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Eighty colour subtractions of cerebral angiograms have been analysed to assess their value in actual diagnosis, particularly of cerebrovascular disease. The method has been found to be so valuable, either for confirmation of the findings seen on the original angiograms or in providing new data about the accurate localization and nature of the lesion, that it has now become a routine for all cerebrovascular cases. A selection of cases is presented and the limitations of the method discussed.

Endocrinologists tend to accept minor variations of the pituitary fossa as evidence of the presence of a pituitary gland abnormality. Neuroradiologists tend to be sceptical. Normal criteria have not been established. In a consecutive series of 85 cases without any clinical evidence of a pituitary lesion, the plain films in 31·7 per cent demonstrated minor duplication of the floor or anterior wall of the pituitary fossa (with or without associated thinning and possible erosion of the lamina dura), which could be mistaken for the early signs of pituitary enlargement by an intrasellar tumour. 16·5 per cent showed thinning of the lamina dura on tomography, a feature previously taken as suggesting early enlargement. It is suggested that these particular diagnostic signs should be interpreted with caution.

This paper describes the initial findings of computerassisted diagnosis of cerebral tumours using Bayes' Theorem and CT scans. For various sets of signs, tables of accuracy and reliability have been constructed, and a computer versus radiologist analysis for three types of tumour has been made. Based only on the results of CT scans, the computer has produced diagnoses relatively quickly, and overall these are of reasonable accuracy when compared with the radiologists' reports. The worst results occurred in the prediction of meningiomas, the reasons for which will be examined in subsequent work.

High-resolution computerized tomography (CT) has been used to investigate abnormalities of the ear and petrous bone. Congenital, traumatic, infective and neoplastic lesions have been evaluated in 30 patients with proven pathology. Some bone changes including abnormalities of the auditory ossicles have been better demonstrated than by conventional tomographic techniques, and high-resolution CT has some advantages in demonstrating both soft tissue abnormality and bone changes in the middle ear in primary neoplastic disease and secondary cholesteatoma. The absence of any practical means of taking sagittal sections with the present scanner design limits the usefulness of high resolution CT of the petrous bone, but this study has shown that the technique may now take its place as an important complementary procedure to pluridirectional tomography.

Regional cerebral blood volume (rCBV) was measured in 14 patients with normal CT scans. An EMI CT 1010 scanner was used in combination with a computer subtraction technique. The mean CBV in the cortex was 5.0 ml/100 ml of tissue and 2.2 in the white matter. Regional differences were not significant and no difference was found between the right and left hemispheres.

Most applications of Bayes theorem in computer-aided diagnosis have been to situations involving the differential diagnosis of a small list of disease categories. In the case of the diagnosis of cerebral tumours, if each tumour type in each main anatomical situation is counted as a single diagnosis, there are about 100 possible disease categories. This paper investigates a method of incorporating expert prior information into the computer-aided diagnosis process so that this large number of categories can be handled.

A computerized subtraction technique has been described to measure regional cerebral blood volume (rCBV) using the EMI-Scanner in a group of 13 patients. Sodium iothalamate was injected intravenously (1·75 ml./kg) to increase the absorption of X rays in the cerebral circulation. Significant regional differences in CBV were shown, values in the frontal and temporal regions being lower than the mean hemisphere value (4·9 ±0·7) and higher in the occipital region. The left hemisphere showed a significantly higher CBV when compared with the right. Measurements of CBV in the cortex showed no regional variation, but the mean cortical value of 6· 0 ± 1· 8 was significantly higher than the hemisphere mean.

Conventional rapid serial angiography and isotope clearance (intracarotid 133Xe) have been combined in the study of 21 patients with completed strokes and 14 with transient ischaemic attacks. Angiography revealed disturbed flow in over half the cases; it correlated reasonably well with the results of isotope clearance, more so in the case of fast flow on angiography with high flow on isotope clearance than in the case of slow flow on angiography with low flow on isotope clearance. The use of isotope studies revealed some areas of flow disturbance not shown by angiography, particularly in cases with transient ischaemic atatcks. The case for combined angiography and isotope clearance is argued for cases in which flow disturbance is thought likely to be present.

