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PubMedDate not supplied

Predictors of patient education by bone densitometry technologists.

OBJECTIVE: This study investigated which factors predict the likelihood of densitometry technologists counseling their patients about osteoporosis prevention. METHOD: Predictors of osteoporosis prevention patient education by bone densitometry technologists were analyzed in a sample of 417 radiologic technologists with ARRT advanced certification in bone densitometry and 158 densitometry technologists, none of whom were ARRT certified in bone densitometry. RESULTS: The regression model accounted for 41% of the variation in reports of bone health counseling. Densitometry technologists with high internal motivation and low personal barriers reported educating their patients about osteoporosis prevention. CONCLUSION: Recommendations for increasing bone health promotion include increasing personal interest through sensitivity training, expanding delivery by promoting models for clinical implementation and creating educational opportunities to strengthen counseling skills.

Absorptiometry, Photon↗
PubMedDate not supplied

[Modifications in diagnosis and therapy of osteoporosis after bone densitometry].

The cost-benefit ratio of diagnostic procedures has become a major problem: in particular, the expense of computerized bone mineral densitometry for osteoporosis diagnosis has brought this issue to public attention. To avoid a procedure considered costly, non-specialists often rely on standard radiography alone for diagnosis. In this study, we evaluated the percent of cases in which densitometry modified diagnosis and therapy based solely on radiographic findings. Over a 10-month period, we recruited 133 consecutive post-menopausal patients (average age 58.3 years, average time since menopause 12 years) who had never undergone densitometry. Bone density at the lumbar (L1-L4) or femoral (non-dominant) level was measured with dual energy X-ray absorptiometry. The average time between densitometry and the last radiographic examination was 13.6 months. Ninety-one patients (68.4%) had a change in diagnosis following densitometry. In 42 cases (31.6%), the previous diagnosis remained unchanged (prevalence ratio 2.2; 95% confidence interval 1.6 to 2.7). Therapy was changed in 75.2% of the cases (100 patients) and remained the same in 24.8% (33 patients; prevalence ratio 3.0; 95% confidence interval 2.3 to 3.7). Our data underscore the importance of densitometry in yielding quantitative data that are utilizable during follow-up and able to support osteoporosis diagnosis and therapy.

Absorptiometry, Photon↗
PubMed1996

The association of patellar ultrasound transmissions and forearm densitometry with vertebral fracture, number and severity: the Saunders County Bone Quality Study.

Ultrasonic measures of bone have been available for clinical research purposes for nearly 10 years, yet there still seems to be a need to compare ultrasound with the accepted gold standard of densitometry. Recently there have been published reports showing that ultrasound measures are associated with both appendicular and hip fracture, in particular after adjustment for densitometry measures. We present here a comparison between speed of sound through the patella and forearm bone densitometry, using their association with prevalent vertebral fractures in a population-based study of women and men. The prospective phase of the Saunders Bone Quality Study includes 1401 women and men who had baseline spine radiographs, patellar ultrasound, and forearm densitometry measurements. Multivariate forward logistic regression was used to determine the age-adjusted odds of vertebral fracture, the number of fractures, and the severity of these fractures, when patellar ultrasound and each of four forearm densitometry measures were entered into the model. Age is the most important factor associated with vertebral fractures, their number, and severity for women, while age is not significantly related to vertebral fractures for men. Of the bone status measures, patellar ultrasound entered the logistic regression models more consistently than any other measure except ulnar bone mineral density for women. The ultrasound measure entered every model for men. We conclude that patellar ultrasound velocity is more consistently associated with the odds of vertebral fractures than radius bone mineral content.

Aged↗
PubMed2002

Bone densitometry in children: a critical appraisal.

Due to the introduction of new therapeutic regimen aimed at increasing and maintaining bone mass, bone densitometry in children has gained interest. As in all new fields of medicine we expect the interest in bone densitometry in children to increase in the coming years. Children pose a unique problem for those involved in the field of bone densitometry, because as time progresses the measured subject changes in shape and volume. It is therefore of importance that radiologists and clinicians gain insight in the available techniques. It is also important to keep in mind that all bone densitometry techniques have been exclusively designed, developed and validated for use in an adult population. In this article we give an overview of the available techniques and discuss the specific problems that can be expected when these techniques are used in children. In the discussion section general problems regarding bone densitometry in children are presented.

