425 research outputs found
Colon centreline calculation for CT colonography using optimised 3D opological thinning
CT colonography is an emerging technique for colorectal
cancer screening. This technique facilitates noninvasive
imaging of the colon interior by generating virtual
reality models of the colon lumen. Manual navigation
through these models is a slow and tedious process.
It is possible to automate navigation by calculating the centreline
of the colon lumen. There are numerous well documented
approaches for centreline calculation. Many of
these techniques have been developed as alternatives to 3D
topological thinning which has been discounted by others
due to its computationally intensive nature. This paper describes
a fully automated, optimised version of 3D topological
thinning that has been specifically developed for calculating
the centreline of the human colon
Development of a synthetic phantom for the selection of optimal scanning parameters in CAD-CT colonography
The aim of this paper is to present the development of a synthetic phantom that can be used for the selection of optimal scanning parameters in computed tomography (CT) colonography. In this paper we attempt to evaluate the influence of the main scanning parameters including slice thickness, reconstruction interval, field of view, table speed and radiation dose on the overall performance of a computer aided detection (CAD)âCTC system. From these parameters the radiation dose received a special attention, as the major problem associated with CTC is the patient exposure to significant levels of ionising radiation. To examine the influence of the scanning parameters we performed 51 CT scans where the spread of scanning parameters was divided into seven different protocols. A large number of experimental tests were performed and the results analysed. The results show that automatic polyp detection is feasible even in cases when the CADâCTC system was applied to low dose CT data acquired with the following protocol: 13 mAs/rotation with collimation of 1.5 mm Ă 16 mm, slice thickness of 3.0 mm, reconstruction interval of 1.5 mm, table speed of 30 mm per rotation. The CT phantom data acquired using this protocol was analysed by an automated CADâCTC system and the experimental results indicate that our system identified all clinically significant polyps (i.e. larger than 5 mm)
Focal Spot, Spring 1999
https://digitalcommons.wustl.edu/focal_spot_archives/1081/thumbnail.jp
A. Training Simulators for Gastrointestinal Endoscopy: Current and Future Perspectives
Over the last decades, visual endoscopy has become a gold standard for the detection and treatment of gastrointestinal cancers. However, mastering endoscopic procedures is complex and requires long hours of practice. In this context, simulation-based training represents a valuable opportunity for acquiring technical and cognitive skills, suiting the different traineesâ learning pace and limiting the risks for the patients. In this regard, the present contribution aims to present a critical and comprehensive review of the current technology for gastrointestinal (GI) endoscopy training, including both commercial products and platforms at a research stage. Not limited to it, the recent revolution played by the technological advancements in the fields of robotics, artificial intelligence, virtual/augmented reality, and computational tools on simulation-based learning is documented and discussed. Finally, considerations on the future trend of this application field are drawn, highlighting the impact of the most recent pandemic and the current demographic trends
Techniques, Clinical Applications and Limitations of 3D Reconstruction in CT of the Abdomen
Enhanced z-axis coverage with thin overlapping slices in breath-hold acquisitions with multidetector CT (MDCT) has considerably enhanced the quality of multiplanar 3D reconstruction. This pictorial essay describes the improvements in 3D reconstruction and technical aspects of 3D reconstruction and rendering techniques available for abdominal imaging. Clinical applications of 3D imaging in abdomen including liver, pancreaticobiliary system, urinary and gastrointestinal tracts and imaging before and after transplantation are discussed. In addition, this article briefly discusses the disadvantages of thin-slice acquisitions including increasing numbers of transverse images, which must be reviewed by the radiologist
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