The use of a computer to assist the diagnosis of intracranial tumours was described by the present authors in 1968. Subsequent work has been concerned with improving the accuracy of the diagnostic program by experimental weighting of more important radiological signs (du Boulay, Popple, and Price 1969) and with the addition of proven cases to the computer's file of data.From the beginning of these studies a second program has been in operation. Its purpose has been to choose, by comparison with past proven cases, what should be the “next test” (in previous publications spoken of as the “next best test”). This next test, carotid angiography for instance, will be seen to be “best” if it can be shown statistically by comparison with previous patients that it is the most likely test to discriminate between the three most probable diagnoses.Theory of the method incorporated in the second program at present is based on the three diagnoses (denoted by i1, i2and i3) which have been given the highest probability by the first program. For each of these values of iand for each investigation, J, not yet made on the new patient the computer calculates: wherej= a basic test, i.e.an individual sign such as pineal displacement, obtained by doing a comprehensive test, e.g.plain film.Nij= total number of patients with the ith type of tumour on whom the jth test was made.

The sella turcica and some other features of the skulls of 25 cases of aqueduct stenosis and 16 cases of communicating hydrocephalus were investigated.Communicating hydrocephalus produces very little pressure change in the sella. It sometimes causes elongation.Aqueduct stenosis in adults results often in a characteristic deformity of the sella, and in nearly all adults there are other alterations of the skull as well.

The dorsum sellae has been studied in 104 elderly subjects without evidence of intracranial disease and in 56 patients with severe hypertension. A high-definition technique has been used.In all of the elderly patients the cortex of the anterior aspect of the dorsum (lamina dura) was intact. It is concluded that an intact lamina dura is a good indication of a normal sella. It enables a distinction to be made between the appearances of old age and the early changes of raised intracranial pressure.In four of the hypertensive patients, changes were seen which were indistinguishable from those of raised intracranial pressure.

The histories, radiographs and, where relevant, the operation notes and pathological findings in 197 cases of intracranial aneurysm have been reviewed in order to throw light on the natural history of the disease.It is concluded that the earliest changes of atherosclerosis are closely associated with the formation of aneurysms and that their subsequent history depends upon a balance between healing processes and advanced atheroma.Grounds are given for discounting the importance of defects in the muscular coat of intracranial arteries in this disease.Sudden (sometimes silent) changes in size and shape may be demonstrated as well as slower ones. Some emphasis is placed upon the benign course of the disease in a proportion of patients and the possibility of permanent healing in others after subarachnoid haemorrhage.The serious significance of loculation is underlined.There are sex differences not only in the demonstration of symptom-producing aneurysms, but also in the natural history of the disease. At first equally proportioned between the sexes or perhaps commoner in men, aneurysms become both commoner and less stable in women in early middle age.This instability manifesting itself by loculation and/or haemorrhage persists through the next three decades. On the other hand large aneurysms with their rather different natural history (fewer subarachnoid haemorrhages, but greater tendency to brain damage) are less uncommon in men.

Telecine has been a routine tool in the investigations of pneumoencephalography and myelography for a number of years. Details of the technical means by which adequate film is ensured are described.Future possibilities in automatic control of the tube current are mentioned.

Seven case are presented; some show typical tentorial branches from the internal carotid arteries in cases of meningioma and arteriovenous malformation: one illustrates the practical importance of recognising the presence of this artery, and one shows a perhaps hitherto undescribed variation of the origin of two left-sided tentorial arteries. Cases of astrocytoma, haemangioblastoma and of cerebral secondary deposits illustrate the fact that any vascular lesion in the region of the tentorium may cause hypertrophy of the tentorial arteries.

The radiographs and notes of 388 patients suffering from ntracranial tumours at a distance from the sella have been reviewed. An additional 212 patients with intracranial tumours were reviewed simply to record the position of the anterior end of the 3rd ventricle and the condition of the pituitary fossa.Various changes in the sella and its vicinity due to raised intracranial pressure may be classified into three categories. This classification provides some limited help in the localisation of tumours.Twenty per cent of patients with pressure changes in the sella due to tumours at a distance from the sella do not have papilloedema. Many of these tumours are slow-growing and benign and first-class radiography is of great importance in discovering them.A mechanism which may operate in causing erosion of the lamina dura is suggested.

The radiographs of 299 captive primates have been examined and an association demonstrated between nutritional bone disease and the development of spondylosis.There are some indications of a similar tendency among captive carnivores.

