It is amazing to discover how little importance has been attached to narrow lumbar canal syndromes up to now. Though H. VERBIEST gave a very accurate description in 1949, the neurologist's and neurosurgeon's preoccupations were mainly focused on discal pathology, disregarding the problem of an exclusively bony origin in canalar stenosis. A. WACKENHEIM and E. BABIN have the merit of becoming aware of the impor tance and originality of this problem; they organized in the beautiful surround ings of the Bischenberg near Strasbourg, a postgraduate course, in which the most eminent European specialists in this field participated. I am very honored to have been asked to write the introduction to this mono graphy, which contains all the studies reported and commented on during this meeting. Before considering the problem from the various radiologic points of view, it is in my opinion indispensable to define the term "stenosis." We could not do so more accurately than by assuming the definition proposed by A. WACKENHEIM and E. BABIN and unanimously confirmed by all those who attented the session."

In this book are published papers presented at the first meeting about tomodensito metry (Computer Tomography) which the CEPUR organized in Luxembourg in March 1977. CEPUR (College d'enseignement post-universitaire de Radiologie) is an international medical association having as its main aim the promotion of courses in advanced radiology. Several sections deal with the subspecializations, one of which is Com puter Tomography. Thanks to the fruitful cooperation of several University Hospitals (Ancona, Leuven, Montpellier, Bruxelles, Strasbourg), the two-day meeting organized by Dr. Capesius in Luxembourg covered a certain number of aspects of clinical tomodensitometry in the brain as well as in the trunk. We hope that this volume will be the first of a series dealing with the actual problems in clinical radiology. Leuven/Bruxelles/Strasbourg A. BAERT L. JEANMART A. WACKENHEIM Contents I. Introduction to the Technology of Computer Tomography K. Ungerer. With 18 Figures ... 2 II. Head Sellar Region: Normal and Pathologic Conditions. U. Salvolini, F. Menichelli, and U. Pasquini. With 40 Figures ...... 14 Empty Sella and Pituitary Gland. J.L. Dietemann and A. Wackenheim. Wi th 3 Figures . . . . . .... . ., 38 Midline Lesions. D. Baleriaux-Waha, L.L. Mortelmans, M. Dupont, and L. Jeanmart. With 17 Figures ....... .. 39 Ventriculocisternal Pathology in Children. D. Touitou. With 9 Figures . . . . . . . . . . . . . . .. ....... 47 Endocranial Calcifications. J.H. Vandresse, G. Cornelis, and A."