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Impacted Lower Third Molar Fused with a Supernumerary Tooth—Diagnosis and Treatment Planning Using Cone-Beam Computed Tomography 被引量:11
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作者 Osny Ferreira-Junior Luciana Dorigatti de .&.Aila +3 位作者 Marcelo Bonifacio da Silva Sampieri Eduardo Dias- Ribeiro Wei-liang Chen Song Fan 《International Journal of Oral Science》 SCIE CAS CSCD 2009年第4期224-228,共5页
This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radio... This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography--which provides precise three- dimensional information--was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomo- graphy. 展开更多
关键词 third molar supernumerary tooth oral surgery cone-beam computed tomography
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Short-term outcomes of radiofrequency ablation for hepatocellular carcinoma using cone-beam computed tomography for planning and image guidance 被引量:4
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作者 Xue-Song Yao Dong Yan +3 位作者 Xian-Xian Jiang Xiao Li Hui-Ying Zeng Huai Li 《World Journal of Clinical Cases》 SCIE 2021年第7期1580-1591,共12页
BACKGROUND Percutaneous radiofrequency ablation(RFA)is an effective treatment for unresectable hepatocellular carcinoma(HCC)and a minimally invasive alternative to hepatectomy for treating tumour recurrence.RFA is oft... BACKGROUND Percutaneous radiofrequency ablation(RFA)is an effective treatment for unresectable hepatocellular carcinoma(HCC)and a minimally invasive alternative to hepatectomy for treating tumour recurrence.RFA is often performed using contrast-enhanced computed tomography(CECT)and/or ultrasonography.In recent years,angiographic systems with flat panel image detectors and advanced image reconstruction algorithms have broadened the clinical applications of cone-beam computed tomography(CBCT),including RFA.Several studies have shown the effectiveness of using CBCT for immediate treatment assessments and follow-ups.AIM To assess the treatment response to RFA for HCC using CBCT.METHODS Forty-eight patients(44 men;aged 37-89 years)with solitary HCC[median size:3.2(1.2-6.6)cm]underwent RFA and were followed for 25.6(median;13.5-35.2)mo.Image fusion of CBCT and pre-operative CECT or magnetic resonance imaging(MRI)was used for tumour segmentation and needle path and ablation zone planning.Real-time image guidance was provided by overlaying the threedimensional image of the tumour and needle path on the fluoroscopy image.Treatment response was categorized as complete response(CR),partial response(PR),stable disease(SD),or progressive disease(PD).Disease progression,death,time to progression(TTP),and overall survival(OS)were recorded.Kaplan-Meier and Cox regression analyses were performed.RESULTS Initial post-RFA CECT/MRI showed 38 cases of CR(79.2%),10 of PR(20.8%),0 of SD,and 0 of PD,which strongly correlated with the planning estimation(42 CR,87.5%;6 PR,12.5%;0 SD;and 0 PD;accuracy:91.7%,P<0.01).Ten(20.8%)patients died,and disease progression occurred in 31(35.4%,median TTP:12.8 mo)patients,resulting in 12-,24-,and 35-mo OS rates of 100%,81.2%,and 72.2%,respectively,and progression-free survival(PFS)rates of 54.2%,37.1%,and 37.1%,respectively.The median dose-area product of the procedures was 79.05 Gy*cm2(range 40.95-146.24 Gy*cm2),and the median effective dose was 10.27 mSv(range 5.32-19.01 mSv).Tumour size<2 cm(P=0.008)was a significant factor for OS,while age(P=0.001),tumour size<2 cm(P<0.001),tumour stage(P=0.010),and initial treatment response(P=0.003)were significant factors for PFS.CONCLUSION Reliable RFA treatment planning and satisfactory outcomes can be achieved with CBCT. 展开更多
关键词 Hepatocellular carcinoma Radiofrequency ablation cone-beam computed tomography SURVIVAL PROGNOSIS EFFECTIVENESS
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Performance evaluation of the simpli¯ed spherical harmonics approximation for cone-beam X-ray luminescence computed tomography imaging 被引量:1
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作者 Haibo Zhang Guohua Geng +6 位作者 Yanrong Chen Fengjun Zhao Yuqing Hou Huangjian Yi Shunli Zhang Jingjing Yu Xiaowei He 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2017年第3期97-106,共10页
As an emerging molecular imaging modality,cone-beam X-ray luminescence computed tomog-raphy(CB-XLCT)uses X-ray-excitable probes to produce near-infrared(NIR)luminescence and then reconst ructs three-dimensional(3D)dis... As an emerging molecular imaging modality,cone-beam X-ray luminescence computed tomog-raphy(CB-XLCT)uses X-ray-excitable probes to produce near-infrared(NIR)luminescence and then reconst ructs three-dimensional(3D)distribution of the probes from surface measurements.A proper photon-transportation model is critical to accuracy of XLCT.Here,we presented a systematic comparison between the common-used Monte Carlo model and simplified spherical harmonics(SPN).The performance of the two methods was evaluated over several main spec-trums using a known XLCT material.We designed both a global measurement based on the cosine similarity and a locally-averaged relative error,to quantitatively assess these methods.The results show that the SP_(3) could reach a good balance between the modeling accuracy and computational efficiency for all of the tested emission spectrums.Besides,the SP_(1)(which is equivalent to the difusion equation(DE))can be a reasonable alternative model for emission wavelength over 692nm.In vivo experiment further demonstrates the reconstruction perfor-mance of the SP:and DE.This study would provide a valuable guidance for modeling the photon-transportation in CB-XLCT. 展开更多
关键词 cone-beam X-ray luminescence computed tomography photon-transportation model .simplified spherical harmonics approximation diffusion equations.
