The use of flat panel volumetric computed tomography (fpVCT) in osteoporosis research.
OBJECTIVE
Improvements in imaging technology have led to the increased use of computed tomography (CT). For example, micro-CT and quantitative CT (QCT) are now often used in osteoporosis research, in which micro-CT is able to analyze small bones or bone samples with high spatial resolution. In contrast, QCT is able to investigate large samples with low spatial resolution. The aim of this study was to test the usefulness of flat-panel volumetric CT (fpVCT) in a rat model of osteopenia.


METHODS
Twenty-two 3-month-old rats underwent ovariectomy and were either left untreated or supplemented with estradiol for 15 weeks. After sacrificing, the rats' second lumbar vertebral body bone mineral density (BMD) was analyzed using fpVCT and ashing. The results were compared to those of a microstructural analysis of the first lumbar vertebrae and a biomechanical evaluation of the fourth lumbar vertebrae.


RESULTS
BMD measurements using both fpVCT (0.39 vs 0.35 mg/cm(3)) and ashing (0.52 vs 0.48 mg/cm(3)) demonstrated a significant improvement after estradiol supplementation. The correlation coefficient of the two methods was 0.858. After estradiol supplementation, the bone microstructural and bone biomechanical parameters were improved, compared to no treatment. The correlations of both the microstructural and the biomechanical evaluations were closer for BMD measured using fpVCT (r = 0.482-0.769) than on the basis of ashing (r = 0.345-0.573). FpVCT was not able to display the trabecular microstructure of the rat lumbar vertebrae.


CONCLUSIONS
The use of fpVCT demonstrated a close relationship between morphologic and biomechanical evaluations in a rat model of osteopenia. Because of its different proportions, fpVCT might be able to bridge the gap between micro-CT and QCT in analyzing larger animals.
Sehmisch
Stephan
S
University of Goettingen, Robert-Koch-Strasse 40, 37075 Goettingen, Germany. stephan.sehmisch@med.uni-goettingen.de
Dullin
Christian
C
Zaroban
Artur
A
Tezval
Mohammad
M
Rack
Thomas
T
Schmelz
Ullrich
U
Seidlova-Wuttke
Dana
D
Dunkelberg
Hartmut
H
Wuttke
Wolfgang
W
Marten
Katharina
K
Stuermer
Klaus-Michael
KM
Stuermer
Ewa Klara
EK
D015502:Absorptiometry, Photon / Q000295:instrumentation / Q000379:methods; D000818:Animals; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*; D014963:X-Ray Intensifying Screens