Estrogen Hormone Replacement

The effects of cyclic hormone replacement therapy (HRT) with either transdermal estrogen or oral estrogen on BMD in the spine and proximal femur were compared to controls by Hillard et al. (126). Ninety-six Caucasian women between 6 months and 7 years postmenopausal participated in this study. Thirty women served as controls. Sixty-six women received either 0.05 mg transdermal 17-P estradiol continuously and 0.25 mg per day of norethisterone for 14 days of each cycle or oral conjugated equine...

The challenge in reporting densitometry results

Images Bone Density Cancer

The knowledge that a densitometrist must bring to bear on the quantitative assessment of bone density to interpret the findings and place them in the appropriate clinical context is considerable. But the conclusions must be carefully crafted in the most succinct fashion possible. Long reports are simply not read. Vague statements will not be understood or appreciated. At present, it is not sufficient to simply say that the patient does or does not have osteoporosis or is or is not at increased...

US Preventive Services Task Force Recommendations

In September 2002, the US Preventive Services Task Force (USPSTF) issued recommendations for bone density testing when screening for postmenopausal osteoporosis (16). Like the recent guidelines from the NOF, AACE, NAMS, and ACOG that preceded the release of these recommendations, the USPSTF recommended that women age 65 and older be routinely screened for osteoporosis. Unlike previous guidelines that also recommended testing for postmenopausal women younger than age 65 who had risk factors for...

ACOG Recommendations for Bone Density Screening for Osteoporosis

In a press release (13) on February 28, 2002, the American College of Obstetricians and Gynecologists (ACOG) announced long-awaited recommendations for the use of bone densitometry. ACOG, like the NOF and AACE, recommended that all postmenopausal women 65 years of age and older be screened for osteoporosis. Similarly, they 2 See Chapter 11 for a discussion of the relationship between precision and rate of change in determining the interval between measurements. ACOG 2001 Recommendations for...

Ehlers Danlos Syndrome

Twenty-three women (average age 37.6 years) with type III Ehlers-Danlos syndrome underwent PA lumbar spine and proximal femur DXA measurements (Lunar DPX) (37). The results were compared with those of 23 healthy women (average age 37.2 years) who were matched for age, menopausal status, and estrogen use. The mean L2-L4 BMD in the Ehlers-Danlos patients was 1.14 0.14 g cm2 compared to 1.21 0.15 g cm2 in the control group. This difference was not statistically significant. BMD in the femoral neck...

Osteoporosis risk assessment instrument

The Osteoporosis Risk Assessment Instrument (ORAI) questionnaire was developed by Cadarette et al. (7) using information obtained at the baseline visit for women participating in the Canadian Multicentre Osteoporosis Study4 (CaMos). There were 926 par- 4 CaMos is a population-based cohort study in which risk factors for osteoporosis, BMD, and osteoporotic fracture are being evaluated over a 5-year period. Demographic Characteristics of the Original ORAI Cohorts Demographic Characteristics of...

Tamoxifen

In a small, uncontrolled trial, eight postmenopausal women beginning tamoxifen 10 mg orally twice a day after a diagnosis of breast cancer were followed every 6 months with BMD measurements of the PA spine with DPA (Lunar) (161). At the end of 6 months, BMD in the lumbar spine had increased an average of 0.0456 g cm2 and at 12 months, 0.0565 g cm2. All eight subjects had increases in BMD in the lumbar spine. The effect of tamoxifen on lumbar spine BMD and the 33 radial site was determined in 70...

Case in Point

This case study illustrates the application of the precision and LSC values in clinical practice in order to answer the questions posed earlier in this chapter about Mrs. C., the postmenopausal women who has begun therapy for the treatment of osteoporosis. Assume that the precision for PA lumbar spine studies at a bone densitometry facility was previously determined to be 1.5 . This is the RMS- CV that was calculated from a study of 15 people, each of whom underwent three studies of the PA...

The fracture index

The FRACTURE Index was developed by Black et al. (17) to identify women at high risk of osteoporotic fracture based on clinical risk factors with or without a bone density measurement. This is not exactly the same as a risk-assessment tool to identify women with a high probability having of low bone mass. Nevertheless, women identified by this fracture risk assessment tool as being at high risk for fracture based on clinical risk factors alone would certainly be considered for bone density...

Recommending a followup densitometry study

The timing of a follow-up study is based on the specific circumstances of patient management. If a prescription medication is started, either for prevention or treatment, the timing of the repeat study and the skeletal site to be used for that measurement are determined by the anticipated effects of the drug on the skeleton and the precision of the measurement at the chosen skeletal site.9 To address all possible contingencies becomes quite difficult. As noted in Chapter 7, several...

Elements of densitometry reports requested by primary care physicians

Inc. (2) conducted focus groups with primary care physicians to determine what was both wanted and needed in reporting the results of densitometry. When asked to rate the extent to which they used either the technical report (the com puter-generated printout) or the summary report (the physician interpretation) for clinical decisions, primary care physicians assigned a score of 86 out of a possible 100 points to the summary report. According to these physicians, the top...

PIXI Peripheral Instantaneous XRay Imager

Peripheral Devices For Bone Density

Manufacturer GE Medical Systems, Madison, WI Skeletal application(s) calcaneus, forearm Percent young-adult and percent age-matched comparisons T-score and z-score Dimensions 12 x 25 x 13 in (30 x 63 x 33 cm) Weight 66 lb (less than 30 kg) Environmental operating temperature 64 to 81 F (18 to 27 C) X-ray source Cone-beam geometry, 250 A current Fig. 13-20. The Stratec XCT 2000 . A peripheral quantitative computed tomography device used to measure bone density in the forearm. Photograph...

