Computed Tomography (CT), Multi-Detector Computed Tomography (MDCT), Micro-CT, and Cone Beam Computed Tomography (CBCT)

2020 ◽  
pp. 111-178
Author(s):  
Gerald J. Conlogue ◽  
Andrew J. Nelson ◽  
Alan G. Lurie
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Micro Ct ◽  
Multi Detector Computed Tomography

Ionizing radiation and its considerations in imaging diagnosis: comparison of absorbed dose between cone beam computed tomography and multi-detector computed tomography in the head and neck

2021 ◽  
Author(s):  
P.L.E. Oliveira ◽  
C.R. Starling ◽  
C.L.P. Maurício ◽  
F.R. Guedes ◽  
M.A. Visconti ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Head And Neck ◽  
Cone Beam Computed Tomography ◽  
Absorbed Dose ◽  
Cone Beam ◽  
Thermoluminescent Dosimeters ◽  
Organ Tissue ◽  
The Mean ◽  
Average Adult ◽  
Multi Detector Computed Tomography

Introduction: The objective of this study was to compare the mean absorbed dose in patients undergoing head and neck examinations using two cone beam computed tomography (CBCT, Kodak and i-CAT) and one multi-detector computed tomography (MDCT). Methods: Three thermoluminescent dosimeters (TLDs), calibrated in air kerma, were positioned in 24 regions of the head and neck of a phantom simulating an average adult. The mean absorbed dose (mGy) values in these positions, for different organs and tissues, were obtained using correction factors, considering the ratio between the mass energy absorption coefficients of organ/tissue and air. Comparison between radiation doses in the most radiosensitive regions was done by calculating the ratio of these dose values, with propagated uncertainty. Results: The dose in all regions was significantly higher for MDCT when compared to CBCT. Concerning CBCT equipment, the Kodak device had a higher absorbed dose than the i-CAT for most of the regions tested. The uncertainty of the i-CAT was greater than that of the Kodak. Conclusion: Due to the considerable difference between absorbed doses, emphasizing the higher dose values obtained in MDCT, the dissemination of CBCT application in medicine is recommended, as well as further studies to broaden the criteria for use.

scholarly journals Root canal segmentation in cone-beam computed tomography

2019 ◽  
Vol 18 ◽  
pp. e191627
Author(s):  
Juliane Freitas Machado ◽  
Paula Maciel Pires ◽  
Thais Maria Pires dos Santos ◽  
Aline de Almeida Neves ◽  
Ricardo Tadeu Lopes ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Root Canal ◽  
Gold Standard ◽  
Automatic Segmentation ◽  
Cone Beam ◽  
Micro Ct ◽  
Gold Standard Method ◽  
Computed Tomography Images ◽  
Segmentation Methods

Aim: The purpose of this study was to compare root canal volumes (RCVs) obtained by means of cone beam computed tomography (CBCT) to those obtained by micro-computed tomography (micro-CT) after applying different segmentation algorithms. Methods: Eighteen extracted human teeth with sound root canals were individually scanned in CBCT and micro-CT using specific acquisition parameters. Two different images segmentation strategies were applied to both acquisition methods (a visual and an automatic threshold). From each segmented tooth, the root canal volume was obtained. A paired t-test was used to identify differences between mean values resulted from the experimental groups and the gold standard. In addition, Pearson correlation coefficients and the agreement among the experimental groups with the gold standard were also calculated. The significance level adopted was 5%. Results: No statistical differences between the segmentation methods (visual and automatic) were observed for micro-CT acquired images. However, significant differences for the two segmentation methods tested were seen when CBCT acquired images were compared with the micro-CT automatic segmentation methods used. In general, an overestimation of the values in the visual method were observed while an underestimation was observed with the automatic segmentation algorithm. Conclusion: Cone beam computed tomography images acquired with parameters used in the present study resulted in low agreement with root canal volumes obtained with a micro-CT tomography gold standard method of RCV calculation.  

