Search PubMed⌕ Search

Biomedical subjects

S Majumdar

Publications and source records attributed to S Majumdar.

At least 163 records · Page 9Linked to original sources
PubMed1998

Impact of spatial resolution on the prediction of trabecular architecture parameters.

Although the efficacy of various measures for the assessment of trabecular bone architecture has been widely studied, the impact of spatial resolution on the estimation of these measures has remained relatively unexplored. In this study, ten cubes each of human trabecular bone from the femur and vertebral bodies were obtained from nine cadavers (four males and five females), aged 23-67 years (mean 42.3 years). These specimens were serially milled and imaged at a resolution of 40 microm to produce three-dimensional digitizations from which traditional morphometric and structural anisotropy measures could be computed based on a three-dimensional approach. The cubes were then artificially degraded to an in-plane resolution of 100 microm and an out-of-plane (slice) resolution of 100-1000 microm. These resolutions mimicked in vivo resolutions as seen using magnetic resonance (MR) imaging. All images, original and degraded, were individually segmented using a thresholding algorithm, and both the traditional morphometric and structural anisotropy measures were recomputed. The choice of slice direction was varied along the superior-inferior (axial), anterior-posterior (coronal), and medial-lateral (sagittal) directions to minimize the impact of the lower slice resolution on the architectural measures. It was found that traditional morphometric measures such as trabecular spacing and trabecular number showed weak resolution dependency; measures such as trabecular thickness, however, showed strong resolution dependency and required very high resolutions for precise measurement. In the case of the femur specimens, both structural anisotropy as well as the preferred orientation showed a strong resolution dependency. The resolution dependency of these parameters could be minimized for the femur and the vertebral body specimens if the slice direction was taken along the superior-inferior direction.

Adult↗
PubMed1998

Lipoarabinomannan induced cytotoxic effects in human mononuclear cells.

Mycobacteria produce large quantities of lipoarabinomannan, a cell wall associated glycolipid, which confers virulence in many of the disease causing members of the genus. We studied the lipoarabinomannan induced altered signaling mechanism in human peripheral mononuclear cells. Lipoarabinomannan isolated from Mycobacterium smegmatis (a non-pathogenic species) at concentrations of 2, 5 and 10 microg ml(-1) was used for the study. It was found that protein kinase C activity of human mononuclear cells was significantly inhibited by lipoarabinomannan at these concentrations in a dose dependent manner. Calcium, phosphatidyl serine and diglyceride dependent phosphorylation of endogenous proteins (mainly 90-, 80-, 66-, 38-, 36- and 34-kDa proteins) were also inhibited. Potentially cytotoxic superoxide anions generated by peripheral blood mononuclear cells were scavenged by lipoarabinomannan. It was also observed that incubation of peripheral blood mononuclear cells with lipoarabinomannan at concentrations of 5 and 10 microg ml(-1) for 6 h directed the cells towards apoptotic cell death, confirmed by DNA degradation analysis, microscopic observation of Wright-Giemsa as well as DAPI stained nuclei. These results clearly demonstrate that lipoarabinomannan from M. smegmatis may exert its cytotoxic activity via inhibition of protein kinase C, a key signaling molecule inside the mononuclear cells, which ultimately affects the phosphorylation of various proteins imperative for cellular defence and survival.

Adult↗
PubMed1998

Morphometric texture analysis of spinal trabecular bone structure assessed using orthogonal radiographic projections.

