X-ray dosage in treatment and radiography (1922) (14758066605)

Identifier: xraydosageintrea00with (find matches)
Title: X-ray dosage in treatment and radiography
Year: 1922 (1920s)
Authors: Witherbee, William Daniel, 1875- Remer, John, 1862- joint author
Subjects: X-rays Radiography X-Ray Therapy Radiography
Publisher: New York : Macmillan
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School



Text Appearing Before Image:
e published the original communicationestablishing the principles and practical applica-tion of this method for both filtered and unaltereddosage in The American Journal of Roentgenology,Vol. IV, No. 6: 1917. CHAPTER VTHE CAUSE OF X-RAY BURNS Recently we have tried out the followingon the skin of a patients back: MA Sp G T5 X 9 X 9/16 min. 6 X 6 D 33^ sec. = 1J4 skin unit = 5 H This is an erythema dose without a filter. Thefiltered erythema dose using 3 mm. of aluminum is as follows: MA Sp G T 5 X 9 X 7.7 min. = 2Y2 skin units = 10 H. 6 D In the photograph (Fig. 2) both areas of ery-thema are identical. No. 1 was produced by theunfiltered erythema dose; No. 2 by the filtered ery-thema dose. Biologically, to all appearances, the 40 THE CAUSE OF X-RAY BURNS 41 erythema produced in 33^ seconds by the unfil-tered ray is the same as that produced in 7 min-utes and 42 seconds by the filtered. If the voltage determines the quality of the ray,then in this experiment the voltage is the same in
Text Appearing After Image:
Fig. 2. both instances; the only difference is the interpo-sition of 3 mm. of aluminum and about ten timeslonger exposure for the filtered dose than for theunfiltered. Here again the quantity of z-rayreaching the skin is materially lessened by the 42 X-RAY DOSAGE aluminum, thus making the enormous differencein the time of exposure. This dose with 3 mm. of aluminum takes a littleover ten times as long to produce an erythema asit does without aluminum. In speaking of thisdose some writers would say that they gave tenerythema doses. This statement without qualifi-cation is misleading. In reality the effects, so faras the skin reaction is concerned, are identical.If then the filtered and unfiltered erythemas arethe same, the only difference being in the numberof rays reaching the skin, thus increasing the time,why is it that a filtered dose is five or ten or anyother number of erythema doses? The fact re-mains that biologically filtered and unfilterederythemas are identical, as exemplifie