Absorptiometry, Photon↗
PubMed1994

Between-laboratory comparison of densitometry and bio-electrical impedance measurements.

Body composition was measured in nine healthy, normal-weight, weight-stable subjects in three different research centres. In each centre the usual procedures for the measurements were followed. It revealed that the measurement procedures in the three centres were comparable. Body composition was measured in each centre between 09.00 and 13.00 hours after a light breakfast by densitometry (underwater weighing) and bio-electrical impedance. A single, total-body-water determination by D2O dilution was used as a reference value. Body fat determined by densitometry was significantly lower in one centre, which, however, could be completely explained by a lower body weight, probably due to water loss (the subjects refrained for a longer time from food and drinks before the measurements in that centre) and, thus, by violation of the assumptions of Siri's (1961) formula. Also, body impedance was slightly higher in that centre, indicating a lower amount of body water. Mean body fat from densitometry was also slightly lower in that centre compared with body fat determined by D2O dilution. Individual differences between body fat from densitometry and from total body water were relatively large, up to 7% body fat. The relationship between fat-free mass from densitometry and bio-electrical impedance was not different between the centres. It is concluded that differences in the relationship between body composition and bio-electrical impedance, as reported in the literature, may be due to differences in standardization procedures and/or differences in reference population.

Adipose Tissue↗
PubMed2002

Screening for childhood anaemia using copper sulphate densitometry.

OBJECTIVE: To evaluate copper sulphate densitometry to screen for childhood anaemia in a primary care setting, with a view to identifying children requiring definitive diagnostic testing and treatment. DESIGN: A cross-sectional screening study. Results of densitometry with a copper sulphate solution of specific gravity (SG) 1.048, corresponding to a haemoglobin (Hb) concentration of 10 g/dl, were compared with laboratory Hb determination. SETTING: Outpatient department of Pretoria Academic Hospital (73 children) and a local crèche (27 children). SUBJECTS: One hundred consecutive children, aged between 6 months and 6 years, with informed written consent by parents. OUTCOME MEASURE(S): Accuracy of copper sulphate densitometry in screening for Hb concentration below 10 g/dl in terms of sensitivity, specificity, positive and negative predictive values, as well as likelihood ratio. RESULTS: The prevalence of anaemia (Hb < 10 g/dl) was 17% (95% confidence interval (CI) 10.2; 25.8). Copper sulphate densitometry had a sensitivity of 88.2% (95% CI 62.3; 97.9), a specificity of 89.2% (95% CI 79.9; 94.6), a positive predictive value of 62.5% (95% CI 40.8; 80.5) and a negative predictive value of 97.4% (95% CI 90.0; 99.5) in screening for anaemia. The likelihood ratio of a positive screening test was 8.17. CONCLUSIONS: Copper sulphate densitometry was accurate in screening for childhood anaemia.

Anemia↗
PubMed1996

Comparison of bone densitometry of the phalanges, distal forearm and axial skeleton in early postmenopausal women participating in the EPIC Study.

We present baseline bone densitometry from the Early Postmenopausal Interventional Cohort study (EPIC, sponsored by Merck, Sharp & Dohme) for the first time, in which 1609 women from England, Oregon, Hawaii and Denmark are participating to investigate the efficacy of daily oral alendronate to prevent early postmenopausal bone loss. We compared radiographic absorptiometry (RA) of the phalanges for bone mineral density (BMD) measurement with single-energy X-ray absorptiometry (SXA) of the distal forearm, and dual-energy X-ray absorptiometry (DXA) of the lumbar spine, proximal femur and distal forearm. In a random subgroup of 308 women, aged 45-60 years, on average 6 years since menopause (YSM), bone densitometry was measured once at baseline by RA of the phalanges besides the mandatory measurements by DXA. Bone densitometry was furthermore measured by SXA at the Danish site (89 women). Sixty-eight of the women had duplicate measurements performed within 1-3 weeks to evaluate the short-term precision error (CV%). One hundred and one healthy premenopausal women, aged 25-48 years, were recruited at the Danish and Hawaiian sites to establish a reference group. The precision error was 1.5% for RA of the phalanges and in the range 1.0-2.2% for SXA and DXA. BMD by RA correlated with BMD measured by SXA and DXA in the range 0.45 < r < 0.72 (p < 0.001). In conclusion, bone densitometry by RA of the phalanges is highly correlated with bone densitometry by SXA and DXA. RA of the phalanges has a short-term precision error comparable to that of SXA and DXA.

