Essays about: "cone-beam"

Showing result 21 - 25 of 33 essays containing the word cone-beam.

1. 21. Segmentation of Cone Beam CT in Stereotactic Radiosurgery

   University essay from KTH/Skolan för teknik och hälsa (STH)

   Author : Awais Ashfaq; [2016]
   Keywords : Cone Beam CT; Convolutional Neural Networks; Image Segmentation; Leksell Gamma Knife Icon; Deep Learning.; Cone Beam CT; neurala nätverk baserade på faltning; bildsegmentering; Leksell Gamma Knife Icon; Djup inlärning.;

   Abstract : C-arm Cone Beam CT (CBCT) systems – due to compact size, flexible geometry and low radiation exposure – inaugurated the era of on-board 3D image guidance in therapeutic and surgical procedures. Leksell Gamma Knife Icon by Elekta introduced an integrated CBCT system to determine patient position prior to surgical session, thus advancing to a paradigm shift in facilitating frameless stereotactic radiosurgeries. READ MORE

3. 22. Effect of bladder volume changes and verification of CTV on CBCT for rectal cancer patients

   University essay from Lunds universitet/Medicinsk strålningsfysik, Lund; Lunds universitet/Sjukhusfysikerutbildningen

   Author : Lina Andersson; [2016]
   Keywords : Medicine and Health Sciences;

   Abstract : Background and purpose: During radiotherapy, rectal cancer patients show inter-fractional internal motion that effects the delivered dose distribution. The purpose of this work is to study I) the inter-fractional bladder volume change, II) the effect of bladder volume change on bowel dose distribution, III) the effect of bladder optimization on the relationship between bladder volume and bowel dose and IV) the possibilities and difficulties of validating the clinical target volume (CTV) using a surrogate on cone-beam computed tomography (CBCT) scans. READ MORE

4. 23. 3D/2D Image Registration for Patient Positioning in Stereotactic Radiosurgery

   University essay from KTH/Skolan för datavetenskap och kommunikation (CSC)

   Author : Simon Hössjer; [2015]
   Keywords : 3D 2D; Image Registration; Radiosurgery;

   Abstract : In the application of stereotactic radiosurgery for treatment of brain tumors it is imperative that patients are positioned with sub-millimetre accuracy so as to not damage surrounding healthy tissue during treatment. We investigate how feasible the technique of digitally reconstructed radiographs is as a registration method for patient positioning in this type of high-accuracy application. READ MORE

5. 24. Micro-CT for small animal imaging : Optimization of the tube voltage for low-contrast imaging

   University essay from KTH/Skolan för teknik och hälsa (STH)

   Author : Massimo Terrin; [2015]
   Keywords : ;

   Abstract : This master thesis evaluated the optimal tube voltage for low-contrast imaging of a micro-CT system (intended for small animal imaging) built at the School of Technology and Health (STH) of the Royal Institute of Technology (KTH). The main goal of this work was to calibrate the above-mentioned device (composed moreover by a Hamamatsu microfocus L10951-01 X-ray tube, a CMOS flat panel Hamamatsu C7942CA-22 and using a Cone-Beam CT reconstruction algorithm) for obtaining the best imaging of low-contrast structures. READ MORE

6. 25. Geometric Misalignment Calibration and Detector Lag Effect Artifact Correction in a Cone-Beam Flat Panel micro-CT System for Small Animal Imaging

   University essay from KTH/Skolan för teknik och hälsa (STH)

   Author : Lorenzo Di Sopra; [2015]
   Keywords : medical; engineering; imaging; CT; microCT; animal; calibration; misalignment; geometric; detector; lag effect; artifact; correction; cone-beam; flat panel;

   Abstract : The cone-beam flat panel micro-CT is a high definition imaging system. It acquires projections of an object or animal to reconstruct a 3D image of its internal structure. The device is basically composed by a radiation tube and a detector panel, which are fixed to a gantry that rotates all around the test subject. READ MORE