I E Bonneville I L. Dietemann Radiology of The Sella Turcica With the Collaboration of 1. c. Demandre G. Didierlaurent c. Edus P. Gresyk M. Pion N. Quantin T. Taillard Illustrations by M. Gaudron Translation Reviewed by 1. Moseley With a Foreword by 1. L. Vezina, a Preface by A. Wackenheim and a Historical Review by 1.. Metzger With 370 Figures in 693 Separate Illustrations Springer-Verlag Berlin Heidelberg New York 1981 Jean Francois Bonneville, M.D. Professor of Radiology, Head of Department of Neuroradiology, University Hospital of Besan90n, 2, Place Saint Jacques, F-25030 Besan90n Jean Louis Dietemann, M.D. Department of Neuroradiology, University Hospital of Strasbourg I, Place de I'Hopital, F-67091 Strasbourg The cover picture shows a lateral view of the normal sella turcica ISBN-13: 978-3-642-67788-5 e-ISBN-13: 978-3-642-67786-1 001: 10.1007/978-3-642-67786-1 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically those of translation, reprinting, re-use of illustrations, broadcasting, repro duction by photocopying machine or similar means, and storage in data banks. Under § 54 of the German Copyright Law where copies are made for other than private use, a fee is payable to the publisher, the amount of the fee to be determined by agreement with the publisher. © by Springer-Verlag Berlin Heidelberg 1981 Softcover reprint of the hardcover 1st edition 1981 The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Reproduction of the figures: Gustav Dreher GmbH, Stuttgart 2127/3130-543210 To my family To my family To my staff J. F. B. J. L. D. v Foreword Master of all endocrine activity and executive organ of one's quality of life, the pituitary gland is tightly lodged in the" turkish saddle." As a bony container, the sella turcica is to the hypophysis what the skull is to the brain; it can therefore be looked upon as a little vault within the cranial vault. Just as the cranium is moulded by the growth of the brain, so is the sella fashioned by its content. It becomes locally enlarged in response to expanding intrasellar lesions, and it tends to return to its original size and shape upon their removal or destruction. Pituitary adenomas have in the past been diagnosed upon enlargement of the sella turcica. In the past decade, as a direct result of interdisciplinary coopera tion, we have learned that tiny adenomas, the immediate cause of some cases of acromegaly, amenorrhea-galactorrhea syndrome, or Cushing's disease, can exist with minimal or no observable effect on the size of the sella. The break through started when radioimmunoassay, as a new method of accurately measur ing specific hormonal output, indicated selective pituitary oversecretions in pa tients with normal-sized sellae. Neurosurgeons highly skilled in the transsphenoi dal approach with the surgical microscope were obliged to operate on some of these patients and confirmed the presence of tiny oversecreting adenomas in their pituitary glands. Their challenge to the neuroradiologist, to come up with a means of diagnosing these tumors, resulted in scrupulous studies of the sella turcica with emphasis on subtle changes of its floor. Hypocycloidal tomography confirmed the neurosurgical findings, and this simple method has become the tool of choice for preoperative diagnosis of microadenomas having reached the threshold size of 4 mm. Diagnosis of smaller lesions awaits the refinements of high resolution coronal computerized tomography. From the point of view of the radiologist, the sella turcica therefore serves two diagnostic purposes. As part of the sphenoid bone, provides direct evidence of systemic or specific bony diseases. As a bony container of the hypophysis, it displays indirect signs of a variety of intrasellar of intracranial lesions. The medical literature has widely reported on bony landmarks of the sella and their variations in health and disease since Oppenheim's pioneering work in 1901. Bonneville and Dietemann include in their book the feature points of these reports along with their own observations. In addition, they set forth the concept of the sella as a mirror of the pathology of the pituitary gland. The material is presented in a cartesian topographical order and it is convincingly illustrated. They are to be complimented for bringing to the literature this new radiologic textbook on the sella turcica. Their work is a splendid contribution to medical learning. Montreal, Canada, September 1980 Jean Lorrain Vezina VII Preface This book by Prof. J.F. Bonneville and Dr. J.L. Dietemann fills a gap in the radiologic literature, for the sellar area has never previously been so accurately studied. Over the past few years we have had the opportunity of listening to lectures and of reading papers on the subject by J.F. Bonneville. His contributions to the field include several very original views and new approaches, and the reputation that he has already earned in France will doubtlessly extend beyond our borders as a result of this remarkably conceived and well-documented work. It might be appropriate to point out that J.F. Bonneville belongs to the transitional generation of radiologists who succeeded in integrating and dealing with computerized tomography, and J.L. Dietemann, to the new generation for whom computerized tomography is a part of routine training. The Strasbourg neuroradiologic school is honored by J.F. Bonneville's friend ship, and I hope that the ties between the neuroradiologic teams of Strasbourg and Besan90n remain productive in the field of scientific research and become even closer in the future. A. Wackenheim Professor and Chainnan of Diagnostic Radiology University of Strasbourg IX Historical Review My good friend J.F. Bonneville has kindly asked me to contribute to his book on the sella turcica and to review the main stages in the development of radiologic knowledge of this region. Naturally, the starting point for this review is Roentgen, to whom the technique owes its name. The way to radiologic assessment of the sella was opened by clinicians and pathologists: in 1886, Pierre Marie described acromegaly, and one year later, Minkowski related this to the existence of a pituitary tumor. It was in 1902, as Fischgold and Bull recalled in their excellent history of neurora diology *, that Antoine B6clt~re described the corresponding radiologic