Bone disease after kidney transplantation.

Post-transplant renal osteopathy (ROP) remains a serious problem, which contributes to substantial long-term morbidity of the graft recipients. Bone loss is most pronounced during the first months after engraftment; concerning bone density development in long-term transplant recipients, controversial data exist. The clinical impact of ROP is a marked increase in fracture rate following kidney transplantation compared with both general population and patients on dialysis treatment. The following review will focus on post-transplant ROP and discuss its epidemiology, the clinical features, factors contributing to the pathogenesis of this complication, as well as the evaluation, prevention and treatment options available for kidney allograft recipients.     

Reduction of bone mineral density in rheumatoid arthritis: A longitudinal study

In the last decade, more accurate quantitative methods to assess bone mass in vivo have become available. We have applied these techniques to assess periodic changes of bone loss in rheumatoid arthritis (RA) patients. In this longitudinal study, 132 female RA patients were divided into two groups. The first group of 90 patients were postmenopausal, with a mean age of 60.2 years (PM group), whereas the second group of 42 patients were premenopausal, with a mean age of 42.7 years (M group). The clinical courses of these patients were followed for an average of 3 years. Bone mineral density (BMD) in the lumbar spine (L2–L4), and the femoral neck were measured by dual-energy X-ray absorptiometry (DXA), and second metacarpal bone mineral density was measured by using densitometric techniques periodically. Reduction of BMD in the lumbar spine was significant in both groups (P<0.01–0.05), but there was no statistical difference between the two groups. The BMD of the femoral neck had a tendency to decrease but this was not significant. The predictors for periodic bone loss in the PM group were aging and nutritional factors, whereas for the M group they were indices of rheumatoid arthritis disease activity.     

Radiolucent Casting Tape Allows for Accurate Measurement of Forearm Bone Mineral Density Using Dual-Energy X-ray Absorptiometry

The ability to perform dual-energy X-ray absorptiometry (DXA) while a patient is in a cast would give investigators the opportunity to follow early changes in bone mineral density (BMD, g/cm2) during fracture healing or to evaluate bone changes related to immobilization. The objective of this study was to determine if accurate and precise DXA scans could be obtained through polyester-based radiolucent casting tape (Delta-Cast Elite [DCE], Johnson & Johnson, Inc., Raynham, MA) and standard fiberglass casting tape (Delta Lite [DL], Johnson & Johnson, Inc.). DXA scans were performed using a Lunar DPXL densitometer. Standard forearm regions of interest were analyzed. Ten normal volunteers had three consecutive scans of their dominant arm with no cast, with a radiolucent (DCE) cast, and with a fiberglass (DL) cast. Precision was calculated using data from three volunteers (three scans each; no cast, DCE, DL). Results of DCE and DL were compared with results with no cast. In a second series, a spine phantom was placed inside rice-filled forearm casts and repetitively scanned; results with DCE and DL were compared with the mean BMD values for the phantom alone. Analyses of the scans through the DL casts were difficult because the radiodensity of the fiberglass interfered with edge detection. This problem was exacerbated by low BMD (i.e., scans for women). Edge detection was not a problem with the DCE scans. Although the group mean BMD values with in vivo no cast, DCE, or DL scans were similar for all regions of interest, the data obtained for ultradistal regions of interest with DL scans were less precise. BMD values for the fiberglass-encased phantom were significantly lower compared with no cast or DCE scans (p = 0.0002). This study demonstrates that it is possible to perform accurate and precise forearm DXA scans through polyester-based radiolucent DCE casting tape.     

Regional Variation in the Denial of Reimbursement for Bone Mineral Density Testing Among US Medicare Beneficiaries

