When selecting a bone density there are only two choices to choose from GE or Hologic. From each of these manufacturers there are a number of different models and some confusion as to which one is right for you.
Hologic has been a leader in the industry since the early 90’s with the introduction of the QDR 1000 series (pencil) beam followed by the QDR 4000.
When Hologic introduced the Hologic QDR 4500 it was state of the art fan beam technology. With this new platform a series of new models were introduced and also some confusion.
Models- C, A, SL, W
What do these letters mean? Isn’t one the same as the next? How do you know how to tell the difference between the 4 options?
Platforms – QDR 4500, Delphi, Explorer, Discovery
Hologic upgraded their basic QDR 4500 platform to introduce the Delphi, then upgraded the Delphi to introduce the Explorer and then the Discovery. Essentially all of the Hologic system platforms are built on the same basic QDR 4500 platform.
For each of the platforms Hologic kept the basic 4 model options as they upgrade their QDR 4500 platform to a Delphi, Explorer and Discovery.
Simple explanation of the models:
C – Compact system
SL- Supine Lateral feature added. C rotates around the patient.
W – Whole body feature added.
A- Research system with all features.
*Note – the vast majority of Hologic systems sold in the US market were of the C models.
How do you choose between platforms and models?
Cost is always a factor in selecting the right bone density system for the practice. However, there is much more that needs to be considered when selecting the right system.
Spine and Femur
Most sites in the US have focused on doing the basic routine Spine and Femur studies. This is great for an entry level option to give patients a very basic report on their bone health. All systems will offer Spine and Femur, whereas the QDR 4500 will only give the basic criteria for bone health – Spine and Femur.
Fracture Risk Assessment
Fracture risk is an important aspect of bone density testing. This feature became available on the Delphi as standard feature as well as the Discovery. This feature is referred to as IVA.
This has been a feature that is now critical at every site to send reports to a PACS, EMR or EHR. This feature is only available on systems running Windows XP or above. Delphi and Discovery platforms run on Windows XP and above. The Hologic QDR 4500 was originally built on Windows 98 software, however, a good profession refurb company can upgrade the QDR 4500 to Windows XP.
It should first be noted that the vast majority of systems that were sold in the US for all platforms QDR 4500, Delphi, Explorer and Discovery were C (or compact) there were very few W systems sold. What this means for todays refurbished market is that in order to get a system with Whole Body feature – it is better to get a Lunar Prodigy. The vast majority of Lunar Prodigy systems that were sold were 8 foot tables with Total Body as a standard feature.
In order to get a Hologic system with WHole Body a W model will need to be found. This is not always easy as they are not always available.
This feature was only offered on system model SL. The SL meaning Supine Lateral and the bone density arm rotates around the patient for lateral view.
QDR 4500 average scan time is 60 seconds
Delphi average scan time is 30 seconds
Discovery average scan time 10 seconds
Buying a Hologic
When buying a Hologic it is important to note the features that are needed. For most sites the most important features are going to be AP Spine, Femur, IVA, DICOM. These are the gold standard features for osteoporosis testing. So the C model will work perfectly fine in majority of facilities.