Frans W. Zonneveld INIS-mf--11125 ComputedTomography of the Temporal Bone and Orbit Technique of Direct Multiplanar, High-resolution CTand Correlative Cryosectional Anatomy Urban & Munich Schwarzenberg Baltimore RIJKSUNIVERSITEIT UTRECHT COMPUTED TOMOGRAPHY OF THE TEMPORAL BONE AND ORBIT Technique of Direct Multiplanar, High-resolution CT and Correlative Cryosectional Anatomy Computer tomografie van het os temporale en de orbita; directe hoge resolutie techniek in meerdere vlakken en gecorreleerd met cryomicrotomische coupe- anatomie. (Met een samenvatting in het Nederlands) PROEFSCHRIFT ter verkrijging van de graad van doctor in de genees- kunde aan de Rijksuniversiteit te Utrecht, op gezag van de rector magnificus Prof. Dr. J.A. van Ginkel, volgens besluit van het college van dekanen in het openbaar te verdedigen op dinsdag20 oktober 1987 des namiddags te 4.15 uur door FRANS WESSEL ZONNEVELD geboren op 15 September 1944 te Eindhoven URBAN & SCHWARZENBERG • MUNICH - WIEN - BALTIMORE 1987 PROMOTORES: Prof. Dr. P.F.G.M. van Waes Prof. Dr. E.H. Huizing REFERENT: Dr. L. Koornneef to my parents to Inez, Lizan and Wessel ACKNOWLEDGEMENTS The studies that form the basis for this book were Groningen), for their help with the cryosection- carried out at the Departments of Diagnostic ing of the orbit. Radiology of the Utrecht University Hospital, the One of my colleagues at Philips Medical Sys- University of Amsterdam, the Free University tems Division, Mr John Op de Beek, has for many Amsterdam in the Netherlands and the Uppsala years been a helpful supporter and companion in University Hospital in Sweden, the Departments studying the technical aspects of computed to- of Anatomy and Embryology of the Universities mography. I am very grateful for this. of Groningen and Utrecht, the Department of I have greatly appreciated the helpful suggestions Ophthalmology of the University of Amsterdam, and scientific judgement of Professor W.J. van the Department of Otorhinolaryngology cf the Doorenmaalen (head of the Department of University of Utrecht and at the Philips Medical Anatomy and Embryology, Utrecht), Professor Systems Division at Best. H. Verbiest (former head of the Department of The list of all those to whom I am indebted, Neurosurgery, Utrecht), Professor G.M. Bleeker colleagues, secretaries, library staff, medical staff (former head of the Orbital Center in Amster- and especially the patients whose examinations dam), Professor J.J. Denier van der Gon (head of form the raw material of this study, is too long to the Department of Medical Physics), Professor allow me to mention them personally. However, J.H. van Bemmel (head of the Department of in extending this first collective word of gratitude, Medical Informatics, Free University Amster- I am conscious of my obligation to each of them dam) and Professor J.C. van der Meulen (head of individually. the Department of Plastic and Reconstructive I am personally very much indebted to Pro- Surgery, Erasmus University, Rotterdam). fessor Paul van Waes for his continuous stimulat- The correlative anatomy in this study could not ing enthusiasm, support and, especially, for his have been realized without the specimens that confidence in my high-resolution CT imaging en- have been made available by the Departments of deavors, to Dr Leo Koornneef (head of the Orbi- Anatomy and Embryology of the Universities of tal Center of the University of Amsterdam) for Amsterdam, Utrecht and Groningen, and the his valuable advice and the tremendous amount Free University Amsterdam. I am extremely of time he spent in guiding the ophthalmological thankful for this, as well as for the preparatory (orbital) aspects of my work and in the numerous work in this respect by Hans Kemperman. discussions about radiology and its clinical use- A special word of thanks is due to the radiologic fulness, and to Professor Egbert Huizing (head technologists (the pioneering work was done by of the Department of Otorhinolaryngology Anncke Hamersma and Wilma Pauw), residents Utrecht) and Dr John de Groot for their guidance and staff of the Departments of Diagnostic and advice with respect to the many otological Radiology of the Utrecht University Hospital, aspects of this study. Free University Amsterdam and University of I also owe a very great deal to Dr Hermann Amsterdam for accurately carrying out and super- Wilbrand (Department of Diagnostic Radiology vising the CT examinations. This appreciation of the University of Uppsala, Sweden) for his applies also to Jan Neggers for making the draw- scientific support, his critical remarks at a very ings, Jan dc Groot, Marcel Metselaar and Joop detailed level and, especially, for his help with the Ramackers for carrying out the CT photography cryosectioning of the temporal bone specimens. and Bert Deddens for the cryosectioning photo- This also applies to Dr Berend Hillen, Dr Peter graphy. I would also like to thank Steven Lobregt