Although the Bone Mass Measurement Act outlines the indications for central dual-energy X-ray absorptiometry (DXA) testing for US Medicare beneficiaries, the specifics regarding the appropriate ICD-9 codes to use for covered indications have not been specified by Medicare and are sometimes ambiguous. We describe the extent to which DXA reimbursement was denied by gender and age of beneficiary, ICD-9 code submitted, time since previous DXA, whether the scan was performed in the physician's office and local Medicare carrier. Using Medicare administrative claims data from 1999 to 2005, we studied a 5% national sample of beneficiaries age ≥65 yr with part A + B coverage who were not health maintenance organization enrollees. We identified central DXA claims and evaluated the relationship between the factors listed above and reimbursement for central DXA (CPT code 76075). Multivariable logistic regression was used to evaluate the independent relationship between DXA reimbursement, ICD-9 diagnosis code, and Medicare carrier. For persons who had no DXA in 1999 or 2000 and who had 1 in 2001 or 2002, the proportion of DXA claims denied was 5.3% for women and 9.1% for men. For repeat DXAs performed within 23 mo, the proportion denied was approximately 19% and did not differ by sex. Reimbursement varied by more than 6-fold according to the ICD-9 diagnosis code submitted. For repeat DXAs performed at <23 mo, the proportion of claims denied ranged from 2% to 43%, depending on Medicare carrier. Denial of Medicare reimbursement for DXA varies significantly by sex, time since previous DXA, ICD-9 diagnosis code submitted, place of service (office vs facility), and local Medicare carrier. Greater guidance and transparency in coding policies are needed to ensure that DXA as a covered service is reimbursed for Medicare beneficiaries with the appropriate indications.     

QCT和DXA对腰椎骨质疏松症检出率的Meta分析

目的 通过对定量CT（quantitative computed tomography,QCT）和双能X线吸收测量仪(dual-energy X-ray absorptiometry,DXA）腰椎骨质疏松症(osteoporosis ,OP)检出率研究数据进行Meta分析,了解QCT和DXA对腰椎OP的诊断价值。方法 检索 PubMed、Web of Science、Cochrane Library、万方、维普及中国知网中自建库以来至2022年1月1日的相关文献,提取目标数据。采用Stata 11.0软件进行数据分析,根据异质性检验结果选择固定效应模型或随机效应模型对数据进行汇总分析。结果 共纳入24篇研究,总样本量为4 008例,其中男性2 265例,女性1743例。24项研究间异质性显著,按随机效应模型分别汇总QCT和DXA对腰椎OP检出率为0.44(95 %CI：0.37~0.52)和0.17(95 %CI：0.14~0.21)。QCT对男、女性腰椎OP检出率分别为0.32(95 %CI：0.22~0.43)和0.45(95 %CI：0.33~0.58),DXA则分别为0.14(95 %CI：0.08~0.20)和0.24(95 %CI：0.17~0.30)。QCT在45~、60~岁和75岁及以上的人群中腰椎OP检出率分别为0.41(95 %CI：0.21~0.61)、0.43(95 %CI：0.33~0.54)和0.48(95 %CI：0.41~0.54),DXA则分别为0.30(95 %CI：0.12~0.49)、0.16(95 %CI：0.11~0.20)和0.15(95 %CI：0.10~0.21)。QCT和DXA对国内人群腰椎OP检出率分别为0.40(95 %CI：0.33~0.47)和0.15(95 %CI：0.12~0.19),对国外人群分别为0.68(95 %CI：0.43~0.93)和0.28(95 %CI：0.18~0.39)。QCT与DXA对腰椎OP检出率的差值(率差)定量合并结果为0.25(95 %CI：0.20~0.31),在男性为0.26(95 %CI：0.18~0.34),在女性为0.28(95 %CI：0.17~0.39),在45~、60~岁和75岁及以上人群中分别为0.10(95 %CI：0.06~0.14)、0.26(95 %CI：0.19~0.33)和0.30(95 %CI：0.18~0.41),及在国内外人群分别为0.23(95 %CI：0.17~0.29)和0.38(95 %CI：0.13~0.64)。结论 QCT比DXA对腰椎OP的检出率高,且QCT对男、女性和各年龄段及不同地区间人群的腰椎OP检出率均高于DXA,率差值随年龄的增加而增大,提示QCT对高年龄组腰椎OP的早期发现可能具有更高的价值。     

Bone mineral densitometry in patients on hemodialysis: difference between genders and what to measure

