Colon dissection: a new three‐dimensional reconstruction tool for computed tomography colonography

2005 ◽  
Vol 46 (3) ◽  
pp. 222-226 ◽  
Author(s):  
R. Röttgen ◽  
F. Fischbach ◽  
M. Plotkin ◽  
H. Herzog ◽  
T. Freund ◽  
...  
Keyword(s):  
Computed Tomography ◽  
3D Reconstruction ◽  
Ct Colonography ◽  
Virtual Colonoscopy ◽  
Three Dimensional ◽  
Virtual Endoscopy ◽  
Helical Ct ◽  
Conventional Colonoscopy ◽  
Colon Polyps ◽  
The Difference

Purpose: To improve the sensitivity of computed tomography (CT) colonography in the detection of polyps by comparing the 3D reconstruction tool “colon dissection” and endoluminal view (virtual colonoscopy) with axial 2D reconstructions. Material and Methods: Forty‐eight patients (22 M, 26 F, mean age 57±21) were studied after intra‐anal air insufflation in the supine and prone positions using a 16‐slice helical CT (16×0.625 mm, pitch 1.7; detector rotation time 0.5 s; 160 mAs und 120 kV) and conventional colonoscopy. Two radiologists blinded to the results of the conventional colonoscopy analyzed the 3D reconstruction in virtual‐endoscopy mode, in colon‐dissection mode, and axial 2D slices. Results: Conventional colonoscopy revealed a total of 35 polyps in 15 patients; 33 polyps were disclosed by CT methods. Sensitivity and specificity for detecting colon polyps were 94% and 94%, respectively, when using the “colon dissection”, 89% and 94% when using “virtual endoscopy”, and 62% and 100% when using axial 2D reconstruction. Sensitivity in relation to the diameter of colon polyps with “colon dissection”, “virtual colonoscopy”, and axial 2D‐slices was: polyps with a diameter >5.0 mm, 100%, 100%, and 71%, respectively; polyps with a diameter of between 3 and 4.9 mm, 92%, 85%, and 46%; and polyps with a diameter <3 mm, 89%, 78%, and 56%. The difference between “virtual endoscopy” and “colon dissection” in diagnosing polyps up to 4.9 mm in diameter was statistically significant. Conclusion: 3D reconstruction software “colon dissection” improves sensitivity of CT colonography compared with the endoluminal view.

A retrospective evaluation of patient acceptance of computed tomography colonography (“virtual colonoscopy”) in comparison with conventional colonoscopy in an average risk screening population

2005 ◽  
Vol 46 (7) ◽  
pp. 664-670 ◽  
Author(s):  
M. S. Juchems ◽  
J. Ehmann ◽  
H.-J. Brambs ◽  
A. J. Aschoff
Keyword(s):  
Computed Tomography ◽  
Conventional Method ◽  
Ct Colonography ◽  
Virtual Colonoscopy ◽  
Conventional Colonoscopy ◽  
Patient Acceptance ◽  
Average Risk ◽  
Retrospective Evaluation ◽  
Examination Procedure ◽  
Screening Population

Purpose: To evaluate patient acceptance of computed tomography (CT) colonography compared with conventional colonoscopy by means of a self-assessed questionnaire. Material and Methods: Four-hundred-and-one patients with valid address information from our patient collective were preselected. Patient acceptance was evaluated retrospectively using a self-assessed questionnaire. The patients underwent CT colonography in our institution using 4× or 16× multi-detector row (MDR) CT. Two-hundred-and-forty-six patients returned a completed questionnaire, 157 of these indicating that they had undergone both virtual and conventional colonoscopy. Results: One-hundred-and-twenty (76.4%) of the 157 patients would undergo another CT colonography if necessary, while only 14 patients would not. One-hundred-and-sixteen (73.9%) patients favored the actual examination procedure of CT colonography ( P<0.0001), while only 6.4% preferred the conventional method. Preparation prior to CT colonography was experienced as more convenient than preparation prior to conventional colonoscopy (52.2% versus 14%). Conclusion: CT colonography was preferred in terms of both preparation and the actual procedure itself.

scholarly journals Research on the Computed Tomography Pebble Flow Detecting System for HTR-PM

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Xin Wan ◽  
Ximing Liu ◽  
Jichen Miao ◽  
Peng Cong ◽  
Yuai Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Helical Ct ◽  
Design Parameters ◽  
Three Dimensional Model ◽  
Safe Operation ◽  
Cross Sectional ◽  
Ct System ◽  
Near Future ◽  
Pebble Flow

Pebble dynamics is important for the safe operation of pebble-bed high temperature gas-cooled reactors and is a complicated problem of great concern. To investigate it more authentically, a computed tomography pebble flow detecting (CT-PFD) system has been constructed, in which a three-dimensional model is simulated according to the ratio of 1 : 5 with the core of HTR-PM. A multislice helical CT is utilized to acquire the reconstructed cross-sectional images of simulated pebbles, among which special tracer pebbles are designed to indicate pebble flow. Tracer pebbles can be recognized from many other background pebbles because of their heavy kernels that can be resolved in CT images. The detecting principle and design parameters of the system were demonstrated by a verification experiment on an existing CT system in this paper. Algorithms to automatically locate the three-dimensional coordinates of tracer pebbles and to rebuild the trajectory of each tracer pebble were presented and verified. The proposed pebble-detecting and tracking technique described in this paper will be implemented in the near future.