The measurement of bone microstructure as well as bone mineral density may improve the estimation of bone strength. Cubic specimens (N = 26, 12 mm X 12 mm X 12 mm) of human cadaver vertebrae were cut along three orthogonal anatomic orientations, i.e., superior-inferior (SI), medial-lateral (ML), and anterior-posterior (AP). Contact radiographs of the bone cubes along all three orientations were obtained and then digitized by a laser scanner with pixel size of 50 microns x 50 microns. The specimens were tested in compression along the 3 orthogonal orientations and the Young's modulus (YM) was calculated for each direction. Quantitative computed tomography (QCT) was used to obtain a measure of trabecular bone mineral density (BMD). Global gray level thresholding and local thresholding algorithms were used to extract the trabecular bone network. Apparent trabecular bone fraction (ABV/TV), mean intercept length (I.TH), mean intercept separation (I.SP), and number of nodes (N.ND) were measured from the extracted trabecular network. Fractal dimension (Fr.D) of the trabecular bone texture was also measured. Paired t-tests showed that the mean values of each texture parameter (except ABV/TV) and of YM along the SI direction were significantly different (p < 0.05) from those along the ML and AP direction. However, the mean values along the ML and AP directions were not significantly different. Multivariate regression of YM as a function of the texture parameters and BMD showed that without adjusting for the effect of BMD, YM was significantly explained by all the texture parameters (R2 = 0.2-0.6). When BMD was included in the regression, although the variations in YM of ML, AP, and SI orientations could be explained by BMD alone, some of the texture parameters did improve the overall prediction of the biomechanical properties, while, some parameters such as ABV/TV and Fr.D in the ML orientation showed a more significant overall effect in explaining mechanical strength than did BMD. In conclusion, trabecular texture parameters correlated significantly with BMD and YM. Trabecular texture parameters from projectional radiographs reflect the anisotropy of trabecular structure. Quantitative radiographic assessment of trabecular structure using fine-detail radiography can potentially improve the estimation of bone strength.

Adult↗
PubMed1998

Proximal femur: assessment for osteoporosis with T2* decay characteristics at MR imaging.

PURPOSE: To use T2* measurements at magnetic resonance (MR) imaging to investigate the trabecular structure of the hip in women with and women without osteoporotic hip fractures and to compare this technique with bone mineral density (BMD) measurements in the diagnosis of fractures. MATERIALS AND METHODS: T2* maps of the proximal femur were obtained at 1.5 T in 23 postmenopausal study patients with osteoporotic hip fractures, 27 age-matched healthy postmenopausal control subjects, and five healthy premenopausal control subjects. A modified gradient-recalled acquisition in the steady state, or GRASS, sequence was used with echo times of 4-40 msec at 4-msec increments. T2* values were measured in five regions of interest: femoral neck, the Ward triangle, trochanter, intertrochanteric region, and total proximal femur. Additionally, BMD measurements of the hip were obtained with dual x-ray absorptiometry. RESULTS: Significant differences between T2* measurements were obtained in all three groups (P < .05). BMD measurements of the hip also showed significant differences (P < .05). For T2* and BMD measurements, odds ratios and areas under the curve in receiver operating characteristic analysis were comparable. Correlations between 1/T2* values and BMD were significant (P < .05). T2* measurements in the proximal femur showed regional variations. CONCLUSION: MR imaging decay characteristics of bone marrow could be used to differentiate between postmenopausal women with and those without osteoporotic hip fractures.

Absorptiometry, Photon↗
PubMed1998

A serial study of new MS lesions and the white matter from which they arise.

OBJECTIVE: To compare MS normal-appearing white matter (NAWM) where new gadolinium-enhancing (Gd+) lesions do and do not arise. METHODS: A total of 22 relapsing-remitting MS patients and 11 healthy control subjects completed as many as 12 monthly brain MRI sessions. Quantitative measures of gadolinium enhancement (GDR), water proton density (PDN), water proton T2 relaxation time constants (T2), magnetization transfer ratio (MTR), and T1-weighted signal intensity (T1N) were followed serially in healthy control and MS NAWM. RESULTS: A total of 129 new Gd+ lesions were identified in 11 patients. PDN, T2, MTR, and T1N were diffusely abnormal in MS NAWM. NAWM regions in which new Gd+ lesions arose have increased GDR, PDN, and T2, and reduced MTR and T1N compared with contralateral homologous NAWM regions in which no new Gd+ lesions arose. Differences between these NAWM regions preceded lesion appearance for at least several months. After lesions became visible, GDR returned to baseline within 2 months, and PDN and MTR had larger residual abnormalities than T2 or T1N. CONCLUSIONS: Quantitative MRI measures are diffusely abnormal in MS NAWM. These measures are, on average, more abnormal in NAWM regions in which new Gd+ lesions arise. After the appearance of Gd+ lesions, measures of PDN and MTR may provide more appealing markers of relatively irreversible tissue damage than measures of T2 and T1N.

Adult↗
PubMed1998

A comparative study of trabecular bone properties in the spine and femur using high resolution MRI and CT.

