Search

All spinal magnetic resonance imaging examinations carried out during a three month period were analysed retrospectively in order to determine the clinical reasons for the scan requests. Technical details of the examinations they received and the clinical profiles formed a data set which revealed 10 separate 'Clinical groups' for management purposes. Hardware, salary and expendables were costed as though the imaging unit had been sited within a National Health Service radiology department. A spread sheet was designed capable of calculating costs per patient for a variety of types of working week and of different staffing structures, sensitive to the mixture of clinical groups referred for examination. The spreadsheet also accomodated straight line depreciation for hardware value and interest rates for borrowed capital. A second, prospectively observed, sample of spinal MR examinations was used to improve the accuracy of the timing of the length of patient examinations. Costs were compared with those for patients submitted for myelography and radiculography at the adjacent hospital during the same period. The comparison indicated that spinal MR was less costly than myelography and radiculography. The most important element of the extra cost of myelography related to the need to admit patients to hospital for at least one night for this examination because of the likelihood of headache and other common (though usually minor) complications following lumbar puncture and/or the injection of contrast medium. From the limited information that it was possible to obtain in the period of follow up, it appeared that MR had either been superior or equivalent to myelography or radiculography in all the clinical groups of patients where both could be tested. There were a number of groups in which no myelograms had been requested, presumably because clinical suspicions had pointed toward conditions like tumours, developmental abnormalities and demyelinating diseases in which neurologists and neurosurgeons have already made up their minds about the superiority of MR. [ABSTRACT FROM AUTHOR]

This paper describes the evaluation of a computer advisor system (BRAINS), which was constructed to aid in the interpretation of CT images of the head. It was developed at the National Hospital for Nervous Diseases, Queen Square, London. The system was transferred, without difficulty, to an 'external', that is previously unassociated, site (the Department of Diagnostic Radiology, University of Manchester) for an external evaluation. Response of external users to the system was mixed. Many were unfamiliar with the concept of formal description of images and the evaluation demonstrated the need for a person to person training programme. Users who accessed the HELP facilities most frequently were the most successful in obtaining accurate descriptions and hence satisfactory diagnostic advice. An objective appraisal of user's success in describing images to obtain the correct diagnosis as first choice indicated that, in general, the system performed well. [ABSTRACT FROM AUTHOR]

This paper discusses the role of a computer advisor in MR image acquisition, interpretation and the diagnosis of cerebral disease. The development of an image and statistical database for use in providing advice is described. [ABSTRACT FROM AUTHOR]

This paper describes a prototype system to aid in the radiological interpretation of CT scan images of patients with cerebral disease. The system is able to provide guidance, both on diagnosis and the need for enhancement. [ABSTRACT FROM AUTHOR]

Although metrizamide is now being superseded by other contrast media, the mechanisms of its side effects may be of fundamental importance. One hundred and four consecutive patients with suspected cervical cord or root lesion were studied prospectively for factors which might influence the side effects of metrizamide myelography. Elderly patients were more prone to develop mental confusion. An earlier onset of dizziness and/or vertigo was associated with the lumbar route of intrathecal injection. Perhaps surprisingly, phenobarbitone prophylaxis shortened the duration of confusion and delayed the onset of headaches. Other factors, viz. sex, excess intracranial flow of metrizamide and myelographic blockage were not shown to have a significant influence on the adverse reactions. [ABSTRACT FROM AUTHOR]

Sixty-nine patients with cervical spondylotic myelopathy (CSM), radiculopathy (CSR), or both (CSMR) were studied with computed tomography (CT). Computer-assisted myelography (CAM) accurately determines the site and nature of spondylotic protrusions and provides good visualisation of the subarachnoid space and cord deformities even in areas with dilute metrizamide. However, excessive vertebral movement and bulging ligamenta flava with their effects on cord deformity, so easily visualised in myelograms, are completely or partially missed. In the assessment of CSM, metrizamide myelography (MM) followed by CAM should be performed, particularly when the myelographic images are unsatisfactory due to contrast dilution or blockage, when cord compression cannot be ascertained with MM and when cord atrophy is suspected. In CSR, the diagnostic information from MM and CAM is comparable. The diagnostic criteria in CAM are, however, less direct and since MM is adequate in uncomplicated cases, CAM is generally not necessary. The APD, APD/TD ratio, area and circularity are sensitive indices of cord deformity and the first two should be used more often to assist visual assessment of cord deformity. The relation between cord parameters and treatment response is better reflected in CSM cases managed conservatively and the results suggest that the degree of cord deformity is helpful in determining the outcome and hence the choice between surgical and conservative treatment. In plain CT, the osteophytes and calcified discs are adequately visualised and canal dimensions measured with accuracy, but the cervical cord and roots cannot be properly assessed and the diagnosis of CSM or CSR cannot be ascertained. At present, its role in cervical spondylosis is therefore limited. [ABSTRACT FROM AUTHOR]

