Quantitative microradiography

FI G U RE 5.1 Top The principle of microradiography — an x-ray absorption technique for quantitative assessment of dry weight (mass). Bottom In addition to the mass information, a specified element can be quantitatively assessed by using two monochromatic radiation wavelengths on each side of an absorption edge for the element. (Adapted from Lindstrom, B., Acta Radiologica Suppl. 125, 206, 1955.)... 

Arends J, Ruben JL, Inaba D Major topics in quantitative microradiography of enamel and dentin R parameter, mineral distribution visualization, and hyper-remineralization. Adv Dent Res 1997 11 403-414. 

Wilson PR, Beynon AD Mineralization differences between human deciduous and permanent enamel measured by quantitative microradiography. Arch Oral Biol 1989 34 85-88. 

Coincident with this new technique for procurement of human bone biopsies was the development of quantitive methods of bone analysis.12 These methods include histochemical analysis of both decalcified and unde-calcified42 48 bone sections, microradiography,44 tetracycline labeling45 and autoradiography.42 The latter two techniques require administration of a tetracycline antibiotic or isotopic tracer prior to procurement of the biopsy. Undecalcified thin sections, prepared with the use of a Jung microtome after the bone core is fixed, dehydrated and embedded in methacrylate,45 are analyzed by intersect and point count methods46 47 which permit three-dimensional assessment.48 49 Tetracycline antibiotics deposit in vivo in sites of bone formation constituting markers which can be studied in undecalcified sections by fluorescence microscopy.45 47 This represents the safest and best tissue time marker for microscopic measurement of bone formation dynamics. 

Contact X-ray microradiography or X-ray contact microscopy (XCM) has been applied to the largest range of specimens due to its simple implementation and considerable versatility. The biological sciences are the most important field of applications for XCM. The nonlinearity of resists makes the resist-based contact microscopy unsuitable for quantitative imaging, which considerably limits its application to materials science. However, quite opposite to the... 

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