X-RAY MICROSCOPY 



of these preliminary experiments awuit 

 further study. 



Future of Microradiography in Medico - 

 Biological Research 



All the advantages and disadvantages of 

 microradiography relevant to mediro-l^iolog- 

 ical research are pointed out in this chapter. 

 One may see from this description that only 

 in a few fields has microradiography brought 

 evidence of its validity. Many fields are not 

 explored at all. 



Research in calcareous tissues is one of the 

 most promising fields for microradiography 

 and this is shown by several works men- 

 tioned above. But even in this field micro- 

 radiography only begins to explore its possi- 

 bilities. The vast field of heterotopic bones 

 and calcifications is only slightly investi- 

 gated via microradiography although more 

 exact knowledge of this deviation from nor- 

 mal is very necessary. Here stain historadi- 

 ography in combination with serial cutting is 

 applicable because it helps to understand the 

 degree of participation of soft tissues and 

 their cells in the process of ossification. 

 Another field for the application of micro- 

 radiography is bone growth. Much has still 

 to be learned of the many interrelations 

 between organic matrix and mineral de- 

 posits, e.g., between cartilage cytoplasm 

 nucleus and calcium. Parallel processes of 

 ossification and resorption in course of bone 

 growth are also far from being clear from a 

 morphological point of view, especially the 

 participation of osteoclasts and osteoblasts in 

 bone reconstruction (rebuilding). Canaliza- 

 tion of bone is another field in which micro- 

 radiography was tried only in a few works, 

 while making use of obsolete technicjues. No 

 attempt is known from the literature to 

 differentiate either between arterial and 

 venous capillaries of bone or between cana- 

 liculi of intraosseous lacunae and bone blood 

 vessels. 



Bone pathology only starts to be investi- 

 gated by microradiography. Here also micro- 



radiography in combination with coloring 

 technique will be of great help. Differences 

 of calcium impregnation have not been ex- 

 plored at all by microradiography in malign 

 and benign neoplasms nor the process of bone 

 resorption during malignant growth. In our 

 short review many bone diseases have been 

 indicated which also are a "must" for micro- 

 radiographical research. Especially impor- 

 tant is the study of calcium behavior during 

 various dystrophic and fibrotic processes in 

 bone. 



Osteoporosis and bone atrophy were in- 

 vestigated only in a few papers which 

 brought forward a new concept of the mech- 

 anism of calcimii loss. This new approach to 

 the understanding of bone atrophic process 

 is very important for the study of aging 

 bone. Obviously, microradiographical data 

 cannot be generally accepted until they have 

 been confirmed by other methods. 



As was shown above microradiograph of 

 bone presents a satisfactory image of calcium 

 distribution even with comparatively low 

 limit of magnification. 



Microradiography of x-ray colored tissues 

 is elaborated only in a few fields. Micro- 

 vasography, for instance, has neither a uni- 

 form technique nor a generally accepted 

 opaque medium. Every author tries his own 

 method and this results in controversial 

 conclusions as in the above cited works of 

 Barclay and Bentley, Benjamin, Herzog, and 

 others. The attempt to work out a satisfac- 

 tory technique of injection is shown in works 

 of Okaw^a and Trombka and Bellman. How- 

 ever, as was mentioned above, these authors 

 left many questions unanswered. The most 

 detailed study of microvasographical tech- 

 nique is also one of the "musts" for future 

 research. One has to be always mindful that 

 to discredit a method is much easier than to 

 bring evidence of its validity. 



Microradiography of biological tissues low 

 in absorbing x-raj^s colored with OM is also 

 an acute problem for future research. Here 

 even less is done than in microvasography. 



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