ABSTRACT
PURPOSE: To compare the orbital volume calculated from various slice thickness facial computed tomography scans using a semi-automated computer program. METHODS: Axial and coronal scans of 2, 2.5, 3 mm slice thickness facial computed tomography scans were used to measure the orbital volume. The cross-sectional area was determined from each slice using a semi-automated computer program (MATLAB 2009a®, MathWorks, Inc., Natick, MA, USA), and then the volume was calculated from serial reconstruction of the cross sections. RESULTS: The measured value in the 2 mm images was 33.14 ± 2.37 cm³ in the right orbit and 34.32 ± 2.60 cm³ in the left orbit for the axial scans, and 35.54 ± 3.58 cm³ in the right orbit and 34.96 ± 4.05 cm³ in the left orbit for the coronal scans. In the 2.5 mm images, the values were 33.28 ± 3.35 cm³ in the right orbit and 33.73 ± 4.10 cm³ in the left orbit for the axial scans, and 35.24 ± 3.98 cm³ in the right orbit and 35.10 ± 3.93 cm³ in the left orbit for the coronal scans. In the 3 mm images, the values were 33.23 ± 2.70 cm³ in the right orbit and 33.39 ± 2.69 cm³ in the left orbit for the axial scans, and 33.20 ± 3.64 cm³ in the right orbit and 32.95 ± 3.45 cm³ in the left orbit for the coronal scans. In the 3 mm image, there was not a significant difference in the calculated volume between the axial and coronal scans (p(3mm) = 0.62). CONCLUSIONS: Because there is no difference in the results of the orbital volumetric measurements between three other slice thicknesses in the axial scan, using axial scan images with a computer program that semi-automatically calculates orbital volume is useful. In addition, the volume measured by thick slice images has more reproducibility than the volume measured by thin slice images.
Subject(s)
OrbitABSTRACT
PURPOSE: To measure the orbital volume from facial CT scans using a semi-automatic computer program. METHODS: Axial and coronal slices of 35 facial CT scans were used to measure the orbital volume. The cross-sectional area was determined from each slice using a semi-automated computer program (MATLAB 2009a). Next, the orbital volume was calculated from serial reconstruction of the cross-sections. RESULTS: The measured value in males was 26.34 +/- 3.09 cm3 in the right orbit and 26.30 +/- 3.21 cm3 in the left orbit from axial scans, and 26.58 +/- 2.76 cm3 in the right orbit and 26.59 +/- 2.75 cm3 in the left orbit from coronal scans. In females, the values were 23.84 +/- 2.29 cm3 in the right orbit and 23.89 +/- 2.33 cm3 in the left orbit from axial scans, and 24.06 +/- 2.90 cm3 in the right orbit and 24.10 +/- 2.82 cm3 in the left orbit from coronal scans. There was high positive correlation (r = +0.832, p = 0.0001) in measured orbital volume between axial and coronal scans. CONCLUSIONS: The orbital volume measurement from facial CT scans using a semi-automatic computer program is very useful. This method should prove useful in further studies examining the correlation of orbital volume variation in many ophthalmologic disorders.
Subject(s)
Female , Humans , Male , Orbit , Tomography, X-Ray ComputedABSTRACT
PURPOSE : The purpose of this study was to develop the radiographic technique for detecting the demineralization which is known as indication of dental caries MATERIALS AND METHODS : This technique was based on the comparing of multiple radiographs which was irradiated by multiple X-ray spectra. For the meaningful comparing, the multiple radiographs were reconstructed to the dosimetrically consistent images using a standard material. The difference of resulting images of same target with multiple spectra represents the difference of response of material as regards the spectra. RESULTS : We have found about 10% of demineralization of dental hard tissues particularly in the proximal region through the analyzing of differences. CONCLUSION : Most intriguing thing in this investigation was that the method to analyze difference shows us to an anatomic structure of dental hard tissues even if absolute values of optical density were excluded during the procedures.