HIGH-RESOLUTION COMPUTED TOMOGRAPHY OF THE PARANASAL SINUSES, PHARYNX AND RELATED REGIONS Impact of CT-identification on diagnosis and patient-management Aan Map Aan mijn ouders HIGH-RESOLUTION COMPUTED TOMOGRAPHY OF THE PARANASAL SINUSES, PHARYNX AND RELATED REGIONS Impact of CT-identification on diagnosis and patient-management Hoge resolutie computertomografie van de sinus paranasales, pharynx en aangrenzende gebieden. Invloed van CT-identificatie op diagnostiek en therapie (met een samenvatting in het Nederlands) PROEFSCHRIFT Ter verkrijging van de graad van Doctor in de Geneeskunde aan de Rijksuniversiteit te Utrecht. Op gezag van de Rector Magnificus Prof. Dr. J.A. van Ginkel. Volgens besluit van het College van Decanen in het openbaar te verdedigen op dinsdag 9 September 1986, des namiddags te 2.30 uur. door Gertrude Maatman geboren op 21 december 1938 te Nijverdal 1986 MARTINUS NIJHOFF PUBLISHERS a member of the KLUWER ACADEMIC PUBLISHERS GROUP DORDRECHT / BOSTON / LANCASTER Promotor: Prof, dr P.F.G.M. van Waes Co-promotor: Prof, dr L.A. Ravasz Referent: Prof, dr J. Vignaud CONTENTS Acknowledgements 1. Introduction 2. Technique 2.1 Equipment 2.2 Scanogram 2.2.1 Purposes 2.2.1.1 Patient positioning and repositioning 2.2.1.2 Registration of slice positions 2.2.1.3 Diagnostic use of the scanogram 2.3 Positioning 2.4 Field of view and diameter of scanned area 2.5 Technique factor selection 2.6 Contrast media 3. Anatomy 9 3.1 Introduction 9 3.2 Nasal cavity 9 3.3 Paranasal sinuses 11 3.3.1 Frontal sinus J] 3.3.2 Ethmoid sinus 11 3.3.3 Maxillary sinus 11 3.3.4 Sphenoid sinus 11 3.4 Pharynx 13 3.4.1 Nasopharynx 13 3.4.2 Oropharynx 15 3.4.3 Hypopharynx 15 3.5 Oral cavity 15 3.5.1 Floor of the mouth and tongue 15 3.6 Spaces 15 3.6.1 Parapharyngeal space 15 3.6.2 Retromaxillary space 17 3.6.2.1 Infratemporal fossa 17 3.6.2.2 Pterygopalatine fossa 17 3.6.2.3 Pterygoid fossa 19 3.6.3 Submandibular space 19 VIII 3.7 Parotid gland 3.8 Lymphatic drainage of the head and neck 4. CT-identification 4. Axial sections 4. Nose, nasal cavity, nasopharynx, paranasal sinuses 4. 1 Level of frontal sinus 4. .2 Level of nasal bone and orbit 4. .3 Level of maxillary sinus, retromaxillary space, upper part of nasopha- rynx and parapharyngeal space 4. .4 Nasopharynx 4. .5 Parapharyngeal space 4. .6 Parotid gland 4. .2 Oropharynx, oral cavity, tongue and floor of the mouth, hypopharynx 4. .3 Identification of lymph nodes on the axial sections 4.2 Coronal sections 5. Pathology of paranasal sinuses 5.1 Introduction 5.2 Review of the literature 5.3 Patients and methods 5.4 Results 5.5 Discussion 5.6 Illustrative patients and pathology 5.7 Conclusions 6. Pathology of pharynx, nasal and oral cavity 131 6.1 Introduction 131 6.2 Review of the literature 131 6.3 Patients and methods 133 6.4 Results 135 6.5 Discussion 136 6.6 Illustrative patients and pathology 137 6.7 Conclusions 163 7. Summary and conclusions 165 Subject Index 167 Samenvatting en conclusies 173 Curriculum Vitae 174 IX ACKNOWLEDGEMENTS This work was performed in the Department of Radiodiagnosis of Utrecht University Hospital, Utrecht, the Netherlands. The author wishes to thank Professors Ravasz and Van Waes for their support and enthusiasm during the writing of this thesis. She would also like to thank Prof, dr J. Vignaud, University of Paris, for her critical comments on the manuscript. She is very grateful to her tutors. Prof, dr A.C. Klinkhamer and Prof, dr C.B. A.J. Puylaert, and their associates for their confidence during the training period and for the hospitality which they provided afterwards, through which it became possible to finish this work. Many thanks are also due to Dr John A.M. de Groot, who spent so much time discussing a large number of patients, to Dr H. Barrowclough, who, voluntarily, undertook to correct the text, and to Mrs Barbara de Witt-Caspers, Instituut Schoevers, Arnhem, who typed the text with great care. She is also indebted to Mr F.W. Zonneveld M.Sc, who provided valuable advice on the principles of CT. The author is also grateful to the photographers Mr Jan de Groot, Mr Marcel Metselaar and Mr Joop Ramaekers for their help in the realization of all the photographs presented, and Miss Ingrid C. Janssen, illustrator, who took care of the drawings (and the coordinates on the CT images) with dedication and accuracy. She would like to thank Mrs Dr C. Verheyen-Voogd and Mrs M. de Nooij-van de Linden, who enabled her to collect reference material. Finally, the author is very grateful to all who followed the proceedings of this work with interest, as- sistance and moral support. Oosterbeek, May 1986. Gertrude Maatman Chapter 1. INTRODUCTION After the first