Umr Guidelines For Bone Density

ABONE instrument, utility, 203, 204 Accuracy, statistical analysis, 81, 82 Acromegaly, bone density effects, 132, 133 Aging, bone density effects, children, 129 men, 132 overview, 127, 128 premenopausal women, 129 women, differences, 129, 131 perimenopause, 130 postmenopause, 131, 132 premenopause, 129 Alara MetriScan, features, 303, 304 Alcoholism, bone density effects, 133-135 Alendroate sodium, bone density effects, 153-155 Amenorrhea, bone density effects, exercise-induced amenorrhea, 134...

National Osteoporosis Foundation Guidelines

The first guidelines or indications for bone mass measurements from a national organization were released in 1988 by the National Osteoporosis Foundation (NOF). These guidelines or clinical indications were developed in response to a report from the Office of Health Technology Assessment (OHTA) of the Public Health Service that had been submitted to the Health Care Finance Administration (HCFA). The report from OHTA concluded that the role of DPA and SPA in clinical practice had not been...

AACE Guidelines

The 2001 guidelines (11) from AACE are an update of the 1996 guidelines. Additional reports in the medical literature published between 1996 and January 2001 were reviewed in preparation for the 2001 guidelines. The 2001 guidelines for bone density testing were part of an extensive treatise on the pathophysiology, detection, and management of osteoporosis. Guidelines for bone density testing were given in two contexts as part of the specific assessment for postmenopausal osteoporosis and as...

Qualitative Risk Assessments

Qualitative fracture risk assessments are descriptions of risk as being low, moderate, or high or as not increased, increased, or markedly increased. At its most basic, a qualitative assessment of fracture risk may be a statement of not at risk versus at risk. This is an assessment of current fracture risk. In 2002, the Canadian Panel of the ISCD recommended that bone density reports contain a qualitative assessment of fracture risk (24). Thresholds for moderate and high fracture risk or...

Peripheral Site TScore Equivalents for the Diagnosis of Osteopenia and Osteoporosis

Bone Density Chart For Women

Attempts to determine site, device, and manufacturer-specific T-scores or T-score ranges at peripheral sites to identify women who are osteopenic or osteoporotic at the spine or proximal femur generally involve the calculation of sensitivity, specificity and area under the receiver operating characteristic curve (AUC) as discussed in Chapter 3. Fig. 9-1. The T-score regression on age for women by site and device, from the reference databases of the various manufacturers. The expected T-score...

Cushings Syndrome

In a retrospective study, Luisetto et al. (32) compared the change in lumbar spine BMD after surgical cure of Cushing's syndrome to the change in BMD seen after successful medical treatment with ketoconazole. Seventeen women and two men with an average age of 41 years underwent DXA bone density studies (Hologic QDR 1000) before and after successful pituitary surgery or treatment with ketoconazole. Nine patients were treated successfully with surgery and 10 patients were treated medically after...

Cerium K Edge Filters Dexa Scan

Manufacturer GE Medical Systems, Madison, WI Total body with soft tissue quantification (with full size table only) PA spine 2 minutes Proximal femur 2 minutes Total body 11 minutes Percent young-adult and percent age-matched comparisons T-score and z-score sBMD (mg cm2) for L2-4 and total hip NHANES III total hip comparisons PA spine or proximal femur less than 3 mRem Total body 0.02 mRem Full-size table 95 x 42 x 52 in (242 x 107 x 133 cm) Compact table 71 x 40 x 52 in (181 x 100 x 133 cm)...

Abone

The ABONE instrument was proposed by Weinstein et al. (9) in 1999. ABONE is a mnemonic for age (A), bulk (B), and never estrogens (ONE). In the creation of the Table 8-8 The SOFSURF Scoring System History of fracture after age 50 1 Age > 65 0.2 for each year above 65 a This is in addition to the 1 point awarded for weight less than 150 lb. From ref. 8. ABONE criteria, 1346 Caucasian, postmenopausal women underwent DXA testing of the spine and proximal femur and completed a risk factor...

References

Bone densitometry for clinical diagnosis and monitoring. In DeLuca HF, Mazess R, eds. Osteoporosis physiologic basis, assessment and treatment. New York Elsevier Science Publishing Company, 1990 63-85. 2. Hui SL, Slemenda CW, Johnston CC. Baseline measurement of bone mass predicts fracture in white women. Ann Intern Med 1989 111 355-361. 3. Gardsell P, Johnell O, Nilsson BE. The predictive value of bone loss for fragility fractures in women a longitudinal study over 15 years. Calcif...

Alcoholism

The effect of chronic alcoholism on lumbar spine BMD was evaluated in 76 Caucasian men using DPA (Lunar DP3) (24). The average age of the subjects was 47 years. Of the 76 men, 22 had spine BMD measurements more than 2 SD below the young-adult mean BMD for healthy men. As a group, the alcoholic subjects had significantly lower spine BMDs than a group of 62 healthy men who served as controls. Of the alcoholic subjects, 36 were found to have vertebral fractures. Sixty-one percent had a history of...