Thirty-six control subjects had computer assisted myelography (CAM) using the EMI CT 5005 scanner. The normal cervical cord is elliptical, more circular at the upper and lower ends and flatter in the mid-segments. Asymptomatic cord deformities, usually mild, were present in nine subjects (25%). Four measurements, namely, sagittal diameter (APD), transverse diameter (TD), area (a) and circumference (c) were made and two more parameters calcultted i.e. APD/TD ratio and circularity (=4 π a/c). These control values form the basis of qualitative and quantitative assessment of cord deformity. When cord measurements are to be used, control values should be obtained for each scanner and procedures should be standardized [ABSTRACT FROM AUTHOR]

The safety of post-myelogram computed tomography (PMCT) as an additional diagnostic procedure to metrizamide myelography was evaluated. One hundred and four consecutive patients with suspected cervical cord lesions were studied prospectively; 50 had both myelography and PMCT, and the 54 acting as controls had only myelography. PMCT did not increase the incidence, severity or duration of common side effects and the majority of patients accepted this additional procedure. It is concluded that as long as care is taken to avoid the occurrence of excessive contrast in the intracranial subarachnoid space, PMCT is a safe procedure. [ABSTRACT FROM AUTHOR]

Experience with the 'BRW' CT stereotactic biopsy system is described and discussed. Some of the implications of CT-guided stereotactic surgery for a busy CT suite are explained. [ABSTRACT FROM AUTHOR]

Rupture of human cerebral arterial aneurysms is followed by prolonged cerebral arterial constriction; there is evidence that cerebrospinal fluid (CSF) from such patients contains vasoconstrictor substances which may cause the arterial constriction. The aim of this study was to develop a small animal model for investigating the effects of such CSF on the calibre of cerebral vessels in situ. Carotid angiography of the cerebral arteries of the rat visualises the internal carotid, middle cerebral, anterior cerebral and stapedial arteries plus the vertebrobasilar system. Prostacyclin was injected during carotid catheterisation to prevent spontaneous and random occlusion of these cerebral arteries; in the presence of prostacyclin there was no arterial occlusion for up to 5 h. The resolution achieved by the angiographic technique, which magnified the cerebral circulations 2.9 times, was sufficient to measure the diameter of the internal carotid and stapedial arteries of the rat. Intracarotid infusion of 1.0 ml CSF collected from patients with ruptured cerebral arterial aneurysms caused a rapidly developing contraction of cerebral arteries lasting up to 5 h. Thus, we consider that the rat may also be used as a model for investigating the aetiology of human cerebral arterial constriction after aneurysmal rupture. [ABSTRACT FROM AUTHOR]

The appearances on computed tomography (CT) in eight patients with mucopolysaccharidosis Type I [five with classical Type IH (Hurler disease)], two with mucopolysaccharidosis Type II (Hunter disease) and two with mucopolysaccharidosis Type IIIB (Sanfilippo B disease) are presented. Reference is also made to two further cases [mucopolysaccharidosis VI and mucopolysacharidosis IIIB] in which the CT showed special features. Follow-up scans were obtained to assess the evolution of the changes. The interplay of neuronal damage, cerebral atrophy and obstruction to the cerebrospinal fluid (CSF) circulation in the production of the cerebral manifestations, and the extent to which non-genetic factors influence the expression of the underlying biochemical lesion, are discussed. This series of patients illustrates the problem of classifying those with α-iduronidase deficiency, who do not have the classical Hurler disease phenotype (mucopolysaccharidosis IS and IH/S; Scheie disease and Hurler/Scheie disease), on the basis of currently available criteria. The place of CT in the diagnosis of complications due to thecal involvement is examined. The density of grey matter on the CT scans was similar to that of normal brain. Inhaled xenon did not produce any special enhancement which could be helpful in assessing the degree of the mucopolysaccharide deposition within cerebral cells. Symmetrical low attenuation in the white matter was a very common finding. It was not specifically associated with hydrocephalus and its relationship to some of the known neuropathological aspects of mucopolysaccharidoses is discussed. This work has shown that the stage in the evolution of the mucopolysaccharidoses at which hydrocephalus develops as a complication is highly variable and CSF diversion procedures are sometimes indicated to improve the quality of the patients' lives. These indications are briefly discussed. We consider that CT is essential for the adequate appraisal of these patients and to identify some treatable complications. [ABSTRACT FROM AUTHOR]

