Development and evaluation of CT acquisition and analysis methods of brain perfusion Alan J ...

154 Pages·2014·2.5 MB·English

by  Alan Riordan

Development and evaluation of CT
acquisition and analysis methods of
brain perfusion

Alan J. Riordan
1
The printing of this thesis was kindly supported by Philips healthcare

Development and evaluation of CT acquisition and analysis methods of brain perfusion
PhD thesis, Utrecht University – with a summary in Dutch
© A.J. Riordan, Utrecht, 2014 [email protected] All rights reserved. No part of this publication may be
reproduced or transmitted in any form or by any means without permission in writing from the author. The
copyright of the articles that have been published or have been accepted for publication has been transferred
to the respective journals.
ISBN: 978-90-8891-990-9
Cover design and layout: Alan Riordan.
Printing by: Proefschriftmaken.nl || Uitgeverij BOXPress
2
Development and evaluation of CT
acquisition and analysis methods of
brain perfusion

Ontwikkeling en evaluatie van CT acquisitie- en analysemethoden voor
perfusiemetingen in de hersenen

(met een samenvatting in het Nederlands)

Proefschrift

ter verkrijging van de graad van doctor aan de Universiteit Utrecht op gezag van
de rector magnificus, prof.dr. G.J. van der Zwaan, ingevolge het besluit van het
college voor promoties in het openbaar te verdedigen op maandag 10 november
2014 des middags te 2.30 uur

door

Alan Jermiah Riordan

geboren op 5 januari 1983 te Cork, Ierland
3
Promotoren: Prof.dr.ir. M. A. Viergever
Prof.dr. W. M. Prokop

Copromotor: Dr. ir. H W. A. M. de Jong

4
CONTENTS
Chapter 1: Introduction .............................................. 9
Motivation ................................................................................................. 10
What is stroke? ........................................................................................ 10
Introduction to CTP .................................................................................. 11
Overview of a clinical CTP acute stroke assessment .............................. 13
Objective of this thesis ............................................................................. 23
Outline of the thesis ................................................................................. 24
Chapter 2: Validation of CT brain perfusion methods
using a realistic dynamic head phantom .................. 29
Abstract .................................................................................................... 30
Introduction............................................................................................... 31
Materials and methods ............................................................................. 32
Results ..................................................................................................... 41
Discussion and conclusions ..................................................................... 47
Chapter 3: Improvements in accuracy and dose
efficiency of CTP by application of a realistic digital
phantom ................................................................... 53
Abstract .................................................................................................... 54
Introduction: ............................................................................................. 55
Materials and methods: ............................................................................ 56
Results. .................................................................................................... 60
Discussion ................................................................................................ 66
Chapter 4: The Effect of Head Movement on CT
Perfusion Summary Maps: Simulations with CT Hybrid
Phantom Data .......................................................... 75
Abstract .................................................................................................... 76
Introduction............................................................................................... 76
5
Methods.................................................................................................... 77
Results ..................................................................................................... 80
Discussion ................................................................................................ 83
Chapter 5: A CT brain perfusion protocol to eliminate
the need for selecting a venous output function ....... 89
Abstract .................................................................................................... 90
Introduction............................................................................................... 91
Materials and methods ............................................................................. 92
Results ..................................................................................................... 96
Discussion .............................................................................................. 100
Chapter 6: Comparison of partial volume effects in
arterial and venous contrast curves in CT brain
perfusion imaging .................................................. 105
Abstract .................................................................................................. 106
Introduction............................................................................................. 107
Materials and methods ........................................................................... 108
Results ................................................................................................... 114
Discussion .............................................................................................. 117
Chapter 7: Summary and general discussion ......... 125
Chapter 2: Validation of CT brain perfusion methods using a realistic
dynamic head phantom .......................................................................... 126
Chapter 3: Improvements in accuracy and dose efficiency of CTP by
application of a realistic digital phantom. ............................................... 127
Chapter 4: The Effect of Head Movement on CT Perfusion Summary
Maps: Simulations with CT Hybrid Phantom Data ................................. 127
Chapter 5: CT Brain Perfusion Protocol to Eliminate the Need for
Selecting a Venous Output Function ..................................................... 128
Chapter 6 Comparison of partial volume effects in arterial and venous
contrast curves in CT brain perfusion imaging....................................... 130
Definition of an optimal CTP process ..................................................... 133
6
General discussion of limitations. .......................................................... 135
General conclusions ............................................................................... 137
Nederlandse Samenvatting .................................... 143
Achtergrond en motivatie ....................................................................... 144
CT perfusie beeldvorming ...................................................................... 144
Doel van het proefschrift ........................................................................ 145
Algemene conclusies ............................................................................. 148
List of publications and articles under
review/submitted .................................................... 149
Published:............................................................................................... 149
Submitted for publication: ....................................................................... 150
Acknowlegments .................................................... 151
Curriculum vitae ..................................................... 153

7
8
CHAPTER 1: INTRODUCTION

9
MOTIVATION
Stroke causes 9% of all deaths globally and is the second most common cause of
death after ischaemic heart disease, stroke-related disability is the sixth most common
cause of reduced disability-adjusted life-years and consumes more than 4% of direct
health-care costs in industrialised countries1-3. Strokes are either ischaemic or
haemorrhagic. Because the management of the stroke is so different for different
types, and extremities, of stroke the clinical distinction is important. This distinction
has been revolutionised by the introduction of CT and MRI with CT being the
workhorse of stroke diagnosis during the past 20 years.
Several treatment options are available, generally aimed at dissolving the obstructing
blood clot (thrombolysis) or removing it (thrombectomy). Accurate diagnosis is key in
treatment decision making. CT brain perfusion (CTP) is a promising tool assist
physicians in treatment decision for stroke patients due to its potential to quantify
various tissue perfusion parameters. However, as of yet the clinical usefulness of the
methodology has to be convincingly proven. CTP still lacks proper methods of
validation and consensus on scanner protocol and analysis methods.
The aim of this thesis is to examine the technical aspects of CTP, from scanner
protocol to diagnostic images, proposing methods and analyses that help to improve
the clinical usefulness of CTP.

WHAT IS STROKE?
There are two main types of stroke, haemorrhagic stroke (intracerebral haemorrhage),
and ischaemic stroke (reduced blood supply). About 80% of all strokes are ischaemic4,
the result of an obstruction of a cerebral artery interrupting or severely reducing the
blood supply to a part of the brain. Since measuring blood perfusion is the goal of CTP
this is the type of stroke that this work will focus on.
10