Validation of computed tomography protocols for simulated mandibular lesions: a comparison study

Abstract

Computed tomography is the choice technique to assess oral and maxillofacial osseous lesions because it provides hard and soft tissues visualization in one examination without superimposition of surrounding structures. This examination offers a significant advance in maxillofacial lesions detection with an excellent anatomic resolution. The aim of this research was to evaluate the validity of two protocols, in axial sections, in simulated mandibular lesions. Two CT protocols were obtained in dry mandibles in which perforations were done simulating lesions. Two observers, previously calibrated, evaluated the images according to different parameters. The results indicated that the sensitivity and specificity in lesion detection were 100% for both protocols, but the detection of loci number of multilocular lesions and the location and detection of medullar invasion obtained reduced validity values, which were influenced by the acquisition protocol. We concluded that thinner axial slices and reconstructions were more effective in detecting early medullar invasion and loci number. Thicker protocols were not considered appropriate to detect multilocular lesions and early stages of medullar invasion.

Comparison between cone-beam and multislice computed tomography for identification of simulated bone lesions

“…16 Pinsky et al 18 used simulated lesions to test linear measurements in CBCT, but they made 4-8-mm defects, which are larger than those prepared in the present work. In these experiments, water was added to produce an environment closer to bone in vivo.…”

“…8,15 MSCT and CBCT represent an important advance because, using these methods, observers can reconstruct and manipulate high resolution images, thus improving the diagnosis. 15,16 Both modalities of image acquisition have advantages and disadvantages regarding radiation dose, acquisition time, cost, scattered radiation and artifacts. 6,7 Drawbacks should be taken into consideration, since they can influence image quality and interpretation accuracy.…”

“…24 Currently, MPR and cross sectional images associated with tridimensional (3D) reconstruction represent the most useful imaging modalities for diagnoses and surgical planning in the oral and maxillofacial regions. 13,14,16,24 Cross sectional images, extensively used for the planning of dental implants, were obtained from original CT images which were directed perpendicularly to a plane previously outlined, and depicted the anatomy better than straight sagittal planes, justifying the choice of that protocol in our research.…”

Assessment of simulated mandibular condyle bone lesions by cone beam computed tomography

“…Similar satisfactory results have been observed in the present work. 3,[14][15][16] More recently, cone beam computed tomography has been the object of study for TMJ evaluation by various authors who consider it the best recom- Table 5 -Specificity of the protocols utilized for each region examined by observer 1. Table 6 -Percentages of agreements in relation to the gold standard in the examination of CBCT using the i-CAT Vision Table 4 -Sensitivity of the protocols utilized for each region examined by observer 1.…”

“…2 Computed tomography (CT) is an exam that is indicated because it presents high specificity and sensitivity, essential to the diagnosis, planning and treatment of TMJ bone lesions. 3 Using CT, it is possible to analyze the boundary of the mandibular condyle, its position in the mandibular fossa and the involvement of the cortical bone in relation to the bone lesions. 4,5 Several bone alterations that occur in the TMJ, such as erosions and osteophytes in the mandibular condyle, are difficult to detect using conventional radiography and thus necessitate the use of CT. 6 CT has been used to diagnose several bone abnormalities of the TMJ, from osteophytes to tumors.…”