Radiology, Vol 124, 395-401, Copyright © 1977 by Radiological Society of North America
Application of longitudinal magnification effect to magnification stereoscopic angiography: a new method of cerebral angiography
K Doi, K Rossmann and EE Duda
A new method of stereoscopic cerebral angiography has been developed which
employs 2X radiographic magnification. In order to obtain the same depth
perception in the object as with conventional contact stereoscopic
angiography, one can made the x-ray exposures at two focal spot positions
which are separated by only 1 inch (2.5 cm), whereas the contact technique
requires a separation of 4 inches (10 cm). The smaller distance is possible
because, with 2X magnification, the transverse detail in the object is
magnified by a factor of two, but the longitudinal detail, which is related
to the stereo effect, is magnified by a factor of four, due to the
longitudinal magnification effect. The small focal spot separation results
in advantages such as improved stereoscopic image detail, better image
quality, and low radiation exposure to the patient.
