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T M Link

Publications and source records attributed to T M Link.

At least 19 recordsLinked to original sources
PubMed2006

The 3D-based scaling index algorithm: a new structure measure to analyze trabecular bone architecture in high-resolution MR images in vivo.

INTRODUCTION: The purpose of this study was to obtain different structure measures as the three-dimensional (3D)-based scaling index method (SIM) and standard two-dimensional (2D) bone histomorphometric parameters from high-resolution (HR) magnetic resonance (MR) images of the distal radius and to compare these parameters with bone mineral density (BMD) in their diagnostic performance to differentiate postmenopausal patients with and without vertebral fractures. METHODS: Axial HR-MR images of the distal radius were obtained at 1.5 T in 40 postmenopausal women (17 with osteoporotic spine fractures and 23 controls). Trabecular microarchitecture analysis was performed using the new structure measure mP(alpha), derived from the SIM, as well as standard morphological 2D parameters. BMD of the spine was obtained using quantitative computed tomography (QCT). Receiver operating characteristic (ROC) analyses were used to determine diagnostic performance in differentiating both groups. Results were validated by bootstrapping techniques. RESULTS: Significant differences between both patient groups were obtained using mP(alpha), 2D parameters, and spine BMD (p<0.05). In comparison with the 2D texture parameters [area under the curve (AUC) up to 0.67], diagnostic performance was significantly higher for mP(alpha)(AUC=0.85; p<0.05). There was a trend for a higher AUC value for mP(alpha) compared with BMD of the spine (AUC=0.71; p=0.81). CONCLUSION: mP(alpha) yielded a robust measure of trabecular bone microarchitecture for HR-MR images of the radius, which significantly improved the diagnostic performance in differentiating postmenopausal women with and without osteoporotic spine fractures compared with standard 2D bone histomorphometric parameters. This 3D characterization of trabecular microarchitecture may provide a new approach to better assess the strength of human cancellous bone using HR-MR image data.

Aged↗
PubMed2006

Proposal for a nomenclature for magnetic resonance imaging based measures of articular cartilage in osteoarthritis.

OBJECTIVE: Magnetic resonance imaging (MRI) of articular cartilage has evolved to be an important tool in research on cartilage (patho)physiology and osteoarthritis (OA). MRI provides a wealth of novel and quantitative information, but there exists no commonly accepted terminology for reporting these metrics. The objective of this initiative was to propose a nomenclature for definitions and names to be used in scientific communications and to give recommendations as to which minimal methodological information should be provided when reporting MRI-based measures of articular cartilage in OA. METHODS: An international group of experts with direct experience in MRI measurement of cartilage morphology or composition reviewed the existing literature. Through an iterative process that included a meeting with a larger group of scientists and clinicians (December 2nd, 2004, Chicago, IL, USA), they discussed, refined, and proposed a nomenclature for MRI-based measures of articular cartilage in OA. RESULTS: The group proposes a nomenclature that describes: (1) the anatomical location and (2) the structural feature being measured, each name consisting of a metric variable combined with a tissue label. In addition, the group recommends minimal methodological information that should be described. CONCLUSIONS: Utilization of this nomenclature should facilitate communication within the scientific community. Further, the uniform adoption of comprehensive nomenclature to describe quantitative MRI- features of articular cartilage should strengthen epidemiological, clinical, and pharmacological studies in OA.

Cartilage, Articular↗
PubMed2006

Structural analysis of trabecular bone of the proximal femur using multislice computed tomography: a comparison with dual X-ray absorptiometry for predicting biomechanical strength in vitro.

