI)-matched control subjects. The average dialysis duration for the patients was 5.5 years (range = 0.96-18.2 years). Three-dimensional (3D) fast large-angle spin-echo (FLASE) MR images of the distal tibia (voxel size = 137 × 137 × 410 μm3) were processed to yield bone volume fraction (BV/TV). From a skeletonized representation of the trabecular bone network, the topology of each bone voxel was determined providing surface and curve voxel densities (SURF and CURV) and the topological erosion index (EI). Further, high-resolution two-dimensional (2D) spin-echo images were collected at the tibial midshaft for measurement of cortical bone cross-sectional area (CCA), relative CCA expressed as a percentage of total bone area (RCA), and mean cortical thickness (MCT).

Results

The data show both RCA and MCT to be lower in the patients (61.2 vs. 69.1%, P = 0.008, and 4.53 vs. 5.19 mm, P = 0.01). BV/TV and SURF were lower, while EI was increased in the patients, although these differences were not quite significant (P = 0.06-0.09). All of the cortical and trabecular findings are consistent with increased bone fragility.

Conclusion

The data suggest that μ-MRI may have potential to characterize the structural implications of metabolic bone disease, potentially providing a noninvasive tool for the evaluation of therapies for ROD. J. Magn. Reson. Imaging 2004;20:83–89. © 2004 Wiley-Liss, Inc.

Ancillary