The entry of I-metrizamide and of I-diatrizoate from blood into brain has been studied in rabbits. The blood-brain barrier is very tight to both molecules, all cerebral regions having spaces between 0.5 and 2% after maintenance of constant blood levels for 4 h. In extraneural tissues both compounds appear to distribute in extracellular fluid except for accumulation of metrizamide by the liver and perhaps the small intestine. Profiles of radioactivity through cerebral gray matter have been obtained following ventriculocisternal perfusion of artificial cerebrospinal fluid containing I-metrizamide. The nature of these profiles and their behavior with time suggest that metrizamide passes through gray matter by simple diffusion, that it is largely distributed in the extracellular fluid and that back movement across the blood-brain barrier is small. [ABSTRACT FROM AUTHOR]

The high resolution CT scanning system introduced by EMI in 1978 has added a new dimension to computerised tomography in otology. The apparatus used for this study was an EMI CT 5005 body scanner adapted for head and neck scanning and incorporating a high resolution facility. The latter has proved most advantageous in areas of relatively high differential absorption, so that its application to the demonstration of abnormalities in the petrous temporal bone, and in particular middle ear disease has been very rewarding. Traumatic ossicular disruptions may now be demonstrated and the high contrast of CT often shows them better than conventional hypocycloidal tomography. The stapes is also better visualised and congenital abnormalities of its superstructure have been recorded. These studies have been achieved with a very acceptable level of radiation to the eye, lens and cornea and the technique is clearly a rival to conventional pluridirectional tomography in the assessment of the petrous temporal bone. With further design improvements high resolution CT could completely replace existing techniques. [ABSTRACT FROM AUTHOR]

The spinal cord is not consistently shown by plain computed tomography or with iodide enhancement. Xenon enhancement increases the attenuation of the spinal cord and visualization is improved considerably; fluid-filled cavities, including syringohydromyelia, do not enhance and are clearly defined. [ABSTRACT FROM AUTHOR]

The case notes of 170 consecutive patients with a suggestive clinical history, or a proven final diagnosis of a posterior fossa lesion have been analyzed in order to determine the precise value of each radiological investigation. All had had CT scans. The patients have been grouped clinically according to their presenting signs and symptoms. The analysis suggests some well-defined regimes of investigation and indicates the successes and failures of radiology. [ABSTRACT FROM AUTHOR]

The value of computerized axial tomography (CAT) in the management of intracranial infections is described and the findings compared with those of other conventional neuroradiological investigations. The most important contribution is in the diagnosis and localization of cerebral abscess. CAT provides not only information of the nature of the lesion but also the number of loculi and the presence of multiple lesions; it is the investigation of choice for follow-up of patients with cerebral abscess treated either by operation or conservatively. CAT is invalueither in the investigation of other infectious conditions affecting the intracranial structures, especially when patients present with a focal neurological deficit and it is vital to exclude an abscess. [ABSTRACT FROM AUTHOR]

Copyright of Neuroradiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Neuroradiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Neuroradiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

CT examination of 497 patients with subsequently proven pathology have been analysed and subjected to computer-aided diagnosis using Bayers' theorem. Our previous work was as accurate and reliable for diagnosing metastases and gliomas as that achieved by skilled radiologists in reporting. The present paper reports an alteration to the programme that has improved the diagnosis of meningioma. [ABSTRACT FROM AUTHOR]