Gerrits and Babs van Leeuwen (Laboratory of for reconstruction of 3-D images, Thijs Adriaansz Anatomy and Embryology, University of for computational support in geometrical simula- Acknowledgements tions. Frits Meeuwsen for performing the detailed the University Hospital in Mainz). Professor orbital histological microtomy and I should also W.N. Hanafee, (Department of Diagnostic- like to extend my grateful thanks to James Lee for Radiology, University of California, Los Ange- his linguistic support. les), Dr Wolfgang Rauschning (Department of I owe a great deal to the Philips Medical Systems Orthopedic Surgery, Uppsala, Sweden) who did Division for giving me the opportunity and means pioneering work in cryosectioning, Dr Frits Bar- to carry out this study in addition to my job. I tels (Department of Otorhinolaryngology. thank Cemax Inc. (Santa Clara, CA, U.S.A.) for Leeuwarden Hospital), who initiated my interest a few special 3-D reconstructions. in the temporal bone, Dr Martin Hendriks, who I wish to acknowledge the hospitality extended to convinced me to select this medical subject of me over the last eight years by the heads of the study, Dr Henk Damsma, who, as the head and Department of Diagnostic Radiology at Utrecht: neck radiologist in Utrecht, has supported my Professor Carl Puylaert and Professor Kees work in more than just the medical aspects. Dr Klinkhamer. I thank the staff of this department Willem Mali, who convinced me to write a mono- for their support and willingness to answer my graph instead of using separate publications, Dr questions and to discuss medical topics. This has Ragnhild de Slegte and Professor Jaap Valk (De- facilitated my integration into the department partment of Neuroradiology at the Free Universi- and has formed the medical basis for my work. I ty Amsterdam) who, to an enormous extent, thank them for creating the stimulating atmos- stimulated the use and development of systematic phere that is necessary for a fruitful undertaking. CT investigations of the orbit. I should also like to mention a few people who, Last but not least, I thank my parents for through their moral support and enthusiam, have creating the opportunities for following the edu- indirectly but significantly contributed to the initi- cation that finally made this dissertation possible. ation and realization of this study: Professor J. I thank my wife Inez, my daughter Lizan and my Vignaud (head of the Department of Diagnostic son Wessel for accepting my dedication of a Radiology of the Fondation OphthSlmologique number of good years of our own lives accom- A. dc Rothschild, Paris), Professor S. Wende, plishing this study. (head of the Department of Neuroradiology at October, 1987. CONTENTS Acknowledgements V 2.5 Image plane orientation 41 Contents VII 2.5.1 Multiplanar reformatting 41 Summary IX 2.5.2 Direct multiplanar scanning .... 41 General introduction X 2.6 3-D surface illumination imaging. 42 2.7 Trade-off considerations 45 References 48 Chapter 1 Principles of computed tomography ... 1 Chapter 3 1.1 Introduction 1 1.2 The concept of CT 1 Technique of cryosectioning 53 1.3* CT scanner generations 3 3.1 Introduction 53 1.4 Image quality parameters 3 3.2 Preparation 55 1.4.1 Spatial resolution 3 3.2.1 Specimen preparation 55 1.4.2 Partial volume averaging 11 3.2.2 CT of the specimen 55 1.4.3 Contrast resolution 12 3.2.3 Specimen block sectioning 57 1.4.4 Artifacts 13 3.2.4 Specimen block mounting 57 1.4.5 Image display and photography . 14 3.3 Cryomicrotomy and photography . 58 1.5 Conclusions 19 3.3.1 Cryomicrotome 58 References 19 3.3.2 Cryosectioning 59 3.3.3 Photographic set-up 60 3.3.4 Section preservation and staining . 61 Chapter 2 References 62 Technique of high-resolution CT 25 2.1 Introduction 25 Chapter 4 2.2 X-ray pencil beam geometry .... 25 2.2.1 Pencil beam width, divergence and Temporal bone imaging 65 attenuation distribution 26 4.1 Introduction 65 2.2.2 Pencil beam height, divergence and 4.2 Patient positioning 65 penumbra radiation 27 4.2.1 Definition of the scan planes . ... 66 2.3 Improvement of spatial 4.2.2 Patient positioning methods and resolution 29 accessories 70 2.3.1 Edge enhancement 29 4.2.3 Modified positions 75 2.3.2 Geometric enlargement 31 4.3 Patient examination 75 2.3.3 Scanner generation dependency of 4.3.1 Patient preparation 75 X-ray geometry 33 4.3.2 Patient instruction 75 2.3.4 MacroView reconstruction 36 4.3.3 Imaging sequence 76 2.4 Reduction of partial volume 4.3.4 Image display and photography . 76 averaging 37 4.3.5 Special techniques (air cisternogra- 2.4.1 Improvement of image phy.Valsalva maneuver) 77 sharpness 37 4.4 Correlative anatomy . ....... 77 2.4.2 Radiation dose and noise 39 4.4.1 Transverse plane 78 2.4.3 Partial volume artifacts 40 4.4.2 Coronal plane 88 VII Contents 4.4.3 Sagittal plane .' 93 6.3.4 Image display and photography • • 141 4.4.4 Semiaxial plane 98 6.3.5 Special techniques (Valsalva) ..