scholarly journals Overview of Radiological Studies on Visualization of Gubernaculum Tracts of Permanent Teeth

2021 ◽  
Vol 10 (14) ◽  
pp. 3051
Author(s):  
Masafumi Oda ◽  
Ikuko Nishida ◽  
Manabu Habu ◽  
Osamu Takahashi ◽  
Hiroki Tsurushima ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Tooth Eruption ◽  
Present Review ◽  
Cone Beam ◽  
Permanent Teeth ◽  
Dental Follicle ◽  
Imaging Characteristics ◽  
Radiological Studies ◽  
Multi Detector Computed Tomography

The eruption pathway from the dental follicle to the gingiva for permanent teeth is known as the gubernaculum tract (GT), a physiologic structure thought to play a role in tooth eruption. Cone beam computed tomography and multi-detector computed tomography have recently been used to visualize the GT, with the results indicating that this structure might be related to the normal eruption of teeth. By contrast, curved and/or constricted GTs may lead to abnormal tooth eruption. In addition, complex odontomas have been reported from within the GT or dental sac of unerupted permanent teeth. If an odontoma occurs within the GT, the tooth will not erupt normally. Moreover, the imaging characteristics of the GT from the top of the odontogenic mass to the alveolar crest are extremely useful for making a differential pathological diagnosis and for differentiating between odontogenic and non-odontogenic masses. Therefore, radiological studies on the GT have been attracting increasing attention. Given this background, the present review aims to clarify the imaging characteristics and review recent studies on the GT considering the importance of the research.

scholarly journals Effect of Scanning Resolution on the Prediction of Trabecular Bone Microarchitectures Using Dental Cone Beam Computed Tomography

Diagnostics ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 368
Author(s):  
Ming-Tzu Tsai ◽  
Rong-Ting He ◽  
Heng-Li Huang ◽  
Ming-Gene Tu ◽  
Jui-Ting Hsu
Keyword(s):  
Computed Tomography ◽  
Trabecular Bone ◽  
Bone Quality ◽  
Cone Beam Computed Tomography ◽  
Correlation Coefficients ◽  
Experimental Results ◽  
Cone Beam ◽  
Micro Ct ◽  
Trabecular Thickness ◽  
Dental Implantation

Assessing bone quality and quantity at the location of dental implants before dental implantation is crucial. In recent years, dental cone-beam computed tomography (dental CBCT) has often been used to assess bone quality and quantity prior to dental implant. However, the effect of scanning resolution on the prediction of trabecular bone microarchitectural parameters (TBMPs) remains unclear. The objective of this study was to examine how dental CBCT with various scanning resolution differs with regard to predicting TBMPs. This study used micro-computed tomography (micro-CT) with 18 μm resolution and dental CBCT with 100 μm and 150 μm resolutions on 28 fresh bovine vertebrae cancellous bone specimens. Subsequently, all images were input into the ImageJ software to measure four TBMPs: bone volume total volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.Sp). One-way analysis of variance and Tukey’s test were subsequently used to assess the differences between three scanning modes for the four TBMPs. In addition, correlations between measurement results obtained from micro-CT and dental CBCT with two resolutions were measured. The experimental results indicated that significant differences in four TBMPs were observed between micro-CT and dental CBCT (p < 0.05). The correlation coefficients between BV/TV, Tb.N, and Tb.Sp obtained from micro-CT and from dental CBCT with 100 μm resolution (0.840, 0.739, and 0.820, respectively) were greater than the correlation coefficients between BV/TV, Tb.N, and Tb.Sp obtained from micro-CT and from dental CBCT with 150 μm resolution (0.758, 0.367, and 0.724, respectively). The experimental results revealed that the TBMPs measured with dental CBCT with two resolutions differed from ideal values, but a higher resolution could provide more accurate prediction results, particularly for BV/TV, Tb.N, and Tb.Sp.

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