manifesta tions: "a notable increase in the anteroposterior diameter of the pituitary fossa, whose margins appear thickened, and which gives the general impression of a hemispherical cup," together with irregular thickening of the skull bones and exaggerated development of the frontal and maxillary sinuses. Another pioneer was Arthur Schuller, of Vienna, in whose work on the skull base, published in 1905, is to be found an analysis of the effects of cerebral tumors on the appearance of the sella turcica. It was also Schuller who advised the surgeon Hirsch to try the nasal approach (through the sphenoid sinus) to pituitary tumors. Subsequently the work of Haas (1925), David and Dilenge (1957), and particu larly that of du Boulay (1957) and Mahmoud (1958) has increased our knowledge of the radiology of the sella turcica. More recently, Vezina (1974) emphasized the possibility of detecting intrasellar microadenomas at an early stage; we also were working along these lines at La Piti6 (1975). Contrast examination of the sellar region started when Dandy injected air or oxygen by the lumbar route, for the study of the intracranial cerebrospinal fluid spaces. Gas encephalography has given valuable information about the sella and its neighboring structures. The use of iodinated contrast instead of gas was a much later development. Egaz Moniz carried out the first cerebral angiogram with sodium iodine solution in 1927, after numerous experimental trials. This method permits analysis not of the sella itself but of the neighboring structures and is of great value for meningiomas of the middle cranial fossa and certain aneurysms. The tech niques of subtraction developed in 19J5 by Ziedses des Plantes and unrecognized for a number of years, and of tomography, by which the skull may be studied in a series of transverse or sagittal planes, must be mentioned. The latter technique combined with pneumoencephalography, has been of inestimable value for the study of pituitary tumors. It would also be quite wrong not to give credit to the technical advances made by Lysholm, firstly with his head-holding device * Fischgo1d, H., Bull, J.: A Short History ofNeuroradio1ogy. VIIIth Symposium Neuroradio1ogicum, September 1967. XI (1931) and subsequently, with Schoenander, in enabling skull radiographs to be obtained in a number of different projections. Finally, computerized tomography, has been developed by the physicists Hounsfield and McCormack, and put into clinical use by Ambrose. It is useful for the study of the skull and its contents and for the sellar region particularly when used in combination with contrast media. This technique also allows us to demonstrate the curious anomaly which Busch in 1951 called the "empty sella" as a result of his detailed anatomic studies of the diaphragma sellae; the term empty sella is, however, inexact, since the pituitary, more or less com pressed, is still detectable. This brief review will, I hope, serve to indicate the great value of, on one hand, clinicoradiologic correlation and, on the other, advances in physics (and more recently computer science) for the study of the skull, particularly the sella turcica. La Piti6, Paris, September 1980 J. Metzger XII Introduction It may be asked whether a monograph on plain radiography of the sella turcica is needed in 1980, that is, in the eT era. Progress in endocrinology and biochem istry and the early demonstration of pituitary dysfunction make it essential for the radiologist to be able to assess the sella accurately and to detect minor variations in its size. Detailed knowledge of the range of morphological variations which simulate pathological changes is indispensable, and for this reason normal variants and pictures which may give rise to confusion are extensively illustrated here alongside the classic pathological appearances. At the end of this work, the reader will also find a chapter presented as a series of exercises allowing him to test his knowledge and to familiarize himself with possible pitfalls. An giographic and cisternographic findings are frequently non-specific in cases of para sellar pathology; furthermore, they are well documented elsewhere and are therefore not considered here. The authors are of the opinion that because of the relatively recent introduction of high resolution computerised tomography and its continu ing refinement, the time is not yet ripe for an ambitious monograph on the sella turcica, which would include all the features of this technique. Nevertheless, in an up-to-date chapter they have collected the main results of eT, illustrating the marvellous possibilities of this exciting new technique. The bibliography is exhaustive: the reader will find essential bibliographical references with the authors' names mentioned directly in the text and can also consult a complete numerical bibliography at the end of each chapter. The most recent references concerning eT scanning of the sella have been added at the end of the bibliog raphy. Besan90n, September 1980 J.F. Bonneville . J.L. Dietemann XIII Contents Chapter 1 Embryology of the Sellar Region A. Development of the Sphenoid Bone 1 I. Membranous Stage 1 II. Cartilaginous Stage .... 1 Ill. Stage of Ossification . . . . 2 1) Ossification Centers, Ossifying Periods, and Fusion . 2 2) Prenatal Development of the Pre- and Postsphenoid Ossification Centers .............. 4 IV. Postnatal Development of the Basisphenoid 4 1) Postsphenoid . . . . . . . 4 2) Presphenoid ....... 4 B. Development of the Sphenoid Sinus 5 I. Prenatal Development . . . . 5 II. Postnatal Development . . . . 5 c: Development of the Pituitary Gland 6 I. Neurohypophysis . . . . . . 6 II. Adenohypophysis . . . . . . 7 Ill. Capsule of the Pituitary Gland 7 D. Main Anomalies in the Fetal Development of the Sellar Region 7 I. In the Postsphenoid . . . . . . . . . . . . 7 II. In the Pre- and Orbitosphenoid . . . . . . . 8 Ill. In the Pituitary Gland and the Pituitary Stalk 8 Chapter 2 Anatomy of the Sellar Region A. Descriptive Anatomy of the Sellar Region 9 I. Sella Turcica . . . . . . . 9 1) Dorsum Sellae . . . . . . . . 9 2) Floor of the Sella Turcica 11 3) Anterior Wall of the Sella Turcica 11 4) Tuberculum Sellae . . . . 11 5) Middle Clinoid Processes . 11 6) Anterior Clinoid Processes 11 7) Carotid Sulcus. . . . . . 11 xv