Deterioration of Trabecular Architecture in Hypogonadal Men

Benito, María; Gomberg, Bryon R.; Wehrli, Félix W.; Weening, Richard; Zemel, Babette S.; Wright, Alexander C.; Song, Hee Kwon; Cucchiara, Andrew J.; Snyder, Peter J.

doi:10.1210/jc.2002-021429

Cited by 144 publications

(107 citation statements)

References 57 publications

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“…In addition, the feasibility of carrying out FE calculations on the basis of in vivo MR images has recently been demonstrated (164). In a pilot study designed to test the hypothesis that TB mechanical properties are impaired in patients with osteoporosis, we examined in vivo m-MRI data from a small study of hypogonadal and eugonadal men published previously (165). A cubic sub-volume of binarized m-MR images of 68.5 Â 68.5 Â 102.5 mm 3 voxel size was converted to voxel-based finite elements and subjected to linear analysis to determine the apparent Young's moduli along the principal (inferior-superior) loading direction using the above methodology (Guo et al, unpublished work).…”

Section: Computational Biomechanicsmentioning

confidence: 99%

“…A further potential motivation is the study of the structural manifestations of metabolic bone disease such as renal osteodystropy (166). Evidence for these developments is the rapid growth of the clinical literature (8,83,84,127,145,165,(167)(168)(169)(170)(171)(172) and also, to a lesser extent, the increased use of CT to characterize TB (14)(15)(16)(173)(174)(175)(176)(177).…”

Section: Clinical Applications Of Trabecular Bone Microstructural Anamentioning

confidence: 99%

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Quantitative MRI for the assessment of bone structure and function

et al. 2006

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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 R 0 2 , the recoverable component of the total transverse relaxation rate. Alternatively, the trabecular network can be quantified by high-resolution MRI (m-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.

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Section: Computational Biomechanicsmentioning

confidence: 99%

Section: Clinical Applications Of Trabecular Bone Microstructural Anamentioning

confidence: 99%

Quantitative MRI for the assessment of bone structure and function

et al. 2006

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“…AD reduces not only cancellous and cortical bone mass (5) but also disrupts the macrostructure (27), microarchitecture (28) and biophysical properties (29) of bone. Each of these factors may contribute to the increased fracture risk associated with male hypogonadism (1,30).…”

Section: Discussionmentioning

confidence: 99%

Adequacy of androgen replacement influences bone density response to testosterone in androgen-deficient men

Aminorroaya

Kelleher²,

Conway³

et al. 2005

eur j endocrinol

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Objective: Androgen deficiency (AD) leads to bone loss and contributes to osteoporotic fractures in men. Although low bone mineral density (BMD) in AD men is improved by testosterone replacement, the responses vary between individuals but the determinants of this variability are not well defined. Design and methods: Retrospective review of dual energy X-ray absorptiometry (DEXA) of the lumbar spine and proximal femur in men with established AD requiring regular androgen replacement therapy (ART). After a DEXA scan all men were treated with testosterone implants (800 mg, , 6 month intervals). Patients were classified as having a congenital, childhood, or post-pubertal onset, as well as according to the adequacy of treatment prior to their first DEXA scan as untreated, partially treated or well treated. Results: Men with AD requiring regular ART (n ¼ 169, aged 46.3^1.1 years, range 22 -84 years) underwent a DEXA scan prior to being treated with testosterone implants (800 mg, ,6 month intervals). In cross-sectional analysis at the time of the first DEXA scan untreated men (n ¼ 24) had significantly reduced age-adjusted BMD at all four sites (L1 -L4, femoral neck, Ward's triangle and trochanter). Well-treated men (n ¼ 77) had significantly better age-adjusted BMD at all four sites compared with those who were partially treated (n ¼ 66) or untreated (n ¼ 24) with their ageadjusted BMD being normalized. In a longitudinal assessment of men (n ¼ 60) who had two or more serial DEXA scans, at the second DEXA scan after a median of 3 years, men who were previously partially treated (n ¼ 19) or untreated (n ¼ 11) had proportionately greater improvements in BMD, significantly for Ward's triangle (P ¼ 0.025) and the trochanter (P ¼ 0.044) compared with men (n ¼ 30) previously well treated. Conclusions: The present study demonstrates a positive relationship between adequacy of testosterone replacement and BMD in men with overt organic AD. Additionally, the BMD of well-treated AD men approximates that of age-matched non-AD controls. The greatest BMD gains are made by those who have been either untreated or partially treated, and optimal treatment over time (median 3 years) normalizes BMD to the level expected for healthy men of the same age.European Journal of Endocrinology 152 881-886

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“…Finally, LIA was applied to in vivo data acquired as part of a previous study 2 in which the effects of testosterone deficiency on TB structure in hypogonadal men were investigated. In that work, the distal tibia of ten untreated hypogonadal subjects and ten eugonadal controls had been imaged using the FLASE pulse sequence 24 with a voxel size of 137ϫ 137ϫ 410 m 3 .…”

Section: Iiic5 Application To In Vivo Mr Imagesmentioning

confidence: 99%

Classification of trabeculae into three‐dimensional rodlike and platelike structures via local inertial anisotropy

2009

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Trabecular bone microarchitecture is a significant determinant of the bone's mechanical properties and is thus of major clinical relevance in predicting fracture risk. The three-dimensional nature of trabecular bone is characterized by parameters describing scale, topology, and orientation of structural elements. However, none of the current methods calculates all three types of parameters simultaneously and in three dimensions. Here the authors present a method that produces a continuous classification of voxels as belonging to platelike or rodlike structures that determines their orientation and estimates their thickness. The method, dubbed local inertial anisotropy ͑LIA͒, treats the image as a distribution of mass density and the orientation of trabeculae is determined from a locally calculated tensor of inertia at each voxel. The orientation entropies of rods and plates are introduced, which can provide new information about microarchitecture not captured by existing parameters. The robustness of the method to noise corruption, resolution reduction, and image rotation is demonstrated. Further, the method is compared with established three-dimensional parameters including the structure-model index and topological surface-to-curve ratio. Finally, the method is applied to data acquired in a previous translational pilot study showing that the trabecular bone of untreated hypogonadal men is less platelike than that of their eugonadal peers.

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Deterioration of Trabecular Architecture in Hypogonadal Men

Cited by 144 publications

References 57 publications

Quantitative MRI for the assessment of bone structure and function

Quantitative MRI for the assessment of bone structure and function

Adequacy of androgen replacement influences bone density response to testosterone in androgen-deficient men

Classification of trabeculae into three‐dimensional rodlike and platelike structures via local inertial anisotropy

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