Category: Morphometric Measurements: (Body Composition, Vertebral Fracture Recognition, Hip Geometry)

27 - Validation of In Vivo Vertebral Fracture Assessment using the Norland Illuminatus Software.

Background: A semiquantitative evaluation of the T9-L4 vertebral column by DXA evaluation of vertebral fracture has been proposed, alongside traditional DXA, as a complimentary reflector of osteoporotic risk that may be useful in bringing some subjects to treatment. The current study seeks to document the performance of the Norland Vertebral Fracture Assessment Module by comparison to a radiographically determined vertebral fracture assessment and by assessing repeatability of the DXA assessed vertebral fracture assessment.

Studies of the T-9 to L4 segment of the spine were obtained for DXA-based assessment on the Norland XR-800 using the Norland Vertebral Fracture Assessment Software Module and by x-ray based assessment on the GE Discovery XR656 Digital Radiography System. Repeatability of the DXA-based assessments was evaluated by assessing repeatability on duplicate studies on six subject to determine an estimated coefficient of variation. The relationship between radiographically and DXA assessed posterior, mid and anterior vertebral body heights was determined from assessments made on fifty vertebral bodies (T-9 to L4) taken on ten subjects. The consistency between these measurements was assessed by regression analysis both for the total sampling and for the posterior, mid and anterior measurement sites.

Examination of duplicate scans showed repeatability of vertebral body heights was 4.8% with posterior, mid and anterior showing repeatability of 4.4%, 5.4% and 4.6%, respectively. Significant positive relationships were found between DXA-based or radiograpically assessed measurements in the 150 measurements (Y = 0.4901X + 12.03; r = 0.4879; p < 0.0001) and the 50 posterior (Y = 0.5281X + 11.43; r = 0.4717, p < 0.0005), 50 mid (Y = 0.4957 + 12.12; r = 0.6198; p < 0.0003) or 50 anterior (Y = 0.4904X + 11.48; r = 0.4971; p < 0.0002) vertebral body heights examined by regression.

In conclusion, when compared to the traditional radiographic vertebral fracture assessment the DXA-based Vertebral Fracture Assessment Module is repeatable and reflective of vertebral morphometry and can be applied when identifying the presence of a mild, moderate or severe wedge, biconcave or crush vertebral fracture.

Tom V. Sanchez

Chief Science Officer
Norland at Swissray
Socorro, New Mexico

Thomas Thuring

Director Design and Development
Swissray Medical AG
Hochdorf, Zug, Switzerland

Jingmei Wang

Director of Densitometry Research
Norland at Swissray
Beijing, Beijing, China (People's Republic)

Yun Sun

Assistant Professor
Hospital of Tsinghua University
Beijing, Beijing, China (People's Republic)