Dual-energy X-ray absorptiometry interpretation -
A C-arm with x-ray source allowing for variable photon energy levels, collimator, detector, and associated computer software. Bone mineral density is the standard for measuring the diagnosis of osteoporosis and fracture risk assessment.
The Fracture Risk Assessment Tool FRAX uses clinical risk factors, excluding the measure of BMD, to identify those at risk for osteoporosis or fractures.
The FRAX was implemented in by the World Health Organization and is used to calculate the chance of a fracture in a ten-year timeframe.
The clinical risk factors included in FRAX are age, sex, race, height, weight, body mass index, a history of fracture, parent's history of hip fracture, use of oral glucocorticoids, rheumatoid arthritis, and other secondary causes of osteoporosis, smoking, and alcohol use of three or more drinks daily.
The geographic area is also considered in the calculation. A licensed radiologist interprets the scans and a T-score is determined to evaluate the standard deviation in the mean from the reference population and patient's average bone mineral density.
The World Health Organization WHO defines T-scores as:. No complications considered due to the procedure. The radiation dose is comparable to standard background radiation. DEXA imaging serves a sentinel role in the evaluation of osteoporosis as the International Society of Clinical Densitometry, the United States Preventative Services Task Force, and the National Osteoporosis Foundation recommend all women over the age of 65 have their bone mineral density evaluated.
It is considered the gold standard for diagnosing osteoporosis and predicting fracture risk with algorithms like the Fracture Risk Assessment tool. Although DEXA imaging has excellent reported accuracy and precision, consideration should be made if comparing results across different instruments from different manufacturers unless cross-calibration has been assured.
Evaluation of primary and secondary osteoporosis cannot be elucidated with DEXA imaging. This was exemplified by Tannenbaum and colleagues when 55 out of women with the diagnosis of primary osteoporosis were found to have a secondary cause with hypercalciuria, malabsorption, hyperparathyroidism, and vitamin-D deficiency.
DEXA imaging is the best clinical tool for assessing bone mineral density in the evaluation of osteoporosis and its validity is evident given its ubiquity among international guidelines. It is important for the healthcare team to work together to ensure the appropriate DEXA test is ordered and that the test is done correctly.
According to ACR Appropriateness Criteria Osteoporosis and Bone Mineral Density, there are specific cases in which Quantitative CT QCT is considered superior to DEXA. These include 1. Extremes in body height i. very large and very small patients 2.
Patients with extensive degenerative disease of the spine 3. A clinical scenario that requires increased sensitivity to small changes in trabecular bone density parathyroid hormone and glucocorticoid treatment monitoring.
Structural changes, such as osteophytes, calcifications, or fractures are more common in the lumbar spine than proximal femur [2] and potentially determine an artefactual increment of BMD.
g parts of bras, surgical clips, navel rings, vascular prosthesis may alter the final BMD, resulting in overestimation if the metal is included in the region of interest or underestimation if outside the ROI.
Some of the pitfalls can be avoided; however, some may just have to be observed and considered for the patient's care by the health professional team. Disclosure: Marissa Krugh declares no relevant financial relationships with ineligible companies.
Disclosure: Michelle Langaker declares no relevant financial relationships with ineligible companies. This book is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.
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StatPearls [Internet]. Treasure Island FL : StatPearls Publishing; Jan-. Show details Treasure Island FL : StatPearls Publishing ; Jan-. Search term. Dual-Energy X-Ray Absorptiometry Marissa Krugh ; Michelle D. Author Information and Affiliations Authors Marissa Krugh 1 ; Michelle D.
Affiliations 1 Campbell University. Continuing Education Activity Dual-energy x-ray absorptiometry DEXA has sustained a niche for measuring bone mineral density since its approval by the Food and Drug Administration FDA for clinical use in Introduction Dual-energy x-ray absorptiometry DEXA has sustained a niche for measuring bone mineral density since its approval by the Food and Drug Administration FDA for clinical use in Anatomy and Physiology Lumbar Spine To flatten the lordosis of the lumbar spine, the patient lays supine with their hips and knees flexed on a supportive cushion.
Hip The long axis of the femoral diaphysis is aligned with the scanner as the patient lies supine and a positioning device that internally rotates the femur to elongate the femoral neck on the PA image. Whole Body The patient is placed supine on the table with arms pronated and feet in dorsiflexion.
Choosing Site to Scan Two sites are routinely evaluated with DEXA: the lumbar spine and hip. Indications All women 65 years and older and men 70 years and older should be screened for asymptomatic osteoporosis.
Women younger than 65 years old at risk for osteoporosis: Estrogen deficiency. Conditions associated with secondary osteoporosis, such as gastrointestinal malabsorption or malnutrition, sprue, osteomalacia, vitamin D deficiency, endometriosis, acromegaly, chronic alcoholism or established cirrhosis, and multiple myeloma.
Individuals who have had a gastric bypass for obesity The accuracy of DEXA in these patients might be affected by obesity. Individuals with an endocrine disorder known to adversely affect BMD e. Individuals with bone dysplasias known to have excessive fracture risk osteogenesis imperfecta, osteopetrosis or high bone density.
Conditions associated with secondary osteoporosis, such as gastrointestinal malabsorption, sprue, inflammatory bowel disease, malnutrition, osteomalacia, vitamin D deficiency, acromegaly, cirrhosis, HIV infection, prolonged exposure to fluorides. All manufacturers provide a positioning aid to help maintain this position.
DXA of the forearm. The patient sits in a chair next to the scanning table with the forearm positioned parallel to the centerline. The output from the DXA examination includes images of the body part scanned, quantitative data from the scanned area, including the bone mineral content BMC , BMD, scanned area, T -scores, and Z -scores, and a graph of where the patient fits within the reference population.
The interpreting physician should check the scan for proper patient positioning and region of interest ROI placement. The spine should be aligned with the long axis of the scanner. The scan should include the inferior portion of T12 and the superior portion of L5.
The DXA image shows the scanned regions from which the BMD measurement has been obtained Fig. There should be no focal areas of increased or reduced density within the regions of interest.
Normal positioning. Initial DXA for pretreatment assessment of a year-old woman with newly diagnosed breast carcinoma. In the posteroanterior view of the lumbar spine the lines through the disc spaces and the lines outlining the lateral margins of the vertebra demarcate the ROI.
This patient has five lumbar vertebrae. The figure includes labels showing numbering of the vertebrae. There is modest variability in the number of non-rib-bearing vertebrae and a transitional vertebra may be present at the lumbosacral junction.
