Design and implementation of a compact low-dose diffraction enhanced medical imaging system.
OBJECTIVE
Diffraction-enhanced imaging (DEI) is a new x-ray imaging modality that differs from conventional radiography in its use of three physical mechanisms to generate contrast. DEI is able to generate contrast from x-ray absorption, refraction, and ultra-small-angle scatter rejection (extinction) to produce high-contrast images with a much lower radiation dose compared to conventional radiography.


METHODS
A prototype DEI system was constructed using a 1-kW tungsten x-ray tube and a single silicon monochromator and analyzer crystal. The monochromator crystal was aligned to reflect the combined Kalpha1 (59.32 keV) and Kalpha2 (57.98 keV) characteristic emission lines of tungsten using a tube voltage of 160 kV. System performance and demonstration of contrast were evaluated using a nylon monofilament refraction phantom, full-thickness breast specimens, a human thumb, and a live mouse.


RESULTS
Images acquired using this system successfully demonstrated all three DEI contrast mechanisms. Flux measurements acquired using this 1-kW prototype system demonstrated that this design can be scaled to use a more powerful 60-kW x-ray tube to generate similar images with an image time of approximately 30 seconds. This single-crystal pair design can be further modified to allow for an array of crystals to reduce clinical image times to <3 seconds.


CONCLUSIONS
This paper describes the design, construction, and performance of a new DEI system using a commercially available tungsten anode x-ray tube and includes the first high-quality low-dose diffraction-enhanced images of full-thickness human tissue specimens.
Departments of Radiology and Biomedical Engineering, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7000, USA. caparham@gmail.com
Christopher
C
Parham
Zhong
Z
Zhong
Dean M
DM
Connor
L Dean
LD
Chapman
Etta D
ED
Pisano
D001822:Body Burden; D004867:Equipment Design; D019544:Equipment Failure Analysis; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000295:instrumentation* / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013673:Technology Assessment, Biomedical; D014961:X-Ray Diffraction / Q000295:instrumentation* / Q000379:methods / Q000639:trends*