The Hologic 4500A DXA Research Densitometer

The Atlanta Research Center, LLC has relied with confidence on Hologic bone densitometers since 1986. They have been the sole densitometer vendor for our facility for the past 31 years. Hologic was the first to design and manufacture the industry standard DXA technology and our center purchased one of the first devices, a QDR 1000 built by Hologic in 1986. It was the first DXA in the Southeastern US. We did thousands of clinical and research scans on that warhorse DXA for 9 years. It served us admirably. In 1995, we upgraded to the QDR 4500A, Hologic’s newly introduced research level bone densitometer the utilized fan beam technology and a high-resolution detector array that produced radiograph-like images introduced not long before by Hologic. Since then, we have upgrade several times always within the 4500A DXA series. Our last major upgrade was to the Discovery 4500A table in 2012. In 2017, we upgraded the table’s computer, its operating system to Windows 7, and all the software applications for Discover to Hologic’s latest versions.

DXA Bone Density Testing in Clinical Research Studies
DXA bone density testing is the gold standard for establishing the subject’s bone density at the entry of a clinical trial and to monitor that subject’s response to the test article during the study. The accuracy of the device is the key metric for determining the baseline bone density measurement. High accuracy is of critical importance for any baseline measurement and the Hologic 4500 series provides the high accuracy. Monitoring depends on the precision of the device or how reproducible the measurement is on repeat testing. This is as important as accuracy. All Hologic 4500 series DXA have the same high accuracy and precision that make them suitable for clinical trials because they all use the same fan beam technology coupled with a high resolution detector array. The same basic Hologic software used by the members of the 4500 family process the data captured, process it and in multicenter studies produce reliable results. Of course there are caveats that depreciate the ideal condition. These are known and is why industry depends on a professional coordinating center like Bioclinica or Nordic Bioscience to pre-qualify DXA sites, continually evaluate their output during a trial, and require them to participate in a phantom QA protocol during a trial.

DXA is unique among all the methods that have emerged since the days of single photon absorptiometry of the wrist that used an iodine isotope. The durability of DXA technology is a testament to its value. The data generated can reliably provide a both a diagnosis and fracture risk prognosis for the subject. No other bone imaging technology provides industry, regulatory bodies, or clinicians with actionable data as meaningful, accurate, precise, easily accessible, as safe and at as low cost for the accurate diagnosis of osteoporosis and the precise follow up of people with osteoporosis. There is no technology on the horizon with these attributes or anything resembling them.

Hologic Discovery 4500A DXA Research Densitometer
Hologic Discovery 4500A DXA Research Densitometer

Hologic sales and service is first rate. Our clinical practice and research work keeps our DXA humming. Our unit needs to be up and running every business day of the year and I could not have a better or more reliable partner than Hologic standing behind their equipment and keeping my units operating. There phone support has often been able to provide us with a solution to the issues that do show up from time to time. When a service technician needs to come out, they arrive timely and are often able to repair the problem at that visit. If they do not have the part on hand, they overnight it from Boston and complete the repair the next day and we as scanning patients again the next business day. That is typical of the service Hologic has provided me for the past 31 years.

The text below and the images are from the website and is Hologic’s description of the densitometer family we have here, the Discovery DXA. Our model is the top of the line 4500A within the Discovery family and has all the features mentioned in the Hologic description plus several others. As you might imagine, the Discovery 4500A represents a highly evolved mature technology that is the definition of stable. Being a technology leader in Women’s Health and radiology Hologic adds applicable enhancements to the soft and hardware to the 4500 DXA family members. In this way Hologic keeps renewing its leadership in the densitometry field and ensuring those of us that depend on them that we too are offering our patients and sponsors the very best quality DXA technology available.

The Discovery DXA system features bone densitometry technology that allows clinicians to assess bone health in patients who may be at risk.

Discovery delivers:

  • High-resolution digital detector array, which improves fracture detection visualization of abdominal aortic calcifications.1
  • Speed and image quality, with images of the hip and spine captured in as fast as 10 seconds
  • Superb visualization, an exclusive Hologic design that utilizes a high-resolution detector array paired with true fan-beam linear acquisition geometry.1
  • Continuous automatic calibration, ensuring precise and consistent measurements results from exam to exam.

