CONVERSION OF CONE BEAM CT

Conversion of Cone Beam CT Date Sets to Voxel Numbers using Matlab for dose calculation.

Abstract

The objective of this work was to describe a clinical mega-voltage cone-beam computed tomography (MV CBCT) system, present the image acquisition and patient setup procedure, discuss the positioning accuracy and image quality, and illustrate its potential use for image-guided radiation therapy (IGRT) through selected clinical examples. The MV CBCT system consists of a standard linear accelerator equipped with an amorphous-silicon flat panel electronic portal-imaging device adapted for mega-electron volt (MeV) photons. An integrated computer workspace provides automated acquisition of projection images, image reconstruction, CT to CBCT image registration, and couch shift calculation. The system demonstrates submillimeter localization precision and sufficient soft-tissue resolution to visualize structures such as the prostate. In our clinic, we have used the MV CBCT system to detect nonrigid spinal cord distortions, monitor tumor growth and shrinkage, and locate and position stationary tumors in the lung. MV CBCT has also greatly improved the delineation of structures in CT images that suffer from metal artifacts. MV CBCT has undergone significant development in the last few years. Current image quality has already proven sufficient for many IGRT applications. Moreover, we expect the range of clinical applications for MV CBCT to grow as imaging technology continues to improve.

Table of Content

ABSTRACT2

CHAPTER ONE5

INTRODUCTION5

CHAPTER TWO8

LITERATURE REVIEW8

REFERENCES29

Chapter One

Introduction

External-beam emission treatment for malignant tumors aspires to sterilize tumor clones while maintaining the body part from which the tumor originates and the surrounding usual tissues. Since the late 1980s, procedures to goal the tumor remedy capacity have step-by-step developed in step with accelerating health imaging technologies adept of three-dimensional (3D) and even four-dimensional (4D) capacity imaging. Current technologies, for example intensity-modulated emission treatment (IMRT) and image-guided emission treatment allow more unquestionable and conformal dose designing and consignment to goal volumes.(1-7) Ideally, throughout designing and consignment, the accurate position and form of the tumor relation to the beam geometry characterised by a health linear accelerator would be known. Although the foregoing assumption is agreeable for tumors in the mind or beside the body exterior, a favorable rigid-body connection does not live in anatomic sites for example the thoracic cavity and the abdomen, predominantly because of respiratory motion. (Bortfeld, 2002, 2203) When the tumor and its bearing body part undergo shift and deformation throughout emission treatment consignment, important discrepancies between the designed and consigned emission doses have been reported. (Bortfeld, 2002, 2203)

 

Key characteristics of Cone Beam CT (CBCT)

Volumetric scanning

Dual and triple scanning

Large aperture dimensions

High value images

 

Benefits of Cone Beam CT (CBCT)

CBCT comes by a capacity of likeness facts and numbers in one 360 stage rotation of the gantry taking 45 seconds.

Up to 45 centimetres of likeness facts and numbers can be came by utilising the automated dual and triple scanning techniques.

Patients can be scrutinized in the genuine remedy position. No alteration to remedy set ups require to be made.

Images can be utilised for designing and/or verification, supplying added CT assets in the identical room as ...