[Measurement procedure for further radiologic analysis of bone. A review of the quantitative radiology of the skeleton].

The reasons for using measurements of bone density for further analysis of changes in metabolic bone diseases are pointed out. Besides the easy methods of visual comparison of X-ray images and "microradioscopy", the methods of quantitative radiology are discussed. The X-ray morphometry method is presented, including the new results of measurement of various bones of the skeleton. Structural analysis of spongy and compact bone tissue from the X-ray image using opto electronic image transformation is demonstrated. The techniques of X-ray photodensitometry and isotope-densitometry are explained. The importance of a reproducible calibration standard and the special value of reference systems containing a known concentration of hydroxyapatite are shown. Special information is given regarding the present status of the development of the new technique of quantitative computer tomography (QCT) or computer tomometry with the aid of a solid reference system. This new reference system is constructed from various concentrations of hydroxyapatite in "solid water" (a polyethylene mixture) and is demonstrated in detail. The results of comparing measurements of the 2nd lumbar vertebral body are shown. Finally, the clinical importance of measurements of the "apatite value" of vertebral trabecular bone tissue and of various trabecular areas of the skeleton is emphasized.