Biomedical subjects

B Lantz

Publications and source records attributed to B Lantz.

52 records · Page 3Linked to original sources

PubMed1975

Spectral variation of the conversion factor of an image intensifier.

The conversion factor of the image intensifier Sirecon duplex 25/15 was investigated by means of a videodensitometer for varying values of the tube potential and varying filtering of the radiation. It was found that the conversion factor can be increased by Cu filtering. By analysis of the measurement data, the spectral variation of the conversion factor was determined. The conversion factor has a maximum for 60 keV photons and falls rapidly for photons of energy below 45 keV. By the method described, the spectral response function of an image intensifier can be determined experimentally without the use of a spectrometer.

Absorptiometry, Photon↗

PubMed1975

Speed of response of a 50 Hz and a 250 Hz TV system.

The speed of response of a newly developed 250 Hz high image rate Plumbicon television system was compared with the ordinary 50 Hz Vidicon and Plumbicon television systems. The high time resolution of the 250 Hz system, almost five times that of the 50 Hz Vidicon and three times that of the 50 Hz Plumbicon system, makes it well adapted for videodensitometry particularly if the velocity of the contrast bolus or the pulse profile within the circulation are to be evaluated.

Absorptiometry, Photon↗

PubMed1975

Relative flow measured by roentgen videodensitometry in hydrodynamic model.

The behaviour of injected iodine contrast medium in a pulsative hydrodynamic model was recorded on videotape in television fluoroscopy and measured by roentgen videodensitometry. By a simple relationship between the integrated densitometric area, the amount of injected contrast medium, and the flow at the site of the injection, it was possible to compare the flow in two different cross-sections of the circulatory system with high accuracy.

Absorptiometry, Photon↗

PubMed1975

Three-dimensional reconstruction of the human heart by video technique.

Three-dimensional reconstruction of different plastic phantoms, organic material and beating human heart was achieved by utilizing a standard roentgen-television system. In continuous stabilized fluoroscopy the television images of the object obtained from different projections were digitized in real time and computerized for reconstruction. Despite a cone beam being used, the spatial resolution seems to be quite adequate for evaluation of gross anatomic structures like the cardiac walls without enhancement by contrast medium.

Absorptiometry, Photon↗

PubMed1973