Dual energy radiography using active detector technology

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:513186

Seibert, J A; Poage, T F ^[1]; Alvarez, R E ^[2]

---

1. Univ. of California, Davis, CA (United States)
2. Aprend Technology, Mountain View, CA (United States)

A new technology has been implemented using an {open_quotes}active-detector{close_quotes} comprised of two computed radiography (CR) imaging plates in a sandwich geometry for dual-energy radiography. This detector allows excellent energy separation, short exposure time, and high signal to noise ratio (SNR) for clinically robust {open_quotes}bone-only{close_quotes} and {open_quotes}soft-tissue only{close_quotes} images with minimum patient motion. Energy separation is achieved by two separate exposures at widely different kVp`s: the high energy (120 kVp + 1.5 mm Cu filter) exposure is initiated first, followed by a short burst of intense light to erase the latent image on the front plate, and then a 50 kVp (low energy) exposure. A personal computer interfaced to the x-ray generator, filter wheel, and active detector system orchestrates the acquisition sequence within a time period of 150 msec. The front and back plates are processed using a CR readout algorithm with fixed speed and wide dynamic range. {open_quotes}Bone-only{close_quotes} and {open_quotes}soft-tissue only{close_quotes} images are calculated by geometric alignment of the two images and application of dual energy decomposition algorithms on a pixel by pixel basis. Resultant images of a calibration phantom demonstrate an increase of SNR{sup 2} / dose by {approximately}73 times when compared to a single exposure {open_quotes}passive-detector{close_quotes} comprised of CR imaging plates, and an {approximately}8 fold increase compared to a screen-film dual-energy cassette comprised of different phosphor compounds. In conclusion, dual energy imaging with {open_quotes}active detector{close_quotes} technology is clinically feasible and can provide substantial improvements over conventional methods for dual-energy radiography.

• OSTI ID: 513186
• Report Number(s): CONF-961123--
• Country of Publication: United States
• Language: English

Related Subjects

44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
CALIBRATION
DESIGN
IMAGE PROCESSING
X-RAY RADIOGRAPHY