The osteoporosis selfassessment tool

Osta Score

Koh and colleagues (11) developed the original Osteoporosis Self-Assessment Tool for Asians (OSTA) based on a study of 860 non-Caucasian, postmenopausal women from eight Asian countries. Risk factors were captured from a self-administered questionnaire and bone density was measured by DXA in the proximal femur. Proximal femur T-scores were based on the manufacturer's reference data for Asian women. Statistical analysis was performed to determine which risk factors were independent predictors of...

The Fracture Threshold

Many experts in the field object strenuously to the concept of a fracture threshold, noting that it is more appropriate to emphasize the existence of a gradient of risk for fracture with risk increasing as the bone density declines. They correctly observe that there is no arbitrary level of bone density above which no one fractures and below which everyone fractures. Nevertheless, the concept of a fracture threshold can be useful in the clinical setting. It suggests a cut-off level of bone...

Which Skeletal Sites Should Be Used for Monitoring

There are four basic rules that govern the choice of skeletal site for the purposes of monitoring the effects of disease or drugs on the skeleton. 1. Measure the skeletal site or type of bone (trabecular or cortical) that you expect to be affected. 2. Of the sites potentially affected, measure the site at which the greatest change in BMD is expected. 3. Of the sites potentially affected, measure the site at which you can measure the BMD with the best precision. 4. Peripheral sites are not used...

Ultrasound bone densitometers Achilles

Hip Exercises For Osteopenia

Manufacturer GE Medical Systems, Madison, WI Skeletal application s Calcaneus SOS m s BUA db MHz Stiffness Index Percent young-adult and percent age-matched comparisons T-score and z-score Precision 2 for Stiffness Index Dimensions 20 x 13 x 24 in 51 x 33 x 61 cm Operating environmental temperature 59 to 95 F 15 to 35 C Operating environmental relative humidity 20 to 80 Operation Self-contained LCD touch screen, thermal printer, 50-measurement memory, built-in carrying handle Fig. 13-22. The...

Central xray densitometers Delphi

Dual Xray Absorptimetry

Manufacturer Hologic, Inc., Bedford, MA PA lumbar spine Proximal femur Forearm IVA lateral spine imaging T4-L4 Dual Hip Whole body on Delphi with Whole Body Scan time in the 60 Hz scan mode PA lumbar spine and proximal femur 15 seconds Forearm 30 seconds Whole body 6.8 minutes Single energy IVA 10 seconds for 15-in scan length Fig. 13-4. The Hologic Delphi . A central fan-array dual-energy X-ray absorptiometry. Photograph courtesy of Hologic, Inc., Bedford, MA. Fig. 13-4. The Hologic Delphi ....

Metri Scan

Bone Density Units

Technique RA with storage phosphor technology Skeletal application s Middle phalanges of the index, long, and ring fingers Estimated phalangeal BMD in arbitrary RA units Percent young-adult and percent age-matched comparisons T-score and z-score Diagnostic classification based on WHO Criteria Radiation exposure 0.0001 mrem scan 0.001 Sv scan Dimensions 16 x 16 x 16 in 40.6 x 40.6 x 40.6 cm Environmental operating temperature 64 F to 95 F 18 to 35 C Environmental operating humidity 5 to 80 ,...

Remaining Lifetime Fracture Probability

Remaining lifetime fracture probability RLFP is a type of future global fracture risk prediction that was proposed by Ross et al. 18 . The concept of RLFP is based on the exponential increase in fracture risk as BMD declines and decreased survival after age 75. Therefore, although a 50-year-old woman and an 80-year-old woman may both have the same low bone density, their RLFP will be quite different. Because the expected life span of the 80-year-old woman is much shorter than that of the...

Guidelines of the International Society for Clinical Densitometry

The guidelines from the International Society for Clinical Densitometry ISCD 5 were initially developed in 1994 during a meeting of an international panel of experts in bone densitometry and published in 1996. On the panel were 22 members from eight countries. The guidelines addressed both the use and interpretation of bone mass measurements in the prevention, detection, and management of all diseases characterized by low bone mass with an emphasis on osteoporosis. The guidelines provided a...

Omnisense 7000S Ultrasound Bone Sonometer

Treatment For Bone Cancer

Manufacturer Sunlight Medical, Israel Skeletal application s Forearm other regions pending FDA approval Scan time Approximately 1 minute Precision 0.4 to 0.8 as the RMS CV, depending on the site Fig. 13-28. The Sunlight Omnisense 7000S. A peripheral quantitative ultrasound device used to measure the radius. Photograph courtesy of Sunlight Medical Ltd., Rehovot, Israel. Fig. 13-28. The Sunlight Omnisense 7000S. A peripheral quantitative ultrasound device used to measure the radius. Photograph...

The precision calculator companion

There is only one Microsoft Excel workbook file in this folder. There are 2 spreadsheets within the workbook. The first spreadsheet is the Precision Calculator Companion. Instructions are given on the spreadsheet. This spreadsheet will allow you to calculate precision as the RMS-SD and RMS- CV for a group of 15 patients studied 3 times each. The spreadsheet will also calculate the 1x1LSC95 for this level of precision. The second spreadsheet is the Statistical Confidence Calculator. The...

Etidronate

The effects of etidronate alone or etidronate preceded by phosphate were evaluated in a double-blind, placebo-controlled trial of 429 postmenopausal women with one to four vertebral compression fractures and radiographic demineralization 136 . The women received either a double placebo, 1 g of phosphate orally twice daily on days 1 through 3 followed by etidronate 400 mg orally daily on days 4 through 17, placebo on days 1 through 3 followed by etidronate on days 4 through 17 or phosphate on...

