共查询到20条相似文献,搜索用时 15 毫秒
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Zixing Fang Jo Anne Smith Alison Kleppinger Susan T. Reisine Denise Emerson Martin Kulldorff 《Journal of clinical densitometry》2002,5(4):421-433
Dual-energy X-ray absorptiometry (DXA) is widely used for bone mineral density (BMD) measurements. Prospective daily quality control procedures such as cumulative sum (CUSUM) plots and Shewhart charts are very important and commonly used for routine monitoring of DXA measurements. These procedures are less suitable for post hoc adjustment of DXA measurements for clinical research studies, if and when that is needed. Extending previous methods, we propose and illustrate a simple statistical method for retrospective quality evaluation that may be used to adjust BMD measurements before they are analyzed in clinical research studies. Using multivariate regression, this method allows for simultaneous adjustment of different types of temporal variation such as sudden jumps, simple linear trends, changes in the slope of these trends, quadratic terms, and seasonal fluctuations. Adjusting the measurements to account for different types of temporal trends decreases the variance of bone mass density measurements and is an inexpensive way to increase the power of a study without increasing the sample size. The method is illustrated with measurements of two different phantoms used on the same DXA, with 2 and 3 yr of data, respectively. Results were consistent for both phantoms, with a gradual trend and a sudden jump, as well as a seasonal fluctuation term. 相似文献
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Shota Ikegami Mikio Kamimura Shigeharu Uchiyama Hiroyuki Nakagawa Hiroyuki Hashidate Kenji Takahara Hiroyuki Kato 《Journal of clinical densitometry》2009,12(3):120-344
In Japan, spinal dual-energy X-ray absorptiometry (DXA) has been commonly performed for diagnosing osteoporosis but scanning the proximal femur is not done widely. The latest Japanese guidelines for prevention and treatment of osteoporosis, revised in 2006, recommend bone mineral density (BMD) measurement at both spine and hip for diagnosing osteoporosis, although there have been no reports that proved the necessity of those measurements. One thousand forty-one women and 485 men with clinical suspicion of osteoporosis were enrolled in this study, and DXA was performed at both spine and hip. The proportions of the patients who had inconsistency between diagnosis of osteoporosis from spinal DXA and that of hip were estimated. As a result, 22% of women and 15% of men had an inconsistency with the diagnosis of osteoporosis using DXA at each measurement site. There was inconsistency in diagnosing osteoporosis using DXA at the spine and proximal femur measurement sites. Because spine and femoral DXA measurements complement each other in the diagnosis of osteoporosis, BMD measurement at both spine and hip should be performed for all Japanese patients who are suspected osteoporosis, regardless of age and sex. 相似文献
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Diffuse Idiopathic Skeletal Hyperostosis Causes Artificially Elevated Lumbar Bone Mineral Density Measured by Dual X-ray Absorptiometry 总被引:3,自引:0,他引:3
A 76-yr-old man with bilateral total hip arthroplasties was referred for a baseline bone mineral density (BMD) measurement. The L1-L4 lumbar bone density revealed a density above the upper expected value for a young individual (i.e., T-score > 2.5) with large intervertebral variation, while the forearm study revealed an osteoporotic measurement. Lumbar spine radiographs demonstrated abundant, flowing ossification of the anterior spinal ligament, predominantly at L3, consistent with diffuse idiopathic skeletal hyperostosis, which accounted for the increased BMD. 相似文献
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C. A. Formica J. W. Nieves F. Cosman P. Garrett R. Lindsay 《Osteoporosis international》1998,8(5):460-467
A measurement of bone mass is the single most important determinant of future fracture. However, controversy exists as to
which technique (dual X-ray absorptiometry (DXA) or peripheral quanitative computed tomography (pQCT)), and which site of
skeletal measurement (axial vs appendicular) provides the best prediction of fracture risk. The aims of this study were: (1)
to determine the ability of pQCT to predict bone mass of the lumbar spine, proximal femur, and distal forearm measured using
DXA, and (2) to compare the ability of DXA and pQCT to discriminate prevalent fractures in women with established osteoporosis.
