PURPOSE: Reduction of radiation dose in x-ray imaging has been recognized as a high priority in the medical community. Here the authors show that a regional adaptive exposure method can reduce dose-area product (DAP) in x-ray fluoroscopy. The authors' method is particularly geared toward providing dose savings for the pediatric population. METHODS: The scanning beam digital x-ray system uses a large-area x-ray source with 8000 focal spots in combination with a small photon-counting detector. An imaging frame is obtained by acquiring and reconstructing up to 8000 detector images, each viewing only a small portion of the patient. Regional adaptive exposure was implemented by varying the exposure of the detector images depending on the local opacity of the object. A family of phantoms ranging in size from infant to obese adult was imaged in anteroposterior view with and without adaptive exposure. The DAP delivered to each phantom was measured in each case, and noise performance was compared by generating noise arrays to represent regional noise in the images. These noise arrays were generated by dividing the image into regions of about 6 mm(2), calculating the relative noise in each region, and placing the relative noise value of each region in a one-dimensional array (noise array) sorted from highest to lowest. Dose-area product savings were calculated as the difference between the ratio of DAP with adaptive exposure to DAP without adaptive exposure. The authors modified this value by a correction factor that matches the noise arrays where relative noise is the highest to report a final dose-area product savings. RESULTS: The average dose-area product saving across the phantom family was (42 ± 8)% with the highest dose-area product saving in the child-sized phantom (50%) and the lowest in the phantom mimicking an obese adult (23%). CONCLUSIONS: Phantom measurements indicate that a regional adaptive exposure method can produce large DAP savings without compromising the noise performance in the image regions with highest noise.
PURPOSE: Reduction of radiation dose in x-ray imaging has been recognized as a high priority in the medical community. Here the authors show that a regional adaptive exposure method can reduce dose-area product (DAP) in x-ray fluoroscopy. The authors' method is particularly geared toward providing dose savings for the pediatric population. METHODS: The scanning beam digital x-ray system uses a large-area x-ray source with 8000 focal spots in combination with a small photon-counting detector. An imaging frame is obtained by acquiring and reconstructing up to 8000 detector images, each viewing only a small portion of the patient. Regional adaptive exposure was implemented by varying the exposure of the detector images depending on the local opacity of the object. A family of phantoms ranging in size from infant to obese adult was imaged in anteroposterior view with and without adaptive exposure. The DAP delivered to each phantom was measured in each case, and noise performance was compared by generating noise arrays to represent regional noise in the images. These noise arrays were generated by dividing the image into regions of about 6 mm(2), calculating the relative noise in each region, and placing the relative noise value of each region in a one-dimensional array (noise array) sorted from highest to lowest. Dose-area product savings were calculated as the difference between the ratio of DAP with adaptive exposure to DAP without adaptive exposure. The authors modified this value by a correction factor that matches the noise arrays where relative noise is the highest to report a final dose-area product savings. RESULTS: The average dose-area product saving across the phantom family was (42 ± 8)% with the highest dose-area product saving in the child-sized phantom (50%) and the lowest in the phantom mimicking an obese adult (23%). CONCLUSIONS: Phantom measurements indicate that a regional adaptive exposure method can produce large DAP savings without compromising the noise performance in the image regions with highest noise.
Authors: Michael A Speidel; Brian P Wilfley; Josh M Star-Lack; Joseph A Heanue; Michael S Van Lysel Journal: Med Phys Date: 2006-08 Impact factor: 4.071
Authors: Michael A Speidel; Brian P Wilfley; Josh M Star-Lack; Joseph A Heanue; Timothy D Betts; Michael S Van Lysel Journal: Med Phys Date: 2006-08 Impact factor: 4.071
Authors: Michael S Stecker; Stephen Balter; Richard B Towbin; Donald L Miller; Eliseo Vañó; Gabriel Bartal; J Fritz Angle; Christine P Chao; Alan M Cohen; Robert G Dixon; Kathleen Gross; George G Hartnell; Beth Schueler; John D Statler; Thierry de Baère; John F Cardella Journal: J Vasc Interv Radiol Date: 2009-07 Impact factor: 3.464
Authors: Donald L Miller; Stephen Balter; Patricia E Cole; Hollington T Lu; Beth A Schueler; Michael Geisinger; Alejandro Berenstein; Robin Albert; Jeffrey D Georgia; Patrick T Noonan; John F Cardella; James St George; Eric J Russell; Tim W Malisch; Robert L Vogelzang; George L Miller; Jon Anderson Journal: J Vasc Interv Radiol Date: 2003-06 Impact factor: 3.464
Authors: David A P Dunkerley; Michael T Tomkowiak; Jordan M Slagowski; Bradley P McCabe; Tobias Funk; Michael A Speidel Journal: Proc SPIE Int Soc Opt Eng Date: 2015-02-21