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P E Undrill

Publications and source records attributed to P E Undrill.

9 recordsLinked to original sources
PubMed1986

The Aberdeen Mark II single-photon-emission tomographic scanner: specification and some clinical applications.

The construction, operation and physical characteristics of a single-section multi-detector single-photon-emission scanner are described. The machine has 24 detectors arranged along the sides of a square. Movements and data collection are under the control of a series of distributed microprocessors. Both head and trunk tomograms can be produced. The spatial resolution at the collimator focus is 9 mm in the transverse plane, and the effective slice thickness is 14 mm. The volume sensitivity is 300 counts/s kBq ml with a 20 cm diameter cylindrical phantom filled with 99Tcm solution. The application of this machine to the examination of the brain, liver and heart has been found to be clinically useful.

Brain↗
PubMed1985

A simple filtering routine for radionuclide bone images.

The evaluation is carried out of a simple filtering routine for improving the detectability of low contrast lesions in bone scans. With this routine, the unprocessed image is displayed together with three filtered versions, the final decision on the presence of abnormalities being made by comparing the four images. Emphasis is placed on producing a routine which is quick in implementation and, therefore, only small filter arrays are used. Using a routine consisting of a low-pass, a median, and a differential filter, 73% more lesions are detected when the filtered images are also used. The whole routine takes less than 1 min to run.

Bone and Bones↗
PubMed1979

An approach to quality and performance control in a computer-assisted clinical chemistry laboratory.

A locally developed, computer-based clinical chemistry laboratory system has been in operation since 1970. This utilises a Digital Equipment Co Ltd PDP 12 and an interconnected PDP 8/F computer. Details are presented of the performance and quality control techniques incorporated into the system. Laboratory performance is assessed through analysis of results from fixed-level control sera as well as from cumulative sum methods. At a simple level the presentation may be considered purely indicative, while at a more sophisticated level statistical concepts have been introduced to aid the laboratory controller in decision-making processes.

Chemistry, Clinical↗
PubMed1979

Cranial scintigraphy: value of adding emission computed tomographic sections to conventional pertechnetate images (512 cases).

A prospective trial was carried out to assess the contribution made by a radionuclide transverse-section view to conventional radionuclide scans of the brain. Each set of scans was reported by two independent teams of observers, but only one team viewed the tomography section. An abnormality rating was used to decide whether a set of scans was positive or normal. The reports for 512 patients were analyzed and compared with the final independent diagnosis. Greater accuracy of diagnosis with the section view was significant at the 0.1% level; the results showed that failure to detect tumors was almost halved while there was a 16% improvement for the detection of infarcts. Abnormality ratings were also used to plot ROC curves and rating curves; these showed that the addition of the tomographic view increased markedly the proportion of true positives without any increase in the proportion of false-positive reports.

Brain Neoplasms↗
PubMed1979

Incorporation of a SMAC analyzer into the data-processing procedures of a computer-assisted laboratory.

This paper describes the incorporation of a SMAC (Technicon) analyzer into data-processing techniques that have been developed on existing computer hardware during several years. The SMAC system is interfaced directly to a small computer, and suitable peripherals produce a manageable form of result tabulation for subsequent reporting, as well as provide quality-control information to the SMAC operators in real time. The design is such as to facilitate the performance analysis of the SMAC system during its initiation period and during normal service operation.

Autoanalysis↗
PubMed1978

An on-line work scheduling and ward requesting pattern information system.

The organisational efficiency of sample admission to the routine laboratory and the allocation to test methods has been improved by a scheduling system based on an on-line mini-computer. A flexible system has been constructed using multiple visual displays, which produce work allocation lists. Computer techniques have been developed which enable maximal use of the on-line system while retaining the general flexibility of high-level language coding, as implemented on an unsophisticated 12-bit processor. The file structure has been designed to provide cumulative information on the requesting patterns appropriate to any of the many sources of samples to the laboratory, and to allow the automatic merging of worksheet and laboratory data, the latter being generated and transmitted from a second mini-computer system.

Chemistry, Clinical↗