The purpose of this study was to use high resolution (HR) magnetic resonance (MR) and computed tomography (CT) images combined with texture analysis to investigate the trabecular structure of human vertebral and femoral specimens and to compare these techniques with bone mineral density (BMD) in the prediction of bone strength. Twenty-nine bone cubes were harvested from 12 proximal femur cadaver specimens and 29 from 8 spines. HR MR and CT images were obtained, and texture analysis techniques were used to assess trabecular structure. Additionally, BMD, elastic modulus (EM), and maximum compressive strength were determined. R2 for EM versus texture measures computed in the MR images was higher (R2 = 0.27-0.64, p < 0.01) in the spine than in the femur specimens (R2 = 0.12-0.22, p < 0.05). R2 values were similar in the CT images. R2 for EM versus BMD was 0.66 (p < 0.01) in the spine and 0.61 (p < 0.01) in the femur specimens. In the MR images, texture measures combined with BMD in a multivariate-regression model significantly increased R2, while improvement was less significant in the CT images. Thus, texture analysis may provide additional information needed to analyze bone strength and quality.

Adult↗
PubMed1998

Trabecular bone mineral and calculated structure of human bone specimens scanned by peripheral quantitative computed tomography: relation to biomechanical properties.

The relationship of cortical bone mineral density (BMD), and geometry to bone strength has been well documented. In this study, we used peripheral quantitative computerized tomography (pQCT) to acquire trabecular BMD and high-resolution images of trabeculae from specimens to determine their relationship with biomechanical properties. Fifty-eight human cubic trabecular bone specimens, including 26 from the vertebral bodies, were scanned in water and air. Trabecular structure was quantitated using software developed with Advanced Visual Systems interfaced on a Sun/Sparc Workstation. BMD was also obtained using a whole-body computerized tomography scanner (QCT). Nondestructive testing of the specimens was performed to assess their elastic modulus. QCT and pQCT measurements of BMD of specimens in water were strongly correlated (r2 = 0.95, p < 0.0001), with a slope (0.96) statistically not significantly different from 1. Strong correlations were found between pQCT measurements of specimens in water and in air, for BMD (r2 = 0.96, p < 0.0001), and for apparent trabecular structural parameters (r2 = 0.89-0.93, p < 0.0001). Correlations were moderate between BMD and apparent trabecular structural parameters (r2 = 0.37-0.64, p < 0.0001). Precision as coefficient of variation (CV) and standardized coefficient of variation (SCV) for these measurements was < 5%. For the vertebral specimens, the correlation was higher between elastic modulus and BMD (r2 = 0.76,p < 0.0001) than between elastic modulus and apparent trabecular structural parameters (r2 = 0.58-0.72, p < 0.0001), while the addition of apparent trabecular nodes and branches to BMD in a multivariate regression model significantly increased the correlation with the elastic modulus (r2 = 0.86, p < 0.01). Thus, pQCT can comparably and reproducibly measure trabecular bone mineral in water or air, and trabecular structure can be quantitated from pQCT images. The combination of volumetric BMD with trabecular structural parameters rather than either alone improves the prediction of biomechanical properties. Such a noninvasive approach may be useful for the preclinical study of osteoporosis.

Adult↗
PubMed1998

In vivo high resolution MRI of the calcaneus: differences in trabecular structure in osteoporosis patients.

The purpose of this study was to use high resolution (HR) magnetic resonance (MR) images of the calcaneus to investigate the trabecular structure of patients with and without osteoporotic hip fractures and to compare these techniques with bone mineral density (BMD) in differentiating fracture and nonfracture patients. Axial and sagittal HR MR images of the calcaneus were obtained in 50 female (23 postmenopausal patients with osteoporotic hip fractures and 27 postmenopausal controls). A three-dimensional gradient-echo sequence was used with a slice thickness of 500 micron and in plane resolution of 195 x 195 micron. Texture analysis was performed using morphological features, analogous to standard histomorphometry and fractal dimension. Additionally, BMd measurements of the hip (dual-energy X-ray absorptiometry) were obtained in all patients. Significant differences between both patient groups were obtained using morphological parameters and fractal dimension as well as hip BMD (p < 0.05). Odds ratios for the texture parameters apparent (app.) bone volume/total volume and app. trabecular separation were higher than for hip BMD. Receiver operator characteristic values of texture measures and hip BMD were comparable. In conclusion, trabecular structure measures derived from HR MR images of the calcaneus can differentiate between postmenopausal women with and without osteoporotic hip fractures.

Absorptiometry, Photon↗
PubMed1998

A review of magnetic resonance (MR) imaging of trabecular bone micro-architecture: contribution to the prediction of biomechanical properties and fracture prevalence.