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Usefulness of intra-procedural cone-beam computed tomography in modified balloon-occluded retrograde transvenous obliteration of gastric varices
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作者 Edward Wolfgang Lee Naomi So +4 位作者 Ryan Chapman Justin P McWilliams Christopher T Loh Ronald W Busuttil Stephen T Kee 《World Journal of Radiology》 CAS 2016年第4期390-396,共7页
AIM:To evaluate whether intra-procedural conebeam computed tomography(CBCT)performed during modified balloon-occluded retrograde transvenous obliteration(mB RTO)can accurately determine technical success of complete v... AIM:To evaluate whether intra-procedural conebeam computed tomography(CBCT)performed during modified balloon-occluded retrograde transvenous obliteration(mB RTO)can accurately determine technical success of complete variceal obliteration.METHODS:From June 2012 to December 2014,15 patients who received CBCT during m BRTO for treatment of portal hypertensive gastric variceal bleeding were retrospectively evaluated.Three-dimensional(3D)CBCT images were performed and evaluated prior to the end of the procedure,and these were further analyzed and compared to the pre-procedure contrast-enhanced computed tomography to determine the technical success of m BRTO including:Complete occlusion/obliteration of:(1)gastrorenal shunt(GRS);(2)gastric varices;and(3)afferent feeding veins.Post-mB RTO contrast-enhanced CT was used to confirm the accuracy and diagnostic value of CBCT within 2-3 d.RESULTS:Intra-procedural 3D-CBCT images were 100% accurate in determining the technical success of m BRTO in all 15 cases.CBCT demonstrated complete occlusion/obliteration of GRS,gastric varices,collaterals and afferent feeding veins during m BRTO,which was confirmed with post-m BRTO CT.Two patients showed incomplete obliteration of gastric varices and feeding veins on CBCT,which therefore required additional gelfoam injections to complete the procedure.No patient required additional procedures or other interventions during their follow-up period(684 ± 279 d).CONCLUSION:CBCT during mB RTO appears to accurately and immediately determine the technical success of mB RTO.This may improve the technical and clinical success/outcome of m BRTO and reduce additional procedure time in the future. 展开更多
关键词 GASTRIC VARICES MODIFIED balloon-occluded RETROGRADE TRANSVENOUS OBLITERATION GASTRIC variceal bleeding cone-beam computed tomography Coilassisted RETROGRADE TRANSVENOUS OBLITERATION
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Comparison of bone alignment and fiducial marker alignment for online cone-beam computed tomography-guided radiation therapy for prostate cancer
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作者 Hussein M.Metwally 《Oncology and Translational Medicine》 2019年第3期131-136,共6页
Objective The aim of the study was to evaluate the coverage of the prostate when prostatic implanted fiducial markers are used to verify setup of the patients in comparison to the pelvic bones while using conebeam com... Objective The aim of the study was to evaluate the coverage of the prostate when prostatic implanted fiducial markers are used to verify setup of the patients in comparison to the pelvic bones while using conebeam computed tomography(CBCT). Methods Seventeen patients with prostate cancer were included. For each patient, daily online CBCT was done. CT planning was matched with CBCT with the help of fiducial markers(3–5 markers) and another matching with done the help of pelvic bony landmarks. Registration of clinical target volume(CTV) 1 including prostate plus seminal vesicles and CTV2 including prostate only was done and were used to confirm the target volume during the process of matching. Delineation of the rectum on every CBCT was done. Two automatic margin representing planning target volume(PTV) were created. PTV1 was generated by adding 1 cm in all directions(PTV1a) and 0.7 cm in the posterior direction(PTV1b). PTV2 was generated by adding 0.5 cm in all directions(PTV2a) and 0.3 cm in the posterior direction(PTV2b). PTV1a was prescribed to receive 46 Gy in conventional fractionation with a boost dose of 30 Gy to PTV1b. The same dose was prescribed to PTV2a and PTV2b. Calculation of the percentage of intersection between CTV1and CTV2 created on CBCT with the original CTV scan was done. A comparison between the two CTVs(CTV1and CTV2) mean dose and the original delineated CTV was done. Then a comparison to the mean dose of the original CTV of PTV1a, PTV2a(CTV1a and CTV2a), and for PTV1b and PTV2b(CTV1b and CTV2b). Calculation of the mean rectal dose and also V60, V70 and V74 was done on the delineated rectum on every CBCT, and then a comparison to the planned original rectal dose. Results The created CTV1and CTV2 intersection percentage with the original CTV1and CTV2 significantly increased by 85%(range, 65%–95%, P < 0.05), when fiducial markers were used. The main difference of the received mean dose was significantly