Purpose. Explore the potential value of displaying information collected by stationary intraoral tomosynthesis (sIOT) as multi-view synthetic radiographs, using vertical root fractures (VRFs) as a model system.
Methods. Filled and unfilled extracted tooth roots containing artificially-induced VRFs were imaged by sIOT and standard periapical radiography. sIOT collected 7 views across a 12° angle span, providing information for an image processing chain that included reconstruction, weighting, and forward projection to generate a set a synthetic two-dimensional (2D) images. Qualitative assessments of fracture conspicuity were used for comparison.
Results. The conspicuity of VRFs changed significantly with the angle of imaging, suggesting benefit to displaying a set of synthetic images across a span of viewing angles. Although high-density in-plane and out-of-plane artifacts, which could limit the conspicuity of VRFs, were prominent in the three-dimensional (3D) stack of reconstructed image slices, these artifacts were minimal in the synthetic radiographs. As such, some fractures were displayed more clearly in the synthetic 2D images compared to the reconstructed 3D image stack. Also, in some cases, the fractures were more conspicuous in the sIOT-generated synthetic images than the standard periapical radiographs.
Conclusion. Multi-view synthetic radiography can improve the display of VRFs in images generated by sIOT. As such, this approach to dental imaging may offer a useful clinical tool, with potential application to a host of imaging tasks.
Despite recent advances in dental radiography, the diagnostic accuracies for some of the most common dental diseases have not improved significantly, and in some cases remain low. Intraoral x-ray is the most commonly used x-ray diagnostic tool in dental clinics. It however suffers from the typical limitations of a 2D imaging modality including structure overlap. Cone-beam computed tomography (CBCT) uses high radiation dose and suffers from image artifacts and relatively low resolution. The purpose of this study is to investigate the feasibility of developing a stationary intraoral tomosynthesis (s-IOT) using spatially distributed carbon nanotube (CNT) x-ray array technology, and to evaluate its diagnostic accuracy compared to conventional 2D intraoral x-ray. A bench-top s-IOT device was constructed using a linear CNT based X-ray source array and a digital intraoral detector. Image reconstruction was performed using an iterative reconstruction algorithm. Studies were performed to optimize the imaging configuration. For evaluation of s-IOT’s diagnostic accuracy, images of a dental quality assurance phantom, and extracted human tooth specimens were acquired. Results show s-IOT increases the diagnostic sensitivity for caries compared to intraoral x-ray at a comparable dose level.