. Radiography, x-ray therapeutics and radium therapy . l ray from the tube can always be located by means of a plumb-lineoperating over the top of the couch. This may also be used for getting thecentre of the plate exactly in the centre of the part to be examined. The part of the patient to be examined should always be as close tothe plate as possible. On the couch some form of compression must beemployed to keep the parts as quiet as possible. When the screening-standis used, the part is first examined by the aid of the fluorescent screen, and 96 EADIOGRAPHY the diaphragm adjusted to cover th
. Radiography, x-ray therapeutics and radium therapy . l ray from the tube can always be located by means of a plumb-lineoperating over the top of the couch. This may also be used for getting thecentre of the plate exactly in the centre of the part to be examined. The part of the patient to be examined should always be as close tothe plate as possible. On the couch some form of compression must beemployed to keep the parts as quiet as possible. When the screening-standis used, the part is first examined by the aid of the fluorescent screen, and 96 EADIOGRAPHY the diaphragm adjusted to cover the part required. The fluorescent screenis replaced by the X-ray plate in a casette and clamped in position, and thepatient may be fixed by a strong linen band or a bandage. The shorter theexposure the less risk is there of movement on the part of the patient spoilingthe result. The Use of the Intensifying Screen Though negatives obtained by the use of the intensifying screen maynot perhaps be of the same high technical quality as the best radiographs. Fig. 86.—Normal hand to illustrate value of an intensifying screen.(a) An intensifying screen was used for this (b) Taken without an intensifying screen with ten radiograph, the exposure being yV ^f that for (b).The radiogTaph was considerably over-exposed. times the exposure. Note the detail in soft parts. made by powerful installations without a screen, it should be noted thatwhen skilfully used, pictures so obtained with apparatus of moderate powerare, from a diagnostic point of view, of much greater value than thoseobtained without a screen. This is especially the case when radiographingparts of the body where movements are constantly going on, as in the chestand abdomen. The plate must not be over-exposed, otherwise grain, dueto contact with the screen, is bound to appear. A soft tube also is necessarywhen the screen is used, and it should be noted that there is not quite thesame degree of latitude in the matter of exposure
Size: 1941px × 1288px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorknoxrobe, bookcentury1900, bookdecade1910, bookyear1915