clinical examination in 1971 especially for E.N.T. specialists, dental surgeons with computerized axial scanning (tomography) of and radiotherapists. the human brain (G.N. Hounsfield, J. Ambrose), After a brief description of the examination very rapid development of this radiological tech- technique (Chapter 2), the normal anatomy of the nique took place. In the beginning, the first scanner paranasal sinuses, pharynx and related regions is (EMI) was restricted to examination of the brain. A described (Chapter 3). Subsequently, we attempted prototype body scanner was then developed and in to identify organs and structures on the normal CT 1974 the first patient was examined. After many re- images in the axial as welt, as the coronal plane servations with regard to the usefulness of whole (Chapter 4). Finally, we attempted to determine body CT, it soon became an integral part of radio- how often CT provided more diagnostic informa- logical armamentarium. The first publications con- tion than clinical examination, and whether CT in- cerning CT examination of the paranasal sinuses fluenced patient management. For this, 134 pa- appeared in about 1976, and soon it proved that CT tients were examined with pathological processes of could provide valuable complementary informa- paranasal sinuses, and pharynx, nasal or oral cavi- tion in clinical examination, especially in deter- ty. The results of this examination are discussed in mining the extension of a pathological process into Chapters 5 and 6. These chapters also present a the soft tissues. Since the soft tissues could not be number of illustrative patients. This study is princi- exactly visualized by the existing radiological tech- pally concerned with the pharynx and paranasal si- niques, we were interested in determining the influ- nuses. The larynx was excluded from this study\ ence of CT examination on patient management, Chapter 2. TECHNIQUE 2.2 Scanogram (CT-survey radiograph, scoulview, 2.1 Equipment topogram. Deltaview. etc.) In 1977, the first 2nd generation CT-scanners A scanogram is obtained by moving the table were installed in the Department of Radiology of with the patient into the gantry, while the X-ray the University Hospital in Utrecht. The Philips To- tube and detectors remain stationary. moscan 200 was replaced in 1979 by a third genera- tion scanner (Tomoscan 300) and in the beginning 2.2.1 Purposes of 1982 a Tomoscan 310 was installed. Our material contains predominantly images from the Philips 2.2.1.1 Patient positioning and repositioning Tomoscan. The location of the scan can be determined on the basis of anatomical radiological landmarks. The angulation angle can be chosen from the lateral scanogram (fig. 2.1) in order to avoid dental fillings Figure 2.1. Registration of the slice positions. A. In the axial plane, supine position. B. In the coronal plane, prone position. Figure 2.2. A. Position for direct coronal CT of the head and neck. The patient is sealed at the rear of ihe gantry. A silaslic shei prevents slipping. (Courtesy: P.F.G.M. van Waes and F. Zonneveld. J. Comput. Assist. Tomogr. 6 (l):55-68,1982). B. Direct coron; CT scan in a patient with a large ameloblastoma of the right mandible (see also Chapter 5. figure 5.8). Figure. 2.3. Position for direct sagittal scanning. (Courtesy: R. Bluemm: Neuroradiology (1982) 22:199-201). 5 or metal prostheses and to approach the optimal in- The prone position can be impossible for pa- clination of the coronal plane. tients suffering from a pathologic process com- pressing the airway. In these patients, and in pa- 2.2.1.2 Registration of slice-positions tients with pathologic changes caudal to the hyoid Since slice positions are known with respect to bone I therefore recommend, direct coronal CT ac- the scanogram, use can be made of this information cording to the technique described by Van Waes to mark these positions on the scanogram. This is (9). The patient is positioned sitting in the cone on relevant for the recognition of anatomical details the rear of the gantry, while reclining slightly back- on the scans and for repositioning of the patient for wards. In this way the head, neck and upper part of a follow-up examination. In planning radiation the chest can be positioned in the scan plane (fig. therapy, this can also be used to document the pa- 2.2). This is possible only with equipment which has tient mould or cast (10). This is achieved by taping a large and wide patient aperture cone. pieces of angiographic catheter, or other radio- Direct sagittal scanning (1.2.3.6.7) proves to opaque material to the skin, connecting the tatoo- be useful for demonstrating all anatomical struc- marks.