We investigated whether trabecular microstructural parameters determined in multislice spiral computed tomographic (MSCT) images of proximal femur specimens differed in male and female donors and improved the prediction of biomechanical strength of the femur compared to bone mineral density (BMD) and content (BMC) determined with dual X-ray absorptiometry (DXA) as the standard diagnostic technique. Proximal femur specimens (n = 119) were harvested from formalin-fixed human cadavers (mean age 80 +/- 10 years). BMD was determined using DXA. Trabecular microstructural parameters (bone volume fraction, fractal dimension, and trabecular thickness, spacing, and number) were calculated in MSCT-derived images of the proximal femur. Failure load (FL) was measured using a biomechanical side-impact test. An age-, height-, and weight-matched subgroup (n = 54) was chosen to compare male and female donors. BMC, BMD, and structural parameters correlated significantly with FL, with r up to 0.75, 0.71, and 0.71, respectively. In a multiple regression model, an increase up to r = 0.82 was obtained when combining trabecular structural parameters and BMC. BMD differed between males and females only at the trochanter. BMC showed significant gender differences in all regions. This experimental study showed that a combination of BMC and microstructural parameters could improve the prediction of FL, suggesting that bone mass and trabecular structure carry overlapping but complementary information and that a combination of the two provides the best prediction of bone strength. Male donors had larger femora even after adjustment for body size and height, but no differences in trabecular structure were found between males and females.

Absorptiometry, Photon↗
PubMed2006

[New techniques for the diagnosis of osteoporosis].

In this review article current developments and applications in quantitative osteoporosis imaging are presented. Developments in the field of DXA include geometrical parameters of the proximal femur such as the "hip axis length" and new ROIs to determine BMD. Advances in QCT are new volumetric techniques to quantify BMD at the lumbar spine and the proximal femur. In addition techniques to determine BMD in standard contrast-enhanced abdominal computed tomography studies are described. Currently with the new bone quality concept in full bloom techniques to quantify trabecular bone architecture as new surrogates of bone strength are of increasing significance. Spatial high-resolution techniques such as magnetic resonance imaging and new computed tomography techniques have shown their potential in assessing trabecular bone structure. In addition ultrasound is considered a low-cost technique to explore bone quality.

Diagnostic Imaging↗
PubMed2006

[Fracture diagnosis in osteoporosis].

As life expectancy rises the prevalence of osteoporosis also increases, which represents a growing burden for the populace and the healthcare system. Vertebral fractures are the most frequent type of all osteoporotic fractures. Since they can be diagnosed by radiology, these examinations are particularly important for devising suitable treatment strategies. The goal of activities undertaken by osteoporosis organizations is to put across to radiologists the importance of accurate evaluation of these fractures. Identification of osteoporotic vertebral fractures is however problematic since the transition from healthy vertebral bodies to those deformed by osteoporosis constitutes a continuum and it is often difficult in deformed vertebral bodies to distinguish between an osteoporotic fracture and a non-osteoporotic deformity. This overview attempts to heighten awareness of the significant role the radiologist plays in the diagnostic work-up of osteoporosis and to provide diagnostic aids for assessing osteoporotic vertebral fractures including differential diagnoses.

Diagnosis, Differential↗
PubMed2005

Detection of osteoporotic vertebral fractures using multidetector CT.

INTRODUCTION: Goals were to compare the performance of lateral radiographs and sagittal reformations (SR) of axial computed tomography (CT) datasets in identification of osteoporotic vertebral fractures and to assess for optimal slice thickness in axial CT datasets needed for reliable classification of these fractures. METHODS: Sixty-five vertebrae were harvested from 21 human cadaver spines and examined with a 64-row multidetector CT scanner. Axial images were acquired with a slice thickness of 0.6, 1, 2, 3 and 5 mm and SR were obtained using these datasets. In addition, specimens were radiographed in antero-posterior and lateral orientation. Vertebrae visualized in the different image datasets were separately graded by four radiologists according to the spinal fracture index (SFI) classification. Fracture status determined in a consensus reading of interactive reformations of the 0.6-mm CT dataset in all three dimensions served as a standard of reference in combination with pathological examinations. RESULTS: The average agreement for the 0.6-mm SR obtained between each radiologist and standard of reference for the grading of the fractures was very good (kappa=0.81). It was good for the 1-, 2- and 3-mm SR (kappa=0.70, 0.69 and 0.64), but only moderate for the radiographs (kappa=0.52), and fair for the 5-mm SR (kappa=0.33). When focusing only on detection of fractures, independent of the grading, all kappa values improved by about 0.15, resulting in excellent values for the 0.6-mm through 3-mm SR (0.95<kappa<0.79) and good values for the radiographs (kappa=0.72). Ninety-five percent of the fractures could be identified using the 1-mm SR, but 18% of the fractures were missed on the radiographs. CONCLUSIONS: Sagittal CT reformations could more accurately assess vertebral fractures than standard radiographs. But for reliable detection of these fractures, SR derived from axial images with a slice thickness of 3 mm or less are required. The thinnest available axial slice thickness performed best in fracture grading.

