Purpose:
The aim of this study was to assess the impact of exposure parameters and image
formats on fractal dimension (FD) values in periapical, panoramic, and CBCT images.
Materials and methods:
Seven dry male mandibles were selected, and a Gutta-Percha was used to identify
identical regions of interest. A periapical radiograph was taken with 60 kVp/7 mA
and exported in DICOM, JPEG, TIFF, and PNG formats. Nine periapical radiographs
(60, 65, 70 kVp; 4, 5, 6 mA) were taken from seven dry human mandibles. Additionally,
12 panoramic radiographs (60, 70, 81, 90 kVp; 5, 8, 13 mA) and 10 CBCT images (with
different scanning options and FOVs) were taken from each mandible. FDs were
measured from a standard area.
Results:
The intra-class correlation coefficient demonstrated a high degree of agreement
between observers. No significant difference was found between TIFF and PNG
formats (p > 0.05). The highest FD mean was found in TIFF format, while the lowest
FD mean was found in JPEG format (p<0.001). There was no significant difference
between kVp and mA settings in periapical images. In panoramic images, a
significant difference was found at 90 kVp (p = 0.001) and 13 mA (p<0.001), with
lower FD values observed at these settings. There was no significant difference
between FOV and resolution in CBCT images (p > 0.05).
Conclusion:
The format of the image can influence FD. For periapical and panoramic radiographs,
kVp and mA settings do not have a significant impact on FD. However, fractal
analysis may not be an ideal method for evaluating three-dimensional images, such
as those obtained with CBCT.