less in comparison to pelvic bone alignment(0.03% to 2% vs 0.03% to 11.6% for PTV1a, P < 0.006;0.01% to 1.8% vs 0.03% to 10.2% for PTV2a, P < 0.014;0.08 to 2.11 vs 0.04 to 11.29 for PTV1b, P < 0.015 and 0.01 to 1.79 vs 0.01 to 9.69 for PTV2b, P < 0.004). With the use of less PTV margins, significant decrease of the rectal mean dose, V60, V70 and V74 by P < 0.004, P < 0.004, P < 0.0005 and P < 0.009, respectively. Reduction of the CTV1a and CTV1b mean dose by 1.13% and 0.28% in comparison to the initial CTV1a and CTV2a.Conclusion A significant improvement of prostatic cancer patients alignment when fiducial markers are used, with more homogenous dose distribution, and with significant decrease in PTV margins. The delivered rectal dose is significantly less allowing prostate dose escalation. 展开更多
关键词 cone-beam computed tomography(CBCT) PROSTATE cancer BONE ALIGNMENT fiducial marker ALIGNMENT
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A Pilot Survey of Odontomas for Size Constancy Using Cone-Beam Computed Tomography: Effect of Age, Sex, Lesion Location, and Histological Type: A Case Series
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作者 Shinichiro Yamada Hizuru Osanai +2 位作者 Katsumitsu Shimada Hiromasa Hasegawa Keiichi Uchida 《Open Journal of Stomatology》 2021年第12期467-477,共11页
<strong>Objectives: </strong>Odontoma is the most common type of odontogenic tumors. Many studies have analyzed the statistical associations between odontoma location and patient age and sex, according to ... <strong>Objectives: </strong>Odontoma is the most common type of odontogenic tumors. Many studies have analyzed the statistical associations between odontoma location and patient age and sex, according to the histological tumor type. However, few studies have assessed odontoma morphological characteristics using cone-beam computed tomography (CBCT). We aimed to evaluate the association between odontoma location and size. <strong>Methods:</strong> We performed CBCT on patients with odontomas (19 patients;10 women, 9 men;average age, 12.6 [range, 6 - 34] years) according to the pathology type at a university hospital between April 2008 and February 2017. The locations of the lesions were noted, and their sizes were measured on CBCT images. Buccolingual, mesiodistal, and vertical diameters of the lesions were recorded on the same slice with the greatest diameters on axial, coronal, and sagittal CBCT images. <strong>Results: </strong>Altogether, 9 (47.4%) and 10 (52.6%) odontomas were located in the mandible and maxilla, respectively. There was no significant difference in the mesiodistal and vertical diameters on the CBCT image between the mandibular and maxillary groups when the odontoma size was compared with location (p < 0.05). However, the average diameters in only the buccolingual diameter were significantly greater in the maxilla. There were no significant differences between the two groups according to sex, age, or histological type. <strong>Conclusions: </strong>These data suggest that the sizes of odontomas in the maxilla are affected by bone expansion in the buccolingual direction, but they may be invariable in most settings. Three-dimensional assessment across the age groups suggests a lack of variation in size. 展开更多
关键词 cone-beam computed tomography (CBCT) ODONTOMA SIZE Location
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Alveolar Ridge Preservation Utilizing Composite (Bioceramics/Collagen) Graft: A Cone-Beam Computed Tomography Assessment in a Randomized Split-Mouth Controlled Trial
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作者 Khalil Yosouf Omar Heshmeh Khaldoun Darwich 《Journal of Biomedical Science and Engineering》 2021年第2期64-73,共10页
Background: The vast percentage of the alveolar bone resorption process happens within the first 12 to 24 weeks post extraction;however, this phenomenon is chronic, and the alveolar ridge continues to resorb. In order... Background: The vast percentage of the alveolar bone resorption process happens within the first 12 to 24 weeks post extraction;however, this phenomenon is chronic, and the alveolar ridge continues to resorb. In order to prevent this reduction or at least recompense the loss of bone dimensions, the alveolar ridge preservation (ARP) technique was developed. Objectives: This research studied the vertical and horizontal bone dimensional changes as a result of non-molar teeth extraction alone against extraction with alveolar ridge preservation utilizing composite (bioceramics/collagen) graft by cone-beam computed tomography radiographies analyses. Material and Methods: This research was a randomized split-mouth controlled trial. 12 patients need extraction of the maxillary non-molar teeth were enrolled and allocated into 2 groups. 