Aged, 80 and over↗
PubMed2005

3.0 vs 1.5 T MRI in the detection of focal cartilage pathology--ROC analysis in an experimental model.

OBJECTIVE: To use receiver operator characteristics (ROC) analysis for assessing the diagnostic performance of three cartilage-specific MR sequences at 1.5 and 3 T in detecting cartilage lesions created in porcine knees. DESIGN: Eighty-four cartilage lesions were created in 27 porcine knee specimens at the patella, the medial and lateral femoral and the medial and lateral tibial cartilage. MR imaging was performed using a fat saturated spoiled gradient echo (SPGR) sequence (in plane spatial resolution/slice thickness: 0.20 x 0.39 mm2/1.5 mm) and two fat saturated proton density weighted (PDw) sequences (low spatial resolution: 0.31 x 0.47 mm2/3 mm and high spatial resolution: 0.20 x 0.26 mm2/2 mm). The images were independently analyzed by three radiologists concerning the absence or presence of lesions using a five-level confidence scale. Significances of the differences for the individual sequences were calculated based on comparisons of areas under ROC curves (A(Z)). RESULTS: The highest A(Z)-values for all three radiologists were consistently obtained for the SPGR (A(Z) = 0.84) and the high-resolution (hr) PDw (A(Z) = 0.79) sequences at 3T. The corresponding A(Z)-values at 1.5 T were 0.77 and 0.69; the differences between 1.5 and 3 T were statistically significant (P < 0.05). A(Z)-values for the low-resolution PDw sequence were lower: 0.59 at 3 T and 0.55 at 1.5 T and the differences between 1.5 and 3T were not significant. CONCLUSION: With optimized hr MR sequences diagnostic performance in detecting cartilage lesions was improved at 3 T. For a standard, lower spatial resolution PDw sequence no significant differences, however, were found.

Animals↗
PubMed2005

Feasibility of in vivo structural analysis of high-resolution magnetic resonance images of the proximal femur.

Previously, high resolution MRI to assess bone structure of deep-seated regions of the skeleton such as the proximal femur was substantially limited by signal-to-noise ratio (SNR). With the advent of new optimized pulse sequences in MRI at 1.5 T and 3 T, it may now be possible to depict and quantify the trabecular microarchitecture in the proximal femur. The purpose of this study was to investigate the feasibility of assessing trabecular microstructure of the human proximal femur in vivo with MR imaging at 1.5 T and 3 T. MR images of six young, healthy male and female subjects were acquired using standard clinical 1.5-T and high-field 3-T whole-body MR scanners. Using a T2/T1-weighted 3D FIESTA sequence (and a 3D FIESTA-C sequence at 3 T to avoid susceptibility artifacts) a resolution of 0.234 x 0.234 x 1.5 mm(3) was achieved in vivo. Structural parameters analogous to standard bone histomorphometry were determined in femoral head and trochanter regions of interest. Bone mineral density (BMD) measurements were also obtained using dual-energy X-ray absorptiometry (DXA) for the femoral trochanter in the same subjects. The bone structure of the proximal femur is substantially better depicted at 3 T than at 1.5 T. Correlation between the structural parameters obtained at both field strengths was up to R =0.86 for both the femoral head and the trochanteric region. However, the resolution of the images limits the application of 3D structural analysis, making the assessment more akin to 2D textural measures, which may be correlated to histomorphometric but are not identical measures. This feasibility study establishes the potential of MRI as a means of imaging proximal femur structure, and improvements in technique and resolution enhancements are warranted.

