The effect of micro-CT rotating step on reconstructed image and data of bovini lumbar cancellous bone

English Keywords:Micro-CT  Rotating step  Three-dimensional reconstructive image  Bone morphometry  Bovini

English Abstract:

  【Abstract】 Objectives: To explore the effects of rotation steps on the scanning time, disc occupation and the image reconstruction of micro computed tomography(micro-CT) under the same scanning distinguishability and to investigate the extent of this effect on the data of bone morphometry after image reconstruction. Methods: 8 fresh isolated lumbar cancellous bones from bovini with the same size were selected, the rotation steps of 0.25°, 0.30°, 0.40°, 0.50°, 0.75°, 1.0°, 1.5°, 2.0° were chosen under the same scanning distinguishability, 0.25° was used as reference control and compared with the other rotation steps with respect to 3D images of bone trabecula, scanning time and disc occupation, statistical analysis on bone morphology. The parameter data included: bone volume(BV), bone surface(BS), trabecular thickness(plate model)[Tb.Th(pl)], trabecular separation(plate model)[Tb.Sp(pl)], trabecular number(plate model) [Tb.N(pl)], trabecular diameter(rod model)[Tb.Dm(rd)], trabecular separation(rod model)[Tb.Sp(rd)], trabecular number(rod model)[Tb.N(rd)], trabecular bone pattern factor(TBPf). Results: Rotation step of 0.25° was the control group. (1)The image quality was decreased from 0.30° to 1.5°, but the structure of trabecula was still well captured, and the characters of cancellous bone were also clearly observed. When the rotation step increased to 2.0°, the structure of the trabecula could not be clearly captured. (2)With the increasing of rotating steps, scanning time and disc occupation showed linear decline. (3)The data of bone morphometry indicated as following: no significant differences were noted between 0.30° and 0.25°(P>0.05), or between 0.40° and 0.25°(P>0.05); but for all results: significant difference was found for BV from 2.0°(P<0.05), for Tb.Sp(rd) and TBPf from 0.50°(P<0.05), and for BS, BS/BV, Tb.Th(pl), Tb.Sp(pl), Tb.N(pl), Tb.Dm(rd) and Tb.N(rd) from 0.75°(P<0.05). Conclusions: Rotation steps of 0.4° can be applied for accurate analysis of three-dimensional data of bone morphometry due to its clear reconstruction image, accurate data, less time of sample scanning and less of disc occupation; rotation steps of 1.5° can be used for fast observation of bone trabecular imaging due to its less time of scanning and less disc occupation despite of the data error; while rotation steps of 2.0° is not recommended due to its indistinct and error image.