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PubMed2003

Osteoporosis in postmenopausal Saudi women using dual x-ray bone densitometry.

OBJECTIVE: A pilot study to estimate the prevalence of osteopenia and osteoporosis in postmenopausal Saudi women. METHODS: Lumbar spine bone density was measured in 830 postmenopausal Saudi women 50-80 years of age (average 59 years), using dual x-ray absorptiometry (DXA) at the King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia between 1989 and 1999. RESULTS: The results of the bone mineral density (BMD) in gm/cm2 were compared to the peak bone density (PBD) in healthy young women (T-score). Based on the definition of World Health Organization (WHO), the T-score value was considered for analysis. Accordingly, 248 (29.9%) subjects showed normal result, mean BMD of 1.117 +/- 0.13 and T-score of -0.66 SD; while 254 (30.6%) subjects showed osteopenia, mean BMD of 0.983 +/- 0.11 and T-score of -2.4 SD and 328(39.5%) subject showed osteoporosis, mean BMD of 0.767 +/- 0.11 and T-score of -3.4 SD. When the 830 subjects were analyzed by decades, there were 42.3% normal, 33.4% osteopenia and 24.3% osteoporosis in age 50-59 years; 11% normal, 27% with osteopenia and 62% with osteoporosis in age 60-69 years while in older age 70-79 years only 4.6% had normal BMD, 21.5% had osteopenia and 73.8% had osteoporosis. CONCLUSION: Osteopenia and osteoporosis are common among postmenopausal Saudi women and should be considered as a matter of public health. Bone densitometry should be used to assess the severity of bone loss, identify those who need therapy and for follow up and early diagnosis of those with osteopenia in order to institute proper therapy and avoid future osteoporosis.

Absorptiometry, Photon↗
PubMedDate not supplied

[Gamma-ray bone densitometry and evaluation of the patient at risk for osteoporosis].

After having briefly illustrated the main theories of photonic ray bone densitometry, the authors describe the various techniques used to evaluate bone mass and bone mineral density as accurately and precisely as possible both at an appendicular level and at lumbar and femoral sites. Since these data only provide a static measurement and are unable to provide information regarding bone mass evolution in time, a method is illustrated which is theoretically capable of identifying high risk subjects, namely those who, on the basis of simple blood and urine tests for some biochemical parameters, are likely to undergo a significant reduction in bone mass in the future. Lastly, the paper reports the preliminary results of a study carried out in immediately post-menopausal women in whom rapid loss of bone mass was followed by a greater reduction in bone mineral density measured at an appendicular level.

Absorptiometry, Photon↗
PubMed1992

[Osteopenia in anorexia nervosa evaluated by dual photon-densitometry. Role of malnutrition and hypogonadism].

30 female patients with anorexia nervosa (AN) were studied and compared with 45 age-matched normal controls. All the patients had severe weight loss and nutritional involvement. Mean and SE body mass index, BMI (kg/m2) were 15.8 +/- 1.8 in anorectics compared to 21.7 +/- 4.7 in normals (p < 0.0001). All the patients presented amenorrhea lasting between 3 and 120 months (mean 24.8 +/- 25.3). A nutritional survey and a dual photon bone densitometry, including spine, hip, total body and total mineral content were performed. The mean values +/- SE in patients and controls were: spine densities (L2-L4) in g/cm2: AN 0.84 +/- 0.1, controls 1.03 +/- 0.1 (p < 0.002). Total mineral content (g): AN mean 1733 +/- 261, controls 2045 +/- 276 (p < 0.0001). In anorectic patients the correlations between bone density and BMI for spine were r: 0.52 (p = 0.002), for hip r: 0.37 (p = 0.04), and total mineral content vs BMI gave r: 0.64 (p = 0.0001). Mean calcium intake in 23 studied patients was lesser than the classic recommended dietary allowance in the whole group, it was less in the pure restricters as compared to vomiters. The relation between duration of amenorrhea and bone density showed than a decrease in the later was evident when the absence of menses was longer than 24 months. In conclusion, in patients with AN there is a real decrease in bone density which is strongly related to low weight and in lesser proportion to the duration of amenorrhea, particularly when it was longer than 24 month.

