Nuclear magnetic resonance in the investigation of cerebral disorder

Magnetic resonance imaging-the Aberdeen perspective on developments in the early years

From the beginnings of medical imaging with radioactivity, an account is given of the development in Aberdeen of CT scanners in nuclear medicine, and their clinical value, leading to the present-day gamma-cameras. Early animal work with electron magnetic resonance is described, which developed into a programme towards nuclear magnetic resonance of water in body tissues. The 1974 NMR image of a mouse, using the nuclear medicine experience, led to a quest to build the first clinically useful whole-body MRI. The work of other teams is outlined, and the steps which led to successful diagnostic images being made with the Aberdeen machine in 1980. The welcome from the medical fraternity, and the output of the multinational medical imaging companies, has led to the present-day, worldwide use of the MRI technique.

Diabetes insipidus secondary to intracranial sarcoidosis confirmed by low-field magnetic resonance imaging

A 32-year-old woman who had been diagnosed as having pulmonary sarcoidosis 18 months previously presented with thirst and polyuria. The diagnosis of diabetes insipidus was confirmed biochemically and magnetic resonance imaging (MRI) revealed sarcoid involvement of the pituitary stalk.

Nuclear magnetic resonance imaging of intraocular tumors

Of 11 patients with intraocular tumors who underwent magnetic resonance imaging, seven had melanoma and one each had lymphoma, metastatic carcinoma, hemangioma, and hemorrhage. All were localized in the choroid. We compared the results of the magnetic resonance imaging examinations with those of ophthalmic ultrasonography, external inspection, and histopathologic studies. Magnetic resonance imaging detected six of the seven choroidal melanomas. Demarcation between the tumor and the sclera was excellent. Extrascleral tumor extension could be excluded. Hemorrhage in and beside the choroidal melanoma could be seen separately. Magnetic resonance imaging differentiates choroidal tumors from the surrounding intraocular and extraocular tissues better than computed tomography does, making it an important new diagnostic procedure.

A description of a low field resistive magnetic resonance imaging system and its application in imaging midline central nervous system pathology

A commercial low field magnetic resonance imaging (MRI) system installed in the Royal Infirmary, Edinburgh at the end of 1983 has since been used for the clinical investigation of over 1000 patients. This system uses an interlaced saturation recovery and inversion recovery pulse sequence which yields four types of clinical image. AT1 weighted image has been found to be the most sensitive for the detection of pathology. Several examples of pathology with negative X-ray computed tomography examinations including three examples of a syrinx and two cases of tonsillar herniation have been demonstrated using this system. It is suggested that the system could provide a routine clinical service for imaging the central nervous system.

Regional alterations in glucose consumption and metabolite levels during postischemic recovery in cat brain

Local CMRgl (LCMRgl) and metabolite levels were measured in the same tissue samples following 4 h of recirculation after 1 h of occlusion of the middle cerebral artery in the cat. The rate of glucose utilization was calculated using direct measurement of tissue deoxyglucose-6-phosphate and using a "lumped" constant corrected in each sample for alterations in tissue glucose. Increased LCMRgl (compared with that in sham-operated animals) occurred in regions with only minor alterations in levels of lactate and phosphocreatine. By contrast, LCMRgl was markedly depressed in regions with major changes in lactate and high-energy phosphates. Interestingly, tissue levels of glucose and unphosphorylated deoxyglucose were abnormally elevated in regions with profound energy failure. These results indicate an inhibition of glucose utilization in regions damaged by ischemia, despite the persistent elevation of tissue lactate. Increased glucose metabolism at 4 h post ischemia was detected only in areas with minor anaerobic alteration of metabolite levels.

Nuclear magnetic resonance (NMR): I. Imaging biochemical change

Nuclear magnetic resonance (NMR) imaging of hydrogen in body water and fat is proving valuable in clinical investigation of the brain. An introduction to the technique and to the biological significance of the images is presented here. The 'multi-parameter' nature of these images is stressed, and the individual parameters described. NMR imaging may well be of value in investigating the pathology of organic and functional psychoses.

Can statistics cause brain damage?

It is hoped that the comments made above will help contributors to the Journal of Cerebral Blood Flow and Metabolism identify weaknesses in their use of statistics. A little extra care in the presentation of results and adherence to the following guidelines should result in major improvement: (1) Give an explicit description of the type of statistical analysis used. (2) Increase the use of confidence intervals. (3) Use the Bonferroni correction (or other appropriate procedures) in multigroup comparisons. (4) Be aware of the assumptions underlying statistical methods and of weakness in experimental design. However, real benefits will be gained when statistics is viewed as being as important to the experiment as the choice of method for assessing cerebral blood flow itself.