A volumetric three-dimensional evaluation of invasiveness of an endoscopic and microscopic approach for transmeatal visualisation of the middle ear

2021 ◽  
pp. 1-5
Author(s):  
A H A Baazil ◽  
J G G Dobbe ◽  
E van Spronsen ◽  
F A Ebbens ◽  
F G Dikkers ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Middle Ear ◽  
Three Dimensional ◽  
Endoscopic Approach ◽  
Microscopic Approach ◽  
Significant Difference ◽  
Computed Tomography Scans ◽  
The Difference ◽  
Group 2 ◽  
Group 1

Abstract Objective This study aimed to compare the necessary scutum defect for transmeatal visualisation of middle-ear landmarks between an endoscopic and microscopic approach. Method Human cadaveric heads were used. In group 1, middle-ear landmarks were visualised by endoscope (group 1 endoscopic approach) and subsequently by microscope (group 1 microscopic approach following endoscopy). In group 2, landmarks were visualised solely microscopically (group 2 microscopic approach). The amount of resected bone was evaluated via computed tomography scans. Results In the group 1 endoscopic approach, a median of 6.84 mm3 bone was resected. No statistically significant difference (Mann–Whitney U test, p = 0.163, U = 49.000) was found between the group 1 microscopic approach following endoscopy (median 17.84 mm3) and the group 2 microscopic approach (median 20.08 mm3), so these were combined. The difference between the group 1 endoscopic approach and the group 1 microscopic approach following endoscopy plus group 2 microscopic approach (median 18.16 mm3) was statistically significant (Mann–Whitney U test, p < 0.001, U = 18.000). Conclusion This study showed that endoscopic transmeatal visualisation of middle-ear landmarks preserves more of the bony scutum than a microscopic transmeatal approach.

Three-Dimensional Reconstruction and Numerical Simulation of Intracranial Aneurysm for Sectional Anatomy Based on Computed Tomography Angiography

2021 ◽  
Vol 11 (7) ◽  
pp. 1957-1962
Author(s):  
Xuefei Deng ◽  
Yu Liu ◽  
Qingling Meng ◽  
Danning Cao ◽  
Quan Bao ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Numerical Simulation ◽  
Intracranial Aneurysm ◽  
3D Reconstruction ◽  
Intracranial Aneurysms ◽  
Three Dimensional ◽  
Control Group ◽  
Observation Group ◽  
Intracranial Artery ◽  
Sectional Anatomy

Objective: The mortality of rebleeding after ruptured intracranial aneurysms was more than 40%. It is essential to identify the intracranial artery in sectional anatomy. However, it is difficult for students to understand the intracranial artery in the section. Therefore, the purpose of this study is to explore the application effect of three-dimensional (3D) reconstruction and numerical simulation of intracranial aneurysm for sectional anatomy based on computed tomography angiography (CTA). Method: Sixty students in medical imaging specialty of our university were divided into two groups. The control group was taught with conventional sectional anatomy and CT images, while the observation group was taught with 3D reconstruction and numerical simulation of intracranial aneurysm. The teaching characteristics and teaching effects were analyzed and compared between the two groups. Result: The 3D reconstruction can accurately express the size, direction, and adjacent relationship of aneurysms. Through rotation of the 3D image, students can easily understand the name and location of cerebral arteries. Combined with the function of 3D positioning, each blood vessel can automatically and accurately locate in the transverse, coronal, and sagittal plane. Abnormal wall shear stress was easily found in the intersection of cerebral artery circle, which was the physiological basis for the occurrence of aneurysms. There was a high shear zone in the root of an aneurysm, which was the physiological factor of rupture. The scores of sectional specimen identification, drawing examination, and theoretical assessment in the observation group were significantly higher than those in the control group (P < 0.05). Conclusion: The 3D reconstruction and numerical simulation can directly display the 3D morphological and physiological characteristics of intracranial aneurysms, which is convenient for students to understand and memorize. It can reach a good teaching effect in sectional anatomy.

scholarly journals Cone Beam Computed Tomography 3D Reconstruction of the Mandibular Condyle

2008 ◽  
Vol 78 (5) ◽  
pp. 880-888 ◽  
Author(s):  
Brian Schlueter ◽  
Ki Beom Kim ◽  
Donald Oliver ◽  
Gus Sortiropoulos
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
3D Reconstruction ◽  
Cone Beam Computed Tomography ◽  
Three Dimensional ◽  
Mandibular Condyle ◽  
Cone Beam ◽  
Low Density ◽  
Mineral Density ◽  
Linear Measurements