Absorptiometry, Photon↗
PubMed1992

[Asymptomatic primary hyperparathyroidism: evaluation of bone mass using dual-photon bone densitometry].

Dual-photon bone densitometry of the lumbar spine and hips was performed in 11 patients (9 females) with asymptomatic primary hyperparathyroidism and in 11 control subjects. The age was 54.7 +/- 14.8 years. The asymptomatic state of the disease was established by the absence of clinical or radiologic evidence of renal, digestive or bone involvement. 10 of 11 patients had histologic confirmation of the disorder, in addition to the biochemical and RIA findings which were present in all. Serum calcium ranged from 10.6 to 11.8 mg/dl, and P levels were decreased in 7 subjects. Alkaline phosphatase levels were elevated in 7 patients. Urinary calcium output was 341 +/- 216 mg/24 h. Bone density was 16% lower at the lumbar spine and 20% lower at the hip in patients compared to controls. In 5 patients bone density was lower than the level associated to increased risk for fractures (compared to 2 controls). No correlation existed between bone density and biochemical indices of hyperparathyroidism. Thus, decreased bone density and increased risk of fracture may exist in patients with hyperparathyroidism even at the asymptomatic stage.

Absorptiometry, Photon↗
PubMed1992

Total bone mineral content and body composition by x-ray densitometry in newborns.

Measurement of total body bone mineral content and body composition has not previously been convenient in the newborn. X-ray densitometry, otherwise known as dual-energy x-ray absorptiometry (DEXA), has been used in adults to assess with accuracy and precision the total body mineral content, lean mass, and fat. Body composition measurements were determined in vivo by DEXA in term newborns, and they were compared with values reported by chemical analysis of the cadaver, with skin-fold thickness measurements, and with bone mineral content measured by single photon absorptiometry. The intermeasurement coefficient of variation was < or = 2.5% for bone mineral content, and < or = 1% for fat and lean mass. The values for bone mineral content, fat, and lean mass fall within the ranges expected based on the reported values measured by chemical analysis of the infant cadaver. Triceps and quadriceps skin-fold measurements were best correlated with total body fat as measured by DEXA. The bone mineral content of the distal third radius site as measured by single photon absorptiometry in newborns showed significant correlation with total body bone mineral content. DEXA provides a reproducible and convenient method for the determination of body composition in newborns.

Absorptiometry, Photon↗
PubMed2004

Sequential analysis of biochemical markers of bone resorption and bone densitometry in multiple myeloma.

BACKGROUND AND OBJECTIVES: Bone lesions often occur in multiple myeloma (MM), but no tests have proven useful in identifying patients with increased risk. Bone marker assays and bone densitometry are non-invasive methods that can be used repeatedly at low cost. This study was performed to evaluate these methods in predicting bone events in MM patients. DESIGN AND METHODS: Thirty newly diagnosed MM patients were enrolled. Serum C-terminal telopeptide (ICTP) and urinary N-terminal telopeptide (NTx) of collagen I were measured for assessment of bone resorption, and serum C-terminal (PICP) and N-terminal (PINP) propeptides of procollagen I, bone-specific alkaline phosphatase, and osteocalcin were measured to estimate bone formation. Dual energy X-ray absorptiometry (DEXA) was used to assess bone mineral density (BMD) of the lumbar spine, hip, and whole body. Serum and urine samples were collected every 6 weeks, DEXA-scans performed every 3 months, and skeletal radiographs were done every 6 months as well as when indicated. RESULTS: Serum ICTP and urinary NTx were predictive of progressive bone events. Markers of bone formation, bone mineral density assessments, and M component measurements were less informative. In Cox analysis, ICTP showed the highest predictive value, but should be replaced with NTx in patients with nephropathy. Pretreatment low lumbar BMD was predictive of early vertebral fractures. INTERPRETATION AND CONCLUSIONS: Sequential DEXA-scans showed heterogeneous local BMD changes, and our data do not support routine use of sequential DEXA-scans. However, lumbar DEXA-scans at diagnosis can identify patients with increased risk of early vertebral collapses. Sequential analyses of serum ICTP and urinary NTx are useful for monitoring bone damage.