Adult↗
PubMed2005

Quantification of trabecular bone structure using magnetic resonance imaging at 3 Tesla--calibration studies using microcomputed tomography as a standard of reference.

The purpose of this study is to use high-resolution magnetic resonance (MR) imaging at 3 Tesla (3T) to quantify trabecular bone structure in vitro using femoral head specimens, and to correlate the calculated structure measures with those that were determined using microcomputed tomography (microCT), the standard of reference. Fifteen cylindrical cores were obtained from fresh femoral heads after total hip arthroplasty. MR images were obtained at 3T using a transmit-receive wrist coil. High-resolution coronal images were acquired using a modified three-dimensional (3D) fast-gradient echo sequence. From these data sets two-dimensional (2D) structural parameters analogous to bone histomorphometry were derived by using both mean intercept length (MIL) methods based on the plate model and the more recent model-assumption free 3D distance-transformation (DT) methods. The parameters measured by the 2D plate model-based MIL method and the DT method included apparent (App). BV/TV (bone volume/total volume), App. Tb.Th (trabecular thickness), App. Tb.Sp (trabecular separation), and App. Tb.N (trabecular number). Identical regions of interest were analyzed in the MR images and the microCT data sets, and similar structure measures were derived. The means and standard deviations of the parameters over all slices were calculated and MR-derived measures were correlated with those derived from the microCT data sets using linear regression analyses. Structure measures were overestimated with MRI, for example, the mean App. BV/TV was 0.45 for MRI and 0.20 for microT, and the slope of the graph was 1.45. App. Tb.Th was overestimated by a factor of 1.9, whereas App. Tb.Sp was underestimated; Tb.N showed the smallest effect. Correlations between the individual parameters were excellent (App. BV/TV, r2 = 0.82; App. Tb.Sp, r2 = 0.84; App. Tb.N, r2 = 0.81), except for App.Tb.Th (r2 = 0.67). The results of this study show that trabecular bone structure measures may be obtained using 3T MR imaging. These measures, although higher than the standard of reference, show a highly significant correlation with true structure measures obtained by microCT.

Aged↗
PubMed2005

Detection of hepatocellular carcinoma: comparison of Gd-DTPA- and ferumoxides-enhanced MR imaging.

The aim was to compare the diagnostic performance of dynamic Gd-DTPA- and ferumoxides-enhanced MRI for hepatocellular carcinoma (HCC). Twenty-five patients with chronic hepatitis or liver cirrhosis underwent both dynamic gadopentetate- and ferumoxides-enhanced MRI studies of the liver for HCC detection on the same day. MR data of both studies were retrospectively and independently analyzed. Two observers determined in consensus the grade of diffuse fibrotic liver changes (mild, moderate or severe) and the number of focal lesions. HCCs were confirmed by histology (n=22) and/or follow-up studies for at least six months (n=64). Differences in results obtained from both MR data sets were tested for significance with the McNemar's test (p<0.05). Ferumoxides-enhanced MR images detected 84 of 99 hepatic lesions, including 82 of 86 HCCs and 2 false positive, nonmalignant lesions, while Gd-DTPA-enhanced MR images detected 92 of 99 hepatic lesions, including 81 of 86 HCCs and 11 false positive, nonmalignant lesions. Sensitivity of MRI for detection of HCCs was not significantly different between ferumoxides-enhanced (95.3%; p>0.05) and Gd-DTPA-enhanced scans (94.2%). Gd-DTPA- and ferumoxides-enhanced MRI perform equally well for HCC detection. The majority of small hypervascular hepatic lesions, detected on dynamic Gd-DTPA-enhanced MRI but not on ferumoxides-enhanced MRI, represent no HCCs.

