scholarly journals 3D printing of brachycephalic and dolichocephalic canine skulls and mandibles: a complement to traditional osteotechnique

2021 ◽  
Vol 15 (2) ◽  
pp. 173-179
Author(s):  
Catia Helena de Almeida Lima Massari ◽  
Yuri Karaccas de Carvalho ◽  
Maria Angélica Miglino
Keyword(s):  
Computed Tomography ◽  
3D Printing ◽  
Ct Scanner ◽  
Anatomical Models ◽  
Complementary Technique ◽  
Volumetric Reconstruction ◽  
Pros And Cons ◽  
Three Stages ◽  
Animal Anatomy ◽  
Synthetic Models

This paper aimed at reporting the creation of brachycephalic and dolichocephalic 3D synthetic anatomical models of canine heads (3D SAMCH) as a complementary technique to traditional osteotechnique using Computed Tomography (CT) images in volumetric reconstruction. The study was carried out in three stages, namely: a) preparation of canine heads in natura; b) creation of digital files of canine heads using CT; and c) 3D printing of synthetic anatomical models of canine heads. As a result, two 3D SAMCH were produced due to rarer availability in Animal Anatomy laboratories collections; the important representation of the cribriform plate was possible, but a remarkable defect presented was the teeth. It concluded that the digital files creation through CT scanner allows a fine representation of canine heads if considered pros and cons regarding the use of synthetic models instead of natural bones.

scholarly journals Cross-sectional anatomy, computed tomography, and magnetic resonance imaging of the banded houndshark (Triakis scyllium)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sang Wha Kim ◽  
Adams Hei Long Yuen ◽  
Cherry Tsz Ching Poon ◽  
Joon Oh Hwang ◽  
Chang Jun Lee ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Evolutionary Developmental Biology ◽  
Phylogenetic Position ◽  
Ct Scanner ◽  
Resonance Imaging ◽  
Cross Sectional

AbstractDue to their important phylogenetic position among extant vertebrates, sharks are an invaluable group in evolutionary developmental biology studies. A thorough understanding of shark anatomy is essential to facilitate these studies and documentation of this iconic taxon. With the increasing availability of cross-sectional imaging techniques, the complicated anatomy of both cartilaginous and soft tissues can be analyzed non-invasively, quickly, and accurately. The aim of this study is to provide a detailed anatomical description of the normal banded houndshark (Triakis scyllium) using computed tomography (CT) and magnetic resonance imaging (MRI) along with cryosection images. Three banded houndsharks were scanned using a 64-detector row spiral CT scanner and a 3 T MRI scanner. All images were digitally stored and assessed using open-source Digital Imaging and Communications in Medicine viewer software in the transverse, sagittal, and dorsal dimensions. The banded houndshark cadavers were then cryosectioned at approximately 1-cm intervals. Corresponding transverse cryosection images were chosen to identify the best anatomical correlations for transverse CT and MRI images. The resulting images provided excellent detail of the major anatomical structures of the banded houndshark. The illustrations in the present study could be considered as a useful reference for interpretation of normal and pathological imaging studies of sharks.

Optimizing Computed Tomography (CT) Scanner Geometry

1979 ◽  
Author(s):  
G. T. Barnes ◽  
M. V. Yester ◽  
M. A. King
Keyword(s):  
Computed Tomography ◽  
Ct Scanner

Effective doses in subjects undergoing computed tomography cardiac imaging with the 256-multislice CT scanner

2008 ◽  
Vol 65 (3) ◽  
pp. 442-448 ◽  
Author(s):  
Shinichiro Mori ◽  
Kanae Nishizawa ◽  
Chisato Kondo ◽  
Mari Ohno ◽  
Keiichi Akahane ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cardiac Imaging ◽  
Multislice Ct ◽  
Ct Scanner ◽  
Effective Doses

Optimal image segmentation protocol for 3D printing of aortic dissection through open-source software

2021 ◽  
Author(s):  
Chia-An Wu ◽  
Andrew Squelch ◽  
Zhonghua Sun
Keyword(s):  
Computed Tomography ◽  
Image Segmentation ◽  
3D Printing ◽  
Aortic Dissection ◽  
Open Source ◽  
Open Source Software ◽  
Type B ◽  
Manual Intervention ◽  
Computed Tomography Images ◽  
Computed Tomography Image

