Aims and objectives
The Penumbra-Effect describes blurring at the margins of an image-profile due to the finite size of the energy source.
We used a computer aided detection (CAD) algorithm based on the De-Convolution Technique  to pinpoint true-edge positions to sub-pixel accuracy and remove the Penumbra-Effect via sub-pixel transfers without trade-off losses .
We assessed enhancement resulting from the removal of the Penumbra-Effect.
We used CR images,
Radial Circle of Willis angiogram MIP (Maximum Intensity Projection) images and CT images of liver lesion for the studies.
Methods and materials
We used Composite phantom and New-York Catphan-500 images for calibration.
We analyzed 2 CR images,
30 radial MRA MIP images,
and 155 CT images and took measurements.
Phantom calibrations: Measurements: At 1% low-contrast,
distance accurate to 1/44th of a pixel,
and area/volume to 1/14th of a pixel.
(1) Computed Radiograph of a 2 year old female infant patient's left Tibia & Fibula were examined.
& 3 illustrated that,
(i) Fig.1 - the original image of Tibia & Fibula at one angle with ROI placed on the fracture,
2a and Fig.
2b - the 'before' and 'after' enhancement of 7x ROI,
which clearly showed...
Accurate measurements of distance,
and volume in CR,
and CT obtained using this de-convolution CAD can be used to monitor disease response to therapy.
For further inquiries,
please contact Dr.
Kui Ming Chui,
either via website: www.iet.org.uk or via e-mail: email@example.com.
 “ A De-Convolution Technique used for NDT in X-ray and CT”,
Oral/Full paper presentation in 17th World Conference on Non-Destructive Testing (17WCNDT),
2008 (NDT.net – The e-Journal & Database of Non-Destructive Testing – ISSN 1435-4934).
 “The removal of the penumbra effect by a CAD based on the de-convolution technique”.
Several field examples were used to demonstrate the merits of this technique to enhance images for clearer diagnosis and accurate measurements.