Introduction: Chronic kidney disease (CKD) and osteoporosis are important health problems. There is an interrelationship between osteoporosis and CKD. Bone densitometry is the “gold” standard in the diagnosis of osteoporosis. Unfortunately, there are some problems with the interpretation of bone densitometry in CKD patients. The goal of this study was to determine bone mineral density (BMD) in CKD patients, to assess the difference between genders and different sites of bone densitometry correlation between BMD and laboratory parameters, and to assess the most optimal measuring site. Methods: We studied 134 hemodialysis (HD) patients (62 females, 72 males). The mean age was 56.4 ± 12.4 years and the mean duration of HD was 54.4 ± 60 months. BMD of the lumbar spine (posterior–anterior projection and lateral projection), hip (femoral neck, trochanter, intertrochanter, total femur, the Ward's Triangle), and forearm (ultradistal (UD), middistal (MID), distal third portion, and total forearm) was measured using dual X-ray absorptiometry (DXA) (Hologic Delphi apparatus). Values were expressed as BMD, T-score, and Z-score. Results: Females had lower values of BMD in all measurement points. There were no significant differences in T- and Z-scores of forearm between males and females. Age was in a positive correlation with lumbar spine BMD in males and females. There was a negative correlation with neck and forearm BMD in both groups. Serum parathyroid hormone (PTH) was also in negative correlation with hip and forearm BMD in both groups. The best correlation of BMD in different sites was between forearm and neck. Conclusion: BMD data in CKD patients should be interpreted with caution and appendicular skeletal sites should be included in the evaluation.     

Bone mineral density in haemodialysis patients: A comparative study of dual-energy X-ray absorptiometry and quantitative ultrasound.

BACKGROUND: Quantitative ultrasound (QUS) of bone is a relatively new technique that appears to assess 'bone quality' in addition to bone mineral density. The purpose of this study was to evaluate the diagnostic potential of QUS of calcaneum and to correlate it with dual energy X-ray absorptiometry (DEXA) in chronic haemodialysis patients. METHODS: Broad-band ultrasound attenuation (BUA; dB/MHz) and speed of sound (SOS; m/s) of calcaneum and DEXA (g/cm(2)) measurements of the lumbar spine and hip were made in 39 patients. The indices obtained by either method were compared with age-and sex-matched controls. Calcaneal measurements were correlated to DEXA and relevant clinical and biochemical data of patients. RESULTS: BUA and SOS values were markedly reduced in dialysis patients compared to controls (59.1+/-13.8 vs 73.0+/-16.2 dB/MHz, P:<0.001 and 1533+/-28 vs 1560+/-29 m/s, P:=0.014 respectively). There was a moderate, but significant association between calcaneal parameters and DEXA (r=0.32-0.53, P:<0.05). Both BUA and SOS scores were inversely correlated with age (r=-0.69, P:<0.001) and duration of menopause (r=-0.74, P:<0.01). Additionally, BUA values showed a moderate negative association with serum intact parathyroid values (r=-0.38, P:=0.018). CONCLUSION: Chronic haemodialysis patients have reduced calcaneal BUA and SOS scores. QUS of the calcaneum is an easy-to-apply and radiation-free technique. It could be a useful substitute for assessment of bone density in such patients. However, further studies in large patient groups and comparisons with plasma markers of bone turnover and bone biopsy findings are needed to assess its potential place in the management of renal osteodystrophy.     

The Ability of Hand Digital X-Ray Radiogrammetry to Identify Middle-Aged and Elderly Women With Reduced Bone Density, as Assessed by Femoral Neck Dual-Energy X-Ray Absorptiometry

In this study, we evaluate the ability of digitized digital X-ray radiogrammetry (DXR) bone mineral density (BMD) to identify women with reduced BMD at femoral neck, assessed by dual-energy X-ray absorptiometry (DXA). The study population contained women with recent low-energy distal radius fracture and women recruited from the general population, all aged 50 yr or older. The correlation between hand BMD and femoral neck BMD was r = 0.65 (p < 0.001). We used a triage approach where 2 cutoffs for DXR T-score were defined at which patients with 90% sensitivity and 90% specificity could be identified to have or not have reduced BMD at femoral neck, defined as T-score ≤ ?2.5 standard deviation (SD). The upper and lower DXR T-score cutoffs were ?1.2 and ?2.7, respectively. Applying the triage approach in the whole cohort, 32% would require a central DXA assessment to determine the presence or absence of femoral neck T-score ≤ ?2.5 SD. Our data suggest that DXR can be used to reduce the numbers of patients in need of DXA femoral neck and may, thus, be of clinical value where access to DXA is limited.     