12 sockets after atraumatic extraction were filled with a composite graft in the role of the test group, 12 sockets left to unassisted healing after atraumatic extraction without any graft materials in the role of the control group. Two CBCT radiographs were taken at baseline and at 4 months after extraction for comparison. Both vertical and horizontal resorptions of the alveolar ridge were analyzed between test and control group by CBCT radiographs. Results: 4 months after extraction, there was a mean of vertical alveolar bone resorption compared with the baseline (0.56 ± 0.15 mm) in the test group and (1.47 ± 0.30 mm) in the control group. Whereas it was a mean of horizontal alveolar bone resorption compared with the baseline (0.90 ± 0.16 mm) in the test group and (2.26 ± 0.30 mm) in the control group. Therefore, there was a significant difference between the two groups. Conclusions: Within the limitations of this research, we demonstrated that the osteogen-plug technique significantly decreased the reduction of the bone dimensional in comparison to the tooth extraction alone, and showed that the dimensional change of the alveolar ridge after tooth extraction was minimized by using an osteogen-plug. 展开更多
关键词 Randomized Controlled Trial Composite Graft Alveolar Ridge Preservation Atraumatic Extraction cone-beam computed tomography
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Lung cancer screening: Computed tomography or chest radiographs?
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作者 Edwin JR van Beek Saeed Mirsadraee John T Murchison 《World Journal of Radiology》 CAS 2015年第8期189-193,共5页
Worldwide, lung cancer is the leading cause of mortalitydue to malignancy. The vast majority of cases of lung cancer are smoking related and the most effective way of reducing lung cancer incidence and mortality is by... Worldwide, lung cancer is the leading cause of mortalitydue to malignancy. The vast majority of cases of lung cancer are smoking related and the most effective way of reducing lung cancer incidence and mortality is by smoking cessation. In the Western world, smoking cessation policies have met with limited success. The other major means of reducing lung cancer deaths is to diagnose cases at an earlier more treatable stage employing screening programmes using chest radiographs or low dose computed tomography. In many countries smoking is still on the increase, and the sheer scale of the problem limits the affordability of such screening programmes. This short review article will evaluate the current evidence and potential areas of research which may benefit policy making across the world. 展开更多
关键词 screening CHEST SMOKING MALIGNANCY DEATHS mortality incidence MAJORITY NODULES benefit
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Advanced 4-dimensional cone-beam computed tomography reconstruction by combining motion estimation, motioncompensated reconstruction, biomechanical modeling and deep learning
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作者 You Zhang Xiaokun Huang Jing Wang 《Visual Computing for Industry,Biomedicine,and Art》 2019年第1期221-235,共15页
4-Dimensional cone-beam computed tomography(4D-CBCT)offers several key advantages over conventional 3DCBCT in moving target localization/delineation,structure de-blurring,target motion tracking,treatment dose accumul... 4-Dimensional cone-beam computed tomography(4D-CBCT)offers several key advantages over conventional 3DCBCT in moving target localization/delineation,structure de-blurring,target motion tracking,treatment dose accumulation and adaptive radiation therapy.However,the use of the 4D-CBCT in current radiation therapy practices has been limited,mostly due to its sub-optimal image quality from limited angular sampling of conebeam projections.In this study,we summarized the recent developments of 4D-CBCT reconstruction techniques for image quality improvement,and introduced our developments of a new 4D-CBCT reconstruction technique which features simultaneous motion estimation and image reconstruction(SMEIR).Based on the original SMEIR scheme,biomechanical modeling-guided SMEIR(SMEIR-Bio)was introduced to further improve the reconstruction accuracy of fine details in lung 4D-CBCTs.To improve the efficiency of reconstruction,we recently developed a U-net-based deformation-vector-field(DVF)optimization technique to leverage a population-based deep learning scheme to improve the accuracy of intra-lung DVFs(SMEIR-Unet),without explicit biomechanical modeling.Details of each of the SMEIR,SMEIR-Bio and SMEIR-Unet techniques were included in this study,along with the corresponding results comparing the reconstruction accuracy in terms of CBCT images and the DVFs.We also discussed the application prospects of the SMEIR-type techniques in image-guided radiation therapy and adaptive radiation therapy,and presented potential schemes on future developments to achieve faster and more accurate 4D-CBCT imaging. 展开更多
关键词 cone-beam computed tomography Image reconstruction Motion estimation Biomechanical modeling Deep learning
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Applied Anatomic Site Study of Palatal Anchorage Implants Using Cone Beam Computed Tomography 被引量:7
