Tuesday, February 17, 2009

Reduce Diffraction Scatter In Radiography

DEI produces detailed x-ray images, while reducing radiation amounts to the body.


Radiography in medicine involves the process of sending an x-ray imaging beam, called a synchrotron beam, at a patient. The beam passes through the person's body and onto an image plate detector. The image detector analyzes the imaging beam into a readable black-and-white, two dimensional x-ray for the doctors to determine if the patient has internal injuries, abnormalities or possible signs of cancerous tumors.


In diffraction-enhanced imaging, the same process is used to create the x-ray, but the beams strikes a double monochromator optical device. The beam then passes through the body, creating a diffraction (or scattering) of light picked up by the image detector. This process creates an MRI-like scan, while using less radiation. To reduce diffraction scatter, an analyzer crystal is placed between the body and the image detector, to produce a better resolution.


Instructions


1. Prep the patient for the diffraction-enhanced imaging. Have the double monochromator device between the patient and the beam.


2. Attach the analyzer crystal to an axle and tangent bar that will be controlled by using a stepper-motor driven translation stage. Place the analyzer crystal between the patient and the image plate detector.


3. Reduce diffraction, by tuning the stepper-motor driven translation stage, as it pushes against the tangent arm, changing the position of the silicon analyzer crystal. Adjust the vertical position of the image plate detector, until scattering intensity disappears to improve image contrast.

Tags: analyzer crystal, image detector, image plate, image plate detector, plate detector, between patient, diffraction-enhanced imaging