In mass examinations, chest X-rays are being taken of clothed individuals, in whom it is impossible to determine accurate conditions on the basis of the A-P breadth of the chest. The author has found a certain relationship between the A-P breadth of the chest and the weight of the subject and applied this in determining the conditions for chest radiography. Especially in photoroentgenography, this "weight-method" showed better results than the usual "Chest-breadth-method".
In order to improve the diagnosis of pulmonary tuberculosis, the author examined some Japanese tomography apparatuses, compared them with some foreign ones, and investigated the formers' defects. On the basis of these studies, he was able to suggest various improvements for Japanese tomography apparatuses.
It is difficult to take frontal or lateral views of the lower cervical and upper thoracic vertebrae, even in normal individuals, because of the overlapping images of scapula, clavicle, humerus, ribs, etc. It is extremely difficult in those whose upper limbs are paralysed. So the authors examined various methods : 1) lateral view of the cervical vertebrae. 2) low r cervical vertebrae. 3) orthogonal tomography (in this method the tube is moved in an orthogonal direction against the axis of the body). In addition, he studied the relation between the voltage and images in high voltage radiography.
With the technical improvement of semi-conductors, the study of the luminescence of fluorescent materilas in an electric field has become important. Therefore, using ZnCdS ; Ag, fluorescent materials used in fluoroscopy, the authors studied the following aspects of the relation of G.P. effect (change in luminescence of fluorescent materials put in an electric field) : 1) The influence of frequency on the G.P. effect. 2) The relation between the phase of the electric field and that of X-ray as an incitement to luminescence. 3) The relation between G.P. effect and intensity of X-ray. 4) The relation between the quantity of fluorescence and the temperature in the field. From these studies, the following results were obtained : 1) The G.P. effect is proportional to the intensity of X-rays. 2) The quantity of fluorescence is in inverse proportion to the temperature.