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作者 Ren-fa Lai Hui Zou +1 位作者 Wei-dong Kong Wei Lin 《International Journal of Oral Science》 SCIE CAS CSCD 2010年第2期98-104,共7页
Aim The purpose of this study was to conduct quantitative research on bone height and bone mineral density of palatal implant sites for implantation, and to provide reference sites for safe and stable palatal implants... Aim The purpose of this study was to conduct quantitative research on bone height and bone mineral density of palatal implant sites for implantation, and to provide reference sites for safe and stable palatal implants. Methodology Three-dimensional reformatting images were reconstructed by cone beam computed tomography (CBCT) in 34 patients, aged 18 to 35 years, using EZ Implant software. Bone height was measured at 20 sites of interest on the palate. Bone mineral density was measured at the 10 sites with the highest implantation rate, classified using K-mean cluster analysis based on bone height and bone mineral density. Results According to the cluster analysis, 10 sites were classified into three clusters. Significant differences in bone height and bone mineral density were detected between these three clusters (P〈0.05). The greatest bone height was obtained in cluster 2, followed by cluster 1 and cluster 3. The highest bone mineral density was found in cluster 3, followed by cluster 1 and cluster 2. Conclusion CBCT plays an important role in pre-surgical treatment planning. CBCT is helpful in identifying safe and stable implantation sites for palatal anchorage. 展开更多
关键词 palatal implant cone-beam computed tomography bone height bone mineral density
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Effect of varying computed tomography acquisition and reconstruction parameters on semi-automated clot volume quantification 被引量:3
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作者 Audrey E Kaufman Alison N Pruzan +4 位作者 Ching Hsu Sarayu Ramachandran Adam Jacobi Zahi A Fayad Venkatesh Mani 《World Journal of Radiology》 CAS 2018年第3期24-29,共6页
AIM To examine effects of computed tomography(CT)image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.METHODS This study was performed in conforman... AIM To examine effects of computed tomography(CT)image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.METHODS This study was performed in conformance with HIPAA and IRB Regulations(March 2015-November 2016).A ten blood clot phantom was designed and scanned on a dual-energy CT scanner(SOMATOM Force,Siemens Healthcare Gm BH,Erlangen,Germany)with varying pitch,iterative reconstruction,energy level and slicethickness.A range of clot and tube sizes were used in an attempt to replicate in vivo emboli found within central and segmental branches of the pulmonary arteries in patients with pulmonary emboli.Clot volume was the measured parameter and was analyzed by a single image analyst using a semi-automated region growing algorithm implemented in the FDA-approved Siemens syngo.via image analysis platform.Mixed model analysis was performed on the data.RESULTS On the acquisition side,the continuous factor of energy showed no statistically significant effect on absolute clot volume quantification(P=0.9898).On the other hand,when considering the fixed factor of pitch,there were statistically significant differences in clot volume quantification(P<0.0001).On the reconstruction side,with the continuous factor of reconstruction slice thickness no statistically significant effect on absolute clot volume quantification was demonstrated(P=0.4500).Also on the reconstruction side,with the fixed factor of using iterative reconstructions there was also no statistically significant effect on absolute clot volume quantification(P=0.3011).In addition,there was excellent R^2 correlation between the scale-measured mass of the clots both with respect to the CT measured volumes and with respect to volumes measure by the water displacement method.CONCLUSION Aside from varying pitch,changing CT acquisition parameters and using iterative reconstructions had no significant impact on clot volume quantification with a semi-automated region growing algorithm. 展开更多
关键词 computed tomography ANGIOGRAPHY radiographIC phantom computER-ASSISTED image analysis Pulmonary EMBOLISM THROMBOLYTIC therapy
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Bone mineral density in cone beam computed tomography:Only a few shades of gray 被引量:3
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作者 Marcio José da Silva Campos Thainara Salgueiro de Souza +2 位作者 Sergio Luiz Mota Júnior Marcelo Reis Fraga Robert Willer Farinazzo Vitral 《World Journal of Radiology》 CAS 2014年第8期607-612,共6页
