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Biomedical subjects

J Griver

Publications and source records attributed to J Griver.

4 recordsLinked to original sources
PubMed1977

A graphic display system for use with a computerized tomographic scanner.

A system for the display and analysis of computerized axial tomography scans has been developed. Selected regions of scans can be outlined using a joystick, allowing rapid statistical analysis. The difference between two scans can be displayed, and coronal and sagittal sections as well as projected displays, can be produced from a series of transverse sections. A special purpose software system has been developed to allow programming on a logical level. The system is used both for the analysis of current scans and the retrospective accumulation of data from past scans.

Computers↗
PubMed1976

The analysis of radioisotope brain scans by comparison with normal patterns of uptake.

A previously described method for the computer analysis of radioisotope brain scans has been further developed. A patient scan is matched with a series of "normal" scans to find the closest fit and the "normal" scan is then subtracted from the patient scan. The results are displayed in terms of the standard deviation from the normal. In a clinical trial the computer assessments were found to be less accurate than those of two groups of observers. One reason for these disappointing results is related to the simple criteria used to choose and fit the best "normal" to a particular patient scan. A second reason is the optimization of the scanner/photoscan combination to 99Tcm pertechnetate as a brain scanning agent which results in patient-to-patient variation becoming more important. This reduces the potential of a simple numerical analysis to improve results.

Brain Diseases↗
PubMed1976

A quantitative study of the EMI values obtained for normal brain cerebral infarction and certain tumours.

A quantitative study has been made of the EMI numbers of normal brain, cerebral infarction and certain tumours. The scans were recorded on magnetic tape and analysed using a minicomuter linked to a graphic display unit. This system not only yielded 16 grey scales compared with the ten currently available, but was programmed to allow selected regions of the scans to be outlined. From these regions the computer calculated the area, the mean EMI number and its standard deviation. It was found that in 15 normal brain scans, the EMI values obtained for normal frontal and temporal lobes were similar, but that the values for the basal ganglia and occipital lobes were significantly different from the first two regions and from each other. Ten cases of cerebral infarction and 30 cases of cerebral tumour were analysed, and it was shown that analysing representative areas was more informative than surveying the whole lesion. Whilst only half of the scans of brain tumours had a significantly altered EMI number compared with that of normal brain, enhancement of tumour density with sodium iothalamate revealed a consistent and significant elevation of the EMI number for all tumours. In particular, the value for enhanced meningiomas was almost double and malignant tumours more than a third larger than normal brain. It was not possible to differentiate quantitatively between astrocytomas and metastases.

Brain↗