Sơ lược về CT giúp người đọc nhanh chóng nắm bắt được kiến thức cốt lõi và kỹ năng cần thiết để chụp cắt lớp vi tính (CT. Được thành lập bởi các tổ chức chụp X quang lớn trên thế giới, bao gồm ASRT và CAMRT. Tiêu đề hoàn toàn mới này mô tả khoa học cơ bản đằng sau CT với sự nhấn mạnh vào lý thuyết cần thiết cho thực hành. Với vô số hình ảnh minh họa, giải thích ngắn gọn, dễ hiểu và hướng dẫn rõ ràng, từng bước, nó bao gồm các nguyên tắc vật lý cơ bản, kỹ thuật, và các chiến lược và thủ tục hình ảnh liên quan đến quét CT. Trong suốt 24 chương môđun ngắn gọn, CT trong nháy mắt bao gồm tất cả các cơ sở cho sinh viên bắt đầu thực hành, bao gồm: Vật lý cơ bản làm cơ sở quét CT Công nghệ multislice hiện đại Chiến lược thu thập dữ liệu Các bộ phận của thiết bị—chức năng và ứng dụng của chúng Tái tạo hình ảnh và kiểm soát chất lượng hình ảnh Liều CT và quy trình tối ưu hóa liều Cơ sở kiểm soát chất lượng Sơ lược về CT là tài nguyên học tập không thể thiếu cho sinh viên các khóa học công nghệ hình ảnh y tế, bao gồm các khóa học về chụp X quang, y học hạt nhân và xạ trị, cũng như cho sinh viên công nghệ kỹ thuật y sinh.
This title is also available as an e-book For more details, please see www.wiley.com/buy/9781118660904 CT at a Glance First Edition Euclid Seeram, PhD, MSc, BSc, FCAMRT Medical Imaging and Radiation Sciences, Honorary Senior Lecturer, Faculty of Health Science, University of Sydney, Australia; Adjunct Associate Professor, Medicine, Nursing, and Health Sciences, Monash University, Australia; Adjunct Professor, Faculty of Science, Charles Sturt University, Australia; Adjunct Associate Professor, Faculty of Health, University of Canberra, Australia This edition first published 2018 © 2018 by John Wiley & Sons Ltd All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by law Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions The right of Euclid Seeram to be identified as the author of this work has been asserted in accordance with law Registered Offices: John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial Office: 9600 Garsington Road, Oxford, OX4 2DQ, UK For details of our global editorial offices, customer services, and more information about Wiley products visit us at www.wiley.com Wiley also publishes its books in a variety of electronic formats and by print-on-demand Some content that appears in standard print versions of this book may not be available in other formats Limit of Liability/Disclaimer of Warranty The contents of this work are intended to further general scientific research, understanding, and discussion only and are not intended and should not be relied upon as recommending or promoting scientific method, diagnosis, or treatment by physicians for any particular patient In view of ongoing research, equipment modifications, changes in governmental regulations, and the constant flow of information relating to the use of medicines, equipment, and devices, the reader is urged to review and evaluate the information provided in the package insert or instructions for each medicine, equipment, or device for, among other things, any changes in the instructions or indication of usage and for added warnings and precautions While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make This work is sold with the understanding that the publisher is not engaged in rendering professional services The advice and strategies contained herein may not be suitable for your situation You should consult with a specialist where appropriate Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages Library of Congress Cataloging-in-Publication Data Names: Seeram, Euclid, author Title: CT at a glance / Euclid Seeram, PhD., MSc., BSc., FCAMRT Description: Hoboken, NJ : John Wiley & Sons, 2017 | Includes index | Identifiers: LCCN 2017025967 (print) | LCCN 2017040984 (ebook) | ISBN 9781118660881 (pdf) | ISBN 9781118660898 (epub) | ISBN 9781118660904 (pbk.) Subjects: LCSH: Tomography Classification: LCC RC78.7.T6 (ebook) | LCC RC78.7.T6 S3715 2017 (print) | DDC 616.07/57—dc23 LC record available at https://lccn.loc.gov/2017025967 Cover image: © Phil Boorman/Gettyimages Cover design by Wiley This book is dedicated with love and affection to my beautiful, smart, and overall cute and witty granddaughters CLAIRE and CHARLOTTE You bring so much joy and happiness to our lives Contents Foreword Preface Acknowledgements Computed tomography: an overview Introduction Radiographic imaging CT imaging Nobel prize for the invention of the CT scanner The technical evolution of CT Major components of a CT scanner Major system components The imaging system The computer system Display, storage, and communication system CT software How CT scanners work Essential steps in the production of CT images The flow of data in a CT scanner The technical evolution of CT Advantages and shortcomings of CT Data acquisition principles Data acquisition methods Data acquisition geometries Data acquisition components X-ray tubes and generator technologies The X-ray generator X-ray tubes X-ray beam filtration and collimation What is a filter? The CT filter X-ray beam collimation Adaptive section collimation Essential physics: radiation attenuation What is radiation attenuation? Attenuation of a homogeneous beam of radiation Attenuation of a heterogeneous beam of radiation Lambert–Beer law Attenuation measurements and CT numbers Attenuation measurements and CT numbers CT numbers and the CT gray-scale image CT numbers for various tissues CT detector technology basics Location and purpose of the CT detectors Characteristics of CT detectors Types of detectors The data acquisition system 10 CT image reconstruction basics Major steps in CT Image reconstruction basics Categories of reconstruction algorithms Iterative algorithms 11 CT image display and storage Three major systems in ct imaging Image display characteristics Image storage “histogram modification (stretching)” see windowing history of CT Hospital Information System (HIS) Hounsfield, Godfrey Newbold Hounsfield scale Hsieh, Jiang image (CT) see CT imaging; digital image; gray-scale image image brightness image contrast image display characteristics image fidelity, optimization image postprocessing linear and non-linear software see also windowing image quality artifacts see artifacts assessment, phantoms contrast resolution see contrast resolution dose and