(500) 
Few people only are able to view stereoscopic images, — even ıf they be 
technically poor and maladjusted — reliably, most of them don’t see them well eR 
or not at all, if they are inaccurate. But the judgment on the method is deter- IPFE 
mined by the many. Recording and evaluation of the roentgen-stereogram bote de) 
should, therefore, be made with the outmost precision. Under optimal condi- arc of 
tions, as many physicians as possible will then be able to view and, if necessary, in spac 
to measure such a stereo-roentgenogram in an appropriate manner. bony à 
To sum up, it can be said that the use of stereo fluoroscopic roentgen- uen ct 
photogrammetry is applicable on a broad basis and that it offers great potential Gurl 
advantages for clinical diagnostics and scientific research. with eh 
: : extenti 
Discussion. relatior 
Mr. Merriam asked if X-ray photogrammetry could be used for accurate diagno: 
investigations on the movements of the human body (skeleton), and if it would longer 
be possible to make an X-ray film of these, so as to make a plotting of the pic- visible 
tures possible. Mr. Burkhardt replied that the firm Wiegelmann in Neheim table st 
(Germany) had constructed an X-ray motion film camera based on two focal these cc 
points (two X-ray tubes) and an alternating diaphragm, working on double the 
usual film frequency. In the beginning the apparatus was built for direct view- COMP 
ing and not for photographing. IN NC 
Mr. Fagerholm asked whether the theory of error of the X-ray photogram- US] 
metry had been treated in Germany. Mr. Burkhardt answered that chiefly med- RESTT 
ical men had been occupied with X-ray stereo photogrammetry. The principal 
task was to get a three-dimensional insight into the human body as clear as pos- 
sible, and the object of the measurements was to find out the most suitable way 
for surgical operations. The X-ray pictures are central perspectives and enlarged 
in relation to the object. Errors in the focal point of the X-ray tube in relation 
to the negative have the character of an error in the inner orientation with an W 
effect theoretically corresponding to this error in the surveying camera in ordi- the Ita 
nary photogrammetry. The problem has been treated in several works, among aeroph 
others by U. Graf and K. Rinner and also by R. Burkhardt. qu 
Mr. Gruner asked if the instrument was provided with one or two projec- Stereoc 
tion surfaces for X-ray pictures. Mr. Burkhardt had not had the opportunity to size 13 
study the instrument in detail. : Fa 
Mr. A. Simpson inquired whether the doctor could see the stereoscopic X- in the 
ray picture and the body of the patient simultaneously. Mr. Burkhardt supposed ^ Tn 
that the stereoscopic picture was projected onto a fluorescing screen with a posi- with ne 
tion to make it possible for the doctor to see both at once. good pi 
matic a 
It 
*X-RAY STEREOPHOTOGRAMMETRY IN PEDIATRICS" been pr 
The cal 
by (a) fo 
Dr. J. Heuser. (b) fo: 
(The communication was delivered by Dr. R. Burkhardt). (a) 
offered 
It is often quite difficult to take X-ray photographs of children because of determi 
their vivacity and lack of understanding of what is going on. Consequently, as the prc 
a “conditio — sine — qua — non” for making stereoscopic X-rays is that the along t 
  
SR EE t ma : M —————— —