Adult↗
PubMed2005

Gender differences in trabecular bone architecture of the distal radius assessed with magnetic resonance imaging and implications for mechanical competence.

High-resolution magnetic resonance imaging (hrMRI) has recently made it possible to evaluate trabecular bone structure in vivo. Despite obvious gender differences in fracture incidence at the distal radius, little is known about gender differences in trabecular bone microarchitecture and its relationship to the structural strength of the forearm. The aim of this study was to determine trabecular bone structure in the distal radius of elderly women and men and its correlation with failure loads of the distal radius as determined in a fall configuration. Specifically, we tested the hypotheses that structural indices differ between women and men and that they offer information that is independent from BMD for predicting structural strength. Intact right arms were obtained from 73 formalin-fixed cadavers (age 80+/-11 years, 43 women, 30 men). Trabecular structural indices (apparent bone volume fraction [app. BV/TV], trabecular number [app. Tb.N], trabecular separation [app. Tb.Sp], trabecular thickness [app. Tb.Th] and fractal dimension [Frac.Dim]) were assessed in the distal metaphysis, using hrMRI with 156 microm in-plane resolution and proprietary digital image analysis, while BMD was measured with dual X-ray absorptiometry (DXA). Women displayed significantly lower BMD (-29.8%, p <0.001), app. BV/TV (-8.2%, p <0.05) and app. Tb.Th (-10.2%, p <0.001) than men, whereas app. Tb.N, app. Tb.Sp. and fractal dimension did not differ significantly. Structural parameters differed between normal and osteopenic women (BV/TV: -11%, p <0.01; Tb.Th: -8%, p <0.001) and between normal and osteoporotic women BV/TV: -21%, p <0.001; Tb.Th: -16%, p <0.001). App. BV/TV, app. Tb.Th and fractal dimension provided information independent from BMD in the prediction of radial failure loads in multiple regression models. These findings imply that it should be of clinical interest to monitor both bone mass and trabecular microstructure for predicting osteoporotic fracture risk.

Absorptiometry, Photon↗
PubMed2005

Comparison of multislice CT arthrography and MR arthrography for the detection of articular cartilage lesions of the elbow.

The objective of this study was to compare the value of multislice CT arthrography and MR arthrography in the assessment of cartilage lesions of the elbow joint. Twenty-six cadaveric elbow specimens were examined with the use of CT arthrography and MR arthrography prior to joint exploration and macroscopic inspection of articular cartilage. Findings at CT and MR arthrography were compared with macroscopic assessments in 104 cartilage areas. At macroscopic inspection, 45 cartilage lesions (six grade 2 lesions, 25 grade 3 lesions, 14 grade 4 lesions) and 59 areas of normal articular cartilage were observed. With macroscopic assessment as the gold standard CT and MR arthrography showed an overall sensitivity/specificity of 80/93% and 78/95% for the detection of cartilage lesions, respectively. Only two of six grade 2 lesions were detected by CT and MR arthrography. For the diagnosis of grade 3 and 4 lesions, the sensitivity/specificity was 87/94% with CT arthrography, and 85/95% with MR arthrography. In an experimental setting multislice CT arthrography and MR arthrography showed a similar performance in the detection of cartilage lesions. Both methods indicated limited value in the diagnosis of grade 2 articular cartilage lesions.

Aged↗
PubMed2004

Can geometry-based parameters from pQCT and material parameters from quantitative ultrasound (QUS) improve the prediction of radial bone strength over that by bone mass (DXA)?

