抄録
1) X-ray diagnosis has been based mainly upon the qualitative impression of the physician on the roentgenogram to be examined. It is the authors' belief that the objective or quantitative informations obtained from the roentgenogram should play more important role in x-ray diagnosis in future. To the first step toward the objective observation of the roentgenogram, authors performed a study of the quantitative analysis on the mineral contents of ulna by means of dosimetric measurement of transmitted x-rays through the forearm, and densitometry on its roentgenogram. 2) The patient's forearm was placed in a water phan tom in order to standardize the thickness of the non-osseous tissues. The distal portion of the ulna was chosen for our measurement. The quantity of the bone salt in the above mentioned port ion was compared with a series of standard absorbers (bone models) by the dosimetric measurement of transmitted x-rays through the portion, and the densitometric measurement at the same portion on the roentgenogram. 3) The dosimeric value in the mineral contents of the bone tended to be slightly higher than the densitometric one. 4) Some results obtained from the clinical applications are as follows; (a) The normal value of distal ulna by the dosimetric method ranged from 300 to 450 mg/ cm3 and, on the other hand, the normal value by the densitometric method ranged from 260 to 400 mg/cm3. (b) The mastectomized patients who had edema of the arm and limitation of motion at shoulder-joint on the same side of the operation showed the remarkable decrease in the mineral contents in ulna in comparison with the normal side. (c) Some other interesting findings were obtained in several diseases such as osteoporosis, disuse bone-atrophy and Hyperostosis generalisata.
Our results were nearly identical with ones reported by others l),2),8),9).