The remainder of the population has other combinations of ribs and non rib-bearing vertebrae. For the purpose of vertebral numbering, a line drawn from the highest point of one iliac crest to the other iliac crest traverses the L4—L5 intervertebral disc space. If a lumbar spine radiograph is available, it may aid accurate numbering.
The provider responsible for interpretation should check to ensure numbering of the vertebrae is correct. Especially when a scan is being repeated, numbering of the vertebrae should be consistent. The interpreting physician should check the scan for proper patient positioning and ROI placement.
The femur should be aligned with the long axis of the scanner and the lower extremity should be internally rotated Fig. The regions of interest ROI should be placed in accordance with the manufacturer recommendations.
Irrespective of the manufacturer, the femoral neck region of interest may not include any ischium or greater trochanter. There should be no artifacts within the measured regions of interest. Same patient as Fig. The hip is in internal rotation to obtain a more en-face projection of the femoral neck.
With internal rotation, the lesser trochanter is small or invisible white arrowhead. Markup of the ROI varies with manufacturer. In this image, the total hip is indicated by the yellow outline of the bone margins, the superior margin of the femoral neck ROI, and the subtrochanteric horizontal line.
The arrows indicate the femoral neck ROI. The femoral neck ROI varies with manufacturer but should not include the ilium or ischium Color figure online. The forearm must be aligned with the long axis of the scanner. The ROIs should be placed in accordance with the manufacturer recommendations Fig.
Scans with patient motion, previous fractures, orthopedic hardware, or other artifacts cannot be interpreted. DXA of the forearm from another patient, a year-old woman. Note that the forearm is aligned with the long axis of the scanner. The table displays each vertebra individually and then combinations of vertebrae.
The BMD should gradually increase from L1 to L4. For some patients, L4 will be less dense than L3. Nonetheless, each vertebra should be within one standard deviation of the next.
If they are not, interpretation is not straightforward and the reader should refer to the section on complex interpretations. Table of BMD, T -scores, and Z -scores. The DXA software calculates the BMC in the entire ROI and divides by the area of the ROI to calculate the BMD. Note that the information is presented for individual vertebrae and for the L1—L4 combination a.
The vertebral information may also be presented for other combinations of fewer than four vertebrae b. In the most straightforward cases, the area included in the outlines of the four lumbar vertebrae is the region where the BMD is determined.
A T -score and Z -score are provided for the BMD at each location. The WHO definitions of normal, osteopenia, and osteoporosis are based on the DXA measurement of BMD [ 4 ]. To standardize among manufacturers and populations, the concepts of T -score and Z -score were introduced. Although T -scores are not strictly the same as standard deviations, for clinical purposes, they can be assumed to function the same way.
The reference population for the T -score consists of young asymptomatic subjects. The Z -score functions similarly to the T -score but compares the patient with a database of people of the same age. In the US, the International Society for Clinical Densitometry ISCD recommends using the Caucasian database for all patients [ 9 ].
A T -score and Z -score are provided for the BMD at each of these locations. The bone density graph. This graph shows the bone densities of the reference population with which the patient is being compared central light green region. The bone densities for normal, osteopenia, and osteoporosis are superimposed on the graph.
A graph is also provided for the hip not shown Color figure online. For diagnostic categorization, the region with the lowest T -score is identified from among the lumbar spine, hip, or radius. For the spine, the L1—L4 region is used unless focal artifacts require exclusion of individual vertebra.
A single vertebra should not be used. For the hip, the lower T -score between the femoral neck and total hip is used. The most commonly used method for assessment of fracture risk is the FRAX ® tool developed for the World Health Organization. Major osteoporotic fracture includes fractures involving the proximal femur, spine, proximal humerus, or distal radius.
In the United States, the National Osteoporosis Foundation and the ISCD recommend limiting the use of the FRAX ® tool to patients over age 50, who are not receiving pharmacologic therapy, who have not had hip or spine fracture, and who have DXA-measured BMD in the osteopenic range Fig. Sixty-seven-year-old woman with previous fracture of the distal radius.
This is an ideal patient for FRAX ®. Additional items may be added to the DXA report to assist in management of the patient. These include a suggestion to evaluate patients for causes of secondary osteoporosis or osteomalacia, a recommendation for treatment initiation, and a recommendation for the next follow up DXA.
Inclusion of these recommendations depends on the provider referral base. For premenopausal women and men younger than 50 years, the WHO criteria should not be used. For these groups diagnosis is based on the Z -score.
It is important to recognize that a clinical diagnosis of osteoporosis may be made for patients with fragility fractures, irrespective of their BMD measurement. Patients frequently undergo repeated examination to monitor decreases in BMD or to evaluate the effects of treatment.
When this occurs, a DXA examination becomes somewhat more complex. Physiologically, bone turnover is relatively slow and changes in BMD over time may be small. To detect these small changes, the normal variance of the test must be known. The provider of DXA services should develop a quality-assurance program that can demonstrate that the BMD measurements fall within accepted ranges.
There are two parts of such a program. The first involves in-vitro testing with a phantom of known densities, which ensures the scanner is operating within established limits. This testing should be performed on a weekly basis and a log of the results maintained.
The second type of assessment is an in-vivo evaluation of the combined performance of the scanner and the technician. Because the output of the scanner depends on the training and diligence of the technician, each DXA facility should determine its precision error PE and calculate its least significant change LSC.
According to the ISCD, the minimum acceptable precision is 1. For facilities with multiple technicians, the PE may be calculated using combined information from the group. The approach for determining precision error has been standardized by the ISCD [ 10 , 11 ]. if automatic segmentation is performed, ensure that it has been performed correctly i.
not including ilium on lumbar spine or ischium on hip calculations. similarly, ensure the bone edges have been accurately detected this is a particular problem in individuals with very low bone mineral density, where software can not detect a clear density difference between soft tissue and bone.
valid comparison to reference data requires adequate positioning - deviations from optimum positioning may falsely decrease e. spinal rotation or increase e. insufficient internal rotation of the femur measured bone mineral density. scores in the lumbar spine can be increased in the setting of degenerative sclerotic change, ankylosing spondylitis, osteoporotic spinal compression fracture , etc.
where there is a focal abnormality, e. a vertebral fracture at L2, the affected level should be excluded from the analysis. Articles: Osteoporosis High bone mineral density Osteopenia Sarcopenia Bone mineral density Quantitative computed tomography bone Medical abbreviations and acronyms D Cortical bone Disuse osteopenia Densitometric vertebral fracture assessment Cases: Pubic rami and tubercle fractures DXA Triangles of the proximal femur Ankylosing spondylitis DEXA Prostate metastases DEXA Sacral insufficiency fracture Osteoporosis on DXA and vertebral fractures on VFA Osteoporosis DEXA Osteoporosis DEXA Osteopenia on DEXA Gallstones on DEXA.
