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SU‐E‐I‐60: Correspondance Between HVLs Measured by Direct Reporting Instruments and Traditional Methods
Author(s) -
Omphroy K,
Prasad G,
Rao U
Publication year - 2011
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3611633
Subject(s) - half value layer , mammography , radiography , range (aeronautics) , filter (signal processing) , medical physics , optics , nuclear medicine , mathematics , computer science , materials science , medicine , physics , radiology , computer vision , cancer , breast cancer , scattering , composite material , mean free path
Purpose: To examine the correspondence between half value layers (HVLs) measured by traditional methods to those obtained by an instrument that reports HVLs with a single open beam. Methods: The HVL was obtained from generating a transmission curve at 60, 80, and 100 kVp in the radiographic range and typically used kVp and target/filter combinations in the mammography range. These HVLs were compared to the ones obtained by instruments which provide direct value with a single open beam. Unfors and Neromax instruments were used to obtain HVL by direct single measurement. A three phase table top radiographic unit was used. Measurements were performed in good geometry using Al 115 H filters supplied Gammex Corporation. This filter is 99.9% pure aluminum. Results: By and large there is good agreement between the HVL obtained by the two methods for regulatory compliance applications. However, there are minor differences when one is interested in a precise value for scientific applications. Conclusions: One can use these direct HVL reporting instruments for routine regulatory compliance measurements.