Detailed observations of pulsatile movements within the cranial and spinal CSF spaces have been made at myelography, pneumoencephalography and Myodil ventriculography; most of them on normal or near-normal patients; but some in cases of obstruction.The effects of the pulsatile movement on CSF circulation, on cyst formation and in cases of obstruction, particularly at the foramen magnum and tentorial opening, are discussed.

A computer program is described whereby the diagnosis of an intracranial tumour may be made from the probabilistic basis by comparison with previous patients. The data employed are signs elicited by radiological examination. A second program predicts the next most informative test not yet performed, e.g., vertebral angiography. Some early results are encouraging.

le May and Jackson in this issue report a cervical disc protrusion which was not revealed by positive contrast myelography in the prone position, but gave the false appearance of an intramedullary tumour and they go on to explain how this may happen.The two cases of meningioma in front of the cord described in the present paper bear some similarity to le May and Jackson's case because of the myelographic difficulties encountered. Both, in addition to this invisibility of the tumour in the prone position at head-down tilting, have it in common that an abnormality was shown by screening in the supine position. Moreover this abnormality might well be, and was in one instance, mis-interpreted as showing a posteriorly placed mass.H. W., a 74-year-old man, referred for X-ray examination at St. Bartholomew's Hospital complained of pain in the left shoulder and back of his head, difficulty in walking and numbness of the left side of his body.Two years previously he had developed pain and stiffness in the left shoulder radiating to the left side of the occiput. The pain was constant and worse when lying in bed. Coughing caused the pain to spread down to the fingers of both hands, first on the left and then on the right. Numbness gradually spread up the arms and more recently had involved the left leg. There was no sphincter disturbance.

An account is given of portal venography carried out on 46 patients suffering from portal hypertension and/or portal stasis. The technique employed has usually been injection of one of the jejunal tributaries with 30 c.c. of 70 per cent diodone. Occasionally some other tributary vein has been used. Of late, when splenectomy is indicated, splenic pulp injection was made at operation. Two radiographs are taken. This gives a rough indication of speed of flow. Percutaneous splenic puncture venography is thought to have some dangers in cases of portal hypertension. The appearances of intra-hepatic block due to cirrhosis, and the different types of extra-hepatic block, are discussed. Portal hypertension and stasis without obstruction are illustrated. The main value of the method has been the demonstration of veins suitable for anastomosis. It has been useful to know from the venogram, that gastric varices are present in a patient who had no oesophageal varices and who subsequently bled. Stream-lining in the portal vein has been observed. The literature is reviewed.

This is a satisfactory monograph, especially in so far as it describes and illustrates, with beautifully designed and produced line drawings, the normal anatomy of the anterior inferior cerebellar artery (AICA) and related vessels.

This is the second book of the two which are devoted to the head in this series of encyclopaedic volumes. A further volume is planned which will cover the subject of “Neuroradiology” separately.The first book was concerned with plain X-ray changes of the vault and base due to general bone disease and to diseases of the brain and cranial nerves.

The eventual size of this encyclopedia may be judged by this first published volume—one of two devoted entirely to the “plain” skull radiograph. A third is to be allocated to the contrast studies of neuroradiology.

Lucien Leger, the author of a number of papers on portal venography, wrote the first part of this monograph with the intention of teaching his technique to those who do not already practice splenic-puncture venography. The remainder of the book is a review of the book is a review of the conditions revealed by the investigation, illustrated from his own experience.

As many English radiologists will know from several visits the authors have paid to this country, direct arteriographic demonstration of spinal angiomas may be achieved by a very exact technique.

Radiology at its best can contribute a great deal to the successful management of diseases of the ear, but because of failures of communication between radiologists and otologists, most of the possibilities are often wasted.

This is a careful analysis of 170 cases of intracranial meningioma observed at the Montreal Neurological Institute, and is intended for neurologists and neurosurgeons as well as radiologists.

Anatomy of the brain is usually taught with a bias towards the functional neurological localisation of disease. As a result of this, postgraduate students may sometimes be able to draw from memory a most complicated diagram of sensory pathways; but are usually quite unable to visualise, for instance, the size and position of the thalamus within the skull. The more distal courses of intracranial arteries are scarcely mentioned in ordinary anatomical text-books, and the shape of the extracerebral subarachnoid space cannot easily be demonstrated in the cadaver.