Aim: To determine the optimal image segmentation protocol that minimizes the amount of manual intervention and correction required while extracting 3D model geometries suitable for 3D printing of aortic dissection (AD) using open-source software. Materials & methods: Computed tomography images of two type B AD cases were selected with images segmented using a 3D Slicer to create a hollow model containing the aortic wall and intimal tear. A workflow composed of filters, lumen extraction and outer surface creation was developed. Results & conclusion: The average difference in measurements at 14 anatomical locations between the Standard Tessellation Language file and the computed tomography image for cases 1 and 2 were 0.29 and 0.32 mm, respectively. The workflow for the image segmentation of type B AD was able to produce a high-accuracy 3D-printed model in a short time through open-source software.

scholarly journals User needs elicitation via analytic hierarchy process (AHP). A case study on a Computed Tomography (CT) scanner

2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Leandro Pecchia ◽  
Jennifer L Martin ◽  
Angela Ragozzino ◽  
Carmela Vanzanella ◽  
Arturo Scognamiglio ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Analytic Hierarchy Process ◽  
User Needs ◽  
Ct Scanner ◽  
Analytic Hierarchy ◽  
Hierarchy Process

scholarly journals Comparison of the Hounsfield Unit Values Obtained From Cone-Beam Computed Tomography (CBCT) and Multidetector Computed Tomography (MDCT) Images for Different Bone Densities

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Atefeh Khavid ◽  
Mojgan Sametzadeh ◽  
Mostafa Godiny ◽  
Mohammad Mehdi Moarrefpour
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Pearson Correlation ◽  
Hounsfield Unit ◽  
Cone Beam ◽  
Ct Scanner ◽  
Significance Level ◽  
Dental Practitioners ◽  
Significant Difference ◽  
The Mean

Background and objective: In recent years, cone-beam computed tomography (CBCT) has become a key diagnostic tool in dentistry. CBCT can provide 3D images of the maxillofacial area to help dental practitioners in diagnosis and treatment, especially implant placement and treatment of pathogenic lesions. This study aimed to compare the Hounsfield Unit (HU) values obtained from CBCT images for bones of different densities with the corresponding HU values from MDCT images. Materials and methods: cube-shaped bone blocks of identical size were cut from the middle section of the cow ribs and femur area such that they had a layer of cortical bone in their buccal, lingual, and top surfaces and trabecular bone in the middle. MDCT scans were performed using a Somatom Sensation Ct Scanner. After determining HU from the results of these scans, nine suitable specimens from different ranges of HU were chosen for comparison. HU of the CBCT images was computed by the dedicated software of the CBCT machine. Finally, HU values obtained from MDCT and CBCT were compared. Data analysis was performed using SPSS version 25 at the 0.05 significance level. Results: The results showed a statistically significant difference between the mean HU from MDCT images and the mean HU from CBCT images (P<0.05). For similar specimens, CBCT produced higher mean HU values than MDCT. The Pearson correlation test detected a significant direct relationship between the HU values of specimens in MDCT and CBCT (P<0.05). Conclusion: For the tools and software used in this study, there was no significant difference between the HU values obtained from MDCT and CBCT, but the mean HU obtained from CBCT was higher than that from MDCT.

scholarly journals Optimization of head computed tomography scan in a tertiary institution in Edo State, South-South Nigeria

2021 ◽  
Vol 8 (4) ◽  
pp. 225-230
Author(s):  
Chikezie Chukwuemeka Udo ◽  
Akintayo Daniel Omojola ◽  
Chukwuemeka Christian Nzotta
Keyword(s):  
Computed Tomography ◽  
Ct Scanner ◽  
Tertiary Institution ◽  
Dose Length Product ◽  
Volume Computed Tomography ◽  
The United Kingdom ◽  
Ct Protocol ◽  
Tube Current ◽  
Edo State ◽  
Computed Tomography Dose Index

Objective: The study is aimed at optimizing the existing CT protocol for head scans in a Specialist Teaching Hospital in Edo State with a 16-slice Siemens Somatom Emotion scanner. Also, the study determined the volume computed tomography dose index (CTDIvol) and Dose Length Product (DLP) from the patient's dose profiles. The results from this study were compared with relevant studies. Materials and Methods: The scanner was used to acquire head CT of 160 patients retrospectively. Also, a locally designed head phantom was used to simulate individual patients using a similar protocol by changing the tube current (mA) and total scan width (TSW) only from the existing protocol. Results: Percentage dose reduction (PDR) for the CTDIvol and DLP ranged 42.00-46.80% and 37.13-43.54% respectively. The optimized CTDIvol and DLP were lowest compared to studies in the United Kingdom (UK), Italy, India, Ireland, Sudan, Nigeria, European Commission (EC), United States of America (USA) and Japan. Only the DLP for India was lower than our optimized value. Conclusion: The need to understudy CT configuration is necessary, this will allow end-users to optimize certain parameters in the CT scanner, which will reduce the patient dose without compromising image quality