Absorptiometry, Photon↗
PubMed1992

[Methods for measuring whole-body adipose tissue: the usefulness of "total body" X-ray densitometry].

"Total body" densitometry, which was first used to determine total-body mineral content, allows, above all in the most recent X-ray (DXA) version, an accurate study to be made of soft tissues in relation to both their adipose and nonadipose components. In addition to being used for overall evaluations, it is possible to use DXA for regional studies of body tissue distribution, thus allowing obesity to be analysed not only in quantitative but also qualitative or more specifically endocrine-metabolic terms. In comparison to other methods DXA is noninvasive, quick to use, low cost and risk free. Given its high accuracy rate it can also be used to monitor patients with demineralizing pathologies, obesity, thinness due to global and/or district edema receiving dietary and/or pharmacological treatment.

Absorptiometry, Photon↗
PubMed2005

New polymer materials in total hip arthroplasty. Evaluation with radiostereometry, bone densitometry, radiography and clinical parameters.

AIMS: To evaluate the outcome of different types of polyethylene, bone cements and one design of uncemented fixation with porous and ceramic coating using radiostereometry, bone densitometry, conventional radiography and clinical parameters. MATERIALS AND METHODS: Study I: 201 patients were extracted from 5 prospective randomised studies to evaluate femoral head penetration at two years with radiostereometry in four basic designs, cemented Lubinus and Reflection cups, uncemented Trilogy and Reflection cups. Studies II and III: 60 patients (61 hips) were randomised to receive either highly cross-linked or conventional all PE cups. 32 patients with bilateral arthrosis received hybrid THA with highly cross-linked PE on one side and conventional on the contra lateral side. Femoral head penetration and the migration of the cups were evaluated with radiostereometry in the supine and standing positions. DEXA and conventional radiography were used to evaluate the bone mineral density and radiolucencies around the cemented acetabular component. Studies IV and V: 90 patients (97 and 96 hips respectively) were stratified depended on age, gender, diagnosis and preoperative BMD to create 3 main groups of socket fixation. In the first group fluoride containing cement was used, in the second group Palacos cum Gentamicin and in the third hybrid THA with porous coated HA/TCP cup. In the hybrid group the fixation of the femoral component was again randomised to either of the two cements. The results on femoral and acetabular sides are presented separately in studies IV and V, respectively. RESULTS: Study I: Cups with polyethylene sterilized in EtO had almost twice the proximal and 3D penetration rates compared with gamma-sterilized polyethylene. Regression analysis showed that the type of sterilization, age and weight was the most important factors affecting the penetration rate. Studies II and III: In the cemented study the proximal penetration was lower in the study group independent of position at 3 years, while in the hybrid study the penetration was lower in the study group only in the supine position at 2 years. The migration of the cup did not differ between the plastics in both studies. At 2 years the periprosthetic radiolucency and BMD did not differ significantly between the 2 types of PE used in the cemented study. Study IV: The subsidence of the stem did not differ between the groups, but the periprosthetic BMD decreased more in fluoride cement group at 2 years. Conventional radiography revealed higher progression of radiolucent lines in the Palacos group, but only in one region. Study V: The proximal migration of the cup was almost similar in all three groups. The three dimensional migration was increased in patients with osteoporosis. Postoperative radiolucent lines tended to disappear with use of porous coating covered with HA/TCP. CONCLUSIONS: Study I: EtO sterilized polyethylene increased the femoral head penetration. Age and weight were also important predictors of the penetration rate. Studies II and III: The highly cross-linked polyethylene decreased the penetration rate mainly after one year probably reflecting less wear. The different mechanical properties of the two types of PE studied did not affect the early fixation of the cemented cup. Study IV: There were no obvious advantage of addition of fluoride to acrylic bone cement when used to fixate the femoral component. Study V: Use of fluoride containing cement or uncemented fixation did not improve the early stability of the socket compared to Palacos with Gentamicin.