McCue CUBAClinical Contact Ultrasound Bone Analyzer

Quantitative Ultrasound Bone Density

Distributor Norland, a CooperSurgical Company, Ft. Atkinson, WI Skeletal application s Calcaneus Percent young-reference and percent age-matched comparisons T-score and z-score Dimensions 17.8 x 13.9 x 10.2 in 45.2 x 35.3 x 25.9 cm Environmental storage temperature 23 to 122 F -5 to 50 C Environmental storage humidity 10 to 95 Quality control Internal phantom and external QA phantom Operation IBM-compatible computer with a minimum of 10 MB free hard drive space, 486DX2 microprocessor at 66...

Dexa Care G4

Bone Density Scan Pictures

Manufacturer Osteometer MediTech, Inc., Hawthorne, CA Skeletal application s Forearm Scan time 2 minutes, distal forearm Percent young-adult and percent age-matched comparisons T-score and z-score Radiation dose 0.1 Sv per scan Dimensions 12.5 x 26 x 15.5 in 32 x 66 x 40 cm Environmental operating temperature 58 to 86 F 15 to 30 C X-ray source 55 kV, 300 A X-ray filtration K-edge filtration Fig. 13-16. The Osteometer DTX-200 DexaCare . A peripheral dual energy X-ray absorptiom-eter used to...

PDEXA

The Absorptiometer

Manufacturer Norland, a CooperSurgical Company, Ft. Atkinson, WI Skeletal application s Forearm Scan time Less than 5 minutes Fig. 13-18. The Norland pDEXA . A peripheral dual energy X-ray absorptiometer used to measure bone density in the forearm. Photograph courtesy of Norland, a CooperSurgical Company, Ft. Atkinson, WI. Fig. 13-18. The Norland pDEXA . A peripheral dual energy X-ray absorptiometer used to measure bone density in the forearm. Photograph courtesy of Norland, a CooperSurgical...

Treatment recommendations

There are two aspects to treatment recommendations whom to treat and how to treat them. The NOF Guidelines 11 for the treatment of postmenopausal osteoporosis are extremely useful as well as clear. In 1998, the NOF recommended that prescription medications be considered for women with a bone density T-score of less than -1.5 in the presence of other risk factors and in women with a bone density T-score less than -2, regardless of other risk factors. It is relatively straightforward then, to...

Performing a precision study

The results of three PA lumbar spine DXA bone density measurements are shown in Table 11-1. Mrs. B., whose bone density studies were previously discussed in Chapter 3 in the explanation of the mean, variance, and SD, is the patient whose results are shown in the table. Remember that these measurements on Mrs. B. were all performed within a few minutes of each other, with only enough time between studies to allow Mrs. B. to get off the scan table and be repositioned by the technologist. The same...

Shewhart rules and cusum charts

The field of analytical chemistry recognized the need for strict quality control many years ago. Like bone densitometry, analytical chemistry involves the use of machines for quantitative measurements. Techniques had to be developed to determine that the machines continued to function properly over long periods of time in order to ensure consistency in the results 4 . The methods common to analytical chemistry have been adapted for use in bone densitometry 5 . These methods utilize the BMD...

DTX200 Dexa Care

Skull Phantom Bone Equivalent

Manufacturer Osteometer MediTech, Inc., Hawthorne, CA Skeletal application s Forearm Fig. 13-17. The Osteometer DTX-200 DexaCare . The forearm is placed into the well in the top of the machine. Photograph courtesy of Osteometer MediTech, Hawthorne, CA. Fig. 13-17. The Osteometer DTX-200 DexaCare . The forearm is placed into the well in the top of the machine. Photograph courtesy of Osteometer MediTech, Hawthorne, CA. Percent young-adult and percent age-matched comparisons T-score and z-score...

The Determination of LSC

The situation then, of one measurement at baseline and one measurement at follow-up effectively changes equation 10 to equation 11, used for the calculation of the 1x1LSC If two measurements are done at baseline and again at follow-up, the sum under the square root sign in equation 9 becomes 1 as shown in equation 12 for the calculation of the 2x2lsc. 2X2LSC Z' Pr 1 1 Z' Pr T 12 This effectively changes the equation for the calculation of the LSC to Thus, for any level of statistical...

Vertebral Morphometry and Fractures

Neck Shaft Angle Femur

The Relationship Between Prevalent Spine Fractures and Future Fracture Risk A number of studies have demonstrated that the presence of a spine fracture is predictive of future fractures, independent of bone density 33-39 . The strongest association is between existing spine fractures and future spine fractures with estimates of the increase in risk from only one prevalent spine fracture of 3- to 11.1-fold. One of the first such studies was from Ross et al. 33 . This study was performed in the...

The importance of precision

When properly performed, bone density measurements are the most precise quantitative measurements in use in clinical medicine today. But it should be clear that until precision studies are performed at a facility, the LSC cannot be determined for any level of statistical confidence, making the interpretation of serial studies impossible. The calculations necessary to determine precision are somewhat tedious but not complex. Such calculations are simple with a relatively inexpensive statistical...

