To advance interdisciplinary health sciences research and innovation by providing high quality bone density and body composition measures to investigators at Brigham and Women’s Hospital (BWH), Partners HealthCare and the broader, medical and research community.
The BWH Bone Density and Body Composition Research Core uses the latest technology to provide high quality, reproducible measures of bone mineral density (BMD) and body composition by dual energy x-ray absorptiometry (DXA). Dr. Meryl S. LeBoff is the Director of the Bone Density and Body Composition Research Core and has extensive experience in assessing bone density and body composition. She is the Chief of the Calcium and Bone Section and Director of the Skeletal Health and Osteoporosis Center and Bone Density Unit in the Endocrinology, Diabetes and Hypertension Division at BWH. She is a trustee for the National Osteoporosis Foundation and served on the 2013 Expert Panel for the International Society for Clinical Densitometry’s (ISCD) Position Statement on Bone Density and Body Composition Measures. She and the staff at the Bone Density and Body Composition Research Core have been performing clinical research scans for more than 25 years and are committed to maintaining the highest standards of quality control.
We are conveniently located at 221 Longwood Avenue, which is accessible by the Partners Masco M2 and Ruggles buses, MBTA buses and the T. Valet parking is also available.
"The Hologic Discovery DXA system enables you to identify patients at risk for osteoporosis and other debilitating conditions. Delivering exceptional precision and pinpoint accuracy, "
Instrument uses software version APEX 18.104.22.168.
For multi-center studies, it is important that the DXA scanners are cross-calibrated using a designated whole body or spine phantom. The basic in vitro procedure includes scanning the designated phantom 20 times, analyzing the scans, copying them onto a CD and transmission (i.e., courier/upload) of the images to other sites or QA center for cross-calibration.
Measurement of the forearm bone density includes the1/3 radius using DXA (dual energy x-ray absorptiometry) Results are expressed as BMD (g/cm2 ), T-scores (compared to mean of young women/men), and Z-scores (matched for age, sex, and race).(Discovery W, Hologic Inc, Bedford, MA).
Example of forearm bone density DXA measurement
Quality control (QC) data will be plotted and sent or uploaded according to the study protocol on a monthly/weekly basis.
Measurement of areal bone mineral density (aBMD) of the spine (L1-L4), hip (total hip and femoral neck) by DXA. Results are expressed as BMD (g/cm2 ), T-scores (compared to mean of young women/men), and Z-scores (matched for age, sex, and race). The bone density reproducibility of least significant change (LSC) at our Core is 0.017 g/cm2 for spine, 0.022 g/cm2 for femoral neck and 0.014 g/cm2 for total hip.
Example of spine bone density DXA measurement
Example of hip bone density DXA measurement
The TBS is an analytical, non-invasive measure performed on DXA images of the lumbar spine and is associated with the skeletal microarchitecture. This technique uses a quantitative algorithm to measure grey-level variation in 2-dimensional projection images to estimate 3-dimensional textural characteristics of vertebrae. Higher TBS is associated with better bone structure and lower risk of fractures. Newly-approved by the Food and Drug Administration (FDA), TBS has been found to predict fracture risk independent of BMD and can be used to in addition to BMD and FRAX ® to improve fracture risk assessments. TBS is generated with the latest TBS iNsight software (Medimaps Group, Geneva, Switzerland).
Example of TBS analysis
VFA imaging by DXA is used to assess for the presence of vertebral fractures along the thoracic and lumbar spine (T4-L4). Vertebral fractures are the most common osteoporotic fractures, and yet only 1/3 are clinically diagnosed. Spine fractures are associated with increased morbidity and mortality and an elevated risk of subsequent fractures independent of BMD.
Example of VFA analysis
We assess body composition measures, including fat and lean mass, and rate of change for fat and lean tissue, by DXA. Color images displaying the distribution of fat, lean mass, and bone are provided. Comprehensive adiposity measures (total and regional) include: total body fat, and fat mass index (FMI; fat mass/height2 ), visceral adipose tissue (VAT), truncal fat, trunk/limb fat mass ratio, % total fat, and % truncal fat/limb fat. We further categorize FMI values by recent thresholds from the NHANES database that are sex, age, and race-specific. Lean body mass measures include lean mass index (LMI; lean mass/height2 ), appendicular lean mass/height2 , and regional lean tissue. CV% for fat and lean tissue measures are 1.09 ± 0.15% and 0.89 ± 0.28%, respectively. The whole body bone density reproducibility of least significant change (LSC) at our Core is 0.008 g/cm2 for males and 0.010 g/cm2 for females.
Example of whole body composition DXA measurement
Example of whole body bone density DXA measurement