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Assessment of 2D and 3D fractal dimension measurements of trabecular bone from high‐spatial resolution magnetic resonance images at 3 T
Author(s) -
AlberichBayarri Angel,
MartiBonmati Luis,
Pérez Maria Angeles,
SanzRequena Roberto,
LermaGarrido Juan José,
GarcíaMartí Gracián,
Moratal David
Publication year - 2010
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3481509
Subject(s) - osteoporosis , cancellous bone , medicine , fractal dimension , magnetic resonance imaging , bone mineral , fractal analysis , bone density , fractal , nuclear medicine , radiology , mathematics , anatomy , mathematical analysis
Purpose: In vivo two‐dimensional (2D) fractal dimension( D 2 D)analysis of the cancellous bone at 1.5 T has been related to bone structural complexity and shown to be a potential imaging‐based biomarker for osteoporosis. The objectives of this study were to assess at 3 T the in vivo feasibility of three‐dimensional (3D) bone fractal dimension( D 3 D)analysis, analyze the relationship ofD 2 DandD 3 Dwith osteoporosis, and investigate the relationship ofD 3 Dwith spinal bone mineral density (BMD). Methods: A total of 24 female subjects ( 67 ± 7 yr old, mean ± SD ) was included in this study. The cohort consisted of 12 healthy volunteers and 12 patients with osteoporosis. MR image acquisitions were performed in the nondominant metaphysis of the distal radius with a 3 T MR scanner and an isotropic resolution of 180 μ m . After segmentation and structural reconstruction, 2D and 3D box‐counting algorithms were applied to calculate the fractal complexity of the cancellous bone.D 2 DandD 3 Dvalues were compared between patients with osteoporosis and healthy subjects, and their relationship with radius BV/TV and spinal BMD was also assessed. Results: Significant differences between healthy subjects and patients with osteoporosis were obtained for D 3 D( p < 0.001 ) , with less differentiation forD 2 D( p = 0.04 ) . The relationship between fractal dimension and BMD was not significant ( r = 0.43 , p = 0.16 and r = 0.23 , p = 0.48 , forD 2 DandD 3 D, respectively). Conclusions: The feasibility of trabecular bone D 3 Dcalculations at 3 T and the relationship of bothD 2 DandD 3 Dparameters with osteoporosis were demonstrated, with a better differentiation for the 3D method. Furthermore, theD 3 Dparameter has probably a different nature of information regarding the trabecular bone status not directly explained by BMD alone. Future studies with subjects with osteopenia and larger sample sizes are warranted to further establish the potential ofD 2 DandD 3 Din the study of osteoporosis.