[Evaluation of the efficiency of the zero-dose-C-arm navigation approach].
BACKGROUND
The efficiency and success of computer-assisted fluoroscopic navigation systems mainly depend on the quality of the process of image acquisition: obtaining the correct view of anatomic structures, relative orientation of multiplanar X-ray images and the necessary amount of radiation dose. These systems may be optimised by using a system called zero-dose c-arm navigation (ZDCAN). We investigate whether the available computer-assisted systems may be used to navigate the c-arm before image acquisition to obtain X-ray images with maximised accuracy and minimal radiation exposure.


METHODS
Based on position data of an optical tracking system combined with statistical deformable bone models, ZDCAN is able to generate a real-time preview of expected X-ray images of the lower extremities without using radiation. We performed a cadaver study on six full-body specimens comparing the zero-dose approach to conventional positioning of the c-arm in order to evaluate efficiency and accuracy. Eight users acquired two perpendicular X-ray images of the hip, the knee and the femoral diaphysis.


RESULTS
The number of X-ray images required to get a satisfying picture could be reduced to seven using the zero-dose approach; the conventional approach needed 11 images. The mean time did not differ significantly. Regarding the image quality, using ZDCAN quasi-orthogonality could be reached while the conventional approach showed a large variation of the relative orientation.


CONCLUSIONS
Using ZDCAN, the amount of radiation can be reduced by requiring less X-ray images as well as reaching better accuracy.
Barbe
A G
AG
Klinik für Orthopädie und Unfallchirurgie, Uniklinikum RWTH Aachen, Pauwelsstraße 30, Aachen.
de la Fuente
M
M
Belei
P
P
Buschmann
C
C
Radermacher
K
K
Mueller
M
M
Mumme
T
T
D001822:Body Burden; D002102:Cadaver; D006801:Humans; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051598:Whole Body Imaging