Sahara Clinical Bone Sonometer

Sahara Clinical Bone Sonometer

Manufacturer Hologic Inc., Bedford, MA Skeletal application s Calcaneus Scan time Less than 10 seconds BMD 3 or 0.014 g cm2 QUI 2.6 or 2.2 Dimensions 17 x 14 x 12 in 43 x 36 x 30 cm Environmental operating temperature 60 to 100 F 15 to 37.7 C Environmental operating relative humidity 20 to 80 noncondensing Quality control Daily, with supplied quality control phantom Operation Embedded microprocessor. Data and command input from touch pad on unit. Built-in strip printer. Quality control phantom...

NOF Guidelines

Tumors Bone Density Test Hip

In 1998, the NOF issued new guidelines for bone densitometry that were limited to the detection and management of postmenopausal osteoporosis 2,3 . The guidelines initially appeared in an extensive document on osteoporosis that was published in Osteoporosis International 2 . With some modification, they subsequently appeared in a document titled Physician's Guide to Prevention and Treatment of Osteoporosis 3 . In the original 1998 document, extensive cost-benefit analyses were undertaken to...

Proximal Femur Morphometry

Femur Fracture Franche

Interest in the measurement of the dimensions and geometry of the proximal femur as part of the assessment of fracture risk was spurred by the initial recognition of hip axis length as an independent predictor of hip fracture risk. Other measures have come under scrutiny as predictors of hip fracture risk as well. These are measures such as the neck-shaft angle and femoral neck width as well as segments of the hip axis length. Hip axis length HAL has been demonstrated to be a predictor of hip...

Statistics in Densitometry

The Mean, Variance, and Standard Deviation Statistical Significance and the P Value Regression Analysis Statistical Evaluations of Diagnostic Tests Many physicians in clinical practice have not had formal training in statistics. A basic knowledge of certain aspects of statistics is essential for the physician densitometrist. Quality control procedures for the various machines require some statistical analyses. The computer-generated reports of bone density data include statistical devices such...

A rtk if b fajt Hr if

Abnormal Bone Density Lumbar

The lumbar spine in the posterior view. A Intact vertebrae. B The transverse processes have been removed. C The vertebral bodies have been removed, leaving only the posterior elements. Adapted from McMinn RMH, Hutchings RT, Pegington J, and Abrahams PH. 1993 Colour Atlas of Human Anatomy, 3rd edition, p. 83. By permission of the publisher Mosby. Fig. 2-3. The lumbar spine in the posterior view. A Intact vertebrae. B The transverse processes have been removed. C The vertebral bodies...

Regional Migratory Osteoporosis

Regional migratory osteoporosis RMO is also known as idiopathic regional osteoporosis, transient osteoporosis, and migratory algodystrophy. It was first described in 1967 88 and its etiology remains unknown. It appears to be closely related to the disorder known as transient osteoporosis of the hip.3 RMO occurs in middle-aged men. It begins as gradually increasing joint pain in the lower extremities with no prior history of trauma. Pain generally reaches a maximum level after 2 months. Symptoms...

Parkinsons Disease

In a study of 52 subjects with Parkinson's disease PD 28 men and 24 women , using DXA Norland XR-26 to measure total body BMC, bone mineral content was found to be significantly decreased when compared to controls 78 . The z-score for men with PD averaged -0.47 and for women, -0.84. In this same study, metacarpal radiogrammetry did not reveal any significant differences between PD patients and controls. A brief report in abstract form from Turc et al. 79 noted that in 19 men with PD BMD in the...

Bone Growth Modeling and Remodeling

The densitometrist works with bone at the macroscopic or gross level. From this perspective, bone appears to be a hard, inert substance. In fact, bone is extremely active at the microscopic level undergoing growth, modeling, or remodeling, depending on the stage of life. Longitudinal growth occurs in the skeleton of the child and adolescent from proliferation of cartilage at the growth plates, which subsequently undergo calcification. Modeling refers to a change in the shape or axis of a bone...

Effect of Arm Dominance on Forearm BMD

Unlike the proximal femur, arm dominance has a pronounced effect on the bone density in the forearm. In healthy individuals, the BMC at the 33 radial site differs by 6 to 9 between the dominant and nondominant arms 39 . A difference of 3 has been reported at the 8-mm site 40 . If the individual is involved in any type of repetitive unilateral arm activity, the difference between the dominant and nondominant arm densities will be magnified to an even greater extent. Two studies of tennis...

Accuracy and precision

Quantitative measurement techniques should be both accurate and precise. In Fig. 3-7, the concepts of accuracy and precision are presented using the analogy of an archer's target. Five arrows have hit the target A. One arrow is in the bull's eye and the other four are close. But of these four arrows, one is off to the right, one is off to the left, and one is below the bull's eye and one is above it. The archer has, at least, hit the target and could be described as being reasonably accurate as...

From dxa machine to dxa machine within manufacturers

It is not uncommon for patients to have had a DXA study at another facility that must be compared to a DXA study at a second facility. Even if the studies have been performed on DXA machines from the same manufacturer, the results may vary slightly. If the machines have been properly calibrated and maintained using good quality control measures, the differences should be minimal. In a study performed at three different locations, three men and two women underwent duplicate total body and lumbar...

Dxa Lumbar Spine

Dxa Lumbar Spine

Adapted from ref. 20 with kind permission from Elsevier Science Ireland Ltd., Bay 15K, Shannon Industrial Estate, Co. Clare, Ireland. Adapted from ref. 20 with kind permission from Elsevier Science Ireland Ltd., Bay 15K, Shannon Industrial Estate, Co. Clare, Ireland. Fig. 2-15. PA and lateral DXA lumbar spine images acquired on the Hologic QDR-4500. The arrow seen in A indicates the faint outline of the calcified aorta that is easily seen on the lateral study in B . Case courtesy of Hologic...

