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.

How can I get the VirtuOst test?
A CT scan is sent to O.N. Diagnostics for analysis and the results are returned within a week. This service model removes capital expenditure, training and personnel costs, and ensures that every analysis is performed expertly to the highest standards of quality.

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?
Electronic transmission. Options vary from drag-and-drop file transfer from a desktop PC — easy to set up, no IT expertise needed — to automated PACS-to-PACS communication. Our staff will work with you to customize a protocol. O.N. Diagnostics is HIPAA-compliant and meets all state and federal regulations for handling of PHI (Protected Health Information).

What is the format of the results summary?
The VirtuOst results summary is provided in PDF or DICOM-encapsulated pdf formats, and is returned either electronically or by fax.

What types of CT scan can be analyzed?
Most typical pelvic, abdomen, spine, and chest scans, and even whole-body scans, can be analyzed. For the hip, the scan needs to include from just below the lesser trochanter to just above the top of the femoral head. For the spine, a single complete vertebral body is needed (diagnostic classifications are provided for any level between L3–T12, but measurements can be provided for any level). A calibration phantom is not required.

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 acqusition 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 contrast, the measurements of BMD and bone strength can over-estimate the true values because the radio-opaque intravenous 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, intravenous contrast material, and scan protocols. Therefore, for images enhanced with intravenous contrast, BCT is only performed at the hip.

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.

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.