One hundred and sixty-five women were studied, including 47 with established osteoporosis (vertebral, hip or Colles' fractures)
as well as 118 who had bone mass measurements to assess osteoporosis risk. Each subject had bone mass measured by DXA at the
lumbar spine and femoral neck, and at the distal radius by both DXA and pQCT. In women with fractures, bone mass, when expressed
as a standardized score, was in general lower using DXA compared with the appendicular skeleton measured using pQCT. Bone
mass determinations at all sites were significantly correlated with each other. The highest correlation coefficients were
observed within the axial skeleton. In women with fractures, the highest odds ratios were observed at skeletal regions measured
using DXA. Likewise, the areas under the receiver-operating characteristic (ROC) curves were comparable at all skeletal regions
measured using DXA; and were significantly greater than the areas under the ROC curves for pQCT measurements. In summary,
the strongest discriminators of prevalent fractures were measurements using DXA. Measurements of bone mass at the appendicular
skeleton, using either DXA or pQCT, were poorly associated with axial bone mass. PQCT has the poorer ability to discriminate
persons with fractures, and appears to be less sensitive than measurements using DXA.
Received: 15 September 1997 / Accepted: 17 February 1998 相似文献
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The availability of bone densitometry in daily clinical practice has revolutionized the capacity to detect osteoporosis, to estimate the risk of future fracture, and to select those patients who are likely to benefit most from preventive or therapeutic measures. In spite of the high availability of densitometry in Belgium and the high incidence of risk factors for osteoporosis in elderly women, osteoporosis is presumably underdiagnosed. It is likely that the limited use of widely available technology to evaluate osteoporosis results from a complex interaction of numerous factors, some of which are discussed. In spite of many unanswered questions, the main conclusion to be drawn from the Belgian experience is that a high density of densitometry facilities is no guarantee that the majority of women who are at greatest risk of fracture will actually become the focus of preventive measures or therapy. 相似文献
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Jean E. Mulder MD Daniel Michaeli Edith R. Flaster MS Ethel Siris MD 《Journal of clinical densitometry》2000,3(4):373-381
The objective of this study was to compare peripheral bone mineral density (BMD) of the phalanges with BMD of the lumbar spine, total hip, femoral neck, and forearm and to determine the clinical value of measuring a single peripheral site (phalanges) in identifying postmenopausal women with osteoporosis. BMD was measured by dual energy X-ray absorptiometry using the accuDEXA((R)) (ADXA-finger) (Schick, New York, NY) and the QDR-4500 (DXA-lumbar spine, hip, forearm) (Hologic, Waltham, MA). Correlation coefficients between ADXA and DXA of the lumbar spine, total hip, femoral neck and one third radial site ranged from 0.53 to 0.73. The sensitivity of an ADXA T-score of -2.5 in identifying patients with a DXA T-score of < or = -2.5 at the femoral neck was 35%. An ADXA T-score cut point of -1.0 improved the sensitivity of ADXA in identifying patients with a femoral neck T-score of < or = -2.5 (85%), but the specificity declined from 88 to 49%. There was substantial discordance in the diagnosis of osteoporosis when a single site was measured, regardless of technique. Within the limitations of single-site measurements, BMD measured by ADXA has adequate sensitivity to identify women with low BMD at the femoral neck, if an appropriate T-score criterion is used. 相似文献
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How Often Does Lateral Spine DXA Detect Low Bone Mass in Patients with Both Normal PA Spine and Hip?