Bone Densitometry in Infants and Young Children: The 2013 ISCD Pediatric Official Positions

Infants and children <5 yr were not included in the 2007 International Society for Clinical Densitometry Official Positions regarding Skeletal Health Assessment of Children and Adolescents. To advance clinical care of very young children, the International Society for Clinical Densitometry 2013 Position Development Conference reviewed the literature addressing appropriate methods and skeletal sites for clinical dual-energy X-ray absorptiometry (DXA) measurements in infants and young children and how results should be reported. DXA whole-body bone mineral content and bone mineral density for children ≥3 yr and DXA lumbar spine measurements for infants and young children 0–5 yr were identified as feasible and reproducible. There was insufficient information regarding methodology, reproducibility, and reference data to recommended forearm and femur measurements at this time. Appropriate methods to account for growth delay when interpreting DXA results for children <5 yr are currently unknown. Reference data for children 0–5 yr at multiple skeletal sites are insufficient and are needed to enable interpretation of DXA measurements. Given the current scarcity of evidence in many areas, it is likely that these positions will change over time as new data become available.     

Bone mineral density in children after renal transplantation

A successful kidney transplantation (Tx) offers good quality of life for children suffering from chronic renal failure. However, some metabolic abnormalities may not be corrected and may persist after Tx despite good graft function. Post-Tx bone disease seems to be a universal finding in adult Tx recipients, and is most probably related to steroids. Reports on bone mineral density (BMD) in children after renal Tx are not uniform. Recent studies suggest that BMD is normal when corrected for height. However, longitudinal studies show a transient decrease in BMD in the early post-Tx period. These controversial results raise the issue of the correct interpretation of dual-energy X-ray absorptiometry in children with stunted growth. Etiopathogenetic factors of the decreased BMD, preventive and thera- peutic measures are discussed. In conclusion, the results of dual energy X-ray absorptiometry should be interpreted with caution, especially in children with disturbed growth. Received: 3 May 1999 / Revised: 16 January 2000 / Accepted: 23 January 2000     

Fracture Burden in Relation to Low Bone Mineral Density and FRAX Probability

Although the risk of fracture increases exponentially with declining bone mineral density, most fragility fractures have been shown to occur in individuals who do not meet the conventional densitometric definition for osteoporosis. The World Health Organization fracture risk assessment tool (FRAX^®) estimates individual 10-yr major osteoporotic and hip fracture probabilities. Intervention criteria based on risk assessment have been proposed by several groups, including the National Osteoporosis Foundation (NOF). We determined the relationship between 10-yr fracture probability and subsequent fracture burden in 36,730 women and 2873 men aged 50 yr and older. Using a major fracture probability cutoff of 20%, 29.4% of major osteoporotic fractures were identified in women and 4.9% in men. Based on a hip fracture probability cutoff of 3%, 54.1% of major osteoporotic fractures were detected in women and 53.4% in men. Using all NOF criteria, 65.9% of major osteoporotic fractures were detected in women and 69.3% in men. We conclude that men and women with FRAX probabilities below the high-risk NOF cutoffs have a high burden of major osteoporotic fractures. Strategies to enhance risk stratification in this group should be developed through international collaborations.     

Outcomes of bisphosphonate therapy in kidney transplant recipients: a systematic review and meta‐analysis

Mineral and bone disorders that precede kidney transplantation are exacerbated in the post‐transplant setting by tertiary hyperparathyroidism and immunosuppressive regimens. Bone mineral density (BMD) decreases following transplantation, leading to increased fracture risk. The effect of bisphosphonates on fracture is unknown. The aim of this study was to update estimates of change in BMD and fracture rates in bisphosphonate‐treated kidney transplant recipients through meta‐analysis. Studies comparing bisphosphonate therapy to standard of care were included if follow‐up duration was more than 6 months. We performed random‐effects meta‐analysis to determine the effect of bisphosphonates on lumbar spine and femoral neck BMD and fracture rates. Bisphosphonates improved femoral neck and lumbar spine BMD compared with controls (0.055 g/cm², 95% CI 0.012–0.099 and 0.053 g/cm², 95% CI 0.032–0.074, respectively) without adversely affecting serum creatinine or calcium. This corresponded to an unweighted improvement in BMD of 6.0% and 7.4%, respectively. There was no difference in fracture incidence in the two groups. Bisphosphonate therapy in kidney transplant recipients is associated with a statistically significant improvement in BMD at the lumbar spine and femoral neck. There was no difference in fracture incidence. Bisphosphonates did not adversely affect allograft dysfunction or serum calcium levels.     