Bone physiology

Although the relevance of bone physiology to clinical densitometry may not be immediately apparent, the density of bone as measured in clinical practice is the outcome of the physiology and pathophysiology of bone. The densitometrist is generally not concerned with the development of bone or changes in bone that occur at the microscopic level. Nevertheless, the bone density at any given time and the changes in bone density that the densitometrist observes and interprets are the direct outcomes...

Intravenous Drug Abuse

A syndrome of diffuse osteosclerosis was first reported with intravenous drug abuse in St. Louis 61 . The syndrome is considered rare and its cause is unknown. Patients have presented with aching limbs and a generalized increase in density throughout the skeleton. One such subject, a 38-year-old Caucasian man underwent BMD measurements with DXA QDR-2000 of the spine and proximal femur and of the spine using QCT General Electric HiSpeed Advantage 62 . The BMD in all regions was dramatically...

Laminectomy

Childs Fused Spine Xray Images

Adapted with permission of the publisher from ref. 25. Values are in g cm2. Adapted with permission of the publisher from ref. 25. Fig. 2-18. A lateral lumbar spine X ray of the patient whose bone density study is shown in Fig. 2-17. The arrows indicate sclerotic regions in the posterior elements. Fig. 2-18. A lateral lumbar spine X ray of the patient whose bone density study is shown in Fig. 2-17. The arrows indicate sclerotic regions in the posterior elements. The...

Mastocytosis

Sixteen patients 6 men and 10 women with mastocytosis underwent bone density measurements of the PA spine, hip, and total body with DXA Lunar DPX and of the distal right radius and ulna with SPA Osteometer DT 100, Roedovre, Denmark 66 . BMD results from the patients with mastocytosis were compared to a reference population of 317 men and 1123 women from the local population. Both low bone density and increased bone density were found in the patients with mastocytosis. Bone density in the...

The Spine in the Lateral Projection

Dxa Lumbar Spine

The effect on BMD measured in the AP or PA projection from aortic calcification, facet sclerosis, osteophytes, and other degenerative changes in the spine can be nullified by quantifying the bone density of the spine in the lateral projection as shown in Fig. 2-15B. In addition, the highly cortical posterior elements and a portion of the cortical shell of the vertebral body can be eliminated from the measurement, resulting in a more trabecular measure of bone density in the spine. The...

The forearm in densitometry Nomenclature

Radius And Ulna Length Measurement

The nomenclature used to describe the various sites in the forearm that are assessed with densitometry is confusing. Commonly measured sites are the 33 or 1 3rd site3, the 50 , and 10 sites, the 5-mm and 8-mm sites, and the ultradistal site. The sites designated by a percentage are named based on the location of the site in relation to the overall length of the ulna. This is true for the site regardless of whether the site is on the ulna or the radius. In other words, the 50 site on the radius...

Effect of Rotation on BMD in the Proximal Femur

The lesser trochanter is an important anatomic structure from the perspective of recognizing the degree to which the femur has been rotated during positioning for a proximal femoral bone density study. Precision in proximal femur bone density testing is highly dependent on reproduction of the degree of rotation of the proximal femur from study to study. In positioning the patient for a proximal femur study, internally rotating the femur 15 to 20 will bring the femoral neck parallel to the plane...

The Hologic Spine and Hip Phantoms

The Hologic anthropomorphic spine phantom, although intended for use with Hologic DXA devices, is often used with DXA devices from other manufacturers. The phantom itself consists of four anatomically correct vertebrae made of calcium hydroxyapatite. The vertebrae are encased in an epoxy resin to simulate soft tissue. The four vertebrae have similar densities and areas and the soft tissue simulation of the epoxy-resin approaches 60 fat. Each Hologic spine phantom will have a factory-specified...

Shewhart Rules

Shewhart2 rules have been used in analytical chemistry since the 1950s. In order to utilize Shewhart rules, it is necessary to establish a baseline value and control limits for the phantom measurement and create a Shewhart chart as described earlier. Establishing the baseline phantom value by scanning the phantom on each of15 to 25 consecutive days, rather than multiple times on the same day is recommended. If, for some reason, this is impractical, a 10-phantom average created by scanning the...

Standard Scores on Bone Density Reports

Score Bone Density Test

T-scores and z-scores are found on the computer-generated bone densitometry printouts from virtually every manufacturer of bone density equipment. Figure 3-2 is the printout from a spine bone density study performed on an older Lunar DPX device. The individual BMD values for each vertebra are listed as well as the BMD values for each possible combination of contiguous vertebrae. The two columns adjacent to the BMD values reflect z-scores. One column is entitled young-adult z and the other,...

The metacarpals phalanges and calcaneus

Metacarpals Atlas

Other skeletal sites can be studied using the techniques available today. The metacarpals, phalanges, and calcaneus were among the very first sites studied with the older techniques of radiographic photodensitometry and radiogrammetry. These sites are increasingly utilized today with the advent of computerized radiographic absorptiometry, computerized radiogrammetry, and DXA and ultrasound units. Figure 2-31 illustrates the anatomy of the hand and the location of the metacarpals and phalanges....