THE IMPACT OF HEAD POSITIONING ON THE IMAGE QUALITY OF MULTI-DETECTOR COMPUTED TOMOGRAPHY

2021 ◽  
pp. 2150050
Author(s):  
Yang-Ting Hsu ◽  
Jo-Chi Jao
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Control Group ◽  
Ct Scanner ◽  
Head Ct ◽  
Radiologic Technologists ◽  
Head Positioning ◽  
The Impact ◽  
Multi Detector Computed Tomography

Radiologic technologists face various types of patients during multi-detector computed tomography (CT) examinations. In emergency departments, it is common to have patients who cannot follow instructions for the examinations. The asymmetric axial view of the head CT might affect the correctness of the clinician’s diagnosis. This study aimed to assess the impact of head positioning on the image quality of head CT using two phantoms. All scans were performed on a 16-slice CT scanner. In the control group, the tilted angle of the phantoms was 0[Formula: see text], and no multiplanar reconstruction (MPR) was performed. In the experimental groups, the tilted angles of the phantoms were 5[Formula: see text], 10[Formula: see text] and 15[Formula: see text], respectively, and MPR was performed afterwards. The results showed that if the head was tilted during the head CT examinations, image asymmetry and artifacts appeared without MPR. After MPR, one phantom showed that there were significant differences and the other phantom showed no significant differences quantitatively in image symmetry and artifacts between experimental groups and the control group, while both phantoms showed no significant differences qualitatively in image symmetry and artifacts between experimental groups and the control group. Although MPR can correct the image asymmetry and artifacts caused by tilted head positioning to some extent, it consumes time. Therefore, technologists should position the head as exactly as possible when performing head CT examinations.

Conversion from dose-length product to effective dose in computed tomography venography of the lower extremities

2022 ◽  
Author(s):  
Yusuke Inoue ◽  
Yuka Yonekura ◽  
Kazunori Nagahara ◽  
Ayuka Uehara ◽  
Hideki Ikuma
Keyword(s):  
Computed Tomography ◽  
Effective Dose ◽  
Conversion Factor ◽  
Lower Extremities ◽  
Pulmonary Angiography ◽  
Ct Scanner ◽  
Dose Length Product ◽  
Ct Venography ◽  
Simplified Method ◽  
Imaging Conditions

Abstract For radiation dose assessement of computed tomography (CT), effective dose (ED) is often estimated by multiplying the dose-length product (DLP), provided automatically by the CT scanner, by a conversion factor. We investigated such conversion in CT venography of the lower extremities performed in conjunction with CT pulmonary angiography. The study subjects consisted of eight groups imaged using different scanners and different imaging conditions (five and three groups for the GE and Siemens scanners, respectively). Each group included 10 men and 10 women. The scan range was divided into four anatomical regions (trunk, proximal thigh, knee and distal leg), and DLP was calculated for each region (regional DLP). Regional DLP was multiplied by a conversion factor for the respective region, to convert it to ED. The sum of the ED values for the four regions was obtained as standard ED. Additionally, the sum of the four regional DLP values, an approximate of the scanner-derived DLP, was multiplied by the conversion factor for the trunk (0.015 mSv/mGy/cm), as a simplified method to obtain ED. When using the simplified method, ED was overestimated by 32.3%−70.2% and 56.5%−66.2% for the GE and Siemens scanners, respectively. The degree of overestimation was positively and closely correlated with the contribution of the middle and distal portions of the lower extremities to total radiation exposure. ED/DLP averaged within each group, corresponding to the conversion factor, was 0.0089−0.0114 and 0.0091−0.0096 mSv/mGy/cm for the GE and Siemens scanners, respectively. In CT venography of the lower extremities, ED is greatly overestimated by multiplying the scanner-derived DLP by the conversion factor for the trunk. The degree of overestimation varies widely depending on the imaging conditions. It is recommended to divide the scan range and calculate ED as a sum of regional ED values.

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