Diagnostic quality of multiplanar reformations obtained with a newly developed cone beam device for maxillofacial imaging

Objective: The aim of this study was to evaluate accuracy of linear measurements assessed from axial tomograms and the influence of the use of different protocols in two cone beam CT (CBCT) units. Methods: A cylinder object consisting of NylonH (Day Brazil, Sao Paulo, Brazil) with radiopaque markers was radiographically examined applying different protocols from NewTom 3G TM (Quantitative Radiology s.r.l, Verona, Veneto, Italy) and i-CAT TM (Imaging Sciences International, Hatfield, PA) units. Horizontal (A-B) and vertical (C-D) distances were assessed from axial tomograms and measured using a digital calliper that provided the gold standard for actual values. Conclusion:The use of different protocols from CBCT machines influences linear measurements assessed from axial images. Linear distances were underestimated in both equipments. Our findings suggest that the best protocol for the i-CAT TM is 13 cm 20 s 0.3 mm and for the NewTom 3G TM , the use of 6 inch or 9 inch is recommended.

Section: Introductionmentioning

confidence: 99%

Accuracy assessment of the axial images obtained from cone beam computed tomography

Panzarella

Junqueira²,

Oliveira³

et al. 2011

“…There is some evidence that the panoramic images reformatted from source axial CT images offer equivalent diagnostic ability to conventional digital panoramic radiography. [2][3][4] The development of 320 MDCT allows a scan length of up to 16 cm at the z-axis with a single rotation, which enables coverage of the entire maxillofacial region. [5][6][7][8] The time required with 0.5 s for one rotation by 320 MDCT is much faster than that by CBCT (10-70 s per rotation); as a consequence, 320 MDCT has the potential for generating much smaller motion artefacts.…”

Section: Introductionmentioning

confidence: 99%

Investigation of an optimized scanning protocol for the dentomaxillofacial region using 320-slice multidetector computed tomography

Lin

Wang

Hsu

et al. 2017

Objectives: To propose an imaging protocol that provides satisfactory image quality for oral examination while minimizing radiation dosage using 320-slice multidetector CT (MDCT). Methods: An anthropomorphic head phantom was scanned using 320 MDCT with protocols combining different scanning modes: volume scanning (whole or local) vs helical scanning (80-or 64-slice detectors); tube voltage settings (80 kVp, 120 kVp and 135 kVp); and tube current settings (60 mA, 80 mA, 100 mA and 120 mA). A total of six anatomical bone structures and three anatomical soft-tissue structures were assessed using quantitative and qualitative analysis in the three orthographic planes (axial, sagittal and coronal). A figure of merit (FOM) was used to determine the optimal imaging protocol in terms of tube voltage, tube current and scanning mode. Results: The 80-kVp setting had the worst quantitative and qualitative results (both p , 0.001) compared with the 135-kVp and 120-kVp settings, especially for soft-tissue structures. A significant difference was noted for the scores obtained using a tube current between 120 mA and 60 mA by quantitative analysis, but not by qualitative analysis. Volume scans using either whole or local modes had a significantly higher FOM than helical scanning of 80 or 64 slices. Conclusions: In 320 MDCT, a protocol using 135 kVp, 80 mA and the volume-scanning mode (whole or local) offers adequate visualization of both soft-tissue and bone structures while keeping the radiation dose as low as possible. This may therefore be considered a first choice among a wide selection of scanning protocols for dentomaxillofacial CT.

“…10 In the last decades, CBCT has been emerging, and now, it is widely used in dentistry, thanks to its high image resolution, low radiation dose and low costs. [11][12][13] Currently, its clinical use in other medical fields is limited and not widespread because of minor soft-tissue contrast; however, many studies confirm that CBCT could be a valid support in otolaryngology also. [14][15][16] Given that the evaluation of NSD in CT images is currently mainly based on subjective clinic and radiologic analyses, many studies are trying to find homogeneous and standard evaluation criteria based on the morphometric analysis of the nasal airways.…”

Section: Introductionmentioning

confidence: 99%

The nasal septum deviation index (NSDI) based on CBCT data

Codari¹,

Zago²,

Guidugli³

et al. 2016

Objective: To assess whether three-dimensional morphometric parameters could be useful in nasal septal deviation (NSD) diagnosis and, secondarily, whether CBCT could be considered an adequate imaging technique for the proposed task. Methods: We analysed images of 46 subjects who underwent CBCT for reasons not related to this study. Two experienced operators divided all the images into healthy and NSD subjects. Subsequently, the images were segmented using ITK Snap in order to obtain the three-dimensional model of the nasal airways and compute four morphological parameters: septal deviation angle (SDA), percentage of volume difference between right and left side of the nasal airways, nasal airway total volume and a new synthetic septal deviation index (SDI). Principal component analysis (PCA) was used to unveil relationships between each variable and the global nasal airway variability. Results: Differences between the groups were found in SDA (p , 0.001), in volume percentage difference (p , 0.05) and in SDI (p , 0.001). PCA showed high correlation between the SDI and the first principal component (0.97, p , 0.001). Conclusions: Among the analysed parameters, SDI seemed to be the most suitable for the quantitative assessment of NSD, and CBCT allowed accurate assessment of airway morphology.