Hologic Discovery 4500A DXA Research Densitometer

The Discovery DXA system offers exceptional precision and accuracy to help you identify patients with osteoporosis and/or who are at risk for fractures.

Features of the Discovery DXA system include:

  • High Definition Instant Vertebral Fracture Assessment (IVA-HD) The IVA-HD tool dramatically improves the detection of vertebral fractures by doubling the resolution of previously available techniques with a low-dose, single-energy image.  Vertebral fracture status, combined with traditional bone density testing, is the gold standard for fracture risk assessment.2
  • Abdominal aortic calcification The IVA-HD tool also allows you to visualize calcified plaques in the abdominal aorta, which may be a significant indicator of heart disease and stroke.3-5 Exclusive to Hologic, this feature provides vital information that may link to coronary heart disease (CHD), which is the leading cause of death for women. In fact, nearly 39 percent of all female deaths in the U.S. are due to CHD.6
  • Advanced Body Composition Assessment and InnerCore Visceral Fat Assessment The Advanced Body Composition assessment feature produces color images displaying the distribution of fat, lean mass, bone and fat mass index. The information is translated into an easy-to-interpret report for improved patient management and counseling. Our DXA systems incorporate the National Health and Nutrition Examination Survey (NHANES) whole body composition reference data.  The Endocrine Society recommends annual bone mineral density and body composition exams for bariatric surgery patients.7
  • FRAX* 10-year Fracture Risk Assessment The FRAX fracture risk assessment tool calculates a patient’s 10-year probability of hip and other osteoporotic fractures.  FRAX was developed by the World Health Organization (WHO) to help healthcare providers identify and proactively treat patients with a high risk of debilitating bone fractures due to low bone mass and other significant risk factors. *FRAX is a trademark of the World Health Organization Collaborating Centre for Metabolic Bone Diseases, located at the University Of Sheffield Medical School, UK.
  • Reporting Solutions Whether you are entering patient data or interpreting patient results, Hologic offers comprehensive tools to streamline bone densitometry workflow to improve your practice’s efficiency, giving you more time to spend with patients. Physicians Report Writer DX is a comprehensive tool that combines the patient’s information, BMD, IVA-HD, and FRAX data into an automated electronic report.
  • UR TECHNOLOGY Our Discovery DXA system offers some of the latest innovations in bone densitometry technology, including:
    OnePass single-sweep scanning, which delivers superb image quality8 and precision.9 Our exclusive design utilizes a multi-element digital detector array paired with true fan-beam acquisition geometry, enabling rapid, dual-energy bone density measurements. OnePass scanning is designed to eliminate beam overlap errors and image distortion found in rectilinear acquisition techniques, resulting in superb image quality and data stability.


1. Lawrence Jankowski et al. Quantifying Image Quality of DXA Scanners Performing Vertebral Fracture Assessment Using Radiographic Phantoms. 2006.
2.  National Osteoporosis Foundation (NOF): Clinician’s Guide to Prevention and Treatment of Osteoporosis. January 2010.
3. Wilson PWF, Kauppila LI, O’Donnell CJ, et al. Abdominal aortic calcific deposits are an important predictor of vascular morbidity and mortality. Circulation. 2001;103(11):1529-34.
4. Hollander M, Hak AE, Koudstaal PJ, et al. Comparison between measures of atherosclerosis and risk of stroke: the Rotterdam Study. Stroke. 2003;34(10):2367-2372.
5. van der Meer IM, Bots ML, Hofman A, del Sol AI, van der Kuip DAM, Witteman JCM. Predictive value of noninvasive measures of atherosclerosis for incident myocardial infarction: the Rotterdam Study. Circulation. 2004;109(9):1089-1094.
6. World Health Organization (WHO). Women’s Health. Fact Sheet  N°334. September 2013.
7. Endocrine and Nutritional Management of the Post-Bariatric Surgery Patient: An Endocrine Society Clinical Practice Guideline.
8. Jankowski, L et al. Quantifying Image Quality of DXA Scanners Performing Vertebral Fracture Assessment Using Radiographic Phantoms. 2006.
9. Hangartner, TN. A study of long-term precision of dual energy X ray absorptiometry bone
densitometers and implications for the validity of the least-significant-change calculation. Osteoporosis Int. 2007;18:513-523. DOI 10.107/s00198-006-0280.