Absorptiometry, Photon↗
PubMed2006

Quality and performance measures in bone densitometry: part 1: errors and diagnosis.

INTRODUCTION: Bone densitometry is one of the main pillars in the assessment of osteoporosis. The most important modalities are dual x-ray absorptiometry (DXA), quantitative computed tomography (QCT), and quantitative ultrasound (QUS). MATERIALS AND METHODS: For each modality a variety of technical solutions and numerous commercial devices are available and widely used for patient measurements. While the field of bone densitometry may be considered mature, new modalities and devices are being introduced. Consequently, there is a constant need to assess and compare the quality of bone densitometry approaches and devices in a rigorous way. RESULTS: The International Commission on Radiation Units has commissioned a report on bone densitometry to address some of these issues, in particular to provide clear definitions of quantities and units used and to describe parameters and methods that can be used to compare and standardize densitometric equipment and measurements. One of the core chapters of the report summarizes quality and performance measures in bone densitometry. It is divided into four sections: physical performance measures, diagnosis, fracture risk, and monitoring. Here we publish part 1 of this chapter containing the first two sections: physical performance measures and issues in diagnosing osteoporosis. CONCLUSION: Following the international standard (ISO 5725-1), trueness, bias, repeatability, and reproducibility are defined along with terms common to osteoporosis research, such as accuracy and precision. Building on the conceptual definition of osteoporosis, diagnostic criteria are defined and discussed including criteria for reference data. Based on this, clinical performance measures commonly used for the diagnosis of osteoporosis are reviewed and discussed.

Absorptiometry, Photon↗
PubMed1999

The Tromsø Study: artifacts in forearm bone densitometry--prevalence and effect.

Suboptimal performance of bone densitometer, operator and/or subject may cause artifacts of consequence both for individual patient management and research. The prevalence and effects of such artifacts are largely unknown in densitometry. A cross-sectional population-based study was carried out of artifacts in forearm bone densitometry with single X-ray Absorptiometry (SXA) of the nondominant hand (distal and ultradistal site). After the screening, all scans were reviewed for artifact detection and reanalysis. The effect on the bone mineral density (BMD) result was found by comparing artifactual scans with a reanalyzed version or with normal repeat scans. All women aged 50-74 years, all men aged 55-74 years and 5-10% samples of other age groups aged >/=25 years attending the fourth Tromso health study were invited to have bone densitometry. The response rate from the background population was 80% (n = 7948). Fourteen percent of subjects had a movement artifact at either the distal or ultradistal site. The individual BMD variation was twice as large in scans with a movement artifact (0.94%) compared with normal scans (0.58%) (p = 0.0027). The radial endplate was inaccurately detected in 74% of the scans. Reanalysis of these scans led to a mean 3.8% decrease in the BMD value and an increase in the prevalence of osteoporosis of 10%. Artifacts were thus common, and their effects were clinically relevant in forearm bone densitometry. Artifacts and their effects need to be characterized in other bone densitometry settings also.

Absorptiometry, Photon↗
PubMed2004

Fall-related risk factors and osteoporosis in older women referred to an open access bone densitometry service.

