Journal of Medical Physics

Year
: 1996  |  Volume : 21  |  Issue : 2  |  Page : 64--70

Two New Formulae For Estimating The Output Of X-Ray Units


Pratik Kumar1, Rashmi Kaul2, M.M Rehani3, Bhawna Sethi4, M Berry5 
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Correspondence Address:
Pratik Kumar


The radiation output from different X-ray machines varies considerably. For a given kVp and mAs, this variation results from voltage waveform from the generator, tube-age and filtration. In routine practices, no exposure meter is fitted in the controls of X-ray machines. The most appropriate way to know entrance skin exposure (ESE) to the patient is by using the standard formulae. But, as yet, no one has evaluated the different formulae available in the literature, for their validity when applied to different machines. In the present study, we have first measured the ESE for seven X-ray machines and then estimated the % error between experimental and calculated values with five formulae and nomogram available in literature. Since all these formulae gave errors exceeding # 35% of the actual value, we have evolved two new formulae and developed appropriate computer programs. These two formulae are able to provide an estimate of ESE within a mean % error of -3.9 + 14.5 and 0.7 + 19.4 respectively, for seven X-ray machines included in the study


How to cite this article:
Kumar P, Kaul R, Rehani M, Sethi B, Berry M. Two New Formulae For Estimating The Output Of X-Ray Units.J Med Phys 1996;21:64-70


How to cite this URL:
Kumar P, Kaul R, Rehani M, Sethi B, Berry M. Two New Formulae For Estimating The Output Of X-Ray Units. J Med Phys [serial online] 1996 [cited 2021 Jan 15 ];21:64-70
Available from: https://www.jmp.org.in/article.asp?issn=0971-6203;year=1996;volume=21;issue=2;spage=64;epage=70;aulast=Kumar;type=0