Michael Maricic MD John Tesser MD Zhao Chen PhD Pamela Lund MD Oscar Gluck MD 《Journal of clinical densitometry》1998,1(3):251-257
The clinical utility of lateral bone mineral density (BMD) measurement for the diagnosis of osteoporosis remains controversial. Since both posterior-anterior (PA) spine and hip scans are universally performed, the true clinical utility of lateral dual-energy X-ray absorptiometry (DXA) should lie in its ability to detect low bone mass independent of both PA spine and hip. We examined lateral, PA and hip BMDs in 2134 referred Caucasian females aged 25-89 using the Hologic 2000. Compared only to PA scans, the additional percentages of women with very low BMD (T-score below -2.5 utilizing the National Health and Nutrition Examination Survey [NHANES] III normative database) on lateral were 7.3, 16.4, 28.2, 33.7, and 26.2% for age groups 25-49, 50-59, 60-69, 70-79, and 80-89, respectively. When the results from both PA and total hip measurements were combined, lower but still significant percentages were found: 5.4, 14.9, 24.4, 26.6, and 17.8% for age groups 25-49, 50-59, 60-69, 70-79, and 80-89, respectively. Utilizing the original Hologic normative database, the additional yield in women with a nonosteoporotic PA spine and femoral neck was quite low: 4.6, 8.5, 13.3, 10.0, and 2.5% for women age 25-49, 50-59, 60-69, 70-79, and 80-89, respectively. Thus, the lateral scans now add more additional patients into the very low BMD category. Whether the relationship to future fracture risk of low BMD and T-scores on lateral is similar to that of PA spine remains to be established. 相似文献
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Osteoporosis After Gastrectomy: Bone Mineral Density of Lumbar Spine Assessed by Dual-Energy X-ray Absorptiometry 总被引:4,自引:0,他引:4
Adachi Y Shiota E Matsumata T Iso Y Yoh R Kitano S 《Calcified tissue international》2000,66(2):119-122
Although osteoporosis is a common clinical disorder associated with gastric surgery, long-term effects of gastrectomy on
bone metabolism are still unclear. The purpose of this study was to clarify the incidence and risk factors of osteoporosis
after gastrectomy using univariate and multivariate analyses of quantitative measurements. The study included 59 patients
who had undergone gastrectomy more than 5 years before. There were 38 men and 21 women, aged 37–81 years, mean 64 years. Bone
mineral density (BMD) of L2–L4 spine was measured using dual-energy X-ray absorptiometry (DXA). Absolute value of BMD (g/cm2) and age- and sex-matched BMD (%) were given. The mean BMD was 0.766 g/cm2, and the incidence of osteoporosis (BMD less than 0.70 g/cm2) was 37%: 18% in men and 71% in women. The mean age- and sex-matched BMD was 85.9%: 87.5% in men and 83.1% in women. Univariate
and multivariate analyses revealed that BMD was significantly associated with the age and sex of patients, but was not influenced
by the type of gastrectomy (partial versus total) and years after operation (<20 versus 20<). Our study clarified the fact
that postgastrectomy osteoporosis was frequent in the aged or female patients. BMD should be evaluated after gastrectomy,
especially in the aged and in women.