Abone203

The Osteoporosis Self-Assessment Weight Selection The FRACTURE Comparing the Performance of Self-Assessment Chapter 9 Diagnosing Guidelines of the Study Group of the WHO for the Diagnosis of Osteoporosis 218 The 1999 WHO and 2000 IOF The Clinical Peripheral Site T-Score Equivalents for the Diagnosis of Osteopenia and Changing the Definition of Diagnosing Osteoporosis in Additional Considerations in Site Selection for Diagnosis 229 Chapter 10 Predicting Fracture The Prevalence of Fracture at...

Standardization of Dxa Bmd Results for the Femoral Neck Trochanter and Wards Area

In 2001, Lu et al. 13 developed equations for an sBMD for the femoral neck, trochanter, and Ward's area based on information obtained from studies of the same 100 women whose data was previously used to create formulas for the sBMD of the spine and total femur 10,12 . The authors developed site-specific standardization formulas for the hip subre-gions. They compared the utility of the subregion formulas in reducing the disparity in BMD results among the three manufacturers' devices to that of...

Qualitative or Categorical Data

If data are classified as belonging to categories, the data are considered qualitative data. Such data are discrete and generally consist of counts or the number of individuals belonging to each category. This type of data is also called categorical data. Categorical data can be ordinal or nominal, depending on whether there is a logical order to the categories. For example, individuals might be placed into height categories of tall, medium or short remember that the actual measurement of...

Ankylosing Spondylitis

Low bone density has been frequently observed in ankylosing spondylitis although its etiology remains uncertain. For 2 years Maillefert et al 23 followed 54 patients with ankylosing spondylitis to determine the prevalence of osteopenia and osteoporosis and the relationship of any observed bone loss to therapy, physical impairment, or inflammation. There were 35 men and 19 women in the study with an average age of 37.3 years and average disease duration of 12.4 years. In 23 patients, the disease...

Artifacts in PA or AP Spine Densitometry

Osteoporosis Lumbar Spine

The PA lumbar spine has been, and continues to be, used extensively in densitometry for diagnosis, fracture prediction, and monitoring. Unfortunately, it is also the skeletal site most often affected by structural changes and artifacts that may limit its utility. The BMD of a fractured vertebra will be increased because of the fracture itself. This increase in density could erroneously lead the physician to conclude that the bone strength is better and the risk for fracture, lower, than is the...

Standardization of Central DXA Absolute BMD Values

In November 1990, the major manufacturers of DXA equipment agreed to work together in the area of standards as part of an international committee, known as the International Committee for Standards in Bone Measurement. Under the auspices of this committee, a study of 100 healthy women 10 was performed in which each of the women underwent PA spine and proximal femur studies on the Hologic QDR-2000, the Norland XR-26 Mark II, and the Lunar DPX-L. The women ranged in age from 20 to 80, with an...

Dxa from lunar to hologic to norland

The central DXA devices from all the major manufacturers have inherently superb accuracy and precision in quantifying the bone density at virtually any skeletal site. The BMD obtained on any one machine, however, will not be identical to the BMD obtained on a device from a different manufacturer. Comparison studies using combinations of machines provide conversion equations for the measurement of bone density on one device to the anticipated value on another device. The Hologic QDR-1000, the...

Hologic DXA and Norland DXA

In vivo comparisons of spine measurements made using the Norland XR-26 and the Hologic QDR-1000 were conducted by Lai et al. 8 in 65 subjects. The correlation for BMD at the spine was 0.990 and was highly significant. BMDs obtained on the Norland XR-26 tended to be lower than those obtained on the QDR-1000. The equation for predicting the Hologic BMD from the measurement of BMD on the Norland XR-26 was Hologic QDR 1000 SpineBMD -0.1 1.09 x Norland XR-26 SpineBMD

Reference databases

Two of the most common applications of bone densitometry are the diagnosis of osteoporosis and the assessment of fracture risk. These applications depend on comparisons of the BMD to the reference database that is supplied by the manufacturer of the bone densitometry equipment. The diagnosis of osteopenia or osteoporosis using WHO criteria depend on comparing the patient's BMD to the average peak BMD of the young adult and noting how many SDs below this value the patient's value lies. In other...

J.bone Miner Res 1994

Kelly TL, Slovik DM, Schoenfeld DA, Neer RM. Quantitative digital radiography versus dual photon absorptiometry of the lumbar spine. J Clin Endocrinol Metab 1988 67 839-844. 2. Pacifici R, Rupich R, Vered I, Fischer KC, Griffin M, Susman N, Avioli LV. Dual energy radiography DER a preliminary comparative study. Calcif Tissue Int 1988 43 189-191. 3. Holbrook TL, Barrett-Connor E, Klauber M, Sartoris D. A population-based comparison of quantitative dual-energy X-ray absorptiometry with...

Acromegaly

Forty-five subjects 24 women and 21 men with acromegaly for an average of 11.4 years underwent PA spine, proximal femur, and total body bone density studies with DXA Lunar DPX 21 . The subjects ranged in age from 21 to 77 years with a median age of 43 years. Twenty-five individuals were Caucasian and 20 were Black. Twenty percent of the individuals had age-matched z-scores in the spine of -1 or poorer, whereas only 8.8 had similar age-matched z-scores in the proximal femur. Osteopenia in the...

Standardization of Forearm DXA Results

The difficulty in creating an sBMD for forearm bone density is compounded by the multitude of potential sites in the forearm and the different definitions of those sites among the various manufacturers of forearm measurement devices. Shepherd and colleagues 14 have developed standardization equations for the ultradistal, mid, and proximal forearm for six devices, five of which employ DXA. The sixth device utilized radiogrammetry. The study was commissioned by the International Committee for...

