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Radiologia Brasileira

Print version ISSN 0100-3984

Abstract

SILVEIRA, Luis Felipe et al. Method for correction of distortions in images acquired by videofluoroscopy. Radiol Bras [online]. 2005, vol.38, n.6, pp. 427-430. ISSN 0100-3984.  http://dx.doi.org/10.1590/S0100-39842005000600009.

OBJECTIVE: To implement a protocol for correction of images acquired by videofluoroscopy based on the mathematical model described by Baltzopoulos (1995) and to evaluate the magnitude of error in the linear and non-linear calibration methods. MATERIALS AND METHODS: The images were acquired using a Axion Siemens Iconos R100 videofluoroscope from one individual during knee extension exercise. A non-linear calibration pattern was used for the correction of the images. Data was processed using a Silicon Graphics 320 capture plate and subsequently analyzed using the Matlab software. RESULTS: In order to demonstrate the method's applicability, the deformation of the patellar ligament was evaluated. The use of a linear calibration pattern produced a maximum error of 0.086 mm, while the non-linear calibration pattern reached a maximum value of 0.019 mm. According to the mean error, the linear calibration was 0.024 mm, and the non-linear presented a value of 0.007 mm. CONCLUSION: The results show the need to use a non-linear calibration procedure.

Keywords : Videofluoroscopy; Images calibration; Patellar ligament; Knee.

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