Received: 5 January 1998 / Accepted: 13 August 1999 相似文献
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M. Sosa D. Hernández S. Estévez M. Rodríguez J.M. Limiñana P. Saavedra P. Láinez P. Diáz P. Betancor 《Journal of clinical densitometry》1998,1(4):385-393
Bone mass measurements play a crucial role in the diagnosis of osteoporosis. According to a World Health Organization (WHO) Working Group, osteoporosis in women can be diagnosed if the value for bone mineral density (BMD) is 2.5 or more standard deviations below the mean value of a young reference population. This definition obviously requires the availability of normal data, which should ideally be obtained locally. The objective was establish normal values of BMD in the female Canarian population, by dual X-ray absorptiometry (DXA) in the lumbar spine and the proximal femur, and by quantitative computed tomography (QCT) in the lumbar spine, and to study the correlation between the results of both techniques and the changes with age. Seven hundred forty-four Healthy Canarian women, from 20-80 yr old were examined. Measurement of bone density was performed by an Hologic QDR 1000 densitometer (DXA) in the lumbar spine and proximal femur, and by a Toshiba scanner model 600 HQ in the lumbar spine. Both methods show that the peak bone mass is achieved in the fourth decade (30-39 yr). Bone density decreases thereafter with age in the lumbar spine (r = -0.3364 DXA and r = -0.6988 for QCT) and in the femoral neck (r = -0.3988). Bone density mean values obtained by DXA are very similar to those described in Spain and in other European female populations, using the same densitometer. The correlations between both techniques (DXA and QCT) were high and statistically significant (p < 0.001 in every case). Normal values in the normal Canarian women for DXA and QCT are provided. Our results are very similar to those previously described. These two techniques have a close correlation. 相似文献
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Effect of Leg Rotation on Hip Bone Mineral Density Measurements 总被引:2,自引:0,他引:2
Bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is widely used in the management of patients with osteoporosis. Factors, which are specific to machine or to operator, can influence the accuracy and precision of BMD estimations. We studied the effect of leg rotation by 10 degrees either internally or externally from the standard position in a group of 50 women (average age 54.9, SD = 11.1 yr) who were free of bone active diseases or medications. External rotation of leg by 10 degrees from the customary position increased the average BMD by 0.005, 0.003, and 0.036 g/cm2 in the femoral neck, trochanter, and Ward's area (p = 0.119, 0.309, and <0.001), respectively. Internal rotation of leg by 10 degrees from the customary position decreased the average BMD by 0.009, 0.005, and 0.006 g/cm2 in the femoral neck, trochanter, and Ward's area (p = <0.001, 0.008, and <0.001), respectively. The number of subjects qualified for the diagnosis of osteoporosis based on the T-scores (equal to or below -2.5) of the femoral neck and trochanter did not change significantly in three different positions (18% in the customary position and after the external rotation and 14% after the internal rotation). A significant change in the femoral neck BMD (defined as 2.77 x precision error) was seen in 12% of subjects after the internal rotation and 8% after the external rotation. Our data emphasize the need for proper positioning of the hip during DXA scanning. Malrotation of the hip can be an important confounding factor when interpreting serial BMD values. 相似文献
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Bone Mineral Density of Opposing Hips Using Dual Energy X-Ray Absorptiometry in Single-Beam and Fan-Beam Design 总被引:2,自引:0,他引:2
Bone densitometry focuses on bone mineral area density (BMD in g/cm2) of the proximal femur and spine in anterior-posterior (AP) projections. Artifacts, such as osteoarthritis and osteophytic
calcifications (OC) influence spine BMD, especially in AP scans. If only two sites are measured, as is usual in clinical practice,
there may be advantages to measuring both femora rather than one femur and the spine. This would not be useful, however, if
there was strong symmetry between the two sides. Furthermore, fan beam (FB) techniques have become available for measuring
BMD with less data acquisition time. We compared densitometry of opposing femora in 421 patients (369 women, mean age 59.0
± 4.8; 52 men, mean age 56.9 ± 7.4) using dual-energy X-ray absorptiometry (DXA): both single-beam (SB) and FB modes were