Cone beam computed tomography(CBCT) has often been used to determine the quality of craniofacial bone structures through the determination of mineral density, which is based on gray scales of the images obtained. Howe... Cone beam computed tomography(CBCT) has often been used to determine the quality of craniofacial bone structures through the determination of mineral density, which is based on gray scales of the images obtained. However, there is no consensus regarding the accuracy of the determination of the gray scales in these exams. This study aims to provide a literature review concerning the reliability of CBCT to determine bone mineral density. The gray values obtained with CBCT show a linear relationship with the attenuation coefficients of the materials, Hounsfield Units values obtained with medical computed tomography, and density values from dual energy X-ray absorciometry. However, errors are expected when CBCT images are used to define the quality of the scanned structures be-cause these images show inconsistencies and arbitrari-ness in the gray values, particularly when related to abrupt change in the density of the object, X-ray beam hardening effect, scattered radiation, projection data discontinuity-related effect, differences between CBCTdevices, changes in the volume of the field of view(FOV), and changes in the relationships of size and position between the FOV and the object evaluated. A few methods of mathematical correction of the gray scales in CBCT have been proposed; however, they do not generate consistent values that are independent of the devices and their configurations or of the scanned objects. Thus, CBCT should not be considered the ex-amination of choice for the determination of bone and soft tissue mineral density at the current stage, par-ticularly when values obtained are to be compared to predetermined standard values. Comparisons between symmetrically positioned structures inside the FOV and in relation to the exomass of the object, as it occurs with the right and left sides of the skull, seem to be viable because the effects on the gray scale in the re-gions of interest are the same. 展开更多
关键词 tomography cone-beam computed tomography Bone mineral density REPRODUCIBILITY of results
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Effective Dose Levels from Computed Tomography of the Head during Contrast Studies in Nigeria 被引量:2
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作者 Thomas Adejoh Nzotta Chukwuemeka Christian +1 位作者 Flavious Bobuin Nkubli Joseph Zira Dlama 《Health》 2015年第8期915-919,共5页
Background: Diagnostic reference levels for a number of common diagnostic radiological examinations against which individual centres could compare their performance have been recommended by relevant international agen... Background: Diagnostic reference levels for a number of common diagnostic radiological examinations against which individual centres could compare their performance have been recommended by relevant international agencies. Due to variations in different populations globally, local and national diagnostic reference levels are more reliable. To the best of our knowledge, no centre-specific study has been carried out and national surveys are not available. Objective: To establish a preliminary local and national diagnostic reference level in Nigeria. Methods: A pro-spective and cross-sectional study involving 30 conscious paediatrics and adult patients referred for head computed tomography scan. They were positioned supine and scanned according to the standard protocol for head computed tomography with manual mA selection. The total dose-length products were recorded at the end of the pre-contrast and post-contrast sequences respectively. The pre-contrast dose was taken into cognizance in the determination of the post-contrast value. The effective dose was established by multiplying the dose-length product by 0.0023 mSv.mGy-1.cm-1, a conversion coefficient for brain tissue adopted from the European Commission. Statistical Package for Social Sciences version 17.0 was used to analyze the data. Results: 30 paediatrics and adult patients of mixed gender participated in the study. Their ages ranged from 1 to 74 years with a mean age of 41.47 ± 23.30 years. The pre-contrast effective dose ranged from 1.93 mSv to 3.32 mSv with mean of 2.56 ± 0.51 mSv and 75th percentile of 3.11 mSv while the post-contrast effective dose ranged from 4.06 mSv to 6.97 mSv with mean of 5.27 ± 0.97 mSv and 75th percentile of 6.13 mSv. The mean effective dose from this work and two other isolated studies was 3.0 mSv. Conclusion: Although our quantified doses are below threshold limits for occupational exposures they are higher than the recommended level for the public. A further optimization of scanning protocols by the radiographers could lower the effective dose for patients undergoing contrast head computed tomography in our centre and in the country. 展开更多
关键词 Effective DOSE Diagnostic Reference Level radiographER computed tomography HEAD
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Endodontic management of a fused left maxillary second molar and two paramolars using cone beam computed tomography: A case report 被引量:1
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作者 Xiao-Han Mei Jin Liu +6 位作者 Wei Wang Qian-Xia Zhang Tao Hong Shi-Zhu Bai Xiao-Gang Cheng Yu Tian Wen-Kai Jiang 《World Journal of Clinical Cases》 SCIE 2022年第23期8367-8374,共8页