Bone mineral density and three-dimensional trabecular structure play a significant role in predicting bone strength and biomechanical properties. MR is a non-invasive technique for determining trabecular architecture both in vivo and in vitro. In this paper we review the use of magnetic resonance imaging to obtain high resolution images of trabecular bone structure and quantify the three-dimensional architecture of the trabecular bone network. Studies assessing the anisotropy of the trabecular architecture in human cadaveric specimens from the distal and proximal femur, and the thoracic and lumbar vertebrae, are reviewed. The contributions of the MR derived measures of 3D trabecular bone structure to the biomechanical strength of the specimen are presented. In vivo, the relationship between the high resolution MR derived trabecular bone structure parameters in the distal radius and calcaneus in patients with hip fractures, are compared to age matched normal controls. MR derived measures are compared to measures of trabecular bone mineral density (BMD) in the hip using dual X-ray absorptiometry (DXA).

Adult↗
PubMed1998

Assessment of cancellous bone mechanical properties from micro-FE models based on micro-CT, pQCT and MR images.

Recently, new micro-finite element (micro-FE) techniques have been introduced to calculate cancellous bone mechanical properties directly from high-resolution images of its internal architecture. Also recently, new peripheral quantitative computed tomography (pQCT) and magnetic resonance (MR) imaging techniques have been developed that can create images of whole bones in vivo with enough detail to visualize the internal cancellous bone architecture. In this study we aim to investigate if the calculation of cancellous bone mechanical properties from micro-FE models based on such new pQCT and MR images is feasible. Three bone specimens were imaged with the pQCT scanning system and the MR-imaging system. The specimens were scanned a second time using a micro-CT scanner with a much higher resolution. Digitized reconstructions were made based on each set of images and converted to micro-FE models from which the bone elastic properties were calculated. It was found that the results of both the pQCT and the MR-based FE-models compared well to those of the more accurate micro-CT based models in a qualitative sense, but correction factors will be needed to get accurate values.

Bone and Bones↗
PubMed1997

The plasma-membrane Ca2+-ATPase of Leishmania donovani is an extrusion pump for Ca2+.

Controlled exposure of Leishmania donovani promastigotes to hypotonic shock results in the formation of deflagellated unsealed ghosts of original polarity that largely retain the pellicular microtubular structure associated with plasma membrane of the parasite. Gentle shearing followed by suspension of the purified membrane in appropriate isotonic buffer containing Mg2+ (4mM) results in the formation of sealed everted vesicles. The presence of Mg2+ (4 mM) appears to be essential for efficient sealing and also to prevent leakiness. ATP-dependent Ca2+ accumulation can be demonstrated in these vesicles Km values for Ca2+ and ATP were 125 nM and 0.8 mM respectively. The accumulated Ca2+ reaches a concentration of 1.1 mM. Ca2+ uptake is completely inhibited by vanadate (40 microM) and several thiol-modifying agents. Using 5,5'-dithiobis-(2-nitrobenzoic acid) as the modifying agent, an excellent correlation between loss of enzyme activity and transport capability and their parallel regeneration in the presence of 2 mM dithiothreitol was demonstrated. Using 2'.7-bis(carboxyethyl)-5(6)-carboxyfluorescein as the fluorescent pH probe, it was observed that Ca2+ entry into the vesicles is accompanied by an outward movement of H+ from the vesicles. Taken together, this paper establishes that the high-affinity transmembrane Ca2+-ATPase [Ghosh, Ray, Sarkar and Bhaduri (1990) J. Biol. Chem. 265, 11345-11351; Majumdar, Mukherjee, Ray and Bhaduri (1992) J. Biol. Chem. 267, 18440-18446] is an extrusion pump for Ca2+ in this human pathogen.

Adenosine Triphosphate↗
PubMed1997

Localization and up-regulation of mucin (MUC2) gene expression in human nasal biopsies of patients with cystic fibrosis.

