Assessment of vertebral bone mineral density using volumetric quantitative CT.
OBJECTIVE
The purpose of this work was to determine the precision and diagnostic efficacy of bone mineral density (BMD) measures based on volumetric quantitative CT (QCT) of the spine.


METHODS
Volumetric CT scans of L1 and L2 (GE-9800Q; 80 kVp, 140 mAs, 3 mm slices) were acquired in a cohort of 62 osteoporotic women (mean age 70.4 years, T(DXA hip or spine) < -2.5), of whom 20 had vertebral fractures and 42 were nonfractured control subjects. An image analysis technique delineated trabecular, cortical, and integral regions in reference to a vertebra-fixed coordinate system. We computed precision values and fracture control differences for these new regions and for single-slice QCT and dual X-ray absorptiometry (DXA) measures synthesized from the volumetric data.


RESULTS
Volumetric trabecular BMD showed higher precision (1.3%) than the synthesized single-slice measures (2.1-2.8%). Volumetric and single-slice trabecular BMD showed equivalent decrements between fractured and nonfractured subjects (17-19%), with integral BMD showing smaller and less significant differences (7-8%).


CONCLUSIONS
Volumetric and single-slice QCT techniques are equivalent for vertebral fracture risk estimation, but volumetric techniques should be superior for monitoring therapy efficacy.
Department of Radiology, University of California, San Francisco 94143-1250, USA.
T F
TF
Lang
J
J
Li
S T
ST
Harris
H K
HK
Genant
D015502:Absorptiometry, Photon; D000368:Aged; D015519:Bone Density; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D015588:Observer Variation; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000000981:diagnostic imaging*; D016103:Spinal Fractures / Q000150:complications; D014057:Tomography, X-Ray Computed