Absorptiometry, Photon↗
PubMed1991

[Bone densitometry of periapical lesions].

The aim of the work was to evaluate the bone density of chronic periapical lesions in the area of maxillary incisors and canines. Twenty-six radiographies were made in a systematic way in patients with periapical lesions and were valued using densitometry (0-256), the grey levels by computer and the analysis program image (IBAS 2000 Kontron, Germany), taking four values in each periapical lesion from the center to the periphery within the same radiography, by using the pseudocolor to identify the four areas, always in the same coloration. Correlation was proved with significative statistically results between lower densitometric values and osteolysis and radiolucency areas.

Absorptiometry, Photon↗
PubMed1991

[Bone densitometry: technical principles and practical value].

X-ray dual photon absorptiometry has replaced isotopic mono and dual photon absorptiometry in the assessment of metabolic bone diseases. This method is a valuable tool for epidemiologic studies. Individual examinations give poor in vivo accuracy and precision. Further technical improvements are needed to give bone densitometry a predictive value for osteoporotic risk.

Absorptiometry, Photon↗
PubMed1991

[Bone mass peak, evaluation using bone densitometry of the whole body in a normal female population in our environment].

Considerable debate exists about when the maximal bone mass, or "bone mass peak" is physiological acquired. In the present study, 140 normal females aged 15 through 19 years (n = 18), 20 through 29 years (n = 58) and 30 through 39 years (n = 64), were assessed in order to determine their total body bone mineral (TBBM) content, as bone mass parameter, by bone densitometry with dual energy X rays. We did not observe significant differences in TBBM values between the different groups. A positive and significant correlation existed between age and TBBM (r = 0.486, p less than 0.05) in female aged 15 to 19 years but not in the rest of the groups. These data suggest that female acquired their maximal bone mass, or bone mass peak, up to the age of 20 years and that it remains stable until, at lest, the age of 39 years. We point up the importance of achieving an adequate skeletal development in females during their first 20 years of life that could perhaps protect them from suffering subsequently from osteoporosis.

Absorptiometry, Photon↗
PubMed1990

[Bone densitometry. A critical review and the authors' own experience].

After an updated review of computerised bone densitometry, personal experience of the bone density found in healthy subjects and rheumatoid arthritis patients both those treated with prednisone and untreated is reported. In addition certain biohumoral parameters like bone calcium, PTH, CT and l'1-25 (OH)2D3 were investigated. The results show significantly lower levels of bone calcium in treated than untreated patients.

Absorptiometry, Photon↗
PubMed1990

The relationship between densitometry of the radius and vertebral fractures.

In 105 postmenopausal women with clinical suspicion of osteoporosis single photon absorptiometry (SPA) of the forearm and fracture percentage of the thoracic and lumbar spine were estimated. SPA was performed on the commonly used mid-radius site as well as on a modified distal radius site where radius and ulna are separated by five mm. Spine fracture percentage was inversely correlated with mid-radius SPA (r = -0.49) but more closely with distal radius SPA (r = -0.61). With bone mineral density values above 0.400 g/cm2 on the distal radius, no fractures were found. Between 0.325 and 0.400 g/cm2, 35% of the patients showed vertebral fractures but only up to a maximum of 30%. Below 0.325 g/cm2, 89% of the women had crushed vertebrae, often more than 30% of those measured. In conclusion, these results indicate that modified distal radius densitometry is superior to the commonly used mid-radius measurement and has some predictive value for the presence of vertebral fractures.

Absorptiometry, Photon↗
PubMed1990

[Principle and instruments of bone densitometry].

