Researchers at the University of California, Davis have invented a device and methods for half-value layer (HVL) characterization in computed tomography (CT) to allow a medical physicist to measure the HVL of an X-ray system while the X-ray tube is rotating - that is, during its normal operation without the necessity to make the x-ray tube stationery.
For medical imaging applications which use X-rays, part of the necessary characterization of the X-ray beam "quality" required the measurement of the half value layer (HVL), which is the thickness, typically in aluminum, which reduces the X-ray intensity of the X-ray beam by 50%. The HVL is routinely measured in projection X-ray imaging situations such as in mammography, radiography, and fluoroscopy. However, for computed tomography (CT), the X-ray source rotates around the gantry and this precludes the measurement of HVL using the standard set-up of an exposure meter with aluminum filters.
Researchers at the University of California, Davis have developed a device and methods for measuring HVL in a CT machine while the X-ray tube is rotating. Therefore, the CT gantry does not need to be placed in a parked position, and a service engineer is not required to help in the measurements. This invention, therefore, makes the measurement of the HVL in CT practical, automated, accurate, and fast. Our researchers have prototyped a case device to be used with a real-time dosimeter; accompanying method packages for estimation of the HVL from the real-time doe measurements have also been developed.
Measurement of X-ray beam quality in CT scanners and in projection radiography settings (including fluoroscopy, radiography and mammography) and enable rapid and reliable characterization of the x-ray beam.
|United States Of America||Issued Patent||9,008,264||04/14/2015||2010-719|
Computed Tomography (CT), Radiography, X-ray Beam Quality, Half layer value, HVL Characterization