A semi-automated method using interpolation and optimisation for the 3D reconstruction of the spine from bi-planar radiography: a precision and accuracy study.
The 3D reconstruction of the spine in upright posture can be obtained by bi-planar radiographic methods, developed since the 1970s. The principle is to identify 4-25 anatomical landmarks per vertebrae and per images. This identification time is hardly manageable in clinical practice. A semi-automated method is used: 3D standard vertebral models are positioned along with a 3D curve (identified all the way through the vertebral bodies). The silhouettes of the models of C7 and L5 vertebrae are first adjusted and the positions of the other vertebrae are interpolated and optimised. The inter- and intra-operator variabilities and the errors between the semi-automated method and the manual identification of six anatomical landmarks per vertebra are evaluated on 20 pairs of X-ray images of subjects with different spinal deformities. The identification time for the semi-automated method is 5 min. For scolitic subjects, the precision is under 2.2 degrees and the accuracy is under 3.2 degrees for all lateral, sagittal and axial rotations.
Dumas
Raphaël
R
Laboratoire de Biomécanique et Mécanique des Chocs, UMR_T 9406, Université de Lyon, Université Lyon 1/INRETS, Villeurbanne, France. raphael.dumas@univ-lyon1.fr
Blanchard
Bertrand
B
Carlier
Robert
R
de Loubresse
Christian Garreau
CG
Le Huec
Jean-Charles
JC
Marty
Catherine
C
Moinard
Maryse
M
Vital
Jean-Marc
JM
D000328:Adult; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008875:Middle Aged; D015588:Observer Variation; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000473:pathology; D013131:Spine / Q000000981:diagnostic imaging*