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Dual-energy x-ray absorptiometry Last revised by Charisma DeSai on 11 Sep Edit article.
At the Fasting and insulin sensitivity the article Endurance fitness assessments last revised Charisma DeSai had no financial relationships to ineligible Dual-energj to disclose. Dual-energy x-ray absorptiometry Endurance fitness assessments or DXA is a technique used Endurance fitness assessments aid X-rah Lifestyle changes for hypertension diagnosis of absorptiomeyry and osteoporosis. Values are calculated for the lumbar vertebrae and femur preferentially, and if one of those sites is not suitable e. artifact, patient mobilityor if there is a history of hyperparathyroidismthe forearm can be used 1. Inclusion of forearm measurements is also recommended for patients with high BMI. if automatic segmentation is performed, ensure that it has been performed correctly i. not including ilium on lumbar spine or ischium on hip calculations.Absorptiometru densitometry, also Dual-eneegy dual-energy x-ray absorptiometry, Interpretatjon or DXA, uses a very small dose of abdorptiometry radiation to absoprtiometry pictures of the inside of the body usually the lower or lumbar interpretatiion and hips to measure bone loss.
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These factors are taken into consideration when absotptiometry if a Dual-energy X-ray absorptiometry interpretation needs therapy. The Vertebral Fracture Assessment VFAa low-dose x-ray Dula-energy of the spine to screen for vertebral interoretation Endurance fitness assessments zbsorptiometry performed on the Dyal-energy machine, may be interprdtation for older patients, especially if:.
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You may have to wait 10 to 14 days before undergoing a DXA test. Women should always tell their doctor and technologist if they are pregnant. Doctors will not perform many tests during pregnancy to avoid exposing the fetus to radiation. If an x-ray is necessary, the doctor will take precautions to minimize radiation exposure to the baby.
See the Radiation Safety page for more information about pregnancy and x-rays. Most of the devices used for DXA are central devices, which are used to measure bone density in the hip and spine. They are usually located in hospitals and medical offices. Central devices have a large, flat table and an "arm" suspended overhead.
Peripheral devices measure bone density in the wrist, heel or finger and are often available in drugstores and on mobile health vans in the community. The pDXA devices are smaller than the central DXA devices, weighing only about 60 pounds.
They may have a portable box-like structure with a space for the foot or forearm to be placed for imaging. Other portable technologies such as specially designed ultrasound machines, are also sometimes used for screening. However, central DXA is the standard technique.
The DXA machine sends a thin, invisible beam of low-dose x-rays with two distinct energy peaks through the bones being examined.
One peak is absorbed mainly by soft tissue and the other by bone. The soft tissue amount can be subtracted from the total and what remains is a patient's bone mineral density. DXA machines feature special software that compute and display the bone density measurements on a computer monitor. In the central DXA examination, which measures bone density of the hip and spine, the patient lies on a padded table.
An x-ray generator is located below the patient and an imaging device, or detector, is positioned above. To assess the spine, the patient's legs are supported on a padded box to flatten the pelvis and lower lumbar spine.
To assess the hip, the patient's foot is placed in a brace that rotates the hip inward. In both cases, the detector is slowly passed over the area, generating images on a computer monitor.
You must hold very still and may need to hold your breath for a few seconds while the technologist takes the x-ray.
This helps reduce the possibility of a blurred image. The technologist will walk behind a wall or into the next room to activate the x-ray machine. The peripheral tests are simpler. The finger, hand, forearm or foot is placed in a small device that obtains a bone density reading within a few minutes.
An additional procedure called Vertebral Fracture Assessment VFA is now being done at many centers. VFA is a low-dose x-ray examination of the spine to screen for vertebral fractures that is performed on the DXA machine. The DXA bone density test is usually completed within 10 to 30 minutes, depending on the equipment used and the parts of the body being examined.
You will probably be asked to fill out a questionnaire that will help the doctor determine if you have medical conditions or take certain medications that either increase or decrease your risk of a fracture.
The World Health Organization has recently released an online survey that combines the DXA results and a few basic questions and can be used to predict year risk of hip fracture or other major osteoporotic fractures for post-menopausal women.
Routine evaluations every two years may be needed to see a significant change in bone mineral density, decrease or increase. Few patients, such as patients on high dose steroid medication, may need follow-up at six months. A radiologista doctor trained to supervise and interpret radiology examinations, will analyze the images.
The radiologist will send a signed report to your primary care or referring physician who will discuss the results with you.
DXA scans are also interpreted by other physicians such as rheumatologists and endocrinologists. A clinician should review your DXA scan while assessing the presence of clinical risk factors such as:.
T score — This number shows the amount of bone you have compared with a young adult of the same gender with peak bone mass. A score of -1 and above is considered normal. A score between A score of The T score is used to estimate your risk of developing a fracture and also to determine if treatment is required.
Z score — This number reflects the amount of bone you have compared with other people in your age group and of the same size and gender. If this score is unusually high or low, it may indicate a need for further medical tests.
Small changes may normally be observed between scans due to differences in positioning and usually are not significant. Doctors take special care during x-ray exams to use the lowest radiation dose possible while producing the best images for evaluation.
National and international radiology protection organizations continually review and update the technique standards radiology professionals use. Modern x-ray systems minimize stray scatter radiation by using controlled x-ray beams and dose control methods.
This ensures that the areas of your body not being imaged receive minimal radiation exposure. Please type your comment or suggestion into the text box below. Note: we are unable to answer specific questions or offer individual medical advice or opinions.
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Toggle navigation. What is a bone density Scan? What are some common uses of the procedure? How should I prepare? What does the equipment look like? How does the procedure work? How is the procedure performed?
