Mobile Bone Densitometry

Rural communities comprise approximately 30% of South Australia's population, but have limited access to advanced diagnostic services such as bone densitometry.

To address this, a mobile DXA service was established to provide bone densitometry with the same cost structures as we use at our Adelaide site. This service initially used corporate sponsorship, but has since been made independent thanks to the contribution of the Royal Adelaide Hospital Auxiliary.

We gratefully acknowledge the generous support of:

• The South Australian Country Women's Association(Inc)
• Soroptimist International

These organisation have worked to raise funds for the continued provision of the service in rural South Australia.

In providing the service, technical, logistic & educational issues have arisen.

Where have we been ?

The service has operated since November 1994, and in this time has seen over 9000 patients, travelling more than 25,000km, including interstate operation. Local communities have used the service to capacity, with some sites requesting extensions or booking the service in advance for the following year.

Where are we going ? (subject to change)

The mobile service program attempts to cover most of South Australia's major population regions, with repeat visits to each region within 12 months.

Request a PDF copy of the lastest Mobile Bone Density Service timetable by email (please note - this is not an automated delivery)

Equipment

The service uses a GE-LUNAR DPX-Pro dual energy X-ray densitometer housed in a custom built 6.5 x 2.4m dual axle, airconditioned caravan, with a total weight of 2.7 tonnes. The caravan is towed to each location by a tow truck.

The caravan provides adequate areas for patient scanning, equipment/consumable storage, operator console & workspace, and patient waiting areas.

Technical issues

• Minimising vibration & motion during travel
  The densitometer is mounted to the floor and subchassis with spring loaded brackets and a mobile frame (provided by the manufacturer) & the normal shipping mounting holes of the densitometer chassis.
  The scan arm is parked over the axles & locking pins are use to stop movement during travel. Additionally, the arm is braced against the wall & the table.
  The caravan suspension is designed to evenly distribute the load over both axles therefore minimising vibration during towing.
• Minimising vibration during scanning
  When parked, the caravan is stabilised with support stands in each corner of the chassis and levelled to within 1° in the longitudinal & lateral planes. The wheels remain in contact with the ground for additional stability.
• Stable & clean electrically clean power supply
  The airconditioner draws up to 12.5A on compressor start up. To avoid power spikes, seperate circuits are used for the airconditioner & electronic systems.
  The computer and scanner are attached to an un-interruptable power supply, which also filters the power. In the event of a power failure, operators have up to 7 minutes to complete their scan and shut down the computer system and scanner.
• Controlled environment
  Outside air temperatures can range from 0° to 45°C. The caravan is sealed & insulated, but in an enclosed environment, temperatures may rise to more than 60°C. A thermostatically controlled, ducted inverter type airconditioner was installed in June 2005 to replace the older units. This device has a heating capaciy of 6.25 kW [17200 BTU/hour] and a cooling capacity of 5.2kW [21300BTU/hour] and helps maintain temperatures at approximately 22°C (± 2°C) when not travelling.
• System operation
  The operator console is a standard Windows XP personal computer. The software includes:
  • the GE-LUNAR densitometry software (the same as that on our RAH campus systems)
  • Report generation using our standard in-house developed reports
  • Applications for data maintenance, including data export to the RAH (via USB drive)
  • Copies of the RAH databases - and software for data extraction - to allow comparisons to be made to RAH performed scans
• Reliable scanner performance
  On arrival and setup of the densitometer at each site, scanner performance is checked with system software, and any deviation reported for action.
  Daily QC is performed on a standard calibration phantom and a spine phantom is used to monitor system stability.

Logistic Issues

• Legislative
  South Australian legislation requires all patients who are irradiated for medical purposes to be referred by a physician. This has been simplified by producing referral pads which list conditions which may lead to osteoporosis.
  The operators also record patient patient details for billing purposes on the back of the referral form.
  Except for a narrow range of indications, bone densitometry costs to the patient are not re-imbursed in Australia.
• Site selection
  Sites are chosen on the basis of region coverage. Patients in rural communities will often travel 50-100km for most services. Visits are arranged to allow access in each region for 6-8 weeks, with 2-3 towns per region as the focii for the visit. This allows the maximum number of patients to be seen.
  On annual return visits to a region, different towns will generally be chosen.
• Staffing & staff support
  The service is operated by a one licensed technologist, who must travel to the site and operate independently. Off site support for the operator is provided in the department by a project officer and the bone densitometry section.
  On site, the local community health service assists in bookings, promotion and basic clerical support.
• Reporting
  All scans performed by the department are verified by a staff physician, but distance from the department makes this difficult with the mobile service.
  To simplify the task :
  • the operator generates reports using our standard reporting software
  • reports are sent to the department via courier
  • reports are checked, billing category determined, and the report is posted to the referring physician.

  Typical return times, even from the furthest sites (up to 800km away) is 3 to 4 days. The proprietary software used with this scanner currently precludes electronic transmission of data.

Educational issues

• Health professionals
  The department has produced an information booklet which covers bone densitometry methods, interpretation, typical report outputs, and management of osteoporosis. Each physician in the region being visited is notified of the visit dates and provided with an education booklet & referral pad.
  The department is actively involved in education of health professionals, and also provided lectures upon request.
• Community
  The community health service in each region is provided with the same information as the local physicians. In addition, they are given
  • a press release
  • site requirements
  • a list of other sites visited in the region
  • information leaflets for patients

  Bone densitometry section staff also provide community seminars on request to explain the procedures and the significance of osteoporosis

Conclusion

The high acceptance and use of the service by both local communities and physicians suggest that a high quality, reliable bone densitometry service may be provided to rural communities at an acceptable cost.