evaluated. The precision errors in vivo (short- and midterm) of total BMD were 0.7% for both SB and FB. The total BMD and BMC of the left hip (0.817 ± 0.124 g/cm2, 31.3 ± 6.4 g) were significantly (P < 0.001) higher (2–3%) than the corresponding values of the right hip (0.801 ± 0.125 g/cm2, 30.3 ± 6.3 g) in both SB and FB (left BMD 0.802 ± 0.117 g/cm2, BMC 30.0 ± 6.2 g versus right BMD 0.795 ± 0.117 g/cm2, BMC 29.3 ± 6.3 g) modes. However, BMD of the femoral neck and Ward's triangle were not significantly (P > 0.05) different between the two sides. The FB results were generally 2% lower than SB results. There were highly significant
(P < 0.001) correlations (r > 0.9) between both hips using both SB and FB. For diagnostic procedures and longitudinal studies,
one should consider that there are bilateral differences of femur BMD, as well as differences between FB and SB scan modes. 相似文献
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Abdellah El Maghraoui Ahmed Anas Guerboub Lahsen Achemlal Aziza Mounach Abderrazak Nouijai Mirieme Ghazi Ahmed Bezza Mohamed Adnane Tazi 《Journal of clinical densitometry》2006,9(4):87
Bone mineral density (BMD) measurements using dual-energy X-ray absorptiometry (DXA) are widely used to diagnose osteoporosis and assess its severity. Previous studies show the necessity to establish reference data for bone mass measurements for each particular population. Such data are lacking for the Moroccan population. The aim of this study was to determine spine and femur BMD reference values for the Moroccan female population and to compare them with values from western and other Arab countries. A cross-sectional study of 569 Moroccan women, (randomly selected in the area of Rabat, the capital of Morocco, aged between 20 and 79 yr) was carried out to establish reference values of BMD. Measurements were taken at the lumbar spine and proximal femurs using DXA (Lunar Prodigy Vision, GE). The data were compared with published normative data taken by United States (U.S.), European, Kuwaiti, Lebanese, and Saudi women over 6 decades of age. The percentage of osteoporosis in postmenopausal women using our reference curve was compared to that observed when the other curves (US, European and Arab) implemented in the Lunar machine was used. Our results showed that the Moroccan women showed the expected decline in BMD at both sites with age after peaking at 20–29 years of age. Moroccan females have lower BMD at the spine than U.S., Europeans, and Kuwaitis (approximately 10–12% for patients older than 50 yr). The BMD values of the total femur in Moroccan females were close to western (European and American), and Kuwaitis, but higher than Lebanese and Saudis. Using our reference database, 37.9% of postmenopausal women had spine osteoporosis vs. 39.6% and 23.4% using US/European and Arabic Lunar reference values respectively. At the femurs, 6.7% had osteoporosis vs. 2.5% using the Arabic Lunar reference values. In conclusion, our study emphasizes the importance of using population-specific reference values for BMD measurements to avoid over or underdiagnosis of osteoporosis. 相似文献
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The feasibility of dual energy X-ray absorptiometry (DXA) using the Norland XR-26 Mark II bone densitometer for measurements
of bone mineral content (BMC) and bone mineral density (BMD) in small rats was evaluated. Thirty-two young, isogenic, Lewis
rats (weights from 119 g to 227 g) were used; normal rats (n = 7) and rats with low BMD obtained from three different vitamin
D-depleted models (n = 25). DXA measurements were performed using the special software for small animals. Duplicate scans
of excised femurs performed at 2 mm/second (pixel size of 0.5 mm × 0.5 mm) were very precise measurements with a coefficient
of variation (CV) below 1.6% in animals with normal BMD; in rats with low BMD, the CV was significantly higher (P= 0.02–0.04), 7.8% and 4.4% for BMC and BMD, respectively. Regression analysis demonstrated that these measurements were related
to the ash weight (R2 > 98.6%). The CV for measurements of the lumbar spine at 10 mm/second (pixel size 0.5 mm × 0.5 mm) was 2.6% and 2.2% for
BMC and BMD, respectively in rats with normal BMD, and again higher (P= 0.03–0.14) in rats with low BMD, 7.3% and 4.7%, respectively, for BMC and BMD. Even though low CVs were obtained for total
body duplicate scans (scan speed of 20 mm/second and a pixel size of 1.5 mm × 1.5 mm), the measurements were problematic for
accuracy because of an overestimation of both BMC and the area of bone. Using these scan parameters the measurements of total
body bone mineral could not be recommended in small rats with low BMD.
Received: 21 May 1999 / Accepted: 3 August 2000 / Online publication: 22 December 2000 相似文献