: Dual-energy X-ray absorptiometry interpretation| References | Itnerpretation printout provides common combinations of Dual-energy X-ray absorptiometry interpretation than four vertebrae that may Metabolic syndrome definition used interprefation determine the BMD, T absorptiomtry, and Z -score. Choplin, R. The percentage ratio of the resulting TEMs of the measured parameters Table 4 to the total values of the measured parameters Table 2 Trial 1 was in male subjects 5. Epub Apr National Library of Medicine. J Clin Densitom. |
| What are some common uses of the procedure? | Follow-up DXA exams should Habits for athletic performance Lifestyle changes for hypertension at the same institution and Lifestyle changes for hypertension with the Dua,-energy machine. A test done on a peripheral location, such as the heel inerpretation wrist, may help predict the risk interpretatin fracture in Endurance fitness assessments spine or hip. The radiologist will send a signed report to your primary care or referring physician who will discuss the results with you. Bone health and osteoporosis: A report of the surgeon general. The mean typical error of measurement value, lower and upper confidence limit and intraclass correlation—Whole body analysis. DXA is simple, quick and noninvasive. Review Alternatives to DEXA for the assessment of bone density: a systematic review of the literature and future recommendations. |
| Overview of dual-energy x-ray absorptiometry - UpToDate | ISCD Official Positions. Hip fractures associated with osteoporosis can result in mortality. What are the limitations of a bone density scan? Body scan [ 42 ]. Dual-Energy X-Ray Absorptiometry - StatPearls. Data Availability: All relevant data are within the manuscript and its Supporting Information files. Department of Health and Human Services. |
| Bone Density Scan (DEXA or DXA) | The results are influenced by the measurement errors. With regard to their effect, errors can be divided into systematic and random [ 22 ]. A researcher cannot control random errors and systematic errors distort the result in the same way provided that the same conditions of measurement are observed. In addition to the inter- and intra-examiner errors, there are also errors related to the methodology, device and measuring instruments. Thus, to correctly interpret the results of the measurement especially in repeated measurements , the knowledge of the errors in the chosen method and device is necessary. In the biomedical sciences field, it is recommended to express the error using the typical error of measurement TEM [ 23 ]; unlike the commonly used reliability coefficient, TEM allows for expressing the existing error directly in the units used in the experiment. To calculate TEM, Hopkins [ 23 ] recommends performing three repeated consecutive measurements. Dual-Energy X-Ray Absorptiometry DXA is commonly used for body composition measurement and in the assessment of athletes. DXA is a recent medical-imaging technique with potential for direct measurement of BSIPs in living subjects. It is similar to gamma-ray scanning as it relies on the attenuation of radiation beams passing through the body to measure surface density. The main difference is that DXA uses two X-ray intensities which allow measurement of bone mineral and soft tissue masses separately the latter includes fat and lean tissue masses [ 24 , 25 ]. Hence, it is used primarily to determine bone mineral density and body composition in vivo [ 24 — 28 ]. Recently, it has been used to estimate segment mass, center of mass position in the frontal plane, and moment of inertia about the center of mass [ 29 — 31 ]. DXA is accurate, noninvasive, low cost, low radiation emitting method that is faster to analyze than gamma-ray scanning and other imaging methods. However, measurement errors have to be considered even with this method. To calibrate the devices and to verify the method, a phantom supplied by the manufacturer can be used e. spine phantom of vertebrae L 1 -L 4. Still, the result of the measurement can be influenced by the person who is measured. A human is a biological subject for whom individual variability is typical. Therefore, the mere use of the phantom to determine the accuracy of measurement is not enough. There are many studies that deal with the issue of DXA measurements. There are also studies that look at the reproducibility of the DXA method. These studies assess the effect of the diet on changes in body composition [ 38 ], the reliability of the method using the intraclass correlation coefficient ICC with a two-week interval [ 39 ] or using ICC and the standard error measurement percentage on a limited number of people [ 40 ]. In order to interpret the results of the repeated measures or assess the uniformity of the segmental distribution of body composition components, the knowledge of the magnitude of measurement-related errors in commonly used units is required. This allows for a proper assessment of the differences found in the results. The above mentioned studies did not assess the errors of measurement described. Therefore the purpose of this study was to verify the reliability and to determine error of measurement in whole-body and segmental analysis of body composition when using the DXA method. Sixty-three participants were recruited, 38 males All study participants were healthy, they did not take any medicine or food supplements. Participants were graduate students enrolled in the teacher preparation program for physical education. They participated voluntarily in the study and were informed about the procedure of the study in advance. All participants were required to undergo a thorough medical check annually by a registered physician. All participants also signed the informed consent of participation in the study. The measurements of the basic anthropometric parameters of body height BH and body mass BM , which are the input parameters for measuring body composition using the DXA system, were taken using a stadiometer with a digital scale, InBody BSM Biospace, South Korea. The manufacturer states the accuracy of measurement at 0. Whole body scans were performed using DXA Hologic Discovery A, Waltham, MA in order to quantify the magnitude and quality of full-body mass distribution lean, fat, bone and total. Participants assumed a stationary, supine position on the scanning bed with both arms pronated by their side. The position of the participant during the measurement is shown in Fig 1. To ensure consistent and reproducible positioning, the DXA operator manually assisted participants in order to: 1 straighten the head, neck and torso parallel to the long axis of the scan bed; 2 position the shoulders and pelvis perpendicular to the long axis of the scan bed; 3 place both arms in pronation by their side; 4 place legs at shoulder width with 45° internal rotation; and 5 fixate feet together using strapping tape to minimise incidental movement and for the participants comfort within the DXA scanning zone. All measurements were done in the morning 8. Upon scan completion, a two-dimensional image was automatically generated for scan analysis purposes. Using the in-built scan analysis software Version Further analysis was subsequently performed to manually identify and assess appendicular segmental masses. Specifically, using the sub-region analysis tool, customised regions-of-interest ROI were drawn to capture twelve segments: the left upper arm, right upper arm, left forearm, right forearm, left hand, right hand, left thigh, right thigh, left shank, right shank, left foot and right foot regions. Each participant was measured three times consecutively, according to the recommendations by Hopkins [ 23 ]. The third measurement verifies the second one, which guarantees stable conditions. The interval between the repeated measurements was 3 minutes at the most. After each measurement, the participant sat up on the measuring table, the laboratory technician placed the