Using digoxigenin-UTP-labelled human HAM-1 (92 bp) or SMUC41 (850 bp) cRNA probes, the expression and localization of MUC2 gene transcripts were determined by in situ hybridization in human nasal tissues obtained as biopsies from 12 patients with cystic fibrosis (CF): all had been part of a gene therapy trial in which CFTR cDNA-liposome complexes had been delivered by topical application to eight and liposome alone to four as a placebo control. For comparison, there were nasal tissues taken at surgical resection from four non-CF subjects and a further four biopsies taken from normal healthy volunteer controls. Both SMUC41 and HAM-1 probes provided a strong signal. MUC2 mRNA transcripts were present in serous and mucous acini of submucosal glands, ciliated and basal cells of the surface epithelium, and occasional mononuclear inflammatory cells. The percentages (mean +/- SEM) of serous and mucous acini showing positivity for MUC2 gene expression in the four samples surgically resected from non-CF subjects were 25.4 +/- 5.6 and 26.7 +/- 3.3 per cent, respectively. Compared with the non-CF subjects, the mean percentage of acini showing MUC2 gene expression in the four placebo-treated CF subjects was significantly higher for serous (80.5 +/- 12.7 per cent; P < 0.05, t-test), but not for mucous acini (53.1 +/- 16.8 per cent; P = 0.38). In CF and non-CF groups, where present, MUC2 positivity was strongly expressed and constituted approximately 84 per cent of the cell area in serous acini, whereas it was less obvious and was confined to the perinuclear area of cells in mucous acini. A significantly greater proportion of the surface epithelium was positive for MUC2 mRNA transcripts in the CF subjects (89.0, +/- 1.4 per cent) than in the surgically resected tissues of the four non-CF subjects (19.4, +/- 4.0 per cent) (P = 0.02). In the eight CFTR-cDNA-treated subjects, there was an overall trend to reduction, but no statistically significant alteration of MUC2 gene expression. It is concluded that the MUC2 gene is expressed at three- to four-fold higher levels in CF nasal mucosa than in non-CF nasal tissue and that it is expressed in a variety of cells additional to submucosal mucus-secreting glands.

Adult↗
PubMed1997

High resolution magnetic resonance imaging of the calcaneus: age-related changes in trabecular structure and comparison with dual X-ray absorptiometry measurements.

A high-resolution magnetic resonance imaging (MRI) protocol, together with specialized image processing techniques, was applied to the quantitative measurement of age-related changes in calcaneal trabecular structure. The reproducibility of the technique was assessed and the annual rates of change for several trabecular structure parameters were measured. The MR-derived trabecular parameters were compared with calcaneal bone mineral density (BMD), measured by dual X-ray absorptiometry (DXA) in the same subjects. Sagittal MR images were acquired at 1.5 T in 23 healthy women (mean age: 49.3 +/- 16.6 [SD]), using a three-dimensional gradient echo sequence. Image analysis procedures included internal gray-scale calibration, bone and marrow segmentation, and run-length methods. Three trabecular structure parameters, apparent bone volume (ABV/TV), intercept thickness (I.Th), and intercept separation (I.Sp) were calculated from the MR images. The short- and long-term precision errors (mean %CV) of these measured parameters were in the ranges 1-2% and 3-6%, respectively. Linear regression of the trabecular structure parameters vs. age showed significant correlation: ABV/TV (r2 = 33.7%, P < 0.0037), I.Th (r2 = 26.6%, P < 0.0118), I.Sp (r2 = 28.9%, P < 0.0081). These trends with age were also expressed as annual rates of change: ABV/TV (-0.52%/year), I.Th (-0.33%/year), and I.Sp (0.59%/year). Linear regression analysis also showed significant correlation between the MR-derived trabecular structure parameters and calcaneal BMD values. Although a larger group of subjects is needed to better define the age-related changes in trabecular structure parameters and their relation to BMD, these preliminary results demonstrate that high-resolution MRI may potentially be useful for the quantitative assessment of trabecular structure.

Absorptiometry, Photon↗
PubMed1997

Artificially produced cartilage lesions in small joints: detection with optimized MRI-sequences.