Comparison of Bone Mineral Density of the Phalanges, Lumbar Spine, Hip, and Forearm for Assessment of Osteoporosis in Postmenopausal Women

The objective of this study was to compare peripheral bone mineral density (BMD) of the phalanges with BMD of the lumbar spine, total hip, femoral neck, and forearm and to determine the clinical value of measuring a single peripheral site (phalanges) in identifying postmenopausal women with osteoporosis. BMD was measured by dual energy X-ray absorptiometry using the accuDEXA((R)) (ADXA-finger) (Schick, New York, NY) and the QDR-4500 (DXA-lumbar spine, hip, forearm) (Hologic, Waltham, MA). Correlation coefficients between ADXA and DXA of the lumbar spine, total hip, femoral neck and one third radial site ranged from 0.53 to 0.73. The sensitivity of an ADXA T-score of -2.5 in identifying patients with a DXA T-score of < or = -2.5 at the femoral neck was 35%. An ADXA T-score cut point of -1.0 improved the sensitivity of ADXA in identifying patients with a femoral neck T-score of < or = -2.5 (85%), but the specificity declined from 88 to 49%. There was substantial discordance in the diagnosis of osteoporosis when a single site was measured, regardless of technique. Within the limitations of single-site measurements, BMD measured by ADXA has adequate sensitivity to identify women with low BMD at the femoral neck, if an appropriate T-score criterion is used.     

Measurement of bone mineral density of lumbar spine and whole body in low-birth-weight infants: comparison of two methods

In the present study, we compared lumbar spinal and whole-body bone mineral density (BMD) measurements to determine which is more suitable for evaluating the bone mineral status of low-birth-weight (LBW) infants. Lumbar spinal and whole-body BMD were assessed simultaneously in a prospective series including 152 Japanese LBW infants (birth weight 453–2400 g, gestational age 24–38 weeks) from the age of 40 weeks post-conception to 2 years of age. Lumbar spinal BMD at 40 weeks post-conception was significantly correlated with birth weight (r = 0.74; P < 0.0001), but whole-body BMD was not correlated with birth weight. No correlation was found between lumbar spinal and whole-body BMD at 40 weeks post-conception. However, after 40 weeks post-conception, a significant correlation was found between lumbar spinal and whole-body BMD (r = 0.65; P < 0.0001). For infants with a body weight of 4 kg or less at the time of measurement, no correlation was found between lumbar spinal and whole-body BMD. However, for infants with a body weight above 4 kg, a significant correlation was found between lumbar spinal and whole-body BMD (r = 0.65; P < 0.0001). Thus, lumbar spinal BMD is more suitable than whole-body BMD for evaluation of the bone mineral status of LBW in early infancy. Therefore, lumbar spinal BMD should be used for serial evaluation of changes in the bone mineral status of LBW infants. Received: April 6, 2000 / Accepted: June 16, 2000     

Spine-Hip T-Score Difference Predicts Major Osteoporotic Fracture Risk Independent of FRAX: A Population-Based Report From CAMOS

The WHO fracture risk assessment tool (FRAX^®) estimates an individual’s 10-yr major osteoporotic and hip fracture probabilities. When bone mineral density (BMD) is included in the FRAX calculation, only the femoral neck measurement can be used. Recently, a procedure was reported for adjusting major osteoporotic fracture probability from FRAX with femoral neck BMD based on the difference (offset) between the lumbar spine and the femoral neck T-score values. The objective of the current analysis was to independently evaluate this algorithm in a population-based cohort of 4575 women and 1813 men aged 50 yr and older from the Canadian Multicentre Osteoporosis Study. For women and men combined, there was a 15% (95% confidence interval 7–24%) increase in major osteoporotic fracture risk for each offset T-score after adjusting for FRAX probability calculated with femoral neck BMD. The effect was stronger in women than men, but a significant sex interaction was not detected. Among the full cohort, 5.5% had their risk category reclassified after using the offset adjustment. Sex- and age-dependent offsets (equivalent to an offset based on Z-scores) showed improved risk classification among individuals designated to be at moderate risk with the conventional FRAX probability measurement. In summary, the T-score difference between the lumbar spine and femoral neck is an independent risk factor for major osteoporotic fractures that is independent of the FRAX probability calculated with femoral neck BMD.     

