Accuracy of densitometry of two cone beam computed tomography equipment in comparison with computed tomography

Abstract

BackgroundThe use of oral implants has been growing, and cone beam computerized tomography (CBCT) has become the method of choice for oral and maxillofacial radiology.ObjectiveTo assess the accuracy of bone densitometry in two different CBCT devices in comparison with MDCT (multi-detector CT).MethodsDifferent concentrations of urografin, including 2.5%, 5%, 7.5%, 10%, 12.5%, were prepared, and the Hounsfield unit of these solution was measured by two CBCT devices (SORDEX CRANEX 3D and NEWTOM 5G) and one spiral CT device (SOMATOM SENSATION). Difference of output Hounsfield units in each concentration was compared in three devices. Correlation of devices with increase of urografin dose also was evaluated. Statistical analyses of the data were performed using SPSS18 and Kruskal–Wallis and Mann–Whitney U tests, along with Spearman’s correlation coefficient.ResultsThe range of gray density for NEWTOM 5G CBCT, SORDEX 3D CBCT, and SOMATOM CT imaging systems was from 781 to 2311, 427 to 1464, and 222 to 994, respectively. There was significant difference between devices in the Hounsfield unit in all urografin concentrations (p<0.001). Also there was a significant correlation between three devices with increasing the urografin dose (p<0.05; r>0.95)ConclusionOur findings indicated a high correlation and linear relationship between different studied imaging systems. Although utilizing CBCT in the assessment of bone density is useful according to its lower emitted dose and less cost, clinicians should be aware of the issue that the voxel value in CBCT is not as perfect as CT.

Facial alveolar bone alterations and gray value changes based on cone beam computed tomography around maxillary anterior implants: A clinical retrospective study of 1–3 years

“…The bone quality, mainly manifested by the bone mineral density (BMD), can be assessed in CT scans by measurements the number of Hounsfield units (HU), and there is a linear relationship between gray scales between the GV in CBCT and the HU in CT (Razi, Niknami, & Alavi Ghazani, ; Valiyaparambil et al, ). It is worth mentioning that the intensity of the GV in a CBCT imaging system could be affected by scatter radiation (Cassetta, Stefanelli, Carlo, Pompa, & Barbato, ; Haghanifar et al, ; Kim, ). Several technique parameters could affect scatter radiation, including the FOV, voltage, exposure time, electron flow, and the resolution (Naitoh, Hirukawa, Katsumata, & Ariji, ).…”

The Use of Biphasic Calcium Phosphate Substitute (BCP) in Mandibular Defects in Dogs: Use of CBCT to Evaluate Bone Healing

“…A recent study compared density measurements from 2 CBCT units (including the CBCT used in our case) and a standard spiral CT, using Urografin ® . 3 There was good correlation between measured density values and iodine concentration, with a linear relationship, for all 3 devices, although there was a significant difference in measurements between the 3 systems for the same iodine concentration. There was also a wider standard deviation in CBCT-derived values when compared with conventional medical grade CT.…”

“…The CBCT slopes of the attenuation plots from the CBCT used in this study were nearly linear compared to the other CBCT tested and it appears that linearity between this CBCT and MDCT plots remain stable with increasing density of the imaged material. 3 In another study evaluating bone density of human mandibles, there was also a good linear correlation between values obtained with the 2 technologies, although the measured densities were always greater with CBCT than with conventional CT. 15 CBCT may appear to be adequate to monitor density variations of mineralized structures with time, even though the values may not be as accurate as with conventional CT. However comparison of gray scale values of CBCT and CT in an in vitro study on dried mandible didn’t reach the same conclusion and stated that determination of gray values in CBCT may not be as accurate as HU value in CT for hyperdense structures.…”

“…1,2 Recent studies have shown that gray scale values derived from CBCT examination demonstrate good correlation with bone density measurements obtained with standard computed tomography. 3 Such measurements obtained from the mandible have provided promising radiomorphometric indices for the detection of osteoporosis in humans. 4 However the reliability of the intensity value of CBCT has been disputed by others.…”

Biphasic Calcium Phosphate Microparticles Mixed With Autologous Blood: Application for the Reconstruction of a Large Mandibular Bone Defect in a Dog

“…The use of density values calculated from CBCT scans has been previously validated as a reliable assessment of bone density, although the actual values may not be the same as those obtained through computed tomography, because of differences in the measurement technology. 37…”