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Biomedical subjects

E J Potchen

Publications and source records attributed to E J Potchen.

At least 55 records · Page 3Linked to original sources
PubMed1986

High-field magnetic resonance imaging of paranasal sinus inflammatory disease.

Magnetic resonance imaging using a 1.5 tesla magnet and a spin echo technique has revealed a remarkably intense signal from abnormal tissue in the human paranasal sinuses. Inflammatory disease in the maxillary, sphenoid, ethmoid, and frontal sinuses has been detected and demonstrated with greater clarity than any other available technique. The pathophysiologic basis for the intense signal has not been defined. These observations do, however, provide an opportunity to discover, clarify, and study paranasal sinus disease. Acute upper respiratory disease, allergic episodes, and the effect of drug treatment based on the MR signal and pathology can now be investigated with this technique. In addition, this may form a basis for assessing the epidemiology of paranasal sinus pathology.

Humans↗
PubMed1985

Application of an information-theoretic method for efficacy assessment.

An information-theoretic pattern recognition method was used to construct descriptive models of data related to 1,674 radioisotope lung scan referrals for the purpose of assessing lung scan influence on diagnosis and management of pulmonary embolism. It was observed that, relative to other clinical information available prior to the scan, the lung scan significantly improved the ability of the models to predict diagnostic and management outcomes, implying that the lung scan has significant influence on these clinical decisions.

Humans↗
PubMed1983

Employment-related administrative roentgenograms: characteristics of policy formulation and current practice.

A significant proportion of diagnostic medical procedures are used in response to public or private policy rather than in response to an individual patient-physician interaction. We have studied the system whereby such policies are developed and implemented in the case of employment-related chest and lumbar spine roentgenograms, which were found to account for about 11% of the total use of diagnostic radiographs in the state of Michigan. We observed that factors influencing formulation of policy are diverse and largely nonmedical, organizational policies developed in similar environments are often very dissimilar and are highly subject to external influence, and perceptions of policy success and examination utility are typically subjective and uncertain. It is concluded that considerable opportunity exists to enhance the efficacy of such radiographic examinations through leverage provided by their policy-driven nature.

Humans↗
PubMed1981

Value judgements in diagnostic radiology: How do we decide?

Value judgements now determine, to a great extent, whether or not the utility of a component of a procedure justifies the cost, in terms of exposure to radiation and financial expenditures. Medical education may ingrain behaviors that emphasize performing procedures that do not justify their costs.

Cost-Benefit Analysis↗
PubMed1975

The measurement of regional ventilation during tidal breathing: a comparison of two methods in healthy subjects, and patients with chronic obstructive lung disease.

Regional ventilation has been measured in 17 healthy volunteers, and 24 patients with chronic obstructive lung disease during tidal breathing using 133-Xe. The wash-in and wash-out of 133-Xe were recorded by a gamma camera interfaced to a small digital computer. Regional ventilation was calculated as the distribution of tidal volume per unit lung volume-a measure of relative ventilation--and from the wash-out curves as the fractional exchange of air per second. Determination of the regional fractional exchange of air showed a significant difference between the patients with chronic obstructive lung disease and normal subjects for all regions. The distribution of tidal volume per unit lung volume did not effect such a clear separation. Significant correlations were found between the whole-lung fractional exchange of air in the patients with chronic obstructive lung disease and their FEV1 r equal 0-70, MMFR r equal 0-70, FVC r equal 0-56 and FEV1/FVC r equal 0-57. It is suggested that measurement of regional ventilation as the fractional exchange of air is more realistic than methods that determine relative ventilation or only make use of the early part of the wash-out 133-Xe.

Adult↗
PubMed1972

Noncytokinetic radiation injury: anticoagulants as radioprotective agents in experimental radiation hepatitis.

Rats that have been irradiated with a single dose of 1500 roentgens directed to the liver show the following abnormalities: increased clearance of colloidal gold by the liver at 30 days, a decreased albumin space index at 30 days, and increased alkaline phosphatase at 60 days. In each of these cases, animals receiving Depo-heparin in dose ranges reasonable for human application had essentially normal values. There was no radioprotective effect with salicylates at the doses used. Higher doses of salicylates resulted in death of the animals.

Albumins↗