Assessment of Bone Mineral Density at the Distal Femur and the Proximal Tibia by Dual-Energy X-ray Absorptiometry in Individuals With Spinal Cord Injury: Precision of Protocol and Relation to Injury Duration

Spinal cord injury (SCI) is characterized by marked bone loss at the knee, and there is a need for established dual-energy X-ray absorptiometry (DXA) protocols to examine bone mineral density (BMD) at this location to track therapeutic progress and to monitor fracture risk. The purpose of this study was to quantify the precision and reliability of a DXA protocol for BMD assessment at the distal femur and the proximal tibia in individuals with SCI. The protocol was subsequently used to investigate the relationship between BMD and duration of SCI. Nine individuals with complete SCI and 9 able-bodied controls underwent 3 repeat DXA scans in accordance with the short-term precision methodology recommended by the International Society of Clinical Densitometry. The DXA protocol demonstrated a high degree of precision with the root-mean-square standard deviation ranging from 0.004 to 0.052?g/cm² and the root-mean-square coefficient of variation ranging from 0.6% to 4.4%, depending on the bone, the region of interest, and the rater. All measurements of intra- and inter-rater reliability were excellent with an intraclass correlation of ≥0.950. The relationship between the BMD and the duration of SCI was well described by a logarithmic trend (r²?=?0.68–0.92). Depending on the region of interest, the logarithmic trends would predict that, after 3?yr of SCI, BMD at the knee would be 43%–19% lower than that in the able-bodied reference group. We believe the DXA protocol has the level of precision and reliability required for short-term assessments of BMD at the distal femur and the proximal tibia in people with SCI. However, further work is required to determine the degree to which this protocol may be used to assess longitudinal changes in BMD after SCI to examine clinical interventions and to monitor fracture risk.     

Age at Transplant—One of the Factors Affecting Bone Mineral Density in Kidney Recipients—A Single-Center Retrospective Study

Abstract

Background: Osteoporosis/osteopenia after kidney transplantation is multifactorial, and the mechanism responsible for this condition is unclear. A cumulative steroid dose and female gender are two likely major risk factors for osteoporosis/osteopenia after transplantation, but there is no consensus as to which risk factors are most strongly associated with reduced bone mineral density (BMD). Methods: We assessed 84 kidney recipients who had received transplants at least 5 months prior to enrollment in the study. BMD at the lumbar spine, hip, and femoral neck was evaluated by dual-energy X-ray absorptiometry. We used the average BMD (BMDa), defined as the average of the sum of the lumbar spine, hip, and femoral neck mineral density values, as representative of body BMD. Results: This retrospective study revealed inverse correlations between the BMDa and creatinine level and age at transplant as well as a positive correlation with male gender. Osteoporosis occurred in transplantations where the duration since transplantation was longer. Conclusion: This retrospective study demonstrated that a decrease in BMD, reflecting a bone condition tending toward osteoporosis/osteopenia, is inversely correlated with male gender, creatinine level, and age at transplant in kidney recipients. Nonetheless, the time since transplant is higher in the osteoporosis group than in the osteopenia group.     

The Effect of Common Artifacts Lateral to the Spine on Bone Mineral Density in the Lumbar Spine

Artifacts such as surgical clips, gallstones, and kidney stones are often present in the soft tissue stripe lateral to vertebral bodies. Using cadaveric specimens, we placed bra wires, gallbladder clips, a large gallstone, a calcium carbonate or a calcium citrate pill lateral to L1, or a large or small calcium-containing kidney stone lateral to L3 and compared the mean bone mineral density (BMD) of individual vertebral bodies and L1–L4 with and without the soft tissue artifact. The specimens used had high BMD (L1–L4 BMD = 1.049 g/cm²) and low BMD (L1–L4 BMD = 0.669 g/cm²) and were scanned with a Hologic Discovery W scanner with 12.7 software in the array mode. None of the artifacts affected L1 or L3 BMD or L1–L4 BMD significantly in the high BMD spine. However, bra wires, a large calcium citrate pill lateral to L1, 3 calcium citrate pills lateral to L1, a calcium carbonate pill over L1, and 3 calcium carbonate pills lateral to L1 did affect L1–L4 BMD in low BMD torso. Gallbladder clips or gallstone did not affect L1–L4 BMD in either specimen. We conclude that artifacts lateral to the spine, particularly in a low BMD spine, can affect the interpretation of L1–L4 BMD using a Hologic Discovery W scanner with 12.7 software in array mode.