| Abstrakt: |
Due to the magnification of X-ray images, calibration is required for recording linear measurements. Clinically, calibration can be performed on a lateral X-ray image, but it is difficult to perform on the PA (posteroanterior) X-ray image due to the unavailability of a calibration scale on cephalometric images. Hence, a novel registration-based method named as RegCal was proposed for the calibration of the PA X-ray image so that linear measurements can be obtained precisely for the diagnosis and treatment planning of patients in clinical practices. The method for the calibration of the PA cephalometric image is based on the lateral image of the same patient. A common distance is identified in both X-ray images, then the PA X-ray image is scaled to the number of pixels in the common distance on the lateral image. Using the scale of the lateral image, calibration was performed which is the same for the already scaled PA image. For the validation purpose, 15 linear measurements and 20 angular measurements were conducted on PA cephalometric image. The maximum and minimum linear measurement errors were found as 0.17 cm and 0 cm on the PA image. The average error on PA image was obtained as 0.06 cm and 0.70 degree for all linear measurements and angular measurements respectively. A calibration method of PA cephalometric image based on the scale of the lateral image was demonstrated which is useful for performing cephalometric analysis for diagnosis and treatment planning. [ABSTRACT FROM AUTHOR] |
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