Frequently Asked Questions (FAQs)

Who can order the VirtuOst test?
As an FDA-registered Class-II medical device, the VirtuOst test must be ordered by a physician or healthcare provider. For more information, refer to Order VirtuOst.

How can I get the VirtuOst test?
You can order VirtuOst directly from the O.N. Diagnostics Medicare-enrolled IDTF, or, from select healthcare providers (hospitals, imaging facilities) who partner with O.N. Diagnostics.

What format is needed for the CT scans?
Standard DICOM formatted scans, not de-identified or altered.

How should the CT scans be sent to O.N. Diagnostics?
Scans from IDTF orders can be mailed to our office. Scans from partnering facilities can be sent electronically. Our staff will work with partners to customize a protocol. O.N. Diagnostics is HIPAA-compliant and meets all state and federal regulations for handling of PHI (Protected Health Information). For more information, see Data Transfer.

What is the format of the results?
The VirtuOst Results report can be returned via fax or secure email in PDF format, or directly to PACS. For PACS, other formats are DICOM encapsulated PDF, DICOM structured report, and DICOM secondary capture image.

What types of CT scan can be analyzed?
Most pelvic, abdomen, spine, and chest scans, and even whole-body scans, can be analyzed. An external calibration phantom is not required.

For Hip BCT, the scan needs to include one femur from just below the lesser trochanter to just above the top of the femoral head. Slice thickness of the scan must be 5.0 mm or less.

For Spine BCT, the scan needs to include one complete lumbar or thoracic vertebral body (T1–L5). Diagnostic classifications are provided only between T12–L3, but measurements can be provided for any level. The scan cannot have intravenous contrast and slice thickness must be 3.0 mm or less.

For VFA, any vertebra between T4–L4 is analyzed. Slice thickness of the scan must be 3.0 mm or less. For more information, see Scans Suitable for VirtuOst.

What types of scan cannot be analyzed?
Scans cannot be analyzed if metal implants reside at the same transverse cross-section as the bone to be analyzed, or if the scan does not cover the proximal femur or a complete vertebral body. Streaking artifacts or poor image quality can disqualify an analysis. If you send us a scan that we cannot analyze, you will not be charged.

What if I want to order a dedicated CT scan specifically for the VirtuOst test?
There are various scan acquisition options to consider for a dedicated scan. Please contact O.N. Diagnostics for more information.

Can scans with intravenous contrast be analyzed?
For CT scans that are enhanced with intravenous (IV) contrast, the measurements of BMD and bone strength can over-estimate the true values because the radio-opaque contrast agent can permeate the bone, making it appear denser and stronger than it actually is. This effect is typically negligible for the hip but for the spine it can be appreciable and highly variable, depending on the CT machine, IV contrast agent, and scan protocols. Therefore, for images enhanced with IV contrast, BCT is only performed at the hip. VFA can be performed with IV contrast since the morphology of the vertebrae is not affected by the contrast agent.

What scan settings should be used?
The VirtuOst test is quite robust so most typical current clinical settings will work. Preferred settings include 120 kVp, standard or equivalent kernel, ≤3 mm slice interval. For more information, see Scans Suitable for VirtuOst.

Can the VirtuOst test be used to monitor treatments?
Yes, VirtuOst has outstanding repeatability precision. However, as with any clinical densitometry, good monitoring precision requires the same machine and imaging protocol to be used at both time points.

What if I have trouble sending the scans or receiving the results?
Please don't hesitate to contact us. We are available Mon.-Fri. 8:30am-6pm PST.

If you are interested in the VirtuOst test for your institution, please contact O.N. Diagnostics using our Contact Us page.