OBJECTIVE: Both falls and low bone density are important in the pathogenesis of osteoporotic fractures. Whilst bone density is routinely measured to assess fracture risk, little attention is given to the assessment of fall risk. In this study we have determined the prevalence and explored relationships between fall-related risk factors and osteoporosis in women referred to our open access bone densitometry service. DESIGN: Cross-sectional study. SETTING: Teaching hospital in south-west London, UK. SUBJECTS: Older women referred for open access bone densitometry. MEASUREMENTS: Bone densitometry by dual-energy X-ray absorptiometry and fall risk assessment (visual acuity, ability to do five stand-ups without arm use and ability to perform heel-toe walking). RESULTS: Data for 558 women seen over an 18 month period were examined. Their mean age was 74.8 years (range 65-93). Fall risk and femoral neck (FN) osteoporosis increased with age, with fall-related risk factors being more prevalent than FN osteoporosis at each tertile of age. Women with both FN osteoporosis and fall-related risk factors ranged from 7% in the youngest tertile to 22% in the oldest tertile. In women with FN osteoporosis, increased fall risk was found in 37% in the youngest tertile, increasing to 63% in the oldest tertile. CONCLUSIONS: Fall-related risk factors are common in older women referred for open access bone densitometry. We recommend that both bone density and fall risk assessment, using simple screening tests for falls, are essential to determine fracture risk in older people referred for bone densitometry. Subsequent management to reduce fracture risk should be individualised for each patient.

Absorptiometry, Photon↗
PubMed2006

Validation of computed tomographic lung densitometry for monitoring emphysema in alpha1-antitrypsin deficiency.

BACKGROUND: Lung densitometry derived from computed tomographic images offers an opportunity to quantify emphysema non-invasively, but a pathological standard cannot be applied to validate its use in longitudinal monitoring studies. Consequently, forced expiratory volume in 1 second (FEV1) remains the standard against which new methods must be judged. We related progression of densitometry (15th percentile point and voxel index, threshold -950 Hounsfield units) to disease stage and FEV1 decline in two studies of subjects with alpha1-antitrypsin deficiency (PiZ). METHODS: Consistency of progression, measured using densitometry and FEV1, was assessed in relation to disease stage in a 2 year study of 74 subjects grouped according to the FEV1 criteria employed in the GOLD guidelines. In the second study of a subgroup of subjects with extended data (n=34), summary statistics were applied to measurements performed annually over 3 years and the rate of progression of densitometry was related to FEV1 decline. RESULTS: The progression of percentile point was consistent across a wide spectrum of disease severity, but voxel index progression varied in association with disease stage (p=0.004). In the second study, FEV1 decline correlated with progression of lung densitometry (percentile point: rS=0.527, p=0.001; voxel index: rS=-0.398, p=0.012). CONCLUSIONS: 15th percentile point is a more consistent measure of lung density loss across a wide range of physiological impairment than voxel index. However, both methods are valid for use in longitudinal and interventional studies in which emphysema is the major outcome target.

Absorptiometry, Photon↗
PubMed1992

Results of bone densitometry affect women's decisions about taking measures to prevent fractures.

OBJECTIVE: To describe how the results of bone densitometry affect women's decisions about measures to prevent fractures and to determine whether labeling women as having below-normal bone density has adverse effects. DESIGN: Mail survey of a random sample of women. SETTING: Four community hospitals in the San Francisco Bay area. PATIENTS: A total of 261 women (response rate, 81.3%) who had undergone bone densitometry. MEASUREMENTS: Bone densitometry and self-report of changes in attitude and behaviors. RESULTS: Fifty-three percent of the women reported that their first bone density measurements were below normal, and 44% said that they were diagnosed as having osteoporosis on the basis of their test results. Women who reported that their bone density measurements were below normal were much more likely than women with normal results to begin some type of measure to prevent fractures (94% compared with 56%; P less than 0.01), to start hormone therapy (38% compared with 8%; P less than 0.01), and to take precautions to avoid falling (50% compared with 9%; P less than 0.01). Women reporting low bone density, however, also became more fearful of falling (38% compared with 2%; P less than 0.01) and limited their activities to avoid falling (24% compared with 2%; P less than 0.01). CONCLUSIONS: The results of bone densitometry substantially influence women's decisions about beginning estrogen replacement therapy and other preventive measures for osteoporotic fractures. The potential effects of labeling a woman as having below-normal bone density need to be considered before densitometry is widely used for unselective screening of women.

Absorptiometry, Photon↗
PubMed1998

Clinical reporting to primary care physicians leads to increased use and understanding of bone densitometry and affects the management of osteoporosis. A randomized trial.