The diagnosis of osteoporosis is generally based on the assessment of bone mineral content with dual X-ray absorptiometry (DXA) but does not account for the spatial distribution and inherent material properties of the tissue. Peripheral quantitative computed tomography (pQCT) permits one to measure the compartment-specific density and geometry-based parameters of cortical bone. Quantitative ultrasound (QUS) parameters are associated with material properties of cortical bone. The purpose of this study was to test the hypothesis that pQCT and cortical QUS provide additional information to DXA in predicting structural strength of the distal radius. The intact right arm and the isolated left radius were harvested from 70 formalin-fixed cadavers (age 79+/-11 years). The bone mineral content (BMC) was assessed with DXA at the radial metaphysis and shaft. pQCT was also used at the metaphysis and the shaft, while QUS was employed only at the shaft. The failure loads of the radius were assessed by use of a 3-point bending test (isolated radius) and a complex fall simulation (intact arm). The BMC (DXA) displayed a correlation of r=0.96 with the failure moments in 3-point bending ( P<0.001). The correlation between failure load and geometry-based parameters (pQCT) ranged from r=0.85 to r=0.96 and was r=0.64 for the speed of sound (QUS) ( P <0.001). Cortical thickness (pQCT) improved the prediction marginally (r=0.964) in combination with DXA. For the fall simulation, the correlation coefficients were r=0.76 for BMC (DXA) of the shaft, r=0.83 for metaphyseal bone content (pQCT), r=0.55 for QUS, and ranged from r=0.59 to r=0.74 for geometry-based parameters at the shaft (pQCT). pQCT and QUS parameters provided no significant improvement versus DXA alone. Measurement of bone mass by DXA or pQCT thus appears to be sufficient as a surrogate of mechanical strength and fracture risk of the distal radius.

Absorptiometry, Photon↗
PubMed2004

Technical considerations for microstructural analysis of human trabecular bone from specimens excised from various skeletal sites.

The purpose of this study was to test the effect of repositioning, systematic displacements of the region of interest (ROI), and acquisition parameters (scan mode and integration time) on quantitative analysis of human trabecular bone microstructure at various skeletal sites, using microcomputed tomographic (microCT) technology. We investigated 28 cylindrical specimens of human trabecular bone (length 14 mm, diameter 8 mm) from four skeletal sites (femoral neck, greater trochanter, second lumbar vertebra, and distal radius). These specimens were selected from over 200 microCT measurements, in order to cover a large range of bone volume fraction (BV/TV) observed at each site. Cylindrical ROIs (length 6 mm, diameter 6 mm) were examined twice at an isotropic resolution of 26 microm, 8 weeks apart. In addition, comparative analyses were performed for displacements of the volumes of interest (VOIs) by 1, 2, 3, and 4 mm (83.4%, 66.6%, 50%, and 33.3% overlap), respectively. Eventually, comparative measurements were obtained at different resolution scan modes and integration times. The results show that microCT measurements are highly reproducible (range of the root mean square coefficient variation % (RMS CV%) = 0.64% to 1.29% for BV/TV at different sites). Displacements of the VOI of up to 4 mm generally led to non significant systematic differences in mean values of < 10%. When comparing various combinations of resolution scan modes and integration times, the use of an integration time of 100 ms was found to be preferable for determining microstructural parameters from human samples with this microCT scanner.

Aged↗
PubMed2004

[Multislice-CT for structure analysis of trabecular bone - a comparison with micro-CT and biomechanical strength].