iterative reconstruction algorithms and noise see noise parameters affecting spatial resolution see spatial resolution temporal resolution see temporal resolution window width/level effect on image quality criteria (IQC) image reconstruction definitions overview projection profiles software image reconstruction algorithm analytical methods Back Projection (BP) categories FBP see Filtered Back Projection (FBP) algorithm in-plane spatial resolution iterative see iterative reconstruction (IR) algorithms image storage see storage of images imaging system see also CT imaging; scanner (CT) innovations, CT in-plane spatial resolution integrated console International Atomic Energy Agency (IAEA) International Commission on Radiological Protection (ICRP) internet browser technology interpolation IR loop iterative cycle iterative reconstruction (IR) algorithms dose optimization FBP algorithm vs justification, CT kilovoltage (kV) contrast resolution and dose optimization noise and Lambert–Beer law linear attenuation coefficient (μ) linear dose–response model without threshold (LNT) linear image processing line pairs matrix array detector matrix size maximum intensity projection (MIP) megabytes, CT image microcomputer milliamperage (mA) see tube current (mA) minimum intensity projection (MIP) MSCT see multislice spiral/helical CT (MSCT) multi-detector CT (MDCT) see multislice spiral/helical CT (MSCT) multiplanar reformation (MPR) multislice spiral/helical CT (MSCT) advantages beam geometry for beating heart collimation effect on slice thickness collimation scheme dose optimization FBP algorithm image quality interpolation number of images pitch principles selectable scan parameters slice-by-slice data acquisition vs slice geometry technical requirements volume visualization image processing multislice spiral/helical (MSCT) scanners detector configurations detector types evolution slip rings volume scanning by networking, and networks Nobel Prize in Medicine (1979) noise definition factors affecting high low measurement phantom vs patient images quality control tests reduction, dose optimization reduction, iterative algorithms non-linear image processing operating console optimization dose see dose optimization radiation protection overbeaming overranging partial volume averaging artifacts patient motion, artifact pencil beam geometry pencil ionization chamber phantoms categories CT quality control dose distribution measurement noise measurement photodiodes photons see X-ray photons Picture Archiving and Communication System (PACS) components controller definition pitch, MSCT pixel size planar images planar section postpatient collimator postprocessing of CT image see image postprocessing potential difference (kV) see also kilovoltage (kV) predetector collimator prepatient collimators preprocessing software primary scan parameters (PSPs) principles of CT processing hardware projection profiles quality assessment quality control (QC) definition and goal frequency of testing phantoms for measuring steps in QC program tests radiation attenuation see attenuation (radiation) background reduction radiation exposure risks radiation protection diagnostic reference levels dose optimization optimization optimization checklist regulations and guidance safety campaigns radiographic imaging spatial and contrast resolution Radiology Information System (RIS) reconstruction see image reconstruction reconstruction algorithm see image reconstruction algorithm reconstruction circle reference detector reformatted raw data relative transmission resolution, image see contrast resolution; spatial resolution rotating anode X-ray tube scaling factor scan field of view (SCOV) scan length, dose–length product and scanner (CT) components developments from prototype flow of data generations of method of operation MSCT see multislice spiral/helical (MSCT) scanners quality control program scan speed scan times scintillation detectors secondary reconstruction parameters (SRPs) single-slice CT (SSCT) conventional development planar section slice geometry spiral/helical single-slice whole-body scanners sinogram slice sensitivity profile (SSP) slice thickness dose optimization noise affected by spatial resolution slip rings soft-copy display workstation software, CT spatial frequency spatial resolution cross-plane (Z-axis) definition and objective dose optimization in-plane (X-Y axis) radiographic vs CT image spiral/helical CT advantages dose optimization and dual-slice multislice see multislice spiral/helical CT (MSCT) single-slice X-ray tubes for spiral/helical geometry SSCT see single-slice CT (SSCT) stochastic effects storage devices storage of images as numerical image see also Picture Archiving and Communication System (PACS) surface shaded display technological developments temporal resolution thermionic emission three-dimensional (3D) CT images tissues contrast resolution CT numbers window width and level tolerance limits transmission readings transverse axial images tube see X-ray tube tube current (mA) contrast resolution and dose optimization effective mAs low-dose CT, noise volume scanning (MSCT) X-ray photon quantity two-dimensional transverse axial CT images visualization software voltage selection, automatic volume data acquisition see also multislice spiral/helical CT (MSCT) volume rendered 3D image volume scanning see also multislice spiral/helical CT (MSCT) volume visualization image processing voxel water attenuation of homogenous beam CT number web server windowing overview window level (WL) effect on image quality window width (WW) effect on image quality workstation, CT X-ray(s) low-energy, filtration X-ray beam attenuation see attenuation (radiation) collimation see collimation filtration geometries hardening heterogeneous homogeneous in MSCT photons see X-ray photons quantity and quality reference spiral/helical geometry width X-ray beam filter X-ray generator X-ray photons low-/high-energy quantity (mA) and quality (kV) X-ray tube alloys used for components (cathode/anode) continuous rotation, volume scanning current see tube current (mA) generator coupled to heat dissipation heat storage capacity rotating anode single or dual spiral/helical path voltage X-Y axis image resolution Z-axis of scanner Z-interpolation WILEY END USER LICENSE AGREEMENT Go to www.wiley.com/go/eula to access Wiley’s ebook EULA