BACKGROUND: A major barrier to wider use of bone densitometry has been a lack of reports that are comprehensible to primary care physicians. OBJECTIVE: To compare the effect of short technical reports and longer clinical reports on use, understanding, and acceptance of bone densitometry by primary care physicians and on management of osteoporosis. DESIGN: Randomized trial. SETTING: Osteoporosis center of a community teaching hospital. SUBJECTS: 57 primary care physicians ordering bone mineral density tests with dual x-ray absorptiometry. INTERVENTION: Physicians were randomly assigned to receive short technical reports or long clinical reports written by endocrinologists with access to clinical information. MEASUREMENTS: Physicians were interviewed by telephone after receiving at least two reports. RESULTS: Before being interviewed, physicians receiving short reports ordered a mean +/- SD of 0.72 +/- 0.71 tests per month; those receiving long reports ordered 1.30 +/- 1.21 tests per month (P = 0.002). At the first interview, 30% of physicians receiving short reports and 86% of those receiving long reports understood the bone mineral density definition of osteoporosis (P < 0.001). Receiving long reports led to more modifications in the pharmacologic treatment of osteoporosis by gynecologists (19% of patients whose reports were short and 61% of patients whose reports were long; P = 0.021) and less confusion about reports by all physicians (36% of physicians receiving short reports and 1% of those receiving long reports; P = 0.003). CONCLUSIONS: Clinical reporting of bone densitometry to primary care physicians increased use and understanding of bone densitometry, changed management of osteoporosis, and was well accepted. It may help achieve appropriate use of bone densitometry and may allow convenient dissemination of information on osteoporosis.

Absorptiometry, Photon↗
PubMed2001

[Bone metabolism as assessed with selected markers of bone turnover as well as densitometry analysis in patients after successful kidney transplantation].

The degree of advancement as well as symptoms of renal osteodystrophy improve significantly in patients after successful kidney transplantation; however bone pathology is still present even after many post-transplant years. The aim of this study was to analyze the bone densitometry in patients during different periods after kidney transplantation and to assess bone metabolism using selected biochemical markers of bone turnover in comparison to healthy controls. Study population consisted of 73 patients of mean age 41.7 +/- 12.6 years (27F, 46M) mean 34 +/- 42 months after kidney transplantation. Mean period of maintenance dialysis prior to surgery was 28.6 +/- 20.3 months. We also analyzed age- and sex-matched control group of 24 subjects. Three-point densitometry was performed with DEXA technique. Serum levels/activity of osteocalcin, C-terminal propeptide of procollagen type I (PCTP), alkaline phosphatase (AP) and its bone-specific isoform (BAP) as well as desoxypiridine (DPD) urine level were analyzed as markers of bone turnover. Serum levels/activity of all mentioned parameters were significantly increased (p < 0.001) and urine DPD--significantly decreased (p < 0.05) in patients as compared to controls. Based on DEXA technique 26% of patients were categorized as having osteoporosis, 32.9%--osteopenia and 41.1% as normal in bone densitometry. Patients with diagnosed osteoporosis spent significantly longer time with functioning graft as compared to those with normal densitometry. In addition, subjects with osteoporosis were characterized by significantly higher serum level of osteocalcin as compared to those with osteopenia and normal DEXA (42.5 +/- 19.9 vs 26.6 +/- 15 ng/ml and 42.5 +/- 19.9 vs 30.2 +/- 104 ng/ml, respectively; p < 0.05). Identical relationship was also observed for serum PTH (128 +/- 42 vs 77.2 +/- 30.4 pg/ml and 128 +/- 42 vs 81.2 +/- 232 pg/ml, respectively; p < 0.001). There was also significant difference in PCTP level in all analyzed groups (203 +/- 85, 171 +/- 69 and 137 +/- 40 ng/ml in subjects with osteoporosis, osteopenia and normal; p < 0.05 for all differences). BAP activity reduction was observed only in the latter group of patients. Results of our study led us to conclude that the prevalence of osteoporosis and osteopenia in three-point densitometry among patients with functioning graft is high. Increased serum levels/activity of osteocalcin, PCTP, AP and BAP with concomitant decrease of urine DPD elimination suggest the predominance of bone formation over the bone resorption process.

Absorptiometry, Photon↗
PubMed2002

[Comparable case finding percentages of osteoporosis despite diverging reasons for ordering bone densitometry by general practitioners and specialists].

