A comparison of six deconvolution techniques

We present results for the comparison of six deconvolution techniques. The methods we consider are based on Fourier transforms, system identification, constrained optimization, the use of cubic spline basis functions, maximum entropy, and a genetic algorithm. We compare the performance of these techniques by applying them to simulated noisy data, in order to extract an input function when the unit impulse response is known. The simulated data are generated by convolving the known impulse response with each of five different input functions, and then adding noise of constant coefficient of variation. Each algorithm was tested on 500 data sets, and we define error measures in order to compare the performance of the different methods. The work described in this paper was carried out as part of Grant GR/J67130 “Identifiability and Indistinguishability of Nonlinear Dynamic Systems” from the U.K. Engineering and Physical Sciences Research Council.     

Abnormal uptake of Technetium‐99 m hydroxymethylene diphosphonate in the liver

Diffuse liver uptake on bone scintigraphy is a rare occurrence with only a few reports in the literature. A case of diffusely increased uptake in a patient with acute hepatitis is presented.     

Acute ischaemic stroke in pregnancy: a severe complication of ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is the most serious complication of sterility treatment. It is characterised by ovarian enlargement, ascites, electrolyte disturbance, hypovolaemia and haemoconcentration. A case of ischaemic stroke due to right middle cerebral artery (MCA) occlusion in a young female with OHSS after pharmacological treatment of sterility is reported. Left central hemiparesis occurred suddenly within a few days after the embryo transfer. Magnetic resonance imaging diffusion-weighted images showed infarction in the right basal ganglia and magnetic resonance angiography (MRA) revealed the occlusion of the M1 segment of the right MCA. The haemodilution and the anticoagulation therapy were effective. Twenty-four hours after the stroke onset, MRA showed MCA recanalisation. The neurological deficit resolved completely within 3 months. The patient delivered 2 healthy infants at term. This case emphasises that the recent advent of ovulation induction and reproductive techniques is a newly recognised cause of cerebral stroke in otherwise healthy females.     

Continuous electrocardiographic monitoring during automobile driving. Studies in normal subjects and patients with coronary disease

The electrocardiogram was continuously recorded during a two and a half hour period of driving in 65 normal subjects and in 66 subjects with documented coronary heart disease.

In normal subjects, except for a variable increase in heart rate, no significant changes were observed.

Among the subjects with coronary heart disease, significant electrocardiographic changes, i.e., ischemic type of S-T depression, multifocal premature contractions, ventricular bigeminal or trigeminal rhythm, were observed in 16.7 per cent. These changes occurred under relatively favorable driving conditions. The relation of such changes to the occurrence of accidents on the highway merits further study. The magnitude of this problem is indicated by the large number of subjects with coronary heart disease who drive.