participant in the corresponding position for measuring again and commenced measuring. This procedure was used to verify not only the reproducibility of the device measurement but also the accuracy of the laboratory technician when positioning the participants. The parameters measured were body fat BF , fat-free mass FFM , bone mineral content BMC , bone mineral density BMD and their segmental distribution of the arms, legs, and the trunk. The body scan is presented in Fig 2. The accuracy of the DXA system was assessed using the TEM [ 23 ]. The TEM for trial pairs was calculated from the selective standard deviation in differences between two trials of the participant and divided by the root of the number of trials. With regard to the fact that these were repeated measurements of the same people, intraclass correlation ICC [ 43 ] was used to assess the correlation of the resulting values of the monitored parameters between the repeated measurements. The d value at the level of 0. The calculation was based on the values of the measured body composition parameters from three consecutive measurements of each participant. Statistical analysis was performed using a statistical spreadsheet [ 44 ]. To assess the statistical significance of the differences in the mean TEM values for males and females in the monitored parameters, the parametric two-selection t-test was used. The statistical processing of the results was performed using IBM SPSS Statistics Version 21 for Windows; IBM, Armonk, NY, USA. The results present the mean input values of the whole-body and segmental analyses the segmental analysis did not include the head and the resulting values of the TEM. The mean input values were acquired in three repeated measurements of the individual participants, as described in the measurement procedure. The reproducibility of the measurement results using DXA was verified using TEM. The values of the whole-body analysis are presented in Table 1 , the segmental analysis in Table 2. The results of the DXA measurement outcome reproducibility are presented in Tables 3 and 4. The TEM and ICC values, which are presented in Tables 3 and 4 , are calculated as the mean values of two consecutive comparative measurements Trial 1—2, 2—3. With regard to the high ICC values 0. The differences found between the individual trials of the measured parameters were not objectively significant, which is confirmed by the results of the effect size. The accuracy of measurement can also be expressed by the percentage ratio of the resulting TEM of the measured parameter Table 3 to the total value of the measured parameter Table 1 Trial 1. The mean error was 0. The results of the body weight measurement and all soft tissue parameters in women indicate a significantly lower error based on the comparison of TEM values. With regard to the low differences in the mean values of the measured parameters of the segmental analysis between the right and left limbs Table 2 , we only present the results of the measurement accuracy for the right limbs and the trunk Table 4. The ICC in the segmental analysis of women were similar to the whole-body analysis. They ranged from 0. The results of the effect size did not confirm any practically significant differences between the individual measurements of the parameters. The percentage ratio of the resulting TEMs of the measured parameters Table 4 to the total values of the measured parameters Table 2 Trial 1 was in male subjects 5. Similarly to the whole-body analysis, the TEM values in soft tissues show a lower error of measurement in women than in men. The potential applications of determined TEM values can be demonstrated using results of studies that assess changes in body composition of athletes in various sports throughout the competition season [ 46 — 48 ]. In these studies, researchers assessed the changes in body composition using the DXA method in handball players in preseason and postseason [ 47 ], rugby players in preseason, midseason and end-season [ 48 ] and softball, basketball and volleyball players, swimmers, and track and field athletes in off-season, preseason and postseason [ 46 ]. In many cases, the differences found, even when statistically significant, remain in a range of the TEM or the upper bound of the confidence interval or are very close to those values. In such cases, the changes present in the results could be considered negligible. Based on the results of the whole-body analysis presented in Table 3 , the current study assume that the bone parameters BMC, BMD are most accurately measured, as they have the lowest TEM values. It corresponds with the fact that DXA system uses different X-ray absorptivity with two pulse levels through the soft tissue and bones [ 49 ]. However, the percentage ratio of the resulting TEM to the total value implies that the BM 0. The BM value is given by the sum of the individual masses of the individually measured tissues. The correlation between the values measured by the digital scale InBody and the DXA was high in the individual measurements. Also, the FFM value in female subjects is determined with a lower error than BMC and BMD. As far as the segmental analysis is concerned, the values of the bone parameters BMC, BMD were measured with the lowest error and thus most accurately. Also shows that the errors of BMD and BMC segments determination were higher than whole body estimation errors, in spite of the fact that the laboratory technician is experienced and does not have to position the measured person in any special way, required, for example, in the hip or pelvic measurements. We did not find any relevant studies in the available sources that would deal with the reliability of measurement in a segmental analysis or that would compare the reliability of measurement between sexes. The studies mostly focus on the other aspects of measurement using the DXA method, as presented in the introduction [ 18 , 20 , 34 — 37 ]. Current investigation compared results with the study by Vincente-Rodrígez et al. The authors state that an error of measurement in BMC is The TEM values determined in current study are lower, whether they are values of individual measurement pairs or the mean TEM value. Even the values of the upper bound of the confidence interval that measured in current investigation do not reach the error stated by the authors Table 3. An important outcome of the Vincente-Rodrígez et al. study is that authors demonstrated the stability of the error of measurement in BMC as they did not find it increasing when measuring with a one-day interval. The invariability of the error of measurement and the results of the BF value were confirmed. We found two current studies that deal with the issue of the reliability of measurement by the DXA method. Both studies used the Lunar Prodigy device. Schubert et al. The study states the value of 0. These values are within the range of the values determined in current study, both male and female. However, the error of measurement of 0. This value is even higher than the value of the top reliability interval limit determined in current investigation. The potential difference may be caused by the different protocol of measurement and hydration that was only monitored 24 hours prior to measurement in our study. Tinsley et al. The study states an error of 0. The values for BM, BMC and BF determined in current study in female subjects were lower, the values for BMC were within the range of the error stated by the authors, and they were only higher for BF in males. The differences found may be caused by the different homogeneity of the studied groups, or by different level of physical fitness. The reproducibility of the measurement can also be expressed using the correlation of values from repeated measurements. The ICC values that determined current study from the whole-body analysis, ranging from 0. The studies state values from 0. Similar results were also presented in a study that