Abstract Objective: To determine the ideal window level and width needed for cone beam computed three-dimensional (3D) reconstruction of the condyle. Materials and Methods: Linear dimensions were measured with a digital caliper to assess the anatomic truth for 50 dry human mandibular condyles. Condyles were scanned with the i-CAT cone beam computed tomography (CBCT) and 3D-models were reconstructed. Three linear three-dimensional measurements were made on each of the 50 condyles at 8 different Hounsfield unit (HU) windows. These measurements were compared with the anatomic truth. Volumetric measurements were also completed on all 50 condyles, at 23 different window levels, to define the volumetric distribution of bone mineral density (BMD) within the condyle. Results: Significant differences were found in two of the three linear measurement groups at and below the recommended viewing window for osseous structures. The most accurate measurements were made within the soft tissue range for HU window levels. Volumetric distribution measurements revealed that the condyles were mostly comprised of low-density bone, and that condyles exhibiting significant changes in linear measurements were shown to have higher percentages of low-density bone than those condyles with little change from the anatomic truth. Conclusions: CBCT assessment of the mandibular condyle, using the 3D reconstruction, is most accurate when accomplished at density levels below that recommended for osseous examination. However, utilizing lower window levels which extend into the soft tissue range, may compromise one's capacity to view the bony topography.

Three-dimensional reconstruction based on images from spiral high-resolution computed tomography of the temporal bone: anatomy and clinical application

2005 ◽  
Vol 119 (9) ◽  
pp. 693-698 ◽  
Author(s):  
Beom-Cho Jun ◽  
Sun-Wha Song ◽  
Ju-Eun Cho ◽  
Chan-Soon Park ◽  
Dong-Hee Lee ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
3D Reconstruction ◽  
Temporal Bone ◽  
Three Dimensional ◽  
Image Data ◽  
Computer Assisted ◽  
Surface Rendering ◽  
High Resolution Computed Tomography

The aim of this study was to investigate the usefulness of a three-dimensional (3D) reconstruction of computed tomography (CT) images in determining the anatomy and topographic relationship between various important structures. Using 40 ears from 20 patients with various otological diseases, a 3D reconstruction based on the image data from spiral high-resolution CT was performed by segmentation, volume-rendering and surface-rendering algorithms on a personal computer. The 3D display of the middle and inner ear structures was demonstrated in detail. Computer-assisted measurements, many of which could not be easily measured in vivo, of the reconstructed structures provided accurate anatomic details that improved the surgeon’s understanding of spatial relationships. A 3D reconstruction of temporal bone CT might be useful for education and increasing understanding of the anatomical structures of the temporal bone. However, it will be necessary to confirm the correlation between the 3D reconstructed images and histological sections through a validation study.

Detection of Colorectal Lesions: Lower-Dose Multi–Detector Row Helical CT Colonography Compared with Conventional Colonoscopy

Radiology ◽  
2003 ◽  
Vol 229 (3) ◽  
pp. 775-781 ◽  
Author(s):  
Riccardo Iannaccone ◽  
Andrea Laghi ◽  
Carlo Catalano ◽  
James A. Brink ◽  
Filippo Mangiapane ◽  
...  
Keyword(s):  
Ct Colonography ◽  
Helical Ct ◽  
Conventional Colonoscopy

Stress Radiography and Stress Examination of the Talocrural and Subtalar Joint on Helical Computed Tomography

1997 ◽  
Vol 18 (8) ◽  
pp. 482-488 ◽  
Author(s):  
F.J. van Hellemondt ◽  
J.W.K. Louwerens ◽  
E.S. Sijbrandij ◽  
A.P.G. van Gils
Keyword(s):  
Computed Tomography ◽  
Subtalar Joint ◽  
Facet Joint ◽  
Three Dimensional ◽  
Helical Ct ◽  
Helical Computed Tomography ◽  
Chronic Instability ◽  
Significant Difference ◽  
Subtalar Instability ◽  
Stress Examination

The main objective of this study was to compare subtalar inversion stress views using the Brodén view with inversion stress views on helical computed tomography (CT). One of the drawbacks of routine radiography is the imaging of three-dimensional structures in a two-dimensional plane. We investigated whether the use of helical CT would lead to a more objective and clearer measurable method to determine the amount of tilt in the subtalar joint. A group of 15 patients with unilateral chronic instability complaints and clinically suspected subtalar instability was examined. The contralateral asymptomatic foot was used as control. A variable amount of subtalar tilt (range, 4° to 18°) was demonstrated in all cases on stress radiographs, without finding significant difference between the symptomatic and asymptomatic feet. However, contrary to the findings at the talocrural level, subtalar tilt was found in none of the patients using helical CT. Thus, we now doubt that the tilt seen during stress examination using the Brodén view is the true amount of tilt. It may be that the lateral opening, seen on these radiographs, largely results from imaging two planes that have made a translatory and rotatory movement relative to each other in an oblique direction. It is concluded that the Brodén stress examination might not be useful for screening patients with subtalar instability. Associated anomalies not visible on the radiographs were detected by helical CT. In four cases, narrowing of the articular cartilage and irregular and hypertrophic bone formation at the middle facet joint of the subtalar joints were found. It is likely that these changes cause disturbance of function of this joint and it is suggested that the subjective complaint of instability with “giving way” is not only caused by hypermobility, but can be caused by other disturbances of normal motion.

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