BACKGROUND Fused teeth usually involve several complications,such as the development of caries in the groove between fused crowns,tooth impaction,diastemas,aesthetic and periodontal problems,and pulpal pathosis,due to... BACKGROUND Fused teeth usually involve several complications,such as the development of caries in the groove between fused crowns,tooth impaction,diastemas,aesthetic and periodontal problems,and pulpal pathosis,due to the complex anatomical structure of fused teeth.A thorough diagnosis is paramount to forming an accurate treatment plan and obtaining a favourable prognosis.With the advent of cone-beam computed tomography(CBCT),accurate 3-dimensional images of teeth and their surrounding dentoalveolar structures can now be readily obtained,and the technology can accurately provide a minimally invasive approach to acquire detailed diagnostic information.Therefore,we utilize CBCT data herein to generate a digital model for the infected region in a patient,and this model enables us to better plan the management of his case.CASE SUMMARY This report details the diagnosis and endodontic treatment of a rare case involving a fused maxillary second molar and two paramolars with apical periodontitis.The patient experienced pain upon biting and cold sensitivity in the area of the maxillary left molar.No caries or other defects were identified in these teeth,and a normal response to a pulp electric viability test was observed.With the aid of CBCT and digital model technology,we initially suspected that the infection originated from the isthmus between the maxillary second molar and two paramolars.Therefore,we only treated the isthmus by an endodontic approach and did not destroy the original tooth structure;furthermore,the vital pulp was retained,and good treatment outcomes were observed at the 24-month follow-up.CONCLUSION This finding may provide new insights and perspectives on the diagnosis and treatment of fused teeth. 展开更多
关键词 cone-beam computed tomography scans Endodontic therapy Fusion of teeth Maxillary molar Digital model technology Case report
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Clinical Endodontic Applications of Cone Beam-Computed Tomography in Modern Dental Practice 被引量:1
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作者 Johnah C. Galicia Jeffrey Kawilarang Peter Z. Tawil 《Open Journal of Stomatology》 2017年第7期314-326,共13页
Nearly two decades since Cone Beam-Computed Tomography (CBCT) was introduced in dentistry, this technology has been proven to be a useful asset in modern dental practice. The information gleaned from a CBCT scan influ... Nearly two decades since Cone Beam-Computed Tomography (CBCT) was introduced in dentistry, this technology has been proven to be a useful asset in modern dental practice. The information gleaned from a CBCT scan influences treatment decisions and prognostication of challenging endodontic cases. The authors present six cases that utilized CBCT to diagnose vertical root fracture, to assess resorption, to guide the clinician in overcoming anatomical complexities, to hurdle diagnostic dilemmas and to perform pre-surgical evaluation. Initially, a thorough clinical assessment was performed;however, conventional periapical radiographs were not able to provide sufficient information to arrive at a definite diagnosis or a thorough treatment plan. CBCT was therefore deemed helpful for these cases. Clearly, there are advantages to using CBCT. With a better understanding of each case, the clinician can plan a definitive treatment plan and offer a clearer case prognosis to their patient. 展开更多
关键词 ENDODONTICS cone-beam computed tomography Case REPORTS radiographY
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Use of dentomaxillofacial cone beam computed tomography in dentistry
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作者 Kivanc Kamburoglu 《World Journal of Radiology》 2015年第6期128-130,共3页
Cone-beam computed tomography(CBCT) was developed and introduced specifically for dento-maxillofacial imaging. CBCT possesses a number of advantages over medical CT in clinical practice, such as lower effective radiat... Cone-beam computed tomography(CBCT) was developed and introduced specifically for dento-maxillofacial imaging. CBCT possesses a number of advantages over medical CT in clinical practice, such as lower effective radiation doses, lower costs, fewer space requirements,easier image acquisition, and interactive display modes such as mutiplanar reconstruction that are applicable to maxillofacial imaging. However, the disadvantages of CBCT include higher doses than two-dimensional imaging; the inability to accurately represent the internal structure of soft tissues and soft-tissue lesions; a limited correlation with Hounsfield Units for standardized quantification of bone density; and the presence of various types of image artifacts, mainly those produced by metal restorations. CBCT is now commonly used for a variety of purposes in oral implantology, dentomaxillofacial surgery, image-guided surgical procedures, endodontics, periodontics and orthodontics. CBCT applications provide obvious benefits in the assessment of dentomaxillofacial region, however; it should be used only in correct indications considering the necessity and the potential hazards of the examination. 展开更多