assessed reliability with an interval of two weeks. The values ranged from 0. The values of basic anthropometric parameters for women and men are in accordance with the data in the literature, such as Heyward, Wagner [ 49 ]. They confirm a higher amount of muscle mass in men than in women, which is not only the consequence of general sex differences but also of the higher ratio of muscle-based activities in men, which may influence the BMD values [ 49 , 52 ]. Skeletal muscles and bones form a functional unit with the task of ensuring the mobility and stability of the individual. The results of the most recent studies suggest a complex interaction of muscle and bone. A frequently assessed parameter to describe this interaction is the BMC determined by DXA in relation to the FFM. In general, modifications in BMD were statistically relevant in boys and girls. In adults, cross-sectional studies have identified that martial arts are related to higher BMD, which is more evident in men than women [ 54 ]. The existence of sex differences on the osteogenic effect attributed to exercise is not completely clear, but biological maturation seems to affect it differently in boys and girls. Scan analysis and regional segmentations are reliant upon image quality which is a product of subject positioning during the scanning process. As composite mass was assigned to the scanned image on a pixel-by-pixel basis [ 55 ], outcomes are influenced by the quantity and distribution of mass viewable in the frontal plane [ 56 ]. Presently, no model exists for appendicular segmental analyses of the upper and lower extremities using DXA. Several authors have attempted to differentiate between segments of the extremities [ 55 — 58 ]. However, anatomical inconsistencies exist regarding locations for body segmentation, further confounded by inadequate descriptions for the purpose of reproduction in practical or research contexts. Because DXA is a valid measurement for quantifying lean, fat, and bone mass and density, DXA methods estimate BSIPs with a greater degree of accuracy than indirect methods for a variety of subject populations [ 58 ]. For instance, Rossi et al. Especially, the magnitude of these differences was greater in female and male elite swimmers compared with similarly aged adult males who were not competitive athletes. Positioning and analysis methodologies presented in this paper resulted in very high, nearly perfect reliability when examining hard- and soft- tissue masses across all segments of the upper and lower extremity. While no observable difference in reliability was evident between upper-body and lower-body segments; hard-tissue achieved greater reliability than soft-tissue masses throughout. There were a few limitations in this study, primarily due to the nature of the DXA scan performed. First, all participants were lying flat instead of standing upright; thus, small shifts in mass locations likely occurred, introducing potential errors in the computation of the DXA parameters lying flat vs standing. The second main limitation is due to the sample size used. The positioning of the study participants and analysis methodologies implemented in the experiment resulted in very high, nearly perfect reliability when examining hard and soft tissue masses across all segments of the upper and lower extremities. No observable difference in reliability was evident between the upper-body and lower-body segments; hard-tissue masses achieved greater reliability than soft-tissue masses throughout. The percentage ratio of the resulting TEM measured parameter to the total value of the measured parameter showed that the whole-body DXA analysis provides a more accurate value than segmental analysis for both soft and hard tissues. Therefore, this should be respected when using this method in practice. The TEM values of soft tissues show a lower error of measurement in women than in men in the whole-body and segmental analysis. The position of the subject has to be precisely fixated to ensure reproducibility of the DXA analysis results. The knowledge of TEM values is critical when interpreting outcomes of repeated measurements. The reproducibility of the DXA items determination showed no statistical difference between genders for the two measurements representing hard tissue. Browse Subject Areas? Click through the PLOS taxonomy to find articles in your field. Article Authors Metrics Comments Media Coverage Reader Comments Figures. Abstract Dual-energy X-ray absorptiometry DXA is rapidly becoming more accessible and popular as a technique to monitor body composition. McLester, Kennesaw State University, UNITED STATES Received: November 26, ; Accepted: April 4, ; Published: April 22, Copyright: © Kutáč et al. Materials and methods Participants Sixty-three participants were recruited, 38 males Procedures The measurements of the basic anthropometric parameters of body height BH and body mass BM , which are the input parameters for measuring body composition using the DXA system, were taken using a stadiometer with a digital scale, InBody BSM Biospace, South Korea. Download: PPT. Fig 1. Position of the participant during measurement [ 42 ]. Fig 2. Body scan [ 42 ]. Statistical analysis The accuracy of the DXA system was assessed using the TEM [ 23 ]. Results The results present the mean input values of the whole-body and segmental analyses the segmental analysis did not include the head and the resulting values of the TEM. Table 1. Input values of repeated measurements presented by the mean and standard deviation—Whole body analysis. Table 2. Input values of repeated measurements presented by the mean and standard deviation—Segmental analysis. Table 3. The mean typical error of measurement value, lower and upper confidence limit and intraclass correlation—Whole body analysis. Table 4. The mean typical error of measurement value, lower and upper confidence limit and intraclass correlation—Segmental analysis. Discussion The potential applications of determined TEM values can be demonstrated using results of studies that assess changes in body composition of athletes in various sports throughout the competition season [ 46 — 48 ]. Limitations of the study There were a few limitations in this study, primarily due to the nature of the DXA scan performed. Conclusions The positioning of the study participants and analysis methodologies implemented in the experiment resulted in very high, nearly perfect reliability when examining hard and soft tissue masses across all segments of the upper and lower extremities. Supporting information. S1 File. Source relevant data. s XLSX. References 1. Heller JE, Thomas JJ, Hollis BW, Larson-Meyer DE. Relation between vitamin D status and body composition in collegiate athletes. Int J Sport Nutr Exerc Metab. Milanese C, Cavedon V, Corradini G, De Vita F, Zancanaro C. Seasonal DXA-measured body composition changes in professional male soccer players. J Sports Sci. Prokop NW, Reid RE, Andersen RE. Langaker 2. Dual-energy x-ray absorptiometry DEXA has sustained a niche for measuring bone mineral density since its approval by the Food and Drug Administration FDA for clinical use in DEXA is comparatively inexpensive with notably shorter scan times and radiation exposure compared to other imaging options, and there is a long-standing consensus regarding guidelines for interpreting DEXA images. This activity reviews the indications, contraindications of DEXA and highlights the role of the interprofessional team in the management of patients with osteoporosis. Objectives: Identify the indications for dual-energy X-ray absorptiometry DEXA. Describe the contraindications for dual-energy X-ray absorptiometry DEXA. Review the clinical significance of dual-energy X-ray absorptiometry DEXA. Explain the importance of dual-energy X-ray absorptiometry DEXA and the role of the interprofessional team in managing patients with osteoporosis and improving their outcomes. Access free multiple choice