The Utility of the sBMD

The sBMD is attractive as a means of comparing a BMD value obtained on one manufacturer's device with a BMD value obtained on another. This is useful in large population studies and clinical trials in which devices from several manufacturers must be used. The root-mean-square RMS error in the calculation of the sBMD is estimated to be 4 for the PA spine and total femur and even larger for the proximal femur subregion 13 . This error is simply too large to base important clinical decisions on...

Peripheral Skeleton

Central And Peripheral Skeleton

Characterizing the Skeleton in Densitometry The Metacarpals, Phalanges, and Calcaneus Densitometry is primarily a quantitative measurement technique rather than a skeletal imaging technique. Nevertheless, there are unique aspects of skeletal anatomy in densitometry that must be appreciated to properly utilize the technology and interpret the quantitative results as well as the skeletal images. characterizing the skeleton in densitometry The bones of the skeleton can be described by four...

Hologic DXA and Lunar DPA

Kelly et al. 1 evaluated the relationship between BMD values in the spine in 85 individuals ranging in age from 21 to 78 years using the Lunar DP4, a 153Gd DPA device, and the Hologic QDR-1000, a pencil-beam DXA device. The correlation for the measurement of spine BMD between the two devices was extremely good with r 0.98. Not surprisingly, however, the two instruments did not give exactly the same results. Values obtained on the QDR-1000 were consistently lower than those obtained on the DP4....

Using the phantom to create control tables and charts

Most daily quality assurance procedures to detect mechanical failures on today's densitometers are automated. The program will indicate a passing or failing condition. Before outright mechanical failure occurs, however, regular scanning of the quality control phantom and the application of Shewhart charts and rules or CUSUM charts can detect drifts or shifts in machine values that require correction in order to ensure continued accuracy and precision. Abrupt shifts in values are generally easy...

Ward S Triangle

Hologic Qdr

Hologic q R-4500A Left Hip U8.15a 3 Hologic q R-4500A Left Hip U8.15a 3 Fig. 2-23. DXA proximal femur studies. Five regions of interest are defined. A Hologic QDR 4500 DXA study. Case courtesy of Hologic Inc., Bedford, MA. B Lunar Prodigy. Four regions of interest are labeled for emphasis on this study. The total region of interest, which is not outlined, includes the neck, trochanter, and shaft. Fig. 2-23. DXA proximal femur studies. Five regions of interest are defined. A Hologic QDR 4500 DXA...

Lunar DXA and Hologic DXA

The Lunar DPX and the Hologic QDR-1000 were compared in a study of 46 women by Pocock et al. 9 . These women underwent lumbar spine and proximal femur studies on both machines on the same day. The correlations were extremely good with r values of 0.98, 0.94, 0.96, and 0.96 for the lumbar spine, femoral neck, Ward's area, and the trochanter, respectively. The absolute BMD values were 16 lower on the QDR-1000 Conversion Formulas for BMDs of the AP Spine Between DXA Devices Hologic QDR-2000...

The European Spine Phantom

The development of the European Spine Phantom ESP resulted from efforts to develop a more perfect spine phantom that could be used on all central devices. It was developed independently of any manufacturer under the direction of the Committee d'Actions Concertes-Biomedical Engineering COMAC-BME 6 . The ESP is a semi-anthropomorphic phantom. Its three vertebrae are made of hydroxyapatite and vary in density, with standardized BMDs of 500, 1000, and 1500 mg cm2 7 . The vertebrae are encased in a...

The Lunar Spine Phantom

The Lunar spine phantom is a rectangular aluminum bar which is intended to replicate the lower half of T12, all of L1, L2, L3, and L4, and the upper half of L5. Each vertebra has a different density that is achieved by varying the thickness of the aluminum. The area of each vertebra is different as well. The densities of L1 to L4 are 0.92, 1.076, 1.239, and 1.403 g cm2, respectively. The L2-L4 BMD is 1.256 g cm2. To simulate soft tissue, the aluminum phantom is submerged in a water bath with a...

Estimated Time To Complete

Radiographic Absorptiometry

We are pleased to award category 1 credit s toward the AMA Physician's Recognition Award. By completing the Review in the CD-ROM Companion in Appendix XIV, you are eligible for up to 30 hours of category 1 credit. After answering all of the questions correctly, complete the review evaluation and enter the required identifying information on the certificate of course completion. This certificate is not valid until signed with authorized signature at the Foundation for Osteoporosis Research. The...

Effect of Leg Dominance on BMD in the Proximal Femur

In general, there does not seem to be a significant difference in the BMD in the regions of the proximal femur between the right and left legs of normal individuals 32-35 . Leg dominance, unlike arm dominance, does not appear to exert a significant effect on the bone densities in the proximal femur and is not used to determine which femur should be studied. When proximal femur bone density studies first became available, the default or automatic positioning mode for the proximal femur was the...

Image Analysis Inc Columbia

Pencil Beam Dxa

An early Lunar DP3 dual-photon absorptiometer. This device utilized 153Gd to generate photon energy. Photo courtesy of GE Medical Systems, Madison, WI. Fig. 1-8. An early Lunar DP3 dual-photon absorptiometer. This device utilized 153Gd to generate photon energy. Photo courtesy of GE Medical Systems, Madison, WI. DPA studies of the spine required approximately 30 minutes to complete. Studies of the proximal femur took 30 to 45 minutes to perform. Total body bone density studies with...