The purpose of this study was to evaluate different magnetic resonance imaging (MRI) pulse sequences in the detection of artificial cartilage lesions in small joints using an animal model. A total of 32 artificial cartilage lesions were created in the knee joints of 20 rabbits. Twenty lesions were produced 4 weeks and 12 lesions 1 h before the MRI examination, performed in an extremity coil at 1.0 T. All joints were examined with five imaging sequences: (1) a conventional T1-weighted spin-echo (SE)-sequence (repetition time [TR] 600 ms, echo time [TE] 15 ms), (2) a T2-weighted turbo-SE-sequence (TR 2000 ms, TE 85 ms), (3) a two-dimensional (2D) gradient echo (GE)-sequence (TR 440 ms, TE 10 ms, flip angle 60 degrees) and (4,5) two three-dimensional (3D) GE-sequences (TR 40 ms, TE 7 ms, flip angle 40 degrees, with fat suppression (FS) and TR 30 ms, TE 9 ms, flip angle 40 degrees). Two examinations had to be excluded because of insufficient image quality and the remaining examinations were analyzed by two experienced radiologists. The MRI images were correlated with the pathologic findings and anatomical structures were scored according to a 5-level scale. Direct comparison of the pathological and MRI findings showed that 19 of the 30 artificially induced cartilage lesions were detected with the FS 3D GE-sequence, 13 with the 2D GE-sequence, 11 with the 3D GE-sequence, 3 with the T1-weighted SE-sequence, and 2 with the T1-weighted SE-sequence. The highest percentage of artificial cartilage lesions was demonstrated using a fat-suppressed 3D GE-sequence. However, the analysis of cartilage defects in small joints with optimized sequences as well as clinical routine hardware and software had limitations. Therefore a pilot study was performed analyzing newly developed high resolution FS 3D GE images obtained from 5 rabbit knees with 10 cartilage lesions at 1.5 T. Two sequences were used with 1.0 and 0.5 mm slice thickness, a matrix of 256 x 256 and 512 x 256 and a field of view of 12 x 6 and 8 x 6 cm. In this small subset detection rates were substantially higher than in the 30 rabbit knees examined before.

Animals↗
PubMed1997

How can we measure bone quality?

Osteoporosis is a systematic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue. This leads to diminished biomechanical competence of the skeleton and is associated with low-trauma or atraumatic fractures. In the past decade, considerable progress has been made in the development of methods for assessing the skeleton non-invasively, so that osteoporosis can be better managed. While dual X-ray absorptiometry (DXA) is still the preferred methodology, several limitations will be addressed. Another densitometric technique which is widely accepted for diagnosis of spinal osteoporosis is single energy QCT. Measurements of vertebral trabecular bone mineral density (BMD) demonstrate larger percentage decrements between vertebrally-fractured subjects and normal controls, and confer higher relative risks for vertebral fracture than either anteroposterior or lateral DXA measurements. As an emerging alternative to photon absorptiometry techniques, there is a growing interest in the use of quantitative ultrasound (QUS) measurements for the non-invasive assessment of osteoporotic fracture risk in the management of osteoporosis. The attractiveness of QUS lies in the fact that indirect and in vitro experience has suggested that ultrasound may give information not only about BMD but also about architecture and elasticity. Whether or not combining QUS and DXA improve fracture prediction is still unclear and needs further analysis. Due to the growing evidence supporting the use of QUS in osteoporosis and the large number of QUS devices already on the market, a general clinical consensus on the application of QUS is urgently needed. Other techniques that are less widely used for the management of osteoporosis. For example, peripheral quantitative computed tomography, quantitative magnetic resonance (QMR) and magnetic resonance microscopy are promising tools for the evaluation of the skeleton. For example, the ability of QMR and high resolution magnetic resonance imaging has been explored and shows promise as a technique for assessing trabecular bone structure in osteoporosis.

Absorptiometry, Photon↗
PubMed1997

Texture analysis of direct magnification radiographs of vertebral specimens: correlation with bone mineral density and biomechanical properties.

RATIONALE AND OBJECTIVES: The authors used direct magnification radiographs, combines with texture analysis, to investigate the trabecular structure of human vertebral specimens and compared these techniques with measurement of bone mineral density (BMD) by using quantitative computed tomography to predict bone strength. METHODS: Direct magnification radiographs and BMD measurements were obtained from 38 motion segments from the thoracolumbar spines of 11 female human cadavers. Maximum compressive strength (MCS) was determined with a materials testing machine. Morphologic parameters, digital skeletons, and fractal dimension were obtained from the radiographs in three different regions of interest. RESULTS: Correlations between BMD and MCS were statistically significant (r = .81, P < .01). With morphologic parameters, correlation coefficients of up to .64 (P < .01) were obtained. Use of multivariate regression analysis with one morphologic parameter (the width of the black pixels, or thicknessB) in addition to BMD improved correlations versus MCS (P < .01). CONCLUSION: In an experimental setting, BMD showed statistically significant correlation with bone strength, whereas the structural parameters demonstrated only modest correlations. BMD together with one of these measures (thicknessB), however, showed the highest correlation.

Adult↗