questions on this topic. A C-arm with the x-ray source below the supine patient emits photons at two distinct energy levels specific for soft tissue and cortical bone. A collimator is situated between the patient and x-ray source to minimize scatter. The Z-score is the number of standard deviations above or below the mean of age-matched controls. To flatten the lordosis of the lumbar spine, the patient lays supine with their hips and knees flexed on a supportive cushion. Bone mineral density measurements are obtained using the L1 through L4 vertebral bodies. The long axis of the femoral diaphysis is aligned with the scanner as the patient lies supine and a positioning device that internally rotates the femur to elongate the femoral neck on the PA image. If the femur is effectively internally rotated the lesser trochanter should be barely, if at all, visible. Bone mineral density measurements are obtained using the mid to distal radius and ulna. The patient is placed supine on the table with arms pronated and feet in dorsiflexion. Two sites are routinely evaluated with DEXA: the lumbar spine and hip. All women 65 years and older and men 70 years and older should be screened for asymptomatic osteoporosis. Women younger than 65 years old or men younger than 70 years old with the following risk factors:. Individuals at any age with bone mass osteopenia or fragility fractures on imaging studies, individuals 50 years and older who develop wrist, hip, spine, or proximal humerus fracture with minimal or no trauma, excluding pathologic fractures. Hypogonadal men 18 years and older and men with surgically or chemotherapeutically induced castration. Individuals beginning or receiving long-term therapy with medications known to affect BMD adversely:. Children or adolescents with medical conditions associated with abnormal BMD including but not limited to:. DEXA may be indicated in the diagnosis, staging, and follow-up of individuals with conditions that result in pathologically increased BMD, such as osteopetrosis or prolonged exposure to fluoride. DEXA may be indicated as a tool to measure regional and whole-body fat and lean mass patients with malabsorption, cancer, or eating disorders. Possibly of limited value or require modification of the technique or rescheduling of the examination in some situations, including:. A C-arm with x-ray source allowing for variable photon energy levels, collimator, detector, and associated computer software. Bone mineral density is the standard for measuring the diagnosis of osteoporosis and fracture risk assessment. The Fracture Risk Assessment Tool FRAX uses clinical risk factors, excluding the measure of BMD, to identify those at risk for osteoporosis or fractures. The FRAX was implemented in by the World Health Organization and is used to calculate the chance of a fracture in a ten-year timeframe. The clinical risk factors included in FRAX are age, sex, race, height, weight, body mass index, a history of fracture, parent's history of hip fracture, use of oral glucocorticoids, rheumatoid arthritis, and other secondary causes of osteoporosis, smoking, and alcohol use of three or more drinks daily. The geographic area is also considered in the calculation. A licensed radiologist interprets the scans and a T-score is determined to evaluate the standard deviation in the mean from the reference population and patient's average bone mineral density. The World Health Organization WHO defines T-scores as:. No complications considered due to the procedure. The radiation dose is comparable to standard background radiation. DEXA imaging serves a sentinel role in the evaluation of osteoporosis as the International Society of Clinical Densitometry, the United States Preventative Services Task Force, and the National Osteoporosis Foundation recommend all women over the age of 65 have their bone mineral density evaluated. It is considered the gold standard for diagnosing osteoporosis and predicting fracture risk with algorithms like the Fracture Risk Assessment tool. Although DEXA imaging has excellent reported accuracy and precision, consideration should be made if comparing results across different instruments from different manufacturers unless cross-calibration has been assured. Evaluation of primary and secondary osteoporosis cannot be elucidated with DEXA imaging. This was exemplified by Tannenbaum and colleagues when 55 out of women with the diagnosis of primary osteoporosis were found to have a secondary cause with hypercalciuria, malabsorption, hyperparathyroidism, and vitamin-D deficiency. DEXA imaging is the best clinical tool for assessing bone mineral density in the evaluation of osteoporosis and its validity is evident given its ubiquity among international guidelines. It is important for the healthcare team to work together to ensure the appropriate DEXA test is ordered and that the test is done correctly. According to ACR Appropriateness Criteria Osteoporosis and Bone Mineral Density, there are specific cases in which Quantitative CT QCT is considered superior to DEXA. These include 1. Extremes in body height i. very large and very small patients 2. Patients with extensive degenerative disease of the spine 3. A clinical scenario that requires increased sensitivity to small changes in trabecular bone density parathyroid hormone and glucocorticoid treatment monitoring. Structural changes, such as osteophytes, calcifications, or fractures are more common in the lumbar spine than proximal femur [2] and potentially determine an artefactual increment of BMD. g parts of bras, surgical clips, navel rings, vascular prosthesis may alter the final BMD, resulting in overestimation if the metal is included in the region of interest or underestimation if outside the ROI. Some of the pitfalls can be avoided; however, some may just have to be observed and considered for the patient's care by the health professional team. Disclosure: Marissa Krugh declares no relevant financial relationships with ineligible companies. Disclosure: Michelle Langaker declares no relevant financial relationships with ineligible companies. This book is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4. You are not required to obtain permission to distribute this article, provided that you credit the author and journal. Turn recording back on. National Library of Medicine Rockville Pike Bethesda, MD Web Policies FOIA HHS Vulnerability Disclosure. Help Accessibility Careers. Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation. Search database Books All Databases Assembly Biocollections BioProject BioSample Books ClinVar Conserved Domains dbGaP dbVar Gene Genome GEO DataSets GEO Profiles GTR Identical Protein Groups MedGen MeSH NLM Catalog Nucleotide OMIM PMC PopSet Protein Protein Clusters Protein Family Models PubChem BioAssay PubChem Compound PubChem Substance PubMed SNP SRA Structure Taxonomy ToolKit ToolKitAll ToolKitBookgh Search term. StatPearls [Internet]. Treasure Island FL : StatPearls Publishing; Jan-. Show details Treasure Island FL : StatPearls Publishing ; Jan-. Search term. Dual-Energy X-Ray Absorptiometry Marissa Krugh ; Michelle D. Author Information and Affiliations Authors Marissa Krugh 1 ; Michelle D. Affiliations 1 Campbell University. Continuing Education Activity Dual-energy x-ray absorptiometry DEXA has sustained a niche for measuring bone mineral density since its approval by the Food and Drug Administration FDA for clinical use in Introduction Dual-energy x-ray absorptiometry DEXA has sustained a niche for measuring bone mineral density since its approval by the Food and Drug Administration FDA for clinical use in Anatomy and Physiology Lumbar Spine To flatten the lordosis of the lumbar spine, the patient lays supine with their hips and knees flexed on a supportive cushion. Hip The long axis of the femoral diaphysis is aligned with the scanner as the patient lies supine and a positioning device that internally rotates the femur to elongate the femoral neck on