Modulation transfer function evaluation of cone beam computed and microcomputed tomography by using slanted edge phantom

Abstract

Modulation transfer function (MTF) is a well known and widely accepted method for evaluating the spatial resolution of a digital radiographic imaging system. In the present study our aim was to evaluate the MTF obtained from CBCT and micro-CT images. A cylinder shaped phantom designed for slanted-edge method was scanned by a CBCT device at a 100 µm isometric voxel size and by a micro-CT device at a 20 µm isometric voxel size, simultaneously. The MTF curves were calculated and the mean spatial resolutions at 10% MTF were 3.33 + 0.29 lp/mm in the case of CBCT images and 13.35 + 2.47 lp/mm in the case of micro-CT images. The values showed a strong positive correlation regarding the CBCT and the micro-CT spatial resolution values, respectively. Our results suggests that CBCT imaging devices with a voxel size of 100 µm or below might aid the validation of fine anatomical structures and allowing the opportunity for reliable micromorphometric examinations

Comparison between Micro-Computed Tomography and Cone-Beam Computed Tomography in the Assessment of Bone Quality and a Long-Term Volumetric Study of the Augmented Sinus Grafted with an Albumin Impregnated Allograft

“…Results of the present study regarding parameters of trabecular microarchitecture were controversial because Tb.Sp showed positive (R = 0.613) and Tb.Th, on the contrary, negative (R = −0.550) correlation between micro-CT and CBCT obtained data (p < 0.05). As a possible explanation, if the same object is scanned by a micro-CT and a CBCT device, the object is expected to be depicted in an extended volume on the CBCT dataset compared to the micro-CT image sequences, most probably as a consequence of the partial volume effect [49]. When a voxel contains tissues of different radiodensity, then the resulting CT value represents the average of their properties [29].…”

“…In our study, the CBCT voxel size was 250 µm, which is commensurable with the size of the trabecules. Hence, high-resolution CBCT with a voxel size of 100 µm or below might be beneficial for the assessment of trabecular bone microarchitecture prior to implant placement [49].…”