Various methods for measurement of bone densitometry have been developed over the past two decades. This paper discribes the basic principle, technical characteristics and clinical performance on the SPA, DPA, QCT and newly developed DEXA. Advantage of SPA is low cost with high precision, but the method is used to measure only the distal radius. QCT can measure only the trabecular bone from the cortex, but requires high radiation dose. DEXA is similar in concept to DPA, but affords many advantages, i.e. higher precision, higher resolution, shorter examination time and lower dose than the DPA. This new DEXA should allow more accurate and precise management in patients with metabolic bone diseases.

Absorptiometry, Photon↗
PubMed1990

Bone densitometry of the axial skeleton.

The role of bone densitometry used as a diagnostic tool is discussed as well as its role in monitoring both the disease process itself and therapy. The QCT method and the DPA/DEXA method are discussed separately, including their regions of interest, calibration, radiation dose, diagnostic sensitivity, precision, and the monitoring and accuracy of changes, and then these two methods are compared with each other.

Absorptiometry, Photon↗
PubMed1989

New developments in bone densitometry.

The new development in QCT and DPA will reduce the time of diagnostic studies to several minutes and improve precision severalfold. It may therefore be feasible to do selective screening procedures at costs as low as $50 to $100. Thus, these advances in QCT and DPA are promising to provide capabilities that have been needed in bone densitometry--high reliability, excellent patient throughput, and services at economical levels.

Bone and Bones↗
PubMed1989

High performance thin-layer chromatography and densitometry of synaptic plasma membrane lipids.

Previously, it has been shown that phospholipids, cholesterol, and glycolipids could be quantitated using the same high performance thin-layer chromatography (HPTLC) method. Here we examined that method in terms of linearity of standards in the nanogram range, recovery of nonacidic and acidic lipids after Sephadex column chromatography, and quantitation of lipids in mouse synaptic plasma membranes (SPM) where lipid content is low. Nonacidic and acidic fractions were separated by Sephadex column chromatography, applied to plates using contact spotting, chromatographed, visualized with cupric acetate, and quantitated using in situ densitometry. Recovery of nonacidic and acidic fractions off the columns was determined with radiolabeled phospholipids. Standards for each lipid class were linear in the nanogram range. Quantitation of SPM lipid classes could be made with as little as 1.5 micrograms of total lipid. Recovery of the nonacidic fraction after Sephadex column chromatography was approximately 100% whereas the acidic fraction was approximately 91%. Phospholipids, cholesterol, and glycolipids could be determined in nanogram amounts using the same method. This method is an efficient method for examining different lipid classes and in samples where lipid content is low.

Animals↗
PubMedDate not supplied

Blood flow determinations utilizing digital densitometry.

A method of obtaining relative and absolute blood flow measurements from digital densitometry was evaluated with a simulated vessel phantom and a hydrodynamic model. A digital vascular imaging system capable of acquisition in 512(2) and 1024(2) mode was used. Relative and absolute blood flow were measured using parameters derived from the densitometric curve. Since application of densitometric data to absolute flow measurements requires the vessel diameter, an algorithm for vessel size determination was created. Gray scale changes were demonstrated to be linearly related to contrast concentration. The variance of vessel size determination was significantly different in all combinations of 1024(2) and 512(2) imaging with 15 cm or 35 cm field size. The error in vessel size determination was significantly less using the larger 1024(2) matrix and the smaller 15 cm image intensifier field size, as shown by the smaller variance. In relative flow determinations, there was good correlation between the flow and four parameters of the densitometric curve with no significant differences between 512(2) and 1024(2) imaging. Absolute flow determinations had slightly lower correlation to actual flow but were not significantly different from relative flow determinations. Relative and absolute blood flow determinations can be performed adequately with either 512(2) or 1024(2) imaging. The increased accuracy in vessel size determination with 1024(2) imaging makes this high resolution system potentially preferable to determine absolute blood flow.

Absorptiometry, Photon↗