This study was undertaken to compare the accuracy of measurements of the ventricular system obtained by the CT scanner and pneumoencephalography (PEG). In it the ventricular system was evaluated in each case by measuring the span of the frontal horns, cellae mediae and third ventricle in relation to the diameter of the inner and outer tables of the skull from the PEG films. The indices of Evans, Schiersmann, and Schaltenbrand and Nürnberger were applied to these measurements. The same indices were obtained using the appropriate CT printouts. A very good measure of agreement was obtained with the indices arrived at from both the CT scan printouts and the pneumoencephalograms. [ABSTRACT FROM AUTHOR]

Two different types of retrospective study of the value of CT have been contrasted. In one, the patients were chosen because of the way they presented (with posterior fossa signs or symptoms) or because they were found to have posterior fossa disease; in the other, all were reported as having, or found to have, gliomas or metastases. The first type of study provides a better basis for evaluation of neuroradiological procedures. [ABSTRACT FROM AUTHOR]

The CT and angiographic appearances in multi-infarct dementia have been compared with those of primary neuronal degeneration. It was possible to make a CT or angiographic diagnosis of multi-infarct dementia in about 405 of patients diagnosed by the ischaemic scoring method of Hachinski et al. [1]. [ABSTRACT FROM AUTHOR]

Copyright of Neuroradiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Neuroradiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

All spinal magnetic resonance imaging examinations carried out during a three month period were analysed retrospectively in order to determine the clinical reasons for the scan requests. Technical details of the examinations they received and the clinical profiles formed a data set which revealed 10 separate "Clinical groups" for management purposes. Hardware, salary and expendables were costed as though the imaging unit had been sited within a National Health Service radiology department. A spread sheet was designed capable of calculating costs per patient for a variety of types of working week and of different staffing structures, sensitive to the mixture of clinical groups referred for examination. The spreadsheet also accomodated straight line depreciation for hardware value and interest rates for borrowed capital. A second, prospectively observed, sample of spinal MR examinations was used to improve the accuracy of the timing of the length of patient examinations. Costs were compared with those for patients submitted for myelography and radiculography at the adjacent hospital during the same period. The comparison indicated that spinal MR was less costly than myelography and radiculography. The most important element of the extra cost of myelography related to the need to admit patients to hospital for at least one night for this examination because of the likelihood of headache and other common (though usually minor) complications following lumbar puncture and/or the injection of contrast medium. From the limited information that it was possible to obtain in the period of follow up, it appeared that MR had either been superior or equivalent to myelography or radiculography in all the clinical groups of patients where both could be tested. There were a number of groups in which no myelograms had been requested, presumably because clinical suspicions had pointed toward conditions like tumours, developmental abnormalities and demyelinating diseases in which neurologists and neurosurgeons have already made up their minds about the superiority of MR.

This paper describes a prototype system to aid in the radiological interpretation of CT scan images of patients with cerebral disease. The system is able to provide guidance, both on diagnosis and the need for enhancement.

The rete, a vascular system between the extra- and intracerebral arteries of certain animals, may have a variety of functions in different species. The calibres of the vessels of the rete and its arteries of supply have been measured under different conditions of blood pressure and PaCO2. It has been shown that the rete and its afferent arteries behave in an autoregulatory fashion down to a blood pressure of 60 mmHg. They also dilate with a rise in PaCO2. It has also been found that some parts of the system dilate even when the blood pressure drops lower than 60 mmHg. It is suggested that this autoregulatory capacity of extradural vessels limits the requirement for CSF spaces to change with blood pressure changes. A general rule has been sought which would link the known facts about cerebral autoregulation and the possession of extra- to intracranial anastomoses with the bodily shape and posture of the particular animal.

Angiography under experimental conditions shows that Urografin has a vasodilator action of the order of 8% upon the basal cerebral arteries of the baboon. This action is not seen within the first 4 sec of the angiogram and the dilator effect of a single injection has passed off completely 15 min later. Three successive injections within 7 min show little evidence of cumulative vasodilatation. The vasodilator action of three successive angiograms has disappeared 22 to 29 min later. Because of wide variations in the degree of vasodilatation shown by individual baboons it may be necessary to use each baboon as its own control in subsequent work.