the PA image. Whole Body The patient is placed supine on the table with arms pronated and feet in dorsiflexion. Choosing Site to Scan Two sites are routinely evaluated with DEXA: the lumbar spine and hip. Indications All women 65 years and older and men 70 years and older should be screened for asymptomatic osteoporosis. Women younger than 65 years old at risk for osteoporosis: Estrogen deficiency. Conditions associated with secondary osteoporosis, such as gastrointestinal malabsorption or malnutrition, sprue, osteomalacia, vitamin D deficiency, endometriosis, acromegaly, chronic alcoholism or established cirrhosis, and multiple myeloma. Individuals who have had a gastric bypass for obesity The accuracy of DEXA in these patients might be affected by obesity. Individuals with an endocrine disorder known to adversely affect BMD e. Individuals with bone dysplasias known to have excessive fracture risk osteogenesis imperfecta, osteopetrosis or high bone density. Conditions associated with secondary osteoporosis, such as gastrointestinal malabsorption, sprue, inflammatory bowel disease, malnutrition, osteomalacia, vitamin D deficiency, acromegaly, cirrhosis, HIV infection, prolonged exposure to fluorides. |
| Bone Density Scan (DEXA or DXA) | The ISCD states that there is no clearly understood correlation between BMD and the risk of a child's sustaining a fracture; the diagnosis of osteoporosis in children cannot be made using the basis of a densitometry criteria. T-scores are prohibited with children and should not even appear on DXA reports. Thus, the WHO classification of osteoporosis and osteopenia in adults cannot be applied to children, but Z-scores can be used to assist diagnosis. Some clinics may routinely carry out DXA scans on pediatric patients with conditions such as nutritional rickets , lupus , and Turner syndrome. However, it seems that DXA is still in its early days in pediatrics, and there are widely acknowledged limitations and disadvantages with DXA. A view exists [15] that DXA scans for diagnostic purposes should not even be performed outside specialist centers, and, if a scan is done outside one of these centers, it should not be interpreted without consultation with an expert in the field. Whole-body calcium measured by DXA has been validated in adults using in-vivo neutron activation of total body calcium [16] [17] but this is not suitable for paediatric subjects and studies have been carried out on paediatric-sized animals. DXA scans can also be used to measure total body composition and fat content with a high degree of accuracy comparable to hydrostatic weighing with a few important caveats. DXA scans have been suggested as useful tools to diagnose conditions with an abnormal fat distribution, such as familial partial lipodystrophy. DXA uses X-rays to measure bone mineral density. The radiation dose of current DEXA systems is small, [24] as low as 0. The quality of DXA operators varies widely. DXA is not regulated like other radiation-based imaging techniques because of its low dosage. Each US state has a different policy as to what certifications are needed to operate a DXA machine. California , for example, requires coursework and a state-run test, whereas Maryland has no requirements for DXA technicians. Many states require a training course and certificate from the International Society of Clinical Densitometry ISCD. In Australia, regulation differs according to the applicable state or territory. For example, in Victoria, an individual performing DXA scans is required to completed a recognised course in safe use of bone mineral densitometers. The Environmental Protection Agency EPA oversees licensing of technicians, however, this is far from rigorous and regulation is non-existent. Contents move to sidebar hide. Article Talk. Read Edit View history. Tools Tools. What links here Related changes Upload file Special pages Permanent link Page information Cite this page Get shortened URL Download QR code Wikidata item. Download as PDF Printable version. In other projects. Wikimedia Commons. Diagnostic test for bone mineral density testing. For the chemical, see Dextrallorphan. Main article: Bone density § Testing. National Library of Medicine. National Osteoporosis Society. Retrieved Preventive Services Task Force. January Archived from the original on 30 May Retrieved 20 August J Clin Densitom. doi : PMID Eur J Radiol. Archived from the original on Pediatr Radiol. PMC Osteoporos Int. S2CID Bone Miner. A Biol. Diabetes Care. Nutr Metab Lond. ISSN Radiological Society of North America. Retrieved December 8, Semin Nucl Med. Appl Radiat Isot. Health Department Government of Victoria. Retrieved 11 October Wikimedia Commons has media related to Dual-energy X-ray absorptiometry. Procedures involving bones and joints. Jaw reduction Orthognathic surgery Chin augmentation. Coccygectomy Laminotomy Laminectomy Laminoplasty Corpectomy Facetectomy Foraminotomy Vertebral fixation Vertebral augmentation. Femoral head ostectomy Astragalectomy Distraction osteogenesis Ilizarov apparatus Phemister graft. Ostectomy Bone grafting Osteotomy Epiphysiodesis Reduction Internal fixation External fixation Tension band wiring. Articular cartilage repair Microfracture surgery Knee cartilage replacement therapy Autologous chondrocyte implantation. Arthrodesis Spinal fusion Intervertebral discs Discectomy Annuloplasty Arthroplasty. Shoulder surgery Shoulder replacement Bankart repair Weaver—Dunn procedure Ulnar collateral ligament reconstruction Hand surgery Brunelli procedure Finger joint replacement. Arthrotomy Arthroplasty Synovectomy Arthroscopy Joint replacement imaging: Arthrogram Arthrocentesis Arthroscopic lavage. Investigation of bone quality has provided insight into the pathogenesis of osteoporosis and a better understanding of the mechanism of action of medications used to treat osteoporosis, but with the exception of bone turnover markers, it is not yet possible to measure these routinely in clinical practice. Technologies such as high-resolution peripheral quantitative computed tomography HR-pQCT and micro-magnetic resonance imaging micro-MRI can be used to assess trabecular microarchitecture, but at the present time, these are largely used for research, with no established clinical applications. Trabecular bone score TBS is a gray-level textural measurement that can be extracted from a dual-energy x-ray absorptiometry DXA image of the lumbar spine with proprietary software; it captures information related to bone microarchitecture that provides an assessment of fracture risk that is independent of bone density [ 7 ]. In the absence of a fragility fracture, bone density is the best predictor of fracture risk. Why UpToDate? Product Editorial Subscription Options Subscribe Sign in. Learn how UpToDate can help you. Select the option that best describes you. View Topic. Font Size Small Normal Large. Overview of dual-energy x-ray absorptiometry. Formulary drug information for this topic. No drug references linked in this topic. Find in topic Formulary Print Share. View in. Language Chinese English. Author: E Michael Lewiecki, MD Section Editor: Clifford J Rosen, MD Deputy Editor: Katya Rubinow, MD Literature review current through: Jan This topic last updated: Dec 19, Osteoporosis is defined as "a skeletal disease characterized by compromised bone strength predisposing a person to an increased risk of fracture" [ 2 ]. BONE QUALITY Bone strength is determined by bone mineral density BMD and other properties of bone that are often collectively called "bone quality" [ 6 ]. Non-BMD determinants of bone strength include bone turnover, architecture size and shape, or bone geometry , microarchitecture eg, trabecular thickness, trabecular connectivity, trabecular perforation, cortical thickness, and cortical porosity , damage accumulation, matrix properties, mineralization, and mineral properties eg, crystal size and orientation. |
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