A device to measure roentgenographic structures

Assessment of bone mineral content and bone mass by non-invasive radiologic methods

Methods for quantitative determination of bone mineral and bone mass in normal subjects and in patients with metabolic bone disorders can be measured by the Compton scattering technique, the neutron activation analysis, by measurement of metacarpal bone mass, by single and dual photon absorptiometry, and by quantitative computed tomography. Measurement on metacarpal bone (radiogrammetry) seems to be able to distinguish between resorption and/or new bone formation at the periosteal and/or endosteal surface. The intraindividual observer variation on combined cortical thickness (D-d), cortical area (D2-d2), metacarpal bone mass (D2-d2)/D2-varies from 0.7 to 2.5 per cent and the interindividual observer variation from 1.0 to 5.8 per cent. Single photon absorptiometry measures bone mineral content in the forearm with great precision. The reproducibility using repeated measurements and automatic selection of the measuring area is about one per cent and can be used to follow changes in mineral content with time in patients with metabolic bone diseases. The dual photon absorptiometry may be used for measurements of bone mineral content in lumbar spine, in the femoral neck and measurement of total body calcium with an accuracy of less than 6 per cent and a precision below 3 per cent. Quantitative computed tomography has the ability to measure trabecular and cortical bone both centrally and peripherally. Using CT scanning, scanner related changes with time (day-to-day variation +/- 4%), patient repositioning (less than 1.5%), and fat concentration (residual uncertainty of approximately 1/6 of the biologic variation) are important factors influencing the accuracy and reproducibility of the values of the measured bone mineral content.(ABSTRACT TRUNCATED AT 250 WORDS)

Amount of bone and bone remodelling in normal subjects and in patients with chronic renal failure

Quantitative radiologic measurements of the second left metacarpal bone were performed on 63 normal men and 71 normal women, 105 patients with non-dialyzed chronic renal failure and on 32 chronic hemodialyzed men and women. For prospective analysis 42 non-dialyzed patients and 31 patients on chronic hemodialysis were available. Measurements of the total width, medullary cavity and combined cortical thickness at the midshaft of the metacarpal bone were made on postero-anterior hand radiographs with a readout of 0.1 mm using a direct reading needle-tipped calliper. Hereafter the cortical area and metacarpal bone mass were calculated. Mean values of the various parameters in the patient groups were compared with mean values of age-matched normal controls. For the prospective analysis the calculated, yearly change of the various parameters during the observation period were compared with the yearly change in normal persons, being estimated by regression analysis between age and radiologic values. Measurements of the amount of bone in normals and in patients with chronic renal failure were reliable, the intraobserver variation coefficient varying from 0.7 to 2.5 per cent and the interobserver variation coefficient from 1.0 to 5.8 per cent. Changes in thickness of the soft tissue of the hand only slightly affected the values, a change of 10 mm resulted in a change of one per cent of the measured and calculated values. Metacarpal bone mass was significantly reduced in normal men and women older than 50 years of age compared with younger persons.(ABSTRACT TRUNCATED AT 250 WORDS)

Metacarpal bone mass in normal adults and in patients with chronic renal failure

In measurements of the metacarpal bone mass the values in normal Danish adults did not differ between the right and left hand, but were significantly higher in women compared with men in subjects 20-59 years of age; beyond that age the bone mass decrease in women compared with men. The metacarpal bone mass decreased significantly during the period of dialysis in patients on chronic hemodialysis and decreased significantly after renal transplantation. Recipients who developed necrosis of bone or spontaneous fractures after transplantation had significantly reduced metacarpal bone mass at the time of transplantation as compared with normal controls whereas recipients without bone lesions after renal transplantation had normal values at the time of transplantation.