关键词 radiographY DENTISTRY Dentomaxillofacial RADIOLOGY cone-beam computed tomography
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Transition to computed radiography: can emergency medicine doctors accurately predict the need of film printing to facilitate optimal patient care? 被引量:1
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作者 Siu Ming Yang Chor Man Lo 《World Journal of Emergency Medicine》 CAS 2011年第1期33-37,共5页
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上颌前牙区多生牙的锥形束CT影像学特征研究
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作者 孙苏 冷迪雅 +5 位作者 王晶艳 顾培玉 杨连丰 吴大明 孙超 张娟 《口腔医学》 CAS 2024年第2期115-120,共6页
目的 利用锥形束CT(cone beam computed tomography,CBCT)分析上颌前牙区多生牙(supernumerary tooth,ST)的影像学特征,为ST的治疗提供帮助。方法 共收集805例CBCT数据,利用专用软件NNT评价ST的影像学特征,包括:数目、形态、位置、方向... 目的 利用锥形束CT(cone beam computed tomography,CBCT)分析上颌前牙区多生牙(supernumerary tooth,ST)的影像学特征,为ST的治疗提供帮助。方法 共收集805例CBCT数据,利用专用软件NNT评价ST的影像学特征,包括:数目、形态、位置、方向、发育情况和并发症,并分析上述影像学特征的性别差异。结果 男女比例2.96∶1,男性和女性ST均以单枚、锥形、牙弓腭侧、倒置和阻生为主,但男性发生2枚ST的比例显著高于女性(P<0.001),女性ST倒置的比例更高(P<0.001)。最常见的ST相关的并发症是鼻腭管管壁骨质吸收,且男性高于女性(P=0.01)。此外,ST累及解剖结构及相关临床并发症还包括鼻底骨质吸收,形成颌骨囊肿,牙滤泡间隙增宽,邻牙阻生、移位或扭转、根吸收。结论 男性和女性上颌前牙区的ST以单枚、锥形、牙弓腭侧、倒置和阻生为主,但发病特点存在性别差异。ST可导致多种并发症,CBCT的准确分析有助于ST的诊断和治疗。 展开更多
关键词 锥形束CT 多生牙 并发症 影像学特征
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Two-stage extraction by partial grinding of impacted mandibular third molar in close proximity to the inferior alveolar nerve
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作者 Guang-Ming Luo Zhang-Shun Yao +2 位作者 Wei-Xiang Huang Lei-Yan Zou Yan Yang 《World Journal of Clinical Cases》 SCIE 2024年第10期1728-1732,共5页
BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third... BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third molar(IMM3)near the IAN to prevent IAN injury during IMM3 extraction.METHODS Between January 1996 and March 2022,25 patients with IMM3 roots near the IAN were enrolled.The first stage of the operation consisted of grinding a major part of the IMM3 crown with a high-speed turbine dental drill to achieve sufficient space between the mandibular second molar and IMM3.After 6 months,when the root tips were observed to be away from the IAN on X-ray examination,the remaining part of the IMM3 was completely removed.RESULTS All IMM3s were extracted easily without symptoms of IAN injury after extraction.CONCLUSION Partial IMM3 grinding may be a good alternative treatment option to avoid IAN injury in high-risk cases. 展开更多
关键词 Partial grinding Impacted mandibular third molar Inferior alveolar nerve cone-beam computed tomography
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A Case Report of Kissing Molars Class II
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作者 Toshiyuki Inou Keiichi Uchida +6 位作者 Keiko Kaneko Anna Fuji Nina Wakimoto Tatsuo Takaya Hiroyuki Kitamura Hiroshi Mori Yuji Kurihara 《Open Journal of Stomatology》 2024年第5期249-254,共6页
Kissing molars (KMs) is a condition of occlusal molar surfaces in a single follicular space with roots extending in opposite directions. Here, we have reported a case of KMs in a 58-year-old woman. The patient complai... Kissing molars (KMs) is a condition of occlusal molar surfaces in a single follicular space with roots extending in opposite directions. Here, we have reported a case of KMs in a 58-year-old woman. The patient complained of pain in the right mandibular molar region and was diagnosed with KMs consisting of the right mandibular second and third molars. Because of the patient’s pain having subsided at the time of the visit and her unwillingness to undergo tooth extraction, the patient was followed up. KMs is classified into three classes (I-III) and is either true-KMs or pseudo-KMs and presents with or without cystic variants of dental follicles. The presents as true-KMs class II without a cystic variant. With reference to the literature and based on our analysis, the mean age of patients affected by this specific case of KMs is 31.7 years and unilateral KMs is relatively more common (85.7%). Histopathological findings of dentigerous cysts are more often indicated (42.9%). The treatment policy for KMs should therefore be based on the classification of KMs. Importantly, the focus should be on preserving the first and second molars as much as possible. The treatment approach, such as the employment of surgical removal or orthodontics, should be determined by considering the associated factors such as the crowns, tissues, and age of the patient. 展开更多
关键词 Kissing Molars Mandibular Second Molar Mandibular Third Molar cone-beam computed tomography
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