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High-resolution imaging of x-ray and gamma-ray distributions can be achieved with cameras that use charge coupled devices (CCDs) for detecting scintillation light flashes. The energy and interaction position of individual gamma photons can be determined by rapid processing of CCD images of individual flashes. Here we investigate the improvement of such a gamma camera when a micro-machined retro-reflector is used to increase the light output of a continuous scintillation crystal. At 122 keV we found that retro-reflectors improve the intrinsic energy resolution (full width at half maximum (FWHM)) by 32% (from 50% to 34%) and the signal-to-noise (SNR) ratio by 18%. The spatial resolution (FWHM) was improved by about 4%, allowing us to obtain a resolution of 159 μm. The full width at tenth maximum (FWTM) improvement was 13%. Therefore, this enhancement is a next step towards realizing compact high-resolution devices for imaging gamma emitters.

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In 23 patients with Ebstein's anomaly of the tricuspid valve, the functional class of the patients has been related to the echocardiographic parameters generally used to diagnose this disorder. These are the extent of apical displacement of the tricuspid valve and the delay in tricuspid valve closure time related to that of the mitral valve. In addition, the functional class of the patients has also been evaluated in relation to the severity of tricuspid valve insufficiency and to the presence or absence of associated cardiac abnormalities. The study revealed that the echocardiographic parameters i.e. the degree of apical displacement of the tricuspid valve and the delayed closure time of the tricuspid valve have no predictive value for the patient's clinical condition. On the other hand, both tricuspid valve insufficiency and the presence of additional anomalies have a direct correlation with the well-being of the patient.