OBJECTIVES: MS-CT (Multislice-Spiral-CT) has a higher spatial resolution compared to the SS-CT (Singleslice-CT). The purpose of this study was to investigate, if the higher spatial resolution of the MS-CT has advantages for structural analyses in the assessment of osteoporosis. MATERIAL AND METHODS: 20 cylindrical trabecular bone specimens (diameter 12 mm, length 15 - 20 mm) were harvested from formalin-fixed human thoracic spines. All specimens were examined by Micro-CT and quantitative, histomorphologic parameters were determined. Analogous structural parameters were calculated from the high-resolution images acquired by both MS- and SS-CT. Additionally, the BMD (bone mineral density) was measured by QCT (quantitative CT). The maximum compressive strength (MCS) was determined in a biomechanical test. The structural parameters were correlated with the histomorphologic parameters and with the MCS. RESULTS: The parameters bone fraction and trabecular separation correlated significantly in both MS- and SS-CT with the analogous parameters from Micro-CT (r (2) = 0.84, p < 0.01) and the MCS (r (2) = 0.81, p < 0.01). The highest correlation with the MCS was calculated using the trabecular number measured by MS-CT in the superior region near the endplate of the vertebra with the high-resolution kernel U90 u (r (2) = 0.85, p < 0.01). This correlation was significantly higher than the correlation between MCS and BMD (r (2) = 0.49, p < 0.01). CONCLUSION: Micro-CT- and MS-CT-determined structural parameters of the trabecular bone showed significant, high correlations. Thus, a characterisation of the trabecular structure seems to be possible. The biomechanical stability of the bone can also be predicted well. The structural parameters acquired by MS-CT show higher correlations with the MCS than the BMD or structural parameters determined by SS-CT do. In this study MS-CT was best suited to predict biomechanical strength of trabecular bone.

Aged↗
PubMed2003

Local 3D scaling properties for the analysis of trabecular bone extracted from high-resolution magnetic resonance imaging of human trabecular bone: comparison with bone mineral density in the prediction of biomechanical strength in vitro.

RATIONALE AND OBJECTIVES: A novel, nonlinear morphologic measure [DeltaP(alpha)] based on local 3D scaling properties was applied to high-resolution magnetic resonance images (HR-MRI) of human trabecular bone to predict biomechanical strength in vitro. METHODS: We extracted DeltaP(alpha) and traditional morphologic parameters (apparent trabecular volume fraction, apparent trabecular separation) from HR-MR images of 32 femoral and 13 spinal bone specimens. Furthermore, bone mineral density (BMD) and maximum compressive strength (MCS) were determined. The morphologic measures were compared with BMD in predicting the biomechanical strength. RESULTS: In the vertebral (femoral) specimens, R2 for MCS versus DeltaP(alpha) was 0.87 (0.61) (P < 0.001). Correlation between BMD and MCS was 0.53 (P = 0.05) (0.79 [P < 0.001]) for the vertebral (femoral) specimens. For the femoral specimens, prediction of MCS could be improved further by combining BMD and morphologic parameters by multiple regression (R2 = 0.88). CONCLUSIONS: Morphologic measures extracted from HR-MRI considering local 3D-scaling properties can be used to predict biomechanical properties of bone in vitro. They are superior to 2-dimensional standard linear morphometric measures and, depending on the anatomic location, more reliably predict bone strength as measured by MCS than does BMD.

Adult↗
PubMed2002

Structure analysis of high resolution magnetic resonance imaging of the proximal femur: in vitro correlation with biomechanical strength and BMD.

The purpose of this study was to use high resolution magnetic resonance imaging (HR-MRI) combined with structure analysis to investigate the trabecular structure of the human proximal femur and to compare this technique with bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA) in the prediction of bone strength in vitro. Thirty-one fresh human proximal femur specimens were examined with HR-MRI using a T1-weighted 3D spinecho-sequence in a coronal plane (voxel size: 0.195 x 0.195 x 0.9 mm and 0.195 x 0.195 x 0.3 mm). In these images structure parameters analogous to standard bone histomorphometry were obtained in a femoral head, neck, and trochanteric region of interest (ROI). In addition, BMD measurements were obtained using DXA and finally, all specimens were tested biomechanically in a materials testing machine, and maximum compressive strength (MCS) was determined. Correlations between BMD and MCS were significant (p <0.01) with R-values up to 0.74. Correlating structure parameters and MCS R-values up to 0.69 (P <0.01) were obtained. Using multivariate regression analysis, combining structure parameters and BMD, improved correlations versus MCS substantially (up to R = 0.93; P <0.01). In conclusion, this study showed that in an experimental setting, structure parameters determined in high resolution MR images of the proximal femur correlated significantly with bone strength. The highest correlations, however, were obtained combining BMD and structure measures.

Aged↗