OBJECTIVE: To assess the use of bone densitometry in practice. DESIGN: Retrospective. METHOD: General practitioners who had ordered bone densitometry for their patients were asked to fill in a questionnaire on the reasons for the request and the subsequent treatment they prescribed. For a similar number of patients from the outpatient clinics of general internal medicine and endocrinology, the medical records were examined to obtain the same information. RESULTS: In 9 months, general practitioners requested 150 bone density measurements; for 117 of these the data were complete. In one year, 150 measurements were requested by the outpatient clinics. Marked differences in the reasons for the request were seen in loss of body height, back pain and requests from the patient (indications for general practitioners) and in osteoporotic fractures and the use of corticosteroids (indications for specialists). The average result of the measurements, however, was the same, with mean T-scores in the lumbar spine of -2.26 and -2.19, respectively and case-finding percentages of osteoporosis of 21% on the basis of the lumbar spine and 40% on the basis of the spine or hip. Bone densitometry carried out after an osteoporotic fracture was associated with the lowest mean bone mineral density, followed by measurement on the basis of abnormal X-rays. Bone densitometry at the patient's request was associated with the highest bone density. The percentage of patients found to have osteoporosis turned out to be dependent on the site of measurement, the used reference ranges, and the method of reporting, especially for patients older than 70 years. When the bone density corresponded to a diagnosis of osteoporosis, nearly all patients were treated, mainly with a bisphosphonate. Treatment was also frequently started when the bone density was reduced, i.e. in case of osteopenia. Some patients with normal bone density were treated as well. The reason for such treatment was not always clear. CONCLUSION: General practitioners and specialists used different risk factors in deciding whether bone densitometry was indicated. However, the two groups used this diagnostic tool with equal efficiency, since both the percentages of osteoporosis detected and the average bone densities were the same.

Absorptiometry, Photon↗
PubMed1987

[Role of photon absorption densitometry of the bone in uremic osteodystrophy].

The aim of this investigation is to evaluate the role of bone photonic densitometry in uremic osteodystrophy. Bone mineral content (BMC) and bone density (BD) have been measured in 80 hemodialyzed patients by double photonic emission densitometry. Photonic densitometry shows an higher sensibility to quantitative changes in bone mineral content than metacarpal index (IM). Photonic densitometry is unable to differentiate osteoporosis from osteomalacia; this differential diagnosis can be obtained by radiological analysis: low BD and low IM means osteoporosis, low BD and resorptive changes in cortical bone means osteomalacia and/or hyperparathyroidism. Photonic densitometry is particularly suitable for uremic osteodystrophy follow-up because of its easy repetitiveness and innocuousness and for its close correlation with iPTH variations.

Adult↗
PubMed2002

Executive summary International Society for Clinical Densitometry position development conference Denver, Colorado July 20-22, 2001.

Bone densitometry is routinely used to assess the skeleton in patients who have diseases or conditions that can cause low bone mass. However, there are some areas of controversy related to the interpretation of bone densitometry results. To address these issues, the International Society for Clinical Densitometry (ISCD) convened a Position Development Conference in Denver, Colorado, July 20-22, 2001. The ISCD is a not-for-profit multidisciplinary society whose main mission is to promote quality in the performance and interpretation of bone densitometry examinations.

Bone Density↗
PubMedDate not supplied

Clinical applications of fundus reflection densitometry.

Fundus reflection densitometry or retinal densitometry is a non-invasive technique to examine the visual photopigment kinetics in living eyes. The technique is based on the comparison of the reflected light from the fundus in a fully light adapted eye (when all visual photopigment has been bleached) with the reflected light following complete dark adaptation (when the retina contains its maximum amount of visual photopigment). The technique provides a measure of the density of visual photopigment, its time constant of regeneration, its distribution and spectral characteristics if measured at a series of wavelengths. Fundus reflection densitometry in the human eye was introduced 40 years ago. Presently, it is the only available technique from which direct and objective insight can be obtained into visual photopigment. This knowledge is particularly relevant in eyes where abnormalities of photoreceptor function are suspected. This paper summarizes the current knowledge of fundus reflection densitometry in the diseased and in the aging human retina, gathered over the last 30 years. Considerable improvements of the instrument for clinical purposes have been obtained, and are also discussed.

Aging↗