Note on the diagnostic and therapeutic value of the Coolidge tube / by Lewis Gregory Cole.

  • Lewis Gregory Cole
Date:
1914
Catalogue details

Licence: In copyright

Credit: Note on the diagnostic and therapeutic value of the Coolidge tube / by Lewis Gregory Cole. Source: Wellcome Collection.

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    penetrating power of the X rays, can be regulated by increasing or dimin ing the voltage on the terminals of the tube. None but a radiographer can realise the practical advantages result from this mode of construction—viz., accuracy of adjustment, stability hardness, exact duplication of results, fixity of the focal point, long . flexibility, tremendous output, and absence of indirect rays. In the ordinary tube the penetration depends entirely upon the adj ment of its vacuum by some regulating device—a method which is 1; inaccurate and most unfavourable to uniform results, since the vacuun difficult to adjust and hard to sustain—whereas the hardness of the Cooli tube can be adjusted to perfect accuracy by simply regulating the curi through the tungsten filament of the cathode. The stability of the tube is no less remarkable. In laboratory test has been run for fifty minutes without any adjustment, and with no ] ceptible variation in hardness, whereas an ordinary tube cannot be opera for more than a few seconds without showing material changes in penetrat Up to the present time radiologists have found it practically imposs to obtain brilliant Roentgenograms with any degree of uniformity. With! new tube it is possible accurately to adjust and sustain a given degree penetration, thus enabling us to obtain exact duplication of previous resi The Roentgenograms obtained with the new tube are not, indeed, m brilliant than selected radiograms obtained occasionally with ordinary tul but extraordinary detail of soft tissues, tendons and bloodvessels, may obtained with a far greater degree of certainty than heretofore. In the ordinary tube, variability of the focal spot is a factor whicl often responsible for blurring of the image, whereas in the Coolidge tube focal spot is an absolutely fixed point. With an ordinary tube flexibility is impossible. To obtain Roentgenogn of various portions of the body, a great number of tubes of different degi of penetration are required, whereas the new tube adapts itself to ev kind of Roentgenographic and therapeutic work. It can be instantly alte from a soft tube, showing the bloodvessels in an infant’s arm, to a hardr never heretofore obtained, and can be maintained at any given degree hardness for an indefinite time. The working life of the new tube has been estimated by Dr. Coolidg( be at least a thousand hours of constant running, a great increase over life of the old tubes. Its tremendous output, both for diagnostic and therapeutic purpose^ perhaps the most wonderful advantage of the tube, making it especk useful in the Roentgenkinematograpliy of the stomach and heart and in ra( therapy of deep-seated cancers. rl lie complete absence of indirect rays in the Coolidge tube is of gi scientific interest and of practical value. The positive bodies in the ordin tube